* [PATCH v6 0/4] Introduce Allwinner H616 PWM controller
@ 2026-04-16 13:40 Richard Genoud
2026-04-16 13:40 ` [PATCH v6 1/4] dt-bindings: pwm: allwinner: add h616 pwm compatible Richard Genoud
` (4 more replies)
0 siblings, 5 replies; 7+ messages in thread
From: Richard Genoud @ 2026-04-16 13:40 UTC (permalink / raw)
To: Uwe Kleine-König, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Chen-Yu Tsai, Jernej Skrabec, Samuel Holland,
Philipp Zabel
Cc: Paul Kocialkowski, Thomas Petazzoni, John Stultz, Joao Schim,
bigunclemax, linux-pwm, devicetree, linux-arm-kernel, linux-sunxi,
linux-kernel, Richard Genoud
Allwinner H616 PWM controller is quite different from the A10 one.
It can drive 6 PWM channels, and like for the A10, each channel has a
bypass that permits to output a clock, bypassing the PWM logic, when
enabled.
But, the channels are paired 2 by 2, sharing a first set of
MUX/prescaler/gate.
Then, for each channel, there's another prescaler (that will be bypassed
if the bypass is enabled for this channel).
It looks like that:
_____ ______ ________
OSC24M --->| | | | | |
APB1 ----->| Mux |--->| Gate |--->| /div_m |-----> PWM_clock_src_xy
|_____| |______| |________|
________
| |
+->| /div_k |---> PWM_clock_x
| |________|
| ______
| | |
+-->| Gate |----> PWM_bypass_clock_x
| |______|
PWM_clock_src_xy -----+ ________
| | |
+->| /div_k |---> PWM_clock_y
| |________|
| ______
| | |
+-->| Gate |----> PWM_bypass_clock_y
|______|
Where xy can be 0/1, 2/3, 4/5
PWM_clock_x/y serve for the PWM purpose.
PWM_bypass_clock_x/y serve for the clock-provider purpose.
The common clock framework has been used to manage those clocks.
This PWM driver serves as a clock-provider for PWM_bypass_clocks.
This is needed for example by the embedded AC300 PHY which clock comes
from PMW5 pin (PB12).
Usually, to get a clock from a PWM driver, we use the pwm-clock driver
so that the PWM driver doesn't need to be a clk-provider itself.
While this works in most cases, here it just doesn't.
That's because the pwm-clock request a period from the PWM driver,
without any clue that it actually wants a clock at a specific frequency,
and not a PWM signal with duty cycle capability.
So, the PWM driver doesn't know if it can use the bypass or not, it
doesn't even have the real accurate frequency information (23809524 Hz
instead of 24MHz) because PWM drivers only deal with periods.
With pwm-clock, we loose a precious information along the way (that we
actually want a clock and not a PWM signal).
That's ok with simple PWM drivers that don't have multiple input clocks,
but in this case, without this information, we can't know for sure which
clock to use.
And here, for instance, if we ask for a 24MHz clock, pwm-clock will
requests 42ns (assigned-clocks doesn't help for that matter). The logic
is to select the highest clock (100MHz) with no prescaler and a duty
cycle value of 2/4 => we have 25MHz instead of 24MHz.
And that's a perfectly fine choice for a PMW, because we still can
change the duty cycle in the range [0-4]/4.
But obviously for a clock, we don't care about the duty cycle, but more
about the clock accuracy.
And actually, this PWM is really a PWM AND a real clock when the bypass
is set.
This series is based onto v7.0
NB: checkpatch is not happy with patch 2, but it's a false positive.
It doesn't detect that PWM_XY_SRC_MUX/GATE/DIV are structures, but as
it's more readable like that, I prefer keeping it that way.
Changes since v5:
- remove trailing junk after commit message in patch 4
- remove Tested-by when it doesn't make sense.
(sorry for the noise)
Changes since v4:
- Fix a bug on bypass for channels greater than 1
- add colons to clarify 2 debug messages
- switch from H616 to sun8i prefix (in code, filename, module name)
- fix consistency issues in macro parameters
- rename some macros with a confusing naming
- rebase on v7.0
Changes since v3:
- gather Acked-by/Tested-by
- fix cast from pointer to integer of different size (kernel test robot
with arc platform)
- add devm_action for clk_hw_unregister_composite as suggested by Philipp
- remove now unused pwm_remove as suggested by Philipp
Changes since v2:
- use U32_MAX instead of defining UINT32_MAX
- add a comment on U32_MAX usage in clk_round_rate()
- change clk_table_div_m (use macros)
- fix formatting (double space, superfluous comma, extra line feed)
- fix the parent clock order
- simplify code by using scoped_guard()
- add missing const in to_h616_pwm_chip() and rename to
h616_pwm_from_chip()
- add/remove missing/superfluous error messages
- rename cnt->period_ticks, duty_cnt->duty_ticks
- fix PWM_PERIOD_MAX
- add .remove() callback
- fix DIV_ROUND_CLOSEST_ULL->DIV_ROUND_UP_ULL
- add H616_ prefix
- protect _reg in macros
- switch to waveforms instead of apply/get_state
- shrink struct h616_pwm_channel
- rebase on v6.19-rc4
Changes since v1:
- rebase onto v6.19-rc1
- add missing headers
- remove MODULE_ALIAS (suggested by Krzysztof)
- use sun4i-pwm binding instead of creating a new one (suggested by Krzysztof)
- retrieve the parent clocks from the devicetree
- switch num_parents to unsigned int
Richard Genoud (4):
dt-bindings: pwm: allwinner: add h616 pwm compatible
pwm: sun8i: Add H616 PWM support
arm64: dts: allwinner: h616: add PWM controller
MAINTAINERS: Add entry on Allwinner sun8i/H616 PWM driver
.../bindings/pwm/allwinner,sun4i-a10-pwm.yaml | 19 +-
MAINTAINERS | 5 +
.../arm64/boot/dts/allwinner/sun50i-h616.dtsi | 47 +
drivers/pwm/Kconfig | 12 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-sun8i.c | 938 ++++++++++++++++++
6 files changed, 1021 insertions(+), 1 deletion(-)
create mode 100644 drivers/pwm/pwm-sun8i.c
base-commit: 028ef9c96e96197026887c0f092424679298aae8
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v6 1/4] dt-bindings: pwm: allwinner: add h616 pwm compatible
2026-04-16 13:40 [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Richard Genoud
@ 2026-04-16 13:40 ` Richard Genoud
2026-04-16 13:40 ` [PATCH v6 2/4] pwm: sun8i: Add H616 PWM support Richard Genoud
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Richard Genoud @ 2026-04-16 13:40 UTC (permalink / raw)
To: Uwe Kleine-König, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Chen-Yu Tsai, Jernej Skrabec, Samuel Holland,
Philipp Zabel
Cc: Paul Kocialkowski, Thomas Petazzoni, John Stultz, Joao Schim,
bigunclemax, linux-pwm, devicetree, linux-arm-kernel, linux-sunxi,
linux-kernel, Richard Genoud, Conor Dooley
Allwinner H616 PWM block is quite different from the A10 or H6, but at
the end, it uses the same clocks as the H6; so the sun4i pwm binding can
be used.
It has 6 channels than can generate PWM waveforms.
If the bypass is enabled (one bypass per channel) the output is no more
a PWM waveform, but a clock that can (and is) used as input for other
devices, like the AC300 PHY.
Acked-by: Conor Dooley <conor.dooley@microchip•com>
Signed-off-by: Richard Genoud <richard.genoud@bootlin•com>
---
.../bindings/pwm/allwinner,sun4i-a10-pwm.yaml | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/pwm/allwinner,sun4i-a10-pwm.yaml b/Documentation/devicetree/bindings/pwm/allwinner,sun4i-a10-pwm.yaml
index 1197858e431f..4f58110ec98f 100644
--- a/Documentation/devicetree/bindings/pwm/allwinner,sun4i-a10-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/allwinner,sun4i-a10-pwm.yaml
@@ -14,6 +14,9 @@ properties:
"#pwm-cells":
const: 3
+ "#clock-cells":
+ const: 1
+
compatible:
oneOf:
- const: allwinner,sun4i-a10-pwm
@@ -36,6 +39,7 @@ properties:
- const: allwinner,sun50i-h5-pwm
- const: allwinner,sun5i-a13-pwm
- const: allwinner,sun50i-h6-pwm
+ - const: allwinner,sun50i-h616-pwm
reg:
maxItems: 1
@@ -62,7 +66,9 @@ allOf:
properties:
compatible:
contains:
- const: allwinner,sun50i-h6-pwm
+ enum:
+ - allwinner,sun50i-h6-pwm
+ - allwinner,sun50i-h616-pwm
then:
properties:
@@ -83,6 +89,17 @@ allOf:
clocks:
maxItems: 1
+ - if:
+ not:
+ properties:
+ compatible:
+ contains:
+ const: allwinner,sun50i-h616-pwm
+
+ then:
+ properties:
+ "#clock-cells": false
+
required:
- compatible
- reg
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v6 2/4] pwm: sun8i: Add H616 PWM support
2026-04-16 13:40 [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Richard Genoud
2026-04-16 13:40 ` [PATCH v6 1/4] dt-bindings: pwm: allwinner: add h616 pwm compatible Richard Genoud
@ 2026-04-16 13:40 ` Richard Genoud
2026-05-25 17:58 ` Uwe Kleine-König
2026-04-16 13:40 ` [PATCH v6 3/4] arm64: dts: allwinner: h616: add PWM controller Richard Genoud
` (2 subsequent siblings)
4 siblings, 1 reply; 7+ messages in thread
From: Richard Genoud @ 2026-04-16 13:40 UTC (permalink / raw)
To: Uwe Kleine-König, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Chen-Yu Tsai, Jernej Skrabec, Samuel Holland,
Philipp Zabel
Cc: Paul Kocialkowski, Thomas Petazzoni, John Stultz, Joao Schim,
bigunclemax, linux-pwm, devicetree, linux-arm-kernel, linux-sunxi,
linux-kernel, Richard Genoud
Add driver for Allwinner H616 PWM controller, supporting up to 6
channels.
Those channels output can be either a PWM signal output or a clock
output, thanks to the bypass.
The channels are paired (0/1, 2/3 and 4/5) and each pair has a
prescaler/mux/gate.
Moreover, each channel has its own prescaler and bypass.
The clock provider part of this driver is needed not only because the
H616 PWM controller provides also clocks when bypass is enabled, but
really because pwm-clock isn't fit to handle all cases here.
pwm-clock would work if the 100MHz clock is requested, but if a lower
clock is requested (like 24MHz), it will request a 42ns period to the
PWM driver which will happily serve, with the 100MHz clock as input a
25MHz frequency and a duty cycle adjustable in the range [0-4]/4,
because that is a sane thing to do for a PWM.
The information missing is that a real clock is resquested, not a PWM.
Tested-by: John Stultz <jstultz@google•com>
Tested-by: Joao Schim <joao@schimsalabim•eu>
Signed-off-by: Richard Genoud <richard.genoud@bootlin•com>
---
drivers/pwm/Kconfig | 12 +
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-sun8i.c | 938 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 951 insertions(+)
create mode 100644 drivers/pwm/pwm-sun8i.c
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 6f3147518376..c4fd682860d6 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -736,6 +736,18 @@ config PWM_SUN4I
To compile this driver as a module, choose M here: the module
will be called pwm-sun4i.
+config PWM_SUN8I
+ tristate "Allwinner sun8i/sun50i PWM support"
+ depends on ARCH_SUNXI || COMPILE_TEST
+ depends on HAS_IOMEM && COMMON_CLK
+ help
+ Generic PWM framework driver for Allwinner H616 SoCs.
+ It supports generic PWM, but can also provides a plain clock.
+ The AC300 PHY integrated in H616 SoC needs such a clock.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-sun8i.
+
config PWM_SUNPLUS
tristate "Sunplus PWM support"
depends on ARCH_SUNPLUS || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 0dc0d2b69025..ba2e0ec7fc17 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_PWM_STM32) += pwm-stm32.o
obj-$(CONFIG_PWM_STM32_LP) += pwm-stm32-lp.o
obj-$(CONFIG_PWM_STMPE) += pwm-stmpe.o
obj-$(CONFIG_PWM_SUN4I) += pwm-sun4i.o
+obj-$(CONFIG_PWM_SUN8I) += pwm-sun8i.o
obj-$(CONFIG_PWM_SUNPLUS) += pwm-sunplus.o
obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
obj-$(CONFIG_PWM_TH1520) += pwm_th1520.o
diff --git a/drivers/pwm/pwm-sun8i.c b/drivers/pwm/pwm-sun8i.c
new file mode 100644
index 000000000000..8f1023e3a2e5
--- /dev/null
+++ b/drivers/pwm/pwm-sun8i.c
@@ -0,0 +1,938 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Allwinner sun8i Pulse Width Modulation Controller
+ *
+ * (C) Copyright 2025 Richard Genoud, Bootlin <richard.genoud@bootlin•com>
+ *
+ * Based on drivers/pwm/pwm-sun4i.c with Copyright:
+ *
+ * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@bootlin•com>
+ *
+ * Limitations:
+ * - As the channels are paired (0/1, 2/3, 4/5), they share the same clock
+ * source and prescaler(div_m), but they also have their own prescaler(div_k)
+ * and bypass.
+ *
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/limits.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+#include <linux/spinlock.h>
+#include <linux/time.h>
+
+/* PWM IRQ Enable Register */
+#define SUN8I_PWM_PIER 0x0
+
+/* PWM IRQ Status Register */
+#define SUN8I_PWM_PISR 0x4
+
+/* PWM Capture IRQ Enable Register */
+#define SUN8I_PWM_CIER 0x10
+
+/* PWM Capture IRQ Status Register */
+#define SUN8I_PWM_CISR 0x14
+
+/* PWMCC Pairs Clock Configuration Registers */
+#define SUN8I_PWM_PCCR(pair) (0x20 + ((pair) * 0x4))
+#define SUN8I_PWM_PCCR_SRC_SHIFT 7
+#define SUN8I_PWM_PCCR_SRC_MASK 1
+#define SUN8I_PWM_PCCR_GATE_BIT 4
+#define SUN8I_PWM_PCCR_BYPASS_BIT(chan) ((chan) % 2 + 5)
+#define SUN8I_PWM_PCCR_DIV_M_SHIFT 0
+
+/* PWMCC Pairs Dead Zone Control Registers */
+#define SUN8I_PWM_PDZCR(pair) (0x30 + ((pair) * 0x4))
+
+/* PWM Enable Register */
+#define SUN8I_PWM_PER 0x40
+#define SUN8I_PWM_ENABLE(chan) BIT(chan)
+
+/* PWM Capture Enable Register */
+#define SUN8I_PWM_CER 0x44
+
+/* PWM Control Register */
+#define SUN8I_PWM_PCR(chan) (0x60 + (chan) * 0x20)
+#define SUN8I_PWM_PCR_PRESCAL_K_SHIFT 0
+#define SUN8I_PWM_PCR_PRESCAL_K_WIDTH 8
+#define SUN8I_PWM_PCR_ACTIVE_STATE BIT(8)
+
+/* PWM Period Register */
+#define SUN8I_PWM_PPR(chan) (0x64 + (chan) * 0x20)
+#define SUN8I_PWM_PPR_PERIOD_MASK GENMASK(31, 16)
+#define SUN8I_PWM_PPR_DUTY_MASK GENMASK(15, 0)
+#define SUN8I_PWM_PPR_PERIOD_VALUE(reg) (FIELD_GET(SUN8I_PWM_PPR_PERIOD_MASK, reg) + 1)
+#define SUN8I_PWM_PPR_DUTY_VALUE(reg) FIELD_GET(SUN8I_PWM_PPR_DUTY_MASK, reg)
+#define SUN8I_PWM_PPR_PERIOD(prd) FIELD_PREP(SUN8I_PWM_PPR_PERIOD_MASK, (prd) - 1)
+#define SUN8I_PWM_DUTY(dty) FIELD_PREP(SUN8I_PWM_PPR_DUTY_MASK, dty)
+#define SUN8I_PWM_PPR_PERIOD_MAX (FIELD_MAX(SUN8I_PWM_PPR_PERIOD_MASK) + 1)
+
+/* PWM Count Register */
+#define SUN8I_PWM_PCNTR(chan) (0x68 + (chan) * 0x20)
+
+/* PWM Capture Control Register */
+#define SUN8I_PWM_CCR(chan) (0x6c + (chan) * 0x20)
+
+/* PWM Capture Rise Lock Register */
+#define SUN8I_PWM_CRLR(chan) (0x70 + (chan) * 0x20)
+
+/* PWM Capture Fall Lock Register */
+#define SUN8I_PWM_CFLR(chan) (0x74 + (chan) * 0x20)
+
+#define SUN8I_PWM_PAIR_IDX(chan) ((chan) >> 1)
+
+/*
+ * Block diagram of the PWM clock controller:
+ *
+ * _____ ______ ________
+ * OSC24M --->| | | | | |
+ * APB1 ----->| Mux |--->| Gate |--->| /div_m |-----> SUN8I_PWM_clock_src_xy
+ * |_____| |______| |________|
+ * ________
+ * | |
+ * +->| /div_k |---> SUN8I_PWM_clock_x
+ * | |________|
+ * | ______
+ * | | |
+ * +-->| Gate |----> SUN8I_PWM_bypass_clock_x
+ * | |______|
+ * SUN8I_PWM_clock_src_xy ---+ ________
+ * | | |
+ * +->| /div_k |---> SUN8I_PWM_clock_y
+ * | |________|
+ * | ______
+ * | | |
+ * +-->| Gate |----> SUN8I_PWM_bypass_clock_y
+ * |______|
+ *
+ * NB: when the bypass is set, all the PWM logic is bypassed.
+ * So, the duty cycle and polarity can't be modified (we just have a clock).
+ * The bypass in PWM mode is used to achieve a 1/2 relative duty cycle with the
+ * fastest clock.
+ *
+ * SUN8I_PWM_clock_x/y serve for the PWM purpose.
+ * SUN8I_PWM_bypass_clock_x/y serve for the clock-provider purpose.
+ *
+ */
+
+/*
+ * Table used for /div_m (diviser before obtaining SUN8I_PWM_clock_src_xy)
+ * It's actually CLK_DIVIDER_POWER_OF_TWO, but limited to /256
+ */
+#define CLK_TABLE_DIV_M_ENTRY(i) { \
+ .val = (i), .div = 1 << (i) \
+}
+
+static const struct clk_div_table clk_table_div_m[] = {
+ CLK_TABLE_DIV_M_ENTRY(0),
+ CLK_TABLE_DIV_M_ENTRY(1),
+ CLK_TABLE_DIV_M_ENTRY(2),
+ CLK_TABLE_DIV_M_ENTRY(3),
+ CLK_TABLE_DIV_M_ENTRY(4),
+ CLK_TABLE_DIV_M_ENTRY(5),
+ CLK_TABLE_DIV_M_ENTRY(6),
+ CLK_TABLE_DIV_M_ENTRY(7),
+ CLK_TABLE_DIV_M_ENTRY(8),
+ { /* sentinel */ }
+};
+
+#define SUN8I_PWM_XY_SRC_GATE(_pair, _reg) \
+struct clk_gate gate_xy_##_pair = { \
+ .reg = (void *)(_reg), \
+ .bit_idx = SUN8I_PWM_PCCR_GATE_BIT, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_gate_ops, \
+ } \
+}
+
+#define SUN8I_PWM_XY_SRC_MUX(_pair, _reg) \
+struct clk_mux mux_xy_##_pair = { \
+ .reg = (void *)(_reg), \
+ .shift = SUN8I_PWM_PCCR_SRC_SHIFT, \
+ .mask = SUN8I_PWM_PCCR_SRC_MASK, \
+ .flags = CLK_MUX_ROUND_CLOSEST, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_mux_ops, \
+ } \
+}
+
+#define SUN8I_PWM_XY_SRC_DIV(_pair, _reg) \
+struct clk_divider rate_xy_##_pair = { \
+ .reg = (void *)(_reg), \
+ .shift = SUN8I_PWM_PCCR_DIV_M_SHIFT, \
+ .table = clk_table_div_m, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_divider_ops, \
+ } \
+}
+
+#define SUN8I_PWM_X_DIV(_idx, _reg) \
+struct clk_divider rate_x_##_idx = { \
+ .reg = (void *)(_reg), \
+ .shift = SUN8I_PWM_PCR_PRESCAL_K_SHIFT, \
+ .width = SUN8I_PWM_PCR_PRESCAL_K_WIDTH, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_divider_ops, \
+ } \
+}
+
+#define SUN8I_PWM_X_BYPASS_GATE(_idx) \
+struct clk_gate gate_x_bypass_##_idx = { \
+ .reg = (void *)SUN8I_PWM_PER, \
+ .bit_idx = _idx, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_gate_ops, \
+ } \
+}
+
+#define SUN8I_PWM_XY_CLK_SRC(_pair, _reg) \
+ static SUN8I_PWM_XY_SRC_MUX(_pair, _reg); \
+ static SUN8I_PWM_XY_SRC_GATE(_pair, _reg); \
+ static SUN8I_PWM_XY_SRC_DIV(_pair, _reg)
+
+#define SUN8I_PWM_X_CLK(_idx) \
+ static SUN8I_PWM_X_DIV(_idx, SUN8I_PWM_PCR(_idx))
+
+#define SUN8I_PWM_X_BYPASS_CLK(_idx) \
+ SUN8I_PWM_X_BYPASS_GATE(_idx)
+
+#define REF_CLK_XY_SRC(_pair) \
+ { \
+ .name = "pwm-clk-src" #_pair, \
+ .mux_hw = &mux_xy_##_pair.hw, \
+ .gate_hw = &gate_xy_##_pair.hw, \
+ .rate_hw = &rate_xy_##_pair.hw, \
+ }
+
+#define REF_CLK_X(_idx, _pair) \
+ { \
+ .name = "pwm-clk" #_idx, \
+ .parent_names = (const char *[]){ "pwm-clk-src" #_pair }, \
+ .num_parents = 1, \
+ .rate_hw = &rate_x_##_idx.hw, \
+ .flags = CLK_SET_RATE_PARENT, \
+ }
+
+#define REF_CLK_BYPASS(_idx, _pair) \
+ { \
+ .name = "pwm-clk-bypass" #_idx, \
+ .parent_names = (const char *[]){ "pwm-clk-src" #_pair }, \
+ .num_parents = 1, \
+ .gate_hw = &gate_x_bypass_##_idx.hw, \
+ .flags = CLK_SET_RATE_PARENT, \
+ }
+
+/*
+ * SUN8I_PWM_clock_src_xy generation:
+ * _____ ______ ________
+ * OSC24M --->| | | | | |
+ * APB1 ----->| Mux |--->| Gate |--->| /div_m |-----> SUN8I_PWM_clock_src_xy
+ * |_____| |______| |________|
+ */
+SUN8I_PWM_XY_CLK_SRC(01, SUN8I_PWM_PCCR(0));
+SUN8I_PWM_XY_CLK_SRC(23, SUN8I_PWM_PCCR(1));
+SUN8I_PWM_XY_CLK_SRC(45, SUN8I_PWM_PCCR(2));
+
+/*
+ * SUN8I_PWM_clock_x_div generation:
+ * ________
+ * | | SUN8I_PWM_clock_x/y
+ * SUN8I_PWM_clock_src_xy -->| /div_k |--------------->
+ * |________|
+ */
+SUN8I_PWM_X_CLK(0);
+SUN8I_PWM_X_CLK(1);
+SUN8I_PWM_X_CLK(2);
+SUN8I_PWM_X_CLK(3);
+SUN8I_PWM_X_CLK(4);
+SUN8I_PWM_X_CLK(5);
+
+/*
+ * SUN8I_PWM_bypass_clock_xy generation:
+ * ______
+ * | |
+ * SUN8I_PWM_clock_src_xy --->| Gate |-------> SUN8I_PWM_bypass_clock_x
+ * |______|
+ *
+ * The gate is actually SUN8I_PWM_PER register.
+ */
+SUN8I_PWM_X_BYPASS_CLK(0);
+SUN8I_PWM_X_BYPASS_CLK(1);
+SUN8I_PWM_X_BYPASS_CLK(2);
+SUN8I_PWM_X_BYPASS_CLK(3);
+SUN8I_PWM_X_BYPASS_CLK(4);
+SUN8I_PWM_X_BYPASS_CLK(5);
+
+struct clk_pwm_data {
+ const char *name;
+ const char **parent_names;
+ unsigned int num_parents;
+ struct clk_hw *mux_hw;
+ struct clk_hw *rate_hw;
+ struct clk_hw *gate_hw;
+ unsigned long flags;
+};
+
+/* Indexes of REF_CLK_BYPASS and REF_CLK_XY_SRC in the array */
+#define CLK_BYPASS_IDX(sun8i_chip, chan) ((sun8i_chip)->data->npwm + (chan))
+#define CLK_XY_SRC_IDX(sun8i_chip, chan) \
+ ((sun8i_chip)->data->npwm * 2 + SUN8I_PWM_PAIR_IDX(chan))
+static struct clk_pwm_data pwmcc_data[] = {
+ REF_CLK_X(0, 01),
+ REF_CLK_X(1, 01),
+ REF_CLK_X(2, 23),
+ REF_CLK_X(3, 23),
+ REF_CLK_X(4, 45),
+ REF_CLK_X(5, 45),
+ REF_CLK_BYPASS(0, 01),
+ REF_CLK_BYPASS(1, 01),
+ REF_CLK_BYPASS(2, 23),
+ REF_CLK_BYPASS(3, 23),
+ REF_CLK_BYPASS(4, 45),
+ REF_CLK_BYPASS(5, 45),
+ REF_CLK_XY_SRC(01),
+ REF_CLK_XY_SRC(23),
+ REF_CLK_XY_SRC(45),
+ { /* sentinel */ }
+};
+
+enum sun8i_pwm_mode {
+ SUN8I_PWM_MODE_NONE,
+ SUN8I_PWM_MODE_PWM,
+ SUN8I_PWM_MODE_CLK,
+};
+
+struct sun8i_pwm_data {
+ unsigned int npwm;
+};
+
+struct sun8i_pwm_channel {
+ struct clk *pwm_clk;
+ enum sun8i_pwm_mode mode;
+};
+
+struct clk_pwm_pdata {
+ struct clk_hw_onecell_data *hw_data;
+ spinlock_t lock;
+ void __iomem *reg;
+};
+
+struct sun8i_pwm_chip {
+ struct clk_pwm_pdata *clk_pdata;
+ struct sun8i_pwm_channel *channels;
+ struct clk *bus_clk;
+ struct reset_control *rst;
+ void __iomem *base;
+ const struct sun8i_pwm_data *data;
+};
+
+struct sun8i_pwm_waveform {
+ u8 enabled:1;
+ u8 active_state:1;
+ u8 bypass_en:1;
+ u16 duty_ticks;
+ u32 period_ticks;
+ unsigned long clk_rate;
+};
+
+static inline struct sun8i_pwm_chip *sun8i_pwm_from_chip(const struct pwm_chip *chip)
+{
+ return pwmchip_get_drvdata(chip);
+}
+
+static inline u32 sun8i_pwm_readl(struct sun8i_pwm_chip *sun8i_chip,
+ unsigned long offset)
+{
+ return readl(sun8i_chip->base + offset);
+}
+
+static inline void sun8i_pwm_writel(struct sun8i_pwm_chip *sun8i_chip,
+ u32 val, unsigned long offset)
+{
+ writel(val, sun8i_chip->base + offset);
+}
+
+static void sun8i_pwm_set_bypass(struct sun8i_pwm_chip *sun8i_chip,
+ unsigned int idx, bool en_bypass)
+{
+ unsigned long flags, reg_offset;
+ u32 val;
+
+ spin_lock_irqsave(&sun8i_chip->clk_pdata->lock, flags);
+
+ reg_offset = SUN8I_PWM_PCCR(SUN8I_PWM_PAIR_IDX(idx));
+ val = sun8i_pwm_readl(sun8i_chip, reg_offset);
+ if (en_bypass)
+ val |= BIT(SUN8I_PWM_PCCR_BYPASS_BIT(idx));
+ else
+ val &= ~BIT(SUN8I_PWM_PCCR_BYPASS_BIT(idx));
+
+ sun8i_pwm_writel(sun8i_chip, val, reg_offset);
+
+ spin_unlock_irqrestore(&sun8i_chip->clk_pdata->lock, flags);
+}
+
+static int sun8i_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
+ struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
+
+ scoped_guard(spinlock_irqsave, &sun8i_chip->clk_pdata->lock) {
+ if (chan->mode == SUN8I_PWM_MODE_CLK)
+ return -EBUSY;
+ chan->mode = SUN8I_PWM_MODE_PWM;
+ }
+
+ return clk_prepare_enable(chan->pwm_clk);
+}
+
+static void sun8i_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
+ struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
+
+ clk_disable_unprepare(chan->pwm_clk);
+ chan->mode = SUN8I_PWM_MODE_NONE;
+}
+
+static int sun8i_pwm_read_waveform(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ void *_wfhw)
+{
+ struct sun8i_pwm_waveform *wfhw = _wfhw;
+ struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
+ struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
+ u32 val;
+
+ wfhw->clk_rate = clk_get_rate(chan->pwm_clk);
+
+ val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PER);
+ wfhw->enabled = !!(SUN8I_PWM_ENABLE(pwm->hwpwm) & val);
+
+ val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PCCR(SUN8I_PWM_PAIR_IDX(pwm->hwpwm)));
+ wfhw->bypass_en = !!(val & BIT(SUN8I_PWM_PCCR_BYPASS_BIT(pwm->hwpwm)));
+
+ val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PCR(pwm->hwpwm));
+ wfhw->active_state = !!(val & SUN8I_PWM_PCR_ACTIVE_STATE);
+
+ val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PPR(pwm->hwpwm));
+ wfhw->duty_ticks = SUN8I_PWM_PPR_DUTY_VALUE(val);
+ wfhw->period_ticks = SUN8I_PWM_PPR_PERIOD_VALUE(val);
+
+ dev_dbg(pwmchip_parent(chip),
+ "pwm%u: %s, bypass: %s, polarity: %s, clk_rate=%lu period_ticks=%u duty_ticks=%u\n",
+ pwm->hwpwm,
+ wfhw->enabled ? "enabled" : "disabled",
+ wfhw->bypass_en ? "enabled" : "disabled",
+ wfhw->active_state ? "normal" : "inversed",
+ wfhw->clk_rate, wfhw->period_ticks, wfhw->duty_ticks);
+
+ return 0;
+}
+
+static int sun8i_pwm_round_waveform_fromhw(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ const void *_wfhw,
+ struct pwm_waveform *wf)
+{
+ const struct sun8i_pwm_waveform *wfhw = _wfhw;
+ u64 tmp, resolution;
+
+ dev_dbg(pwmchip_parent(chip),
+ "pwm%u: %s, bypass: %s, polarity: %s, clk_rate=%lu period_ticks=%u duty_ticks=%u\n",
+ pwm->hwpwm,
+ wfhw->enabled ? "enabled" : "disabled",
+ wfhw->bypass_en ? "enabled" : "disabled",
+ wfhw->active_state ? "normal" : "inversed",
+ wfhw->clk_rate, wfhw->period_ticks, wfhw->duty_ticks);
+
+ wf->duty_offset_ns = 0;
+
+ if (!wfhw->enabled || !wfhw->clk_rate) {
+ wf->period_length_ns = 0;
+ wf->duty_length_ns = 0;
+ return 0;
+ }
+
+ if (wfhw->bypass_en) {
+ wf->period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC,
+ wfhw->clk_rate);
+ wf->duty_length_ns = DIV_ROUND_UP_ULL(wf->period_length_ns, 2);
+ return 0;
+ }
+
+ tmp = NSEC_PER_SEC * (u64)wfhw->period_ticks;
+ wf->period_length_ns = DIV_ROUND_UP_ULL(tmp, wfhw->clk_rate);
+
+ tmp = NSEC_PER_SEC * (u64)wfhw->duty_ticks;
+ wf->duty_length_ns = DIV_ROUND_UP_ULL(tmp, wfhw->clk_rate);
+ if (!wfhw->active_state) {
+ /*
+ * For inverted polarity, we have to fix cases where
+ * computed duty_length_ns > requested duty_length_ns
+ * For that, we subtract the actual resolution of the PWM
+ * registers
+ */
+ wf->duty_offset_ns = wf->duty_length_ns;
+ wf->duty_length_ns = wf->period_length_ns - wf->duty_length_ns;
+
+ resolution = DIV_ROUND_UP_ULL(NSEC_PER_SEC, wfhw->clk_rate);
+
+ if (wf->duty_offset_ns >= resolution)
+ wf->duty_offset_ns -= resolution;
+ }
+
+ dev_dbg(pwmchip_parent(chip),
+ "pwm%u period_length_ns=%llu duty_length_ns=%llu duty_offset_ns=%llu\n",
+ pwm->hwpwm, wf->period_length_ns, wf->duty_length_ns,
+ wf->duty_offset_ns);
+
+ return 0;
+}
+
+static int sun8i_pwm_write_waveform(struct pwm_chip *chip,
+ struct pwm_device *pwm, const void *_wfhw)
+{
+ const struct sun8i_pwm_waveform *wfhw = _wfhw;
+ struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
+ struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
+ unsigned long flags;
+ u32 val;
+ int ret;
+
+ ret = clk_set_rate(chan->pwm_clk, wfhw->clk_rate);
+ if (ret)
+ return ret;
+
+ sun8i_pwm_set_bypass(sun8i_chip, pwm->hwpwm, wfhw->bypass_en);
+
+ val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PCR(pwm->hwpwm));
+ if (wfhw->active_state)
+ val |= SUN8I_PWM_PCR_ACTIVE_STATE;
+ else
+ val &= ~SUN8I_PWM_PCR_ACTIVE_STATE;
+ sun8i_pwm_writel(sun8i_chip, val, SUN8I_PWM_PCR(pwm->hwpwm));
+
+ val = SUN8I_PWM_DUTY(wfhw->duty_ticks);
+ val |= SUN8I_PWM_PPR_PERIOD(wfhw->period_ticks);
+ sun8i_pwm_writel(sun8i_chip, val, SUN8I_PWM_PPR(pwm->hwpwm));
+
+ spin_lock_irqsave(&sun8i_chip->clk_pdata->lock, flags);
+
+ val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PER);
+ if (wfhw->enabled)
+ val |= SUN8I_PWM_ENABLE(pwm->hwpwm);
+ else
+ val &= ~SUN8I_PWM_ENABLE(pwm->hwpwm);
+ sun8i_pwm_writel(sun8i_chip, val, SUN8I_PWM_PER);
+
+ spin_unlock_irqrestore(&sun8i_chip->clk_pdata->lock, flags);
+
+ return 0;
+}
+
+static int sun8i_pwm_round_waveform_tohw(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ const struct pwm_waveform *wf,
+ void *_wfhw)
+{
+ struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
+ struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
+ struct sun8i_pwm_waveform *wfhw = _wfhw;
+ unsigned long max_rate;
+ long calc_rate;
+ u64 period_ratio, double_duty_ratio, freq, duty_cycle;
+
+ dev_dbg(pwmchip_parent(chip),
+ "pwm%u period_length_ns=%llu duty_length_ns=%llu duty_offset_ns=%llu\n",
+ pwm->hwpwm, wf->period_length_ns, wf->duty_length_ns,
+ wf->duty_offset_ns);
+
+ if (wf->period_length_ns == 0) {
+ wfhw->enabled = 0;
+ return 0;
+ }
+
+ wfhw->enabled = 1;
+
+ duty_cycle = wf->duty_length_ns;
+ if (wf->duty_length_ns + wf->duty_offset_ns < wf->period_length_ns)
+ wfhw->active_state = 1;
+ else
+ wfhw->active_state = 0;
+
+ dev_dbg(pwmchip_parent(chip), "polarity: %s\n",
+ wfhw->active_state ? "normal" : "inversed");
+
+ /*
+ * Lowest possible period case:
+ * Without bypass, the lowest possible period is when:
+ * duty cycle = 1 and period cycle = 2 (0x10001 in period register)
+ * E.g. if the input clock is 100MHz, we have a lowest period of 20ns.
+ * Now, with the bypass, the period register is ignored and we directly
+ * have the 100MHz clock as PWM output, that can act as a 10ns period
+ * with 5ns duty.
+ * So, to detect this lowest period case, just get the maximum possible
+ * rate from chan->pwm_clk and compare it with requested period and
+ * duty_cycle.
+ *
+ * But, to get the maximum possible rate, we have to use U32_MAX instead
+ * of (unsigned long)-1.
+ * This is because clk_round_rate() uses ultimately DIV_ROUND_UP_ULL()
+ * that in turn do_div(n,base). And base is uint32_t divisor.
+ */
+ max_rate = clk_round_rate(chan->pwm_clk, U32_MAX);
+
+ dev_dbg(pwmchip_parent(chip), "max_rate: %ld Hz\n", max_rate);
+
+ period_ratio = mul_u64_u64_div_u64(wf->period_length_ns,
+ max_rate, NSEC_PER_SEC);
+ double_duty_ratio = mul_u64_u64_div_u64(duty_cycle, (u64)max_rate * 2,
+ NSEC_PER_SEC);
+ if (period_ratio == 1) {
+ if (double_duty_ratio == 0)
+ /* requested period and duty are too small */
+ return -EINVAL;
+ /*
+ * If the requested period is to small to be generated by the
+ * PWM, but matches the highest clock with a
+ * duty_cycle >= period*2, just bypass the PWM logic
+ */
+ freq = div64_u64(NSEC_PER_SEC, wf->period_length_ns);
+ wfhw->bypass_en = true;
+ } else {
+ wfhw->bypass_en = false;
+ freq = div64_u64(NSEC_PER_SEC * (u64)SUN8I_PWM_PPR_PERIOD_MAX,
+ wf->period_length_ns);
+ /*
+ * Same remark as above, this is to prevent a value to big for
+ * clk_round_rate() to handle
+ */
+ if (freq > U32_MAX)
+ freq = U32_MAX;
+ }
+
+ dev_dbg(pwmchip_parent(chip), "bypass: %s\n",
+ wfhw->bypass_en ? "enabled" : "disabled");
+
+ calc_rate = clk_round_rate(chan->pwm_clk, freq);
+ if (calc_rate <= 0)
+ return calc_rate ? calc_rate : -EINVAL;
+
+ dev_dbg(pwmchip_parent(chip), "calc_rate: %ld Hz\n", calc_rate);
+
+ wfhw->period_ticks = mul_u64_u64_div_u64(calc_rate,
+ wf->period_length_ns,
+ NSEC_PER_SEC);
+ if (wfhw->period_ticks > SUN8I_PWM_PPR_PERIOD_MAX)
+ wfhw->period_ticks = SUN8I_PWM_PPR_PERIOD_MAX;
+
+ /* min value in period register is 1 */
+ if (wfhw->period_ticks == 0)
+ return -EINVAL;
+
+ wfhw->duty_ticks = mul_u64_u64_div_u64(calc_rate, duty_cycle,
+ NSEC_PER_SEC);
+
+ if (wfhw->duty_ticks > wfhw->period_ticks)
+ wfhw->duty_ticks = wfhw->period_ticks;
+
+ if (!wfhw->active_state)
+ wfhw->duty_ticks = wfhw->period_ticks - wfhw->duty_ticks;
+
+ dev_dbg(pwmchip_parent(chip),
+ "pwm%u period_ticks=%u duty_cycle=%llu duty_ticks=%u\n",
+ pwm->hwpwm, wfhw->period_ticks, duty_cycle, wfhw->duty_ticks);
+
+ wfhw->clk_rate = calc_rate;
+
+ return 0;
+}
+
+static const struct pwm_ops sun8i_pwm_ops = {
+ .request = sun8i_pwm_request,
+ .free = sun8i_pwm_free,
+ .sizeof_wfhw = sizeof(struct sun8i_pwm_waveform),
+ .round_waveform_tohw = sun8i_pwm_round_waveform_tohw,
+ .round_waveform_fromhw = sun8i_pwm_round_waveform_fromhw,
+ .read_waveform = sun8i_pwm_read_waveform,
+ .write_waveform = sun8i_pwm_write_waveform,
+};
+
+static struct clk_hw *sun8i_pwm_of_clk_get(struct of_phandle_args *clkspec,
+ void *data)
+{
+ struct sun8i_pwm_chip *sun8i_chip = data;
+ struct clk_hw_onecell_data *hw_data = sun8i_chip->clk_pdata->hw_data;
+ unsigned int idx = clkspec->args[0];
+ struct sun8i_pwm_channel *chan;
+ struct clk_hw *ret_clk = NULL;
+ unsigned long flags;
+
+ if (idx >= sun8i_chip->data->npwm)
+ return ERR_PTR(-EINVAL);
+
+ chan = &sun8i_chip->channels[idx];
+
+ spin_lock_irqsave(&sun8i_chip->clk_pdata->lock, flags);
+
+ if (chan->mode == SUN8I_PWM_MODE_PWM) {
+ ret_clk = ERR_PTR(-EBUSY);
+ } else {
+ chan->mode = SUN8I_PWM_MODE_CLK;
+ ret_clk = hw_data->hws[CLK_BYPASS_IDX(sun8i_chip, idx)];
+ }
+ spin_unlock_irqrestore(&sun8i_chip->clk_pdata->lock, flags);
+
+ if (IS_ERR(ret_clk))
+ goto out;
+
+ sun8i_pwm_set_bypass(sun8i_chip, idx, true);
+out:
+ return ret_clk;
+}
+
+static int sun8i_add_composite_clk(struct clk_pwm_data *data,
+ void __iomem *reg, spinlock_t *lock,
+ struct device *dev, struct clk_hw **hw)
+{
+ const struct clk_ops *mux_ops = NULL, *gate_ops = NULL, *rate_ops = NULL;
+ struct clk_hw *mux_hw = NULL, *gate_hw = NULL, *rate_hw = NULL;
+ struct device_node *node = dev->of_node;
+
+ if (data->mux_hw) {
+ struct clk_mux *mux;
+
+ mux_hw = data->mux_hw;
+ mux = to_clk_mux(mux_hw);
+ mux->lock = lock;
+ mux_ops = mux_hw->init->ops;
+ mux->reg = (uintptr_t)mux->reg + reg;
+ }
+
+ if (data->gate_hw) {
+ struct clk_gate *gate;
+
+ gate_hw = data->gate_hw;
+ gate = to_clk_gate(gate_hw);
+ gate->lock = lock;
+ gate_ops = gate_hw->init->ops;
+ gate->reg = (uintptr_t)gate->reg + reg;
+ }
+
+ if (data->rate_hw) {
+ struct clk_divider *rate;
+
+ rate_hw = data->rate_hw;
+ rate = to_clk_divider(rate_hw);
+ rate_ops = rate_hw->init->ops;
+ rate->lock = lock;
+ rate->reg = (uintptr_t)rate->reg + reg;
+
+ if (rate->table) {
+ const struct clk_div_table *clkt;
+ int table_size = 0;
+
+ for (clkt = rate->table; clkt->div; clkt++)
+ table_size++;
+ rate->width = order_base_2(table_size);
+ }
+ }
+
+ /*
+ * Retrieve the parent clock names from DTS for pwm-clk-srcxy
+ */
+ if (!data->parent_names) {
+ data->num_parents = of_clk_get_parent_count(node);
+ if (data->num_parents == 0)
+ return -ENOENT;
+
+ data->parent_names = devm_kzalloc(dev,
+ sizeof(*data->parent_names),
+ GFP_KERNEL);
+ for (unsigned int i = 0; i < data->num_parents; i++)
+ data->parent_names[i] = of_clk_get_parent_name(node, i);
+ }
+
+ *hw = clk_hw_register_composite(dev, data->name, data->parent_names,
+ data->num_parents, mux_hw,
+ mux_ops, rate_hw, rate_ops,
+ gate_hw, gate_ops, data->flags);
+
+ return PTR_ERR_OR_ZERO(*hw);
+}
+
+static int sun8i_pwm_init_clocks(struct platform_device *pdev,
+ struct sun8i_pwm_chip *sun8i_chip)
+{
+ struct clk_pwm_pdata *pdata;
+ struct device *dev = &pdev->dev;
+ int num_clocks = 0;
+ int ret;
+
+ pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return dev_err_probe(dev, -ENOMEM,
+ "Failed to allocate clk_pwm_pdata\n");
+
+ while (pwmcc_data[num_clocks].name)
+ num_clocks++;
+
+ pdata->hw_data = devm_kzalloc(dev, struct_size(pdata->hw_data, hws, num_clocks),
+ GFP_KERNEL);
+ if (!pdata->hw_data)
+ return dev_err_probe(dev, -ENOMEM,
+ "Failed to allocate hw clocks\n");
+
+ pdata->hw_data->num = num_clocks;
+ pdata->reg = sun8i_chip->base;
+
+ spin_lock_init(&pdata->lock);
+
+ for (int i = 0; i < num_clocks; i++) {
+ struct clk_hw **hw = &pdata->hw_data->hws[i];
+
+ ret = sun8i_add_composite_clk(&pwmcc_data[i], pdata->reg,
+ &pdata->lock, dev, hw);
+ if (ret) {
+ dev_err_probe(dev, ret,
+ "Failed to register hw clock %s\n",
+ pwmcc_data[i].name);
+ for (i--; i >= 0; i--)
+ clk_hw_unregister_composite(pdata->hw_data->hws[i]);
+ return ret;
+ }
+ }
+
+ sun8i_chip->clk_pdata = pdata;
+
+ return 0;
+}
+
+static void sun8i_pwm_unregister_clk(void *data)
+{
+ struct clk_hw_onecell_data *hw_data = data;
+
+ for (unsigned int i = 0; i < hw_data->num; i++)
+ clk_hw_unregister_composite(hw_data->hws[i]);
+}
+
+static int sun8i_pwm_probe(struct platform_device *pdev)
+{
+ const struct sun8i_pwm_data *data;
+ struct device *dev = &pdev->dev;
+ struct sun8i_pwm_chip *sun8i_chip;
+ struct pwm_chip *chip;
+ int ret;
+
+ data = of_device_get_match_data(dev);
+ if (!data)
+ return dev_err_probe(dev, -ENODEV,
+ "Missing specific data structure\n");
+
+ chip = devm_pwmchip_alloc(dev, data->npwm, sizeof(*sun8i_chip));
+ if (IS_ERR(chip))
+ return dev_err_probe(dev, PTR_ERR(chip),
+ "Failed to allocate pwmchip\n");
+
+ sun8i_chip = sun8i_pwm_from_chip(chip);
+ sun8i_chip->data = data;
+ sun8i_chip->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(sun8i_chip->base))
+ return dev_err_probe(dev, PTR_ERR(sun8i_chip->base),
+ "Failed to get PWM base address\n");
+
+ sun8i_chip->bus_clk = devm_clk_get_enabled(dev, "bus");
+ if (IS_ERR(sun8i_chip->bus_clk))
+ return dev_err_probe(dev, PTR_ERR(sun8i_chip->bus_clk),
+ "Failed to get bus clock\n");
+
+ sun8i_chip->channels = devm_kmalloc_array(dev, data->npwm,
+ sizeof(*(sun8i_chip->channels)),
+ GFP_KERNEL);
+ if (!sun8i_chip->channels)
+ return dev_err_probe(dev, -ENOMEM,
+ "Failed to allocate %d channels array\n",
+ data->npwm);
+
+ chip->ops = &sun8i_pwm_ops;
+
+ ret = sun8i_pwm_init_clocks(pdev, sun8i_chip);
+ if (ret)
+ return ret;
+
+ for (unsigned int i = 0; i < data->npwm; i++) {
+ struct sun8i_pwm_channel *chan = &sun8i_chip->channels[i];
+ struct clk_hw **hw = &sun8i_chip->clk_pdata->hw_data->hws[i];
+
+ chan->pwm_clk = devm_clk_hw_get_clk(dev, *hw, NULL);
+ if (IS_ERR(chan->pwm_clk)) {
+ ret = dev_err_probe(dev, PTR_ERR(chan->pwm_clk),
+ "Failed to register PWM clock %d\n", i);
+ return ret;
+ }
+ chan->mode = SUN8I_PWM_MODE_NONE;
+ }
+
+ ret = devm_of_clk_add_hw_provider(dev, sun8i_pwm_of_clk_get, sun8i_chip);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to add HW clock provider\n");
+
+ ret = devm_add_action_or_reset(dev, sun8i_pwm_unregister_clk,
+ sun8i_chip->clk_pdata->hw_data);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to add devm action\n");
+
+ /* Deassert reset */
+ sun8i_chip->rst = devm_reset_control_get_shared_deasserted(dev, NULL);
+ if (IS_ERR(sun8i_chip->rst))
+ return dev_err_probe(dev, PTR_ERR(sun8i_chip->rst),
+ "Failed to get reset control\n");
+
+ ret = devm_pwmchip_add(dev, chip);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
+
+ platform_set_drvdata(pdev, chip);
+
+ return 0;
+}
+
+static const struct sun8i_pwm_data sun50i_h616_pwm_data = {
+ .npwm = 6,
+};
+
+static const struct of_device_id sun8i_pwm_dt_ids[] = {
+ {
+ .compatible = "allwinner,sun50i-h616-pwm",
+ .data = &sun50i_h616_pwm_data,
+ }, {
+ /* sentinel */
+ }
+};
+MODULE_DEVICE_TABLE(of, sun8i_pwm_dt_ids);
+
+static struct platform_driver sun8i_pwm_driver = {
+ .driver = {
+ .name = "sun8i-pwm",
+ .of_match_table = sun8i_pwm_dt_ids,
+ },
+ .probe = sun8i_pwm_probe,
+};
+module_platform_driver(sun8i_pwm_driver);
+
+MODULE_AUTHOR("Richard Genoud <richard.genoud@bootlin•com>");
+MODULE_DESCRIPTION("Allwinner sun8i PWM driver");
+MODULE_LICENSE("GPL");
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v6 3/4] arm64: dts: allwinner: h616: add PWM controller
2026-04-16 13:40 [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Richard Genoud
2026-04-16 13:40 ` [PATCH v6 1/4] dt-bindings: pwm: allwinner: add h616 pwm compatible Richard Genoud
2026-04-16 13:40 ` [PATCH v6 2/4] pwm: sun8i: Add H616 PWM support Richard Genoud
@ 2026-04-16 13:40 ` Richard Genoud
2026-04-16 13:40 ` [PATCH v6 4/4] MAINTAINERS: Add entry on Allwinner sun8i/H616 PWM driver Richard Genoud
2026-05-25 21:15 ` [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Andre Przywara
4 siblings, 0 replies; 7+ messages in thread
From: Richard Genoud @ 2026-04-16 13:40 UTC (permalink / raw)
To: Uwe Kleine-König, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Chen-Yu Tsai, Jernej Skrabec, Samuel Holland,
Philipp Zabel
Cc: Paul Kocialkowski, Thomas Petazzoni, John Stultz, Joao Schim,
bigunclemax, linux-pwm, devicetree, linux-arm-kernel, linux-sunxi,
linux-kernel, Richard Genoud
The H616 has a PWM controller that can provide PWM signals, but also
plain clocks.
Add the PWM controller node and pins in the device tree.
Tested-by: John Stultz <jstultz@google•com>
Signed-off-by: Richard Genoud <richard.genoud@bootlin•com>
---
.../arm64/boot/dts/allwinner/sun50i-h616.dtsi | 47 +++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi
index 8d1110c14bad..1c7628a6e4bb 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi
@@ -236,6 +236,17 @@ watchdog: watchdog@30090a0 {
clocks = <&osc24M>;
};
+ pwm: pwm@300a000 {
+ compatible = "allwinner,sun50i-h616-pwm";
+ reg = <0x0300a000 0x400>;
+ clocks = <&osc24M>, <&ccu CLK_BUS_PWM>;
+ clock-names = "mod", "bus";
+ resets = <&ccu RST_BUS_PWM>;
+ #pwm-cells = <3>;
+ #clock-cells = <1>;
+ status = "disabled";
+ };
+
pio: pinctrl@300b000 {
compatible = "allwinner,sun50i-h616-pinctrl";
reg = <0x0300b000 0x400>;
@@ -340,6 +351,42 @@ nand_rb1_pin: nand-rb1-pin {
bias-pull-up;
};
+ /omit-if-no-ref/
+ pwm0_pin: pwm0-pin {
+ pins = "PD28";
+ function = "pwm0";
+ };
+
+ /omit-if-no-ref/
+ pwm1_pin: pwm1-pin {
+ pins = "PG19";
+ function = "pwm1";
+ };
+
+ /omit-if-no-ref/
+ pwm2_pin: pwm2-pin {
+ pins = "PH2";
+ function = "pwm2";
+ };
+
+ /omit-if-no-ref/
+ pwm3_pin: pwm3-pin {
+ pins = "PH0";
+ function = "pwm3";
+ };
+
+ /omit-if-no-ref/
+ pwm4_pin: pwm4-pin {
+ pins = "PI14";
+ function = "pwm4";
+ };
+
+ /omit-if-no-ref/
+ pwm5_pin: pwm5-pin {
+ pins = "PA12";
+ function = "pwm5";
+ };
+
/omit-if-no-ref/
spi0_pins: spi0-pins {
pins = "PC0", "PC2", "PC4";
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v6 4/4] MAINTAINERS: Add entry on Allwinner sun8i/H616 PWM driver
2026-04-16 13:40 [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Richard Genoud
` (2 preceding siblings ...)
2026-04-16 13:40 ` [PATCH v6 3/4] arm64: dts: allwinner: h616: add PWM controller Richard Genoud
@ 2026-04-16 13:40 ` Richard Genoud
2026-05-25 21:15 ` [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Andre Przywara
4 siblings, 0 replies; 7+ messages in thread
From: Richard Genoud @ 2026-04-16 13:40 UTC (permalink / raw)
To: Uwe Kleine-König, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Chen-Yu Tsai, Jernej Skrabec, Samuel Holland,
Philipp Zabel
Cc: Paul Kocialkowski, Thomas Petazzoni, John Stultz, Joao Schim,
bigunclemax, linux-pwm, devicetree, linux-arm-kernel, linux-sunxi,
linux-kernel, Richard Genoud
Add myself as maintainer of Allwinner SUN8I PWM driver.
Signed-off-by: Richard Genoud <richard.genoud@bootlin•com>
---
MAINTAINERS | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index d1cc0e12fe1f..256ab8be19f1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -912,6 +912,11 @@ S: Maintained
F: Documentation/devicetree/bindings/hwlock/allwinner,sun6i-a31-hwspinlock.yaml
F: drivers/hwspinlock/sun6i_hwspinlock.c
+ALLWINNER SUN8I PWM DRIVER
+M: Richard Genoud <richard.genoud@bootlin•com>
+S: Maintained
+F: drivers/pwm/pwm-sun8i.c
+
ALLWINNER THERMAL DRIVER
M: Vasily Khoruzhick <anarsoul@gmail•com>
M: Yangtao Li <tiny.windzz@gmail•com>
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v6 2/4] pwm: sun8i: Add H616 PWM support
2026-04-16 13:40 ` [PATCH v6 2/4] pwm: sun8i: Add H616 PWM support Richard Genoud
@ 2026-05-25 17:58 ` Uwe Kleine-König
0 siblings, 0 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2026-05-25 17:58 UTC (permalink / raw)
To: Richard Genoud
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Chen-Yu Tsai,
Jernej Skrabec, Samuel Holland, Philipp Zabel, Paul Kocialkowski,
Thomas Petazzoni, John Stultz, Joao Schim, bigunclemax, linux-pwm,
devicetree, linux-arm-kernel, linux-sunxi, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 35888 bytes --]
Hello Richard,
I cannot say much about the clk part of this driver and thus would like
to get some input from the clk people. Can you please add them to the
list of recipents for the next revision?
On Thu, Apr 16, 2026 at 03:40:35PM +0200, Richard Genoud wrote:
> Add driver for Allwinner H616 PWM controller, supporting up to 6
> channels.
> Those channels output can be either a PWM signal output or a clock
> output, thanks to the bypass.
>
> The channels are paired (0/1, 2/3 and 4/5) and each pair has a
> prescaler/mux/gate.
> Moreover, each channel has its own prescaler and bypass.
>
> The clock provider part of this driver is needed not only because the
> H616 PWM controller provides also clocks when bypass is enabled, but
> really because pwm-clock isn't fit to handle all cases here.
> pwm-clock would work if the 100MHz clock is requested, but if a lower
> clock is requested (like 24MHz), it will request a 42ns period to the
> PWM driver which will happily serve, with the 100MHz clock as input a
> 25MHz frequency and a duty cycle adjustable in the range [0-4]/4,
> because that is a sane thing to do for a PWM.
> The information missing is that a real clock is resquested, not a PWM.
>
> Tested-by: John Stultz <jstultz@google•com>
> Tested-by: Joao Schim <joao@schimsalabim•eu>
> Signed-off-by: Richard Genoud <richard.genoud@bootlin•com>
> ---
> drivers/pwm/Kconfig | 12 +
> drivers/pwm/Makefile | 1 +
> drivers/pwm/pwm-sun8i.c | 938 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 951 insertions(+)
> create mode 100644 drivers/pwm/pwm-sun8i.c
>
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index 6f3147518376..c4fd682860d6 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -736,6 +736,18 @@ config PWM_SUN4I
> To compile this driver as a module, choose M here: the module
> will be called pwm-sun4i.
>
> +config PWM_SUN8I
> + tristate "Allwinner sun8i/sun50i PWM support"
> + depends on ARCH_SUNXI || COMPILE_TEST
> + depends on HAS_IOMEM && COMMON_CLK
> + help
> + Generic PWM framework driver for Allwinner H616 SoCs.
> + It supports generic PWM, but can also provides a plain clock.
> + The AC300 PHY integrated in H616 SoC needs such a clock.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called pwm-sun8i.
> +
> config PWM_SUNPLUS
> tristate "Sunplus PWM support"
> depends on ARCH_SUNPLUS || COMPILE_TEST
> diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
> index 0dc0d2b69025..ba2e0ec7fc17 100644
> --- a/drivers/pwm/Makefile
> +++ b/drivers/pwm/Makefile
> @@ -67,6 +67,7 @@ obj-$(CONFIG_PWM_STM32) += pwm-stm32.o
> obj-$(CONFIG_PWM_STM32_LP) += pwm-stm32-lp.o
> obj-$(CONFIG_PWM_STMPE) += pwm-stmpe.o
> obj-$(CONFIG_PWM_SUN4I) += pwm-sun4i.o
> +obj-$(CONFIG_PWM_SUN8I) += pwm-sun8i.o
> obj-$(CONFIG_PWM_SUNPLUS) += pwm-sunplus.o
> obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
> obj-$(CONFIG_PWM_TH1520) += pwm_th1520.o
> diff --git a/drivers/pwm/pwm-sun8i.c b/drivers/pwm/pwm-sun8i.c
> new file mode 100644
> index 000000000000..8f1023e3a2e5
> --- /dev/null
> +++ b/drivers/pwm/pwm-sun8i.c
> @@ -0,0 +1,938 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for Allwinner sun8i Pulse Width Modulation Controller
> + *
> + * (C) Copyright 2025 Richard Genoud, Bootlin <richard.genoud@bootlin•com>
> + *
> + * Based on drivers/pwm/pwm-sun4i.c with Copyright:
> + *
> + * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@bootlin•com>
> + *
> + * Limitations:
> + * - As the channels are paired (0/1, 2/3, 4/5), they share the same clock
> + * source and prescaler(div_m), but they also have their own prescaler(div_k)
> + * and bypass.
> + *
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/limits.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/reset.h>
> +#include <linux/spinlock.h>
> +#include <linux/time.h>
> +
> +/* PWM IRQ Enable Register */
> +#define SUN8I_PWM_PIER 0x0
> +
> +/* PWM IRQ Status Register */
> +#define SUN8I_PWM_PISR 0x4
> +
> +/* PWM Capture IRQ Enable Register */
> +#define SUN8I_PWM_CIER 0x10
> +
> +/* PWM Capture IRQ Status Register */
> +#define SUN8I_PWM_CISR 0x14
> +
> +/* PWMCC Pairs Clock Configuration Registers */
> +#define SUN8I_PWM_PCCR(pair) (0x20 + ((pair) * 0x4))
> +#define SUN8I_PWM_PCCR_SRC_SHIFT 7
> +#define SUN8I_PWM_PCCR_SRC_MASK 1
> +#define SUN8I_PWM_PCCR_GATE_BIT 4
> +#define SUN8I_PWM_PCCR_BYPASS_BIT(chan) ((chan) % 2 + 5)
> +#define SUN8I_PWM_PCCR_DIV_M_SHIFT 0
> +
> +/* PWMCC Pairs Dead Zone Control Registers */
> +#define SUN8I_PWM_PDZCR(pair) (0x30 + ((pair) * 0x4))
> +
> +/* PWM Enable Register */
> +#define SUN8I_PWM_PER 0x40
> +#define SUN8I_PWM_ENABLE(chan) BIT(chan)
> +
> +/* PWM Capture Enable Register */
> +#define SUN8I_PWM_CER 0x44
> +
> +/* PWM Control Register */
> +#define SUN8I_PWM_PCR(chan) (0x60 + (chan) * 0x20)
> +#define SUN8I_PWM_PCR_PRESCAL_K_SHIFT 0
> +#define SUN8I_PWM_PCR_PRESCAL_K_WIDTH 8
> +#define SUN8I_PWM_PCR_ACTIVE_STATE BIT(8)
> +
> +/* PWM Period Register */
> +#define SUN8I_PWM_PPR(chan) (0x64 + (chan) * 0x20)
> +#define SUN8I_PWM_PPR_PERIOD_MASK GENMASK(31, 16)
> +#define SUN8I_PWM_PPR_DUTY_MASK GENMASK(15, 0)
> +#define SUN8I_PWM_PPR_PERIOD_VALUE(reg) (FIELD_GET(SUN8I_PWM_PPR_PERIOD_MASK, reg) + 1)
> +#define SUN8I_PWM_PPR_DUTY_VALUE(reg) FIELD_GET(SUN8I_PWM_PPR_DUTY_MASK, reg)
> +#define SUN8I_PWM_PPR_PERIOD(prd) FIELD_PREP(SUN8I_PWM_PPR_PERIOD_MASK, (prd) - 1)
> +#define SUN8I_PWM_DUTY(dty) FIELD_PREP(SUN8I_PWM_PPR_DUTY_MASK, dty)
> +#define SUN8I_PWM_PPR_PERIOD_MAX (FIELD_MAX(SUN8I_PWM_PPR_PERIOD_MASK) + 1)
> +
> +/* PWM Count Register */
> +#define SUN8I_PWM_PCNTR(chan) (0x68 + (chan) * 0x20)
> +
> +/* PWM Capture Control Register */
> +#define SUN8I_PWM_CCR(chan) (0x6c + (chan) * 0x20)
> +
> +/* PWM Capture Rise Lock Register */
> +#define SUN8I_PWM_CRLR(chan) (0x70 + (chan) * 0x20)
> +
> +/* PWM Capture Fall Lock Register */
> +#define SUN8I_PWM_CFLR(chan) (0x74 + (chan) * 0x20)
> +
> +#define SUN8I_PWM_PAIR_IDX(chan) ((chan) >> 1)
> +
> +/*
> + * Block diagram of the PWM clock controller:
> + *
> + * _____ ______ ________
> + * OSC24M --->| | | | | |
> + * APB1 ----->| Mux |--->| Gate |--->| /div_m |-----> SUN8I_PWM_clock_src_xy
> + * |_____| |______| |________|
> + * ________
> + * | |
> + * +->| /div_k |---> SUN8I_PWM_clock_x
> + * | |________|
> + * | ______
> + * | | |
> + * +-->| Gate |----> SUN8I_PWM_bypass_clock_x
> + * | |______|
> + * SUN8I_PWM_clock_src_xy ---+ ________
> + * | | |
> + * +->| /div_k |---> SUN8I_PWM_clock_y
> + * | |________|
> + * | ______
> + * | | |
> + * +-->| Gate |----> SUN8I_PWM_bypass_clock_y
> + * |______|
> + *
> + * NB: when the bypass is set, all the PWM logic is bypassed.
> + * So, the duty cycle and polarity can't be modified (we just have a clock).
> + * The bypass in PWM mode is used to achieve a 1/2 relative duty cycle with the
> + * fastest clock.
> + *
> + * SUN8I_PWM_clock_x/y serve for the PWM purpose.
> + * SUN8I_PWM_bypass_clock_x/y serve for the clock-provider purpose.
> + *
> + */
> +
> +/*
> + * Table used for /div_m (diviser before obtaining SUN8I_PWM_clock_src_xy)
> + * It's actually CLK_DIVIDER_POWER_OF_TWO, but limited to /256
> + */
> +#define CLK_TABLE_DIV_M_ENTRY(i) { \
> + .val = (i), .div = 1 << (i) \
> +}
> +
> +static const struct clk_div_table clk_table_div_m[] = {
> + CLK_TABLE_DIV_M_ENTRY(0),
> + CLK_TABLE_DIV_M_ENTRY(1),
> + CLK_TABLE_DIV_M_ENTRY(2),
> + CLK_TABLE_DIV_M_ENTRY(3),
> + CLK_TABLE_DIV_M_ENTRY(4),
> + CLK_TABLE_DIV_M_ENTRY(5),
> + CLK_TABLE_DIV_M_ENTRY(6),
> + CLK_TABLE_DIV_M_ENTRY(7),
> + CLK_TABLE_DIV_M_ENTRY(8),
> + { /* sentinel */ }
> +};
> +
> +#define SUN8I_PWM_XY_SRC_GATE(_pair, _reg) \
> +struct clk_gate gate_xy_##_pair = { \
> + .reg = (void *)(_reg), \
> + .bit_idx = SUN8I_PWM_PCCR_GATE_BIT, \
> + .hw.init = &(struct clk_init_data){ \
> + .ops = &clk_gate_ops, \
> + } \
> +}
> +
> +#define SUN8I_PWM_XY_SRC_MUX(_pair, _reg) \
> +struct clk_mux mux_xy_##_pair = { \
> + .reg = (void *)(_reg), \
> + .shift = SUN8I_PWM_PCCR_SRC_SHIFT, \
> + .mask = SUN8I_PWM_PCCR_SRC_MASK, \
> + .flags = CLK_MUX_ROUND_CLOSEST, \
> + .hw.init = &(struct clk_init_data){ \
> + .ops = &clk_mux_ops, \
> + } \
> +}
> +
> +#define SUN8I_PWM_XY_SRC_DIV(_pair, _reg) \
> +struct clk_divider rate_xy_##_pair = { \
> + .reg = (void *)(_reg), \
> + .shift = SUN8I_PWM_PCCR_DIV_M_SHIFT, \
> + .table = clk_table_div_m, \
> + .hw.init = &(struct clk_init_data){ \
> + .ops = &clk_divider_ops, \
> + } \
> +}
> +
> +#define SUN8I_PWM_X_DIV(_idx, _reg) \
> +struct clk_divider rate_x_##_idx = { \
> + .reg = (void *)(_reg), \
> + .shift = SUN8I_PWM_PCR_PRESCAL_K_SHIFT, \
> + .width = SUN8I_PWM_PCR_PRESCAL_K_WIDTH, \
> + .hw.init = &(struct clk_init_data){ \
> + .ops = &clk_divider_ops, \
> + } \
> +}
> +
> +#define SUN8I_PWM_X_BYPASS_GATE(_idx) \
> +struct clk_gate gate_x_bypass_##_idx = { \
> + .reg = (void *)SUN8I_PWM_PER, \
> + .bit_idx = _idx, \
> + .hw.init = &(struct clk_init_data){ \
> + .ops = &clk_gate_ops, \
> + } \
> +}
> +
> +#define SUN8I_PWM_XY_CLK_SRC(_pair, _reg) \
> + static SUN8I_PWM_XY_SRC_MUX(_pair, _reg); \
> + static SUN8I_PWM_XY_SRC_GATE(_pair, _reg); \
> + static SUN8I_PWM_XY_SRC_DIV(_pair, _reg)
> +
> +#define SUN8I_PWM_X_CLK(_idx) \
> + static SUN8I_PWM_X_DIV(_idx, SUN8I_PWM_PCR(_idx))
> +
> +#define SUN8I_PWM_X_BYPASS_CLK(_idx) \
> + SUN8I_PWM_X_BYPASS_GATE(_idx)
> +
> +#define REF_CLK_XY_SRC(_pair) \
> + { \
> + .name = "pwm-clk-src" #_pair, \
> + .mux_hw = &mux_xy_##_pair.hw, \
> + .gate_hw = &gate_xy_##_pair.hw, \
> + .rate_hw = &rate_xy_##_pair.hw, \
> + }
> +
> +#define REF_CLK_X(_idx, _pair) \
> + { \
> + .name = "pwm-clk" #_idx, \
> + .parent_names = (const char *[]){ "pwm-clk-src" #_pair }, \
> + .num_parents = 1, \
> + .rate_hw = &rate_x_##_idx.hw, \
> + .flags = CLK_SET_RATE_PARENT, \
> + }
> +
> +#define REF_CLK_BYPASS(_idx, _pair) \
> + { \
> + .name = "pwm-clk-bypass" #_idx, \
> + .parent_names = (const char *[]){ "pwm-clk-src" #_pair }, \
> + .num_parents = 1, \
> + .gate_hw = &gate_x_bypass_##_idx.hw, \
> + .flags = CLK_SET_RATE_PARENT, \
> + }
> +
> +/*
> + * SUN8I_PWM_clock_src_xy generation:
> + * _____ ______ ________
> + * OSC24M --->| | | | | |
> + * APB1 ----->| Mux |--->| Gate |--->| /div_m |-----> SUN8I_PWM_clock_src_xy
> + * |_____| |______| |________|
> + */
> +SUN8I_PWM_XY_CLK_SRC(01, SUN8I_PWM_PCCR(0));
> +SUN8I_PWM_XY_CLK_SRC(23, SUN8I_PWM_PCCR(1));
> +SUN8I_PWM_XY_CLK_SRC(45, SUN8I_PWM_PCCR(2));
> +
> +/*
> + * SUN8I_PWM_clock_x_div generation:
> + * ________
> + * | | SUN8I_PWM_clock_x/y
> + * SUN8I_PWM_clock_src_xy -->| /div_k |--------------->
> + * |________|
> + */
> +SUN8I_PWM_X_CLK(0);
> +SUN8I_PWM_X_CLK(1);
> +SUN8I_PWM_X_CLK(2);
> +SUN8I_PWM_X_CLK(3);
> +SUN8I_PWM_X_CLK(4);
> +SUN8I_PWM_X_CLK(5);
> +
> +/*
> + * SUN8I_PWM_bypass_clock_xy generation:
> + * ______
> + * | |
> + * SUN8I_PWM_clock_src_xy --->| Gate |-------> SUN8I_PWM_bypass_clock_x
> + * |______|
> + *
> + * The gate is actually SUN8I_PWM_PER register.
> + */
> +SUN8I_PWM_X_BYPASS_CLK(0);
> +SUN8I_PWM_X_BYPASS_CLK(1);
> +SUN8I_PWM_X_BYPASS_CLK(2);
> +SUN8I_PWM_X_BYPASS_CLK(3);
> +SUN8I_PWM_X_BYPASS_CLK(4);
> +SUN8I_PWM_X_BYPASS_CLK(5);
> +
> +struct clk_pwm_data {
> + const char *name;
> + const char **parent_names;
> + unsigned int num_parents;
> + struct clk_hw *mux_hw;
> + struct clk_hw *rate_hw;
> + struct clk_hw *gate_hw;
> + unsigned long flags;
> +};
> +
> +/* Indexes of REF_CLK_BYPASS and REF_CLK_XY_SRC in the array */
> +#define CLK_BYPASS_IDX(sun8i_chip, chan) ((sun8i_chip)->data->npwm + (chan))
> +#define CLK_XY_SRC_IDX(sun8i_chip, chan) \
> + ((sun8i_chip)->data->npwm * 2 + SUN8I_PWM_PAIR_IDX(chan))
> +static struct clk_pwm_data pwmcc_data[] = {
> + REF_CLK_X(0, 01),
> + REF_CLK_X(1, 01),
> + REF_CLK_X(2, 23),
> + REF_CLK_X(3, 23),
> + REF_CLK_X(4, 45),
> + REF_CLK_X(5, 45),
> + REF_CLK_BYPASS(0, 01),
> + REF_CLK_BYPASS(1, 01),
> + REF_CLK_BYPASS(2, 23),
> + REF_CLK_BYPASS(3, 23),
> + REF_CLK_BYPASS(4, 45),
> + REF_CLK_BYPASS(5, 45),
> + REF_CLK_XY_SRC(01),
> + REF_CLK_XY_SRC(23),
> + REF_CLK_XY_SRC(45),
> + { /* sentinel */ }
> +};
> +
> +enum sun8i_pwm_mode {
> + SUN8I_PWM_MODE_NONE,
> + SUN8I_PWM_MODE_PWM,
> + SUN8I_PWM_MODE_CLK,
> +};
> +
> +struct sun8i_pwm_data {
> + unsigned int npwm;
> +};
> +
> +struct sun8i_pwm_channel {
> + struct clk *pwm_clk;
> + enum sun8i_pwm_mode mode;
> +};
> +
> +struct clk_pwm_pdata {
> + struct clk_hw_onecell_data *hw_data;
> + spinlock_t lock;
> + void __iomem *reg;
> +};
> +
> +struct sun8i_pwm_chip {
> + struct clk_pwm_pdata *clk_pdata;
> + struct sun8i_pwm_channel *channels;
> + struct clk *bus_clk;
> + struct reset_control *rst;
> + void __iomem *base;
> + const struct sun8i_pwm_data *data;
> +};
> +
> +struct sun8i_pwm_waveform {
> + u8 enabled:1;
> + u8 active_state:1;
> + u8 bypass_en:1;
> + u16 duty_ticks;
> + u32 period_ticks;
> + unsigned long clk_rate;
> +};
> +
> +static inline struct sun8i_pwm_chip *sun8i_pwm_from_chip(const struct pwm_chip *chip)
> +{
> + return pwmchip_get_drvdata(chip);
> +}
> +
> +static inline u32 sun8i_pwm_readl(struct sun8i_pwm_chip *sun8i_chip,
> + unsigned long offset)
> +{
> + return readl(sun8i_chip->base + offset);
> +}
> +
> +static inline void sun8i_pwm_writel(struct sun8i_pwm_chip *sun8i_chip,
> + u32 val, unsigned long offset)
> +{
> + writel(val, sun8i_chip->base + offset);
> +}
> +
> +static void sun8i_pwm_set_bypass(struct sun8i_pwm_chip *sun8i_chip,
> + unsigned int idx, bool en_bypass)
> +{
> + unsigned long flags, reg_offset;
> + u32 val;
> +
> + spin_lock_irqsave(&sun8i_chip->clk_pdata->lock, flags);
> +
> + reg_offset = SUN8I_PWM_PCCR(SUN8I_PWM_PAIR_IDX(idx));
> + val = sun8i_pwm_readl(sun8i_chip, reg_offset);
> + if (en_bypass)
> + val |= BIT(SUN8I_PWM_PCCR_BYPASS_BIT(idx));
> + else
> + val &= ~BIT(SUN8I_PWM_PCCR_BYPASS_BIT(idx));
> +
> + sun8i_pwm_writel(sun8i_chip, val, reg_offset);
> +
> + spin_unlock_irqrestore(&sun8i_chip->clk_pdata->lock, flags);
> +}
> +
> +static int sun8i_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> + struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
> + struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
> +
> + scoped_guard(spinlock_irqsave, &sun8i_chip->clk_pdata->lock) {
> + if (chan->mode == SUN8I_PWM_MODE_CLK)
> + return -EBUSY;
> + chan->mode = SUN8I_PWM_MODE_PWM;
> + }
> +
> + return clk_prepare_enable(chan->pwm_clk);
> +}
> +
> +static void sun8i_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> + struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
> + struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
> +
> + clk_disable_unprepare(chan->pwm_clk);
> + chan->mode = SUN8I_PWM_MODE_NONE;
> +}
> +
> +static int sun8i_pwm_read_waveform(struct pwm_chip *chip,
> + struct pwm_device *pwm,
> + void *_wfhw)
> +{
> + struct sun8i_pwm_waveform *wfhw = _wfhw;
> + struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
> + struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
> + u32 val;
> +
> + wfhw->clk_rate = clk_get_rate(chan->pwm_clk);
> +
> + val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PER);
> + wfhw->enabled = !!(SUN8I_PWM_ENABLE(pwm->hwpwm) & val);
> +
> + val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PCCR(SUN8I_PWM_PAIR_IDX(pwm->hwpwm)));
> + wfhw->bypass_en = !!(val & BIT(SUN8I_PWM_PCCR_BYPASS_BIT(pwm->hwpwm)));
> +
> + val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PCR(pwm->hwpwm));
> + wfhw->active_state = !!(val & SUN8I_PWM_PCR_ACTIVE_STATE);
> +
> + val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PPR(pwm->hwpwm));
> + wfhw->duty_ticks = SUN8I_PWM_PPR_DUTY_VALUE(val);
> + wfhw->period_ticks = SUN8I_PWM_PPR_PERIOD_VALUE(val);
> +
> + dev_dbg(pwmchip_parent(chip),
> + "pwm%u: %s, bypass: %s, polarity: %s, clk_rate=%lu period_ticks=%u duty_ticks=%u\n",
> + pwm->hwpwm,
> + wfhw->enabled ? "enabled" : "disabled",
> + wfhw->bypass_en ? "enabled" : "disabled",
> + wfhw->active_state ? "normal" : "inversed",
> + wfhw->clk_rate, wfhw->period_ticks, wfhw->duty_ticks);
> +
> + return 0;
> +}
> +
> +static int sun8i_pwm_round_waveform_fromhw(struct pwm_chip *chip,
> + struct pwm_device *pwm,
> + const void *_wfhw,
> + struct pwm_waveform *wf)
> +{
> + const struct sun8i_pwm_waveform *wfhw = _wfhw;
> + u64 tmp, resolution;
> +
> + dev_dbg(pwmchip_parent(chip),
> + "pwm%u: %s, bypass: %s, polarity: %s, clk_rate=%lu period_ticks=%u duty_ticks=%u\n",
> + pwm->hwpwm,
> + wfhw->enabled ? "enabled" : "disabled",
> + wfhw->bypass_en ? "enabled" : "disabled",
> + wfhw->active_state ? "normal" : "inversed",
> + wfhw->clk_rate, wfhw->period_ticks, wfhw->duty_ticks);
> +
> + wf->duty_offset_ns = 0;
> +
> + if (!wfhw->enabled || !wfhw->clk_rate) {
> + wf->period_length_ns = 0;
> + wf->duty_length_ns = 0;
> + return 0;
> + }
> +
> + if (wfhw->bypass_en) {
> + wf->period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC,
> + wfhw->clk_rate);
> + wf->duty_length_ns = DIV_ROUND_UP_ULL(wf->period_length_ns, 2);
> + return 0;
> + }
> +
> + tmp = NSEC_PER_SEC * (u64)wfhw->period_ticks;
> + wf->period_length_ns = DIV_ROUND_UP_ULL(tmp, wfhw->clk_rate);
> +
> + tmp = NSEC_PER_SEC * (u64)wfhw->duty_ticks;
> + wf->duty_length_ns = DIV_ROUND_UP_ULL(tmp, wfhw->clk_rate);
> + if (!wfhw->active_state) {
> + /*
> + * For inverted polarity, we have to fix cases where
> + * computed duty_length_ns > requested duty_length_ns
> + * For that, we subtract the actual resolution of the PWM
> + * registers
> + */
> + wf->duty_offset_ns = wf->duty_length_ns;
> + wf->duty_length_ns = wf->period_length_ns - wf->duty_length_ns;
> +
> + resolution = DIV_ROUND_UP_ULL(NSEC_PER_SEC, wfhw->clk_rate);
> +
> + if (wf->duty_offset_ns >= resolution)
> + wf->duty_offset_ns -= resolution;
This looks wrong. If you have
clk_rate = 300000
period_ticks = 3000
duty_ticks = 440
active_state = 0
you're supposed to report:
.period_length_ns = roundup(3000 * 1000000000 / 300000) = 10000000
.duty_length_ns = roundup((3000 - 440) * 1000000000 / 300000) = 8533334
.duty_offset_ns = roundup(440 * 1000000000 / 300000) = 1466667
> + }
> +
> + dev_dbg(pwmchip_parent(chip),
> + "pwm%u period_length_ns=%llu duty_length_ns=%llu duty_offset_ns=%llu\n",
> + pwm->hwpwm, wf->period_length_ns, wf->duty_length_ns,
> + wf->duty_offset_ns);
Can you please only use a single output that has both the register state
and the waveform representation? Currently the waveform part is also
skipped on the early returns above. Also please use "%lld/%lld [+%lld]"
to represent the waveform.
> + return 0;
> +}
> +
> +static int sun8i_pwm_write_waveform(struct pwm_chip *chip,
> + struct pwm_device *pwm, const void *_wfhw)
> +{
> + const struct sun8i_pwm_waveform *wfhw = _wfhw;
> + struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
> + struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
> + unsigned long flags;
> + u32 val;
> + int ret;
> +
> + ret = clk_set_rate(chan->pwm_clk, wfhw->clk_rate);
> + if (ret)
> + return ret;
> +
> + sun8i_pwm_set_bypass(sun8i_chip, pwm->hwpwm, wfhw->bypass_en);
> +
> + val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PCR(pwm->hwpwm));
> + if (wfhw->active_state)
> + val |= SUN8I_PWM_PCR_ACTIVE_STATE;
> + else
> + val &= ~SUN8I_PWM_PCR_ACTIVE_STATE;
> + sun8i_pwm_writel(sun8i_chip, val, SUN8I_PWM_PCR(pwm->hwpwm));
> +
> + val = SUN8I_PWM_DUTY(wfhw->duty_ticks);
> + val |= SUN8I_PWM_PPR_PERIOD(wfhw->period_ticks);
> + sun8i_pwm_writel(sun8i_chip, val, SUN8I_PWM_PPR(pwm->hwpwm));
> +
> + spin_lock_irqsave(&sun8i_chip->clk_pdata->lock, flags);
> +
> + val = sun8i_pwm_readl(sun8i_chip, SUN8I_PWM_PER);
> + if (wfhw->enabled)
> + val |= SUN8I_PWM_ENABLE(pwm->hwpwm);
> + else
> + val &= ~SUN8I_PWM_ENABLE(pwm->hwpwm);
> + sun8i_pwm_writel(sun8i_chip, val, SUN8I_PWM_PER);
> +
> + spin_unlock_irqrestore(&sun8i_chip->clk_pdata->lock, flags);
> +
> + return 0;
> +}
> +
> +static int sun8i_pwm_round_waveform_tohw(struct pwm_chip *chip,
> + struct pwm_device *pwm,
> + const struct pwm_waveform *wf,
> + void *_wfhw)
> +{
> + struct sun8i_pwm_chip *sun8i_chip = sun8i_pwm_from_chip(chip);
> + struct sun8i_pwm_channel *chan = &sun8i_chip->channels[pwm->hwpwm];
> + struct sun8i_pwm_waveform *wfhw = _wfhw;
> + unsigned long max_rate;
> + long calc_rate;
> + u64 period_ratio, double_duty_ratio, freq, duty_cycle;
> +
> + dev_dbg(pwmchip_parent(chip),
> + "pwm%u period_length_ns=%llu duty_length_ns=%llu duty_offset_ns=%llu\n",
> + pwm->hwpwm, wf->period_length_ns, wf->duty_length_ns,
> + wf->duty_offset_ns);
> +
> + if (wf->period_length_ns == 0) {
> + wfhw->enabled = 0;
> + return 0;
> + }
> +
> + wfhw->enabled = 1;
> +
> + duty_cycle = wf->duty_length_ns;
> + if (wf->duty_length_ns + wf->duty_offset_ns < wf->period_length_ns)
> + wfhw->active_state = 1;
> + else
> + wfhw->active_state = 0;
Please look at pwm-stm32.c on how to determine if inversed polarity
should be used or not.
> + dev_dbg(pwmchip_parent(chip), "polarity: %s\n",
> + wfhw->active_state ? "normal" : "inversed");
> +
> + /*
> + * Lowest possible period case:
> + * Without bypass, the lowest possible period is when:
> + * duty cycle = 1 and period cycle = 2 (0x10001 in period register)
> + * E.g. if the input clock is 100MHz, we have a lowest period of 20ns.
> + * Now, with the bypass, the period register is ignored and we directly
> + * have the 100MHz clock as PWM output, that can act as a 10ns period
> + * with 5ns duty.
> + * So, to detect this lowest period case, just get the maximum possible
> + * rate from chan->pwm_clk and compare it with requested period and
> + * duty_cycle.
> + *
> + * But, to get the maximum possible rate, we have to use U32_MAX instead
> + * of (unsigned long)-1.
> + * This is because clk_round_rate() uses ultimately DIV_ROUND_UP_ULL()
> + * that in turn do_div(n,base). And base is uint32_t divisor.
> + */
> + max_rate = clk_round_rate(chan->pwm_clk, U32_MAX);
> +
> + dev_dbg(pwmchip_parent(chip), "max_rate: %ld Hz\n", max_rate);
> +
> + period_ratio = mul_u64_u64_div_u64(wf->period_length_ns,
> + max_rate, NSEC_PER_SEC);
> + double_duty_ratio = mul_u64_u64_div_u64(duty_cycle, (u64)max_rate * 2,
> + NSEC_PER_SEC);
> + if (period_ratio == 1) {
> + if (double_duty_ratio == 0)
> + /* requested period and duty are too small */
> + return -EINVAL;
> + /*
> + * If the requested period is to small to be generated by the
> + * PWM, but matches the highest clock with a
> + * duty_cycle >= period*2, just bypass the PWM logic
> + */
> + freq = div64_u64(NSEC_PER_SEC, wf->period_length_ns);
> + wfhw->bypass_en = true;
> + } else {
> + wfhw->bypass_en = false;
> + freq = div64_u64(NSEC_PER_SEC * (u64)SUN8I_PWM_PPR_PERIOD_MAX,
> + wf->period_length_ns);
> + /*
> + * Same remark as above, this is to prevent a value to big for
> + * clk_round_rate() to handle
> + */
> + if (freq > U32_MAX)
> + freq = U32_MAX;
> + }
> +
> + dev_dbg(pwmchip_parent(chip), "bypass: %s\n",
> + wfhw->bypass_en ? "enabled" : "disabled");
> +
> + calc_rate = clk_round_rate(chan->pwm_clk, freq);
> + if (calc_rate <= 0)
> + return calc_rate ? calc_rate : -EINVAL;
> +
> + dev_dbg(pwmchip_parent(chip), "calc_rate: %ld Hz\n", calc_rate);
> +
> + wfhw->period_ticks = mul_u64_u64_div_u64(calc_rate,
> + wf->period_length_ns,
> + NSEC_PER_SEC);
> + if (wfhw->period_ticks > SUN8I_PWM_PPR_PERIOD_MAX)
> + wfhw->period_ticks = SUN8I_PWM_PPR_PERIOD_MAX;
> +
> + /* min value in period register is 1 */
> + if (wfhw->period_ticks == 0)
> + return -EINVAL;
> +
> + wfhw->duty_ticks = mul_u64_u64_div_u64(calc_rate, duty_cycle,
> + NSEC_PER_SEC);
> +
> + if (wfhw->duty_ticks > wfhw->period_ticks)
> + wfhw->duty_ticks = wfhw->period_ticks;
> +
> + if (!wfhw->active_state)
> + wfhw->duty_ticks = wfhw->period_ticks - wfhw->duty_ticks;
> +
> + dev_dbg(pwmchip_parent(chip),
> + "pwm%u period_ticks=%u duty_cycle=%llu duty_ticks=%u\n",
> + pwm->hwpwm, wfhw->period_ticks, duty_cycle, wfhw->duty_ticks);
As for the fromhw callback: Please emit a single line here and stick to
the common format for *wf.
> +
> + wfhw->clk_rate = calc_rate;
> +
> + return 0;
> +}
> +
> +static const struct pwm_ops sun8i_pwm_ops = {
> + .request = sun8i_pwm_request,
> + .free = sun8i_pwm_free,
> + .sizeof_wfhw = sizeof(struct sun8i_pwm_waveform),
> + .round_waveform_tohw = sun8i_pwm_round_waveform_tohw,
> + .round_waveform_fromhw = sun8i_pwm_round_waveform_fromhw,
> + .read_waveform = sun8i_pwm_read_waveform,
> + .write_waveform = sun8i_pwm_write_waveform,
> +};
> +
> +static struct clk_hw *sun8i_pwm_of_clk_get(struct of_phandle_args *clkspec,
> + void *data)
> +{
> + struct sun8i_pwm_chip *sun8i_chip = data;
> + struct clk_hw_onecell_data *hw_data = sun8i_chip->clk_pdata->hw_data;
> + unsigned int idx = clkspec->args[0];
> + struct sun8i_pwm_channel *chan;
> + struct clk_hw *ret_clk = NULL;
> + unsigned long flags;
> +
> + if (idx >= sun8i_chip->data->npwm)
> + return ERR_PTR(-EINVAL);
> +
> + chan = &sun8i_chip->channels[idx];
> +
> + spin_lock_irqsave(&sun8i_chip->clk_pdata->lock, flags);
> +
> + if (chan->mode == SUN8I_PWM_MODE_PWM) {
> + ret_clk = ERR_PTR(-EBUSY);
> + } else {
> + chan->mode = SUN8I_PWM_MODE_CLK;
> + ret_clk = hw_data->hws[CLK_BYPASS_IDX(sun8i_chip, idx)];
> + }
> + spin_unlock_irqrestore(&sun8i_chip->clk_pdata->lock, flags);
> +
> + if (IS_ERR(ret_clk))
> + goto out;
> +
> + sun8i_pwm_set_bypass(sun8i_chip, idx, true);
> +out:
> + return ret_clk;
> +}
> +
> +static int sun8i_add_composite_clk(struct clk_pwm_data *data,
> + void __iomem *reg, spinlock_t *lock,
> + struct device *dev, struct clk_hw **hw)
> +{
> + const struct clk_ops *mux_ops = NULL, *gate_ops = NULL, *rate_ops = NULL;
> + struct clk_hw *mux_hw = NULL, *gate_hw = NULL, *rate_hw = NULL;
> + struct device_node *node = dev->of_node;
> +
> + if (data->mux_hw) {
> + struct clk_mux *mux;
> +
> + mux_hw = data->mux_hw;
> + mux = to_clk_mux(mux_hw);
> + mux->lock = lock;
> + mux_ops = mux_hw->init->ops;
> + mux->reg = (uintptr_t)mux->reg + reg;
> + }
> +
> + if (data->gate_hw) {
> + struct clk_gate *gate;
> +
> + gate_hw = data->gate_hw;
> + gate = to_clk_gate(gate_hw);
> + gate->lock = lock;
> + gate_ops = gate_hw->init->ops;
> + gate->reg = (uintptr_t)gate->reg + reg;
> + }
> +
> + if (data->rate_hw) {
> + struct clk_divider *rate;
> +
> + rate_hw = data->rate_hw;
> + rate = to_clk_divider(rate_hw);
> + rate_ops = rate_hw->init->ops;
> + rate->lock = lock;
> + rate->reg = (uintptr_t)rate->reg + reg;
> +
> + if (rate->table) {
> + const struct clk_div_table *clkt;
> + int table_size = 0;
> +
> + for (clkt = rate->table; clkt->div; clkt++)
> + table_size++;
> + rate->width = order_base_2(table_size);
> + }
> + }
> +
> + /*
> + * Retrieve the parent clock names from DTS for pwm-clk-srcxy
> + */
> + if (!data->parent_names) {
> + data->num_parents = of_clk_get_parent_count(node);
> + if (data->num_parents == 0)
> + return -ENOENT;
> +
> + data->parent_names = devm_kzalloc(dev,
> + sizeof(*data->parent_names),
> + GFP_KERNEL);
> + for (unsigned int i = 0; i < data->num_parents; i++)
> + data->parent_names[i] = of_clk_get_parent_name(node, i);
> + }
> +
> + *hw = clk_hw_register_composite(dev, data->name, data->parent_names,
> + data->num_parents, mux_hw,
> + mux_ops, rate_hw, rate_ops,
> + gate_hw, gate_ops, data->flags);
> +
> + return PTR_ERR_OR_ZERO(*hw);
> +}
> +
> +static int sun8i_pwm_init_clocks(struct platform_device *pdev,
> + struct sun8i_pwm_chip *sun8i_chip)
> +{
> + struct clk_pwm_pdata *pdata;
> + struct device *dev = &pdev->dev;
> + int num_clocks = 0;
> + int ret;
> +
> + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> + if (!pdata)
> + return dev_err_probe(dev, -ENOMEM,
> + "Failed to allocate clk_pwm_pdata\n");
> +
> + while (pwmcc_data[num_clocks].name)
> + num_clocks++;
> +
> + pdata->hw_data = devm_kzalloc(dev, struct_size(pdata->hw_data, hws, num_clocks),
> + GFP_KERNEL);
> + if (!pdata->hw_data)
> + return dev_err_probe(dev, -ENOMEM,
> + "Failed to allocate hw clocks\n");
> +
> + pdata->hw_data->num = num_clocks;
> + pdata->reg = sun8i_chip->base;
> +
> + spin_lock_init(&pdata->lock);
> +
> + for (int i = 0; i < num_clocks; i++) {
> + struct clk_hw **hw = &pdata->hw_data->hws[i];
> +
> + ret = sun8i_add_composite_clk(&pwmcc_data[i], pdata->reg,
> + &pdata->lock, dev, hw);
If you register the unregister call here, cleanup gets a bit easier.
> + if (ret) {
> + dev_err_probe(dev, ret,
> + "Failed to register hw clock %s\n",
> + pwmcc_data[i].name);
> + for (i--; i >= 0; i--)
> + clk_hw_unregister_composite(pdata->hw_data->hws[i]);
> + return ret;
> + }
> + }
> +
> + sun8i_chip->clk_pdata = pdata;
If you copy the content of *pdata to sun8i_chip you can save an
allocation here and several pointer dereferences during runtime.
> +
> + return 0;
> +}
> +
> +static void sun8i_pwm_unregister_clk(void *data)
> +{
> + struct clk_hw_onecell_data *hw_data = data;
> +
> + for (unsigned int i = 0; i < hw_data->num; i++)
> + clk_hw_unregister_composite(hw_data->hws[i]);
> +}
> +
> +static int sun8i_pwm_probe(struct platform_device *pdev)
> +{
> + const struct sun8i_pwm_data *data;
> + struct device *dev = &pdev->dev;
> + struct sun8i_pwm_chip *sun8i_chip;
> + struct pwm_chip *chip;
> + int ret;
> +
> + data = of_device_get_match_data(dev);
> + if (!data)
> + return dev_err_probe(dev, -ENODEV,
> + "Missing specific data structure\n");
> +
> + chip = devm_pwmchip_alloc(dev, data->npwm, sizeof(*sun8i_chip));
> + if (IS_ERR(chip))
> + return dev_err_probe(dev, PTR_ERR(chip),
> + "Failed to allocate pwmchip\n");
> +
> + sun8i_chip = sun8i_pwm_from_chip(chip);
> + sun8i_chip->data = data;
> + sun8i_chip->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(sun8i_chip->base))
> + return dev_err_probe(dev, PTR_ERR(sun8i_chip->base),
> + "Failed to get PWM base address\n");
> +
> + sun8i_chip->bus_clk = devm_clk_get_enabled(dev, "bus");
> + if (IS_ERR(sun8i_chip->bus_clk))
> + return dev_err_probe(dev, PTR_ERR(sun8i_chip->bus_clk),
> + "Failed to get bus clock\n");
> +
> + sun8i_chip->channels = devm_kmalloc_array(dev, data->npwm,
> + sizeof(*(sun8i_chip->channels)),
> + GFP_KERNEL);
I wonder if the clk framework ensures that after
devm_of_clk_release_provider() (i.e. the unregister part of
devm_of_clk_add_hw_provider()) sun8i_pwm_of_clk_get() isn't called any
more. If not this might trigger a use-after-free.
> + if (!sun8i_chip->channels)
> + return dev_err_probe(dev, -ENOMEM,
> + "Failed to allocate %d channels array\n",
> + data->npwm);
> +
> + chip->ops = &sun8i_pwm_ops;
Apart from the clk_get_rate() call in the callbacks you could set
.atomic=true.
Also use clk_rate_exclusive_get() to prevent that the parent clk rate
changes while the hardware emits a waveform. (Then also the need to have
clk_rate in sun8i_pwm_waveform goes away.)
> +
> + ret = sun8i_pwm_init_clocks(pdev, sun8i_chip);
> + if (ret)
> + return ret;
> +
> + for (unsigned int i = 0; i < data->npwm; i++) {
> + struct sun8i_pwm_channel *chan = &sun8i_chip->channels[i];
> + struct clk_hw **hw = &sun8i_chip->clk_pdata->hw_data->hws[i];
> +
> + chan->pwm_clk = devm_clk_hw_get_clk(dev, *hw, NULL);
> + if (IS_ERR(chan->pwm_clk)) {
> + ret = dev_err_probe(dev, PTR_ERR(chan->pwm_clk),
> + "Failed to register PWM clock %d\n", i);
> + return ret;
Please shorten that to
return dev_err_probe(....);
> + }
> + chan->mode = SUN8I_PWM_MODE_NONE;
> + }
> +
> + ret = devm_of_clk_add_hw_provider(dev, sun8i_pwm_of_clk_get, sun8i_chip);
> + if (ret)
> + return dev_err_probe(dev, ret, "Failed to add HW clock provider\n");
> +
> + ret = devm_add_action_or_reset(dev, sun8i_pwm_unregister_clk,
> + sun8i_chip->clk_pdata->hw_data);
> + if (ret)
> + return dev_err_probe(dev, ret, "Failed to add devm action\n");
> +
> + /* Deassert reset */
> + sun8i_chip->rst = devm_reset_control_get_shared_deasserted(dev, NULL);
> + if (IS_ERR(sun8i_chip->rst))
> + return dev_err_probe(dev, PTR_ERR(sun8i_chip->rst),
> + "Failed to get reset control\n");
> +
> + ret = devm_pwmchip_add(dev, chip);
> + if (ret < 0)
> + return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
> +
> + platform_set_drvdata(pdev, chip);
this isn't used, so please drop it.
> + return 0;
> +}
> +
> +static const struct sun8i_pwm_data sun50i_h616_pwm_data = {
> + .npwm = 6,
> +};
Do you expect that other variants of this hardware will appear that have
!= 6 channels? If not, please use the 6 directly in .probe().
> +static const struct of_device_id sun8i_pwm_dt_ids[] = {
> + {
> + .compatible = "allwinner,sun50i-h616-pwm",
> + .data = &sun50i_h616_pwm_data,
> + }, {
> + /* sentinel */
> + }
> +};
> +MODULE_DEVICE_TABLE(of, sun8i_pwm_dt_ids);
> +
> +static struct platform_driver sun8i_pwm_driver = {
> + .driver = {
> + .name = "sun8i-pwm",
> + .of_match_table = sun8i_pwm_dt_ids,
> + },
> + .probe = sun8i_pwm_probe,
> +};
> +module_platform_driver(sun8i_pwm_driver);
> +
> +MODULE_AUTHOR("Richard Genoud <richard.genoud@bootlin•com>");
> +MODULE_DESCRIPTION("Allwinner sun8i PWM driver");
> +MODULE_LICENSE("GPL");
Best regards
Uwe
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v6 0/4] Introduce Allwinner H616 PWM controller
2026-04-16 13:40 [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Richard Genoud
` (3 preceding siblings ...)
2026-04-16 13:40 ` [PATCH v6 4/4] MAINTAINERS: Add entry on Allwinner sun8i/H616 PWM driver Richard Genoud
@ 2026-05-25 21:15 ` Andre Przywara
4 siblings, 0 replies; 7+ messages in thread
From: Andre Przywara @ 2026-05-25 21:15 UTC (permalink / raw)
To: Richard Genoud
Cc: Uwe Kleine-König, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Chen-Yu Tsai, Jernej Skrabec, Samuel Holland,
Philipp Zabel, Paul Kocialkowski, Thomas Petazzoni, John Stultz,
Joao Schim, bigunclemax, linux-pwm, devicetree, linux-arm-kernel,
linux-sunxi, linux-kernel
On Thu, 16 Apr 2026 15:40:33 +0200
Richard Genoud <richard.genoud@bootlin•com> wrote:
Hi Richard,
> Allwinner H616 PWM controller is quite different from the A10 one.
>
> It can drive 6 PWM channels, and like for the A10, each channel has a
> bypass that permits to output a clock, bypassing the PWM logic, when
> enabled.
>
> But, the channels are paired 2 by 2, sharing a first set of
> MUX/prescaler/gate.
> Then, for each channel, there's another prescaler (that will be bypassed
> if the bypass is enabled for this channel).
>
> It looks like that:
> _____ ______ ________
> OSC24M --->| | | | | |
> APB1 ----->| Mux |--->| Gate |--->| /div_m |-----> PWM_clock_src_xy
> |_____| |______| |________|
> ________
> | |
> +->| /div_k |---> PWM_clock_x
> | |________|
> | ______
> | | |
> +-->| Gate |----> PWM_bypass_clock_x
> | |______|
> PWM_clock_src_xy -----+ ________
> | | |
> +->| /div_k |---> PWM_clock_y
> | |________|
> | ______
> | | |
> +-->| Gate |----> PWM_bypass_clock_y
> |______|
>
> Where xy can be 0/1, 2/3, 4/5
>
> PWM_clock_x/y serve for the PWM purpose.
> PWM_bypass_clock_x/y serve for the clock-provider purpose.
> The common clock framework has been used to manage those clocks.
>
> This PWM driver serves as a clock-provider for PWM_bypass_clocks.
> This is needed for example by the embedded AC300 PHY which clock comes
> from PMW5 pin (PB12).
>
> Usually, to get a clock from a PWM driver, we use the pwm-clock driver
> so that the PWM driver doesn't need to be a clk-provider itself.
> While this works in most cases, here it just doesn't.
> That's because the pwm-clock request a period from the PWM driver,
> without any clue that it actually wants a clock at a specific frequency,
> and not a PWM signal with duty cycle capability.
> So, the PWM driver doesn't know if it can use the bypass or not, it
> doesn't even have the real accurate frequency information (23809524 Hz
> instead of 24MHz) because PWM drivers only deal with periods.
>
> With pwm-clock, we loose a precious information along the way (that we
> actually want a clock and not a PWM signal).
> That's ok with simple PWM drivers that don't have multiple input clocks,
> but in this case, without this information, we can't know for sure which
> clock to use.
> And here, for instance, if we ask for a 24MHz clock, pwm-clock will
> requests 42ns (assigned-clocks doesn't help for that matter). The logic
> is to select the highest clock (100MHz) with no prescaler and a duty
> cycle value of 2/4 => we have 25MHz instead of 24MHz.
Didn't we discuss this choice of "highest clock" before? I dimly
remember asking whether we cannot use a least-error approach, so
considering all clocks and choosing the one which matches the target
best?
> And that's a perfectly fine choice for a PMW, because we still can
> change the duty cycle in the range [0-4]/4.
> But obviously for a clock, we don't care about the duty cycle, but more
> about the clock accuracy.
Thanks for your research into this and summarising this up! I see your
point, and always found the choice to use nanoseconds in PWM somewhat
problematic, especially when looking at the rounding errors.
And while turning the PWM into a clock provider looks like a clever
solution, this is somewhat arbitrary - why do we have this for those
SoCs and not the other (older) ones? The 24 MHz != 1/42ns problem is
the same there.
What also bugs me a bit is also that this is actually a decision
affecting the generic hardware devicetree description of the system,
but its rooted in a Linux implementation detail (ns resolution periods).
So before we consider going this route:
- Can we change the internal interface in Linux, maybe introducing
some special interface from pwm-clock to the pwm drivers, to convey
frequencies directly, instead of period lengths?
- Can we add an optional interface for pwm drivers in general, to use
a frequency / duty-cycle pair to describe a PWM setup? I would naively
think those to be some kind of natural PWM parameters.
- Can we at least add a picosecond precision interface? That doesn't
solve the rounding issue for those number not only divisible by
2 or 5 (like 24), but at least it seems to mitigate it:
24 MHz => 41666 ps => 24.000384 MHz
I see that having a clock provider seems like a more sustainable and
fitting choice, but as mentioned it's something that affects the DT
description, so I don't want to change that lightly.
Cheers,
Andre
> And actually, this PWM is really a PWM AND a real clock when the bypass
> is set.
>
> This series is based onto v7.0
>
> NB: checkpatch is not happy with patch 2, but it's a false positive.
> It doesn't detect that PWM_XY_SRC_MUX/GATE/DIV are structures, but as
> it's more readable like that, I prefer keeping it that way.
>
> Changes since v5:
> - remove trailing junk after commit message in patch 4
> - remove Tested-by when it doesn't make sense.
> (sorry for the noise)
>
> Changes since v4:
> - Fix a bug on bypass for channels greater than 1
> - add colons to clarify 2 debug messages
> - switch from H616 to sun8i prefix (in code, filename, module name)
> - fix consistency issues in macro parameters
> - rename some macros with a confusing naming
> - rebase on v7.0
>
> Changes since v3:
> - gather Acked-by/Tested-by
> - fix cast from pointer to integer of different size (kernel test robot
> with arc platform)
> - add devm_action for clk_hw_unregister_composite as suggested by Philipp
> - remove now unused pwm_remove as suggested by Philipp
>
> Changes since v2:
> - use U32_MAX instead of defining UINT32_MAX
> - add a comment on U32_MAX usage in clk_round_rate()
> - change clk_table_div_m (use macros)
> - fix formatting (double space, superfluous comma, extra line feed)
> - fix the parent clock order
> - simplify code by using scoped_guard()
> - add missing const in to_h616_pwm_chip() and rename to
> h616_pwm_from_chip()
> - add/remove missing/superfluous error messages
> - rename cnt->period_ticks, duty_cnt->duty_ticks
> - fix PWM_PERIOD_MAX
> - add .remove() callback
> - fix DIV_ROUND_CLOSEST_ULL->DIV_ROUND_UP_ULL
> - add H616_ prefix
> - protect _reg in macros
> - switch to waveforms instead of apply/get_state
> - shrink struct h616_pwm_channel
> - rebase on v6.19-rc4
>
> Changes since v1:
> - rebase onto v6.19-rc1
> - add missing headers
> - remove MODULE_ALIAS (suggested by Krzysztof)
> - use sun4i-pwm binding instead of creating a new one (suggested by Krzysztof)
> - retrieve the parent clocks from the devicetree
> - switch num_parents to unsigned int
>
> Richard Genoud (4):
> dt-bindings: pwm: allwinner: add h616 pwm compatible
> pwm: sun8i: Add H616 PWM support
> arm64: dts: allwinner: h616: add PWM controller
> MAINTAINERS: Add entry on Allwinner sun8i/H616 PWM driver
>
> .../bindings/pwm/allwinner,sun4i-a10-pwm.yaml | 19 +-
> MAINTAINERS | 5 +
> .../arm64/boot/dts/allwinner/sun50i-h616.dtsi | 47 +
> drivers/pwm/Kconfig | 12 +
> drivers/pwm/Makefile | 1 +
> drivers/pwm/pwm-sun8i.c | 938 ++++++++++++++++++
> 6 files changed, 1021 insertions(+), 1 deletion(-)
> create mode 100644 drivers/pwm/pwm-sun8i.c
>
>
> base-commit: 028ef9c96e96197026887c0f092424679298aae8
>
^ permalink raw reply [flat|nested] 7+ messages in thread
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Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2026-04-16 13:40 [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Richard Genoud
2026-04-16 13:40 ` [PATCH v6 1/4] dt-bindings: pwm: allwinner: add h616 pwm compatible Richard Genoud
2026-04-16 13:40 ` [PATCH v6 2/4] pwm: sun8i: Add H616 PWM support Richard Genoud
2026-05-25 17:58 ` Uwe Kleine-König
2026-04-16 13:40 ` [PATCH v6 3/4] arm64: dts: allwinner: h616: add PWM controller Richard Genoud
2026-04-16 13:40 ` [PATCH v6 4/4] MAINTAINERS: Add entry on Allwinner sun8i/H616 PWM driver Richard Genoud
2026-05-25 21:15 ` [PATCH v6 0/4] Introduce Allwinner H616 PWM controller Andre Przywara
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