Subject: Re: [PATCH v6 09/10] clk: realtek: Add RTD1625-ISO clock controller driver

From: Brian Masney <[email-masked]>
Date: Fri, 3 Apr 2026 11:29:44 -0400

Hi Yu-Chun,

On Thu, Apr 02, 2026 at 03:39:56PM +0800, Yu-Chun Lin wrote:
> From: Cheng-Yu Lee <[email-masked]>
> 
> Add support for the ISO (Isolation) domain clock controller on the Realtek
> RTD1625 SoC. This controller manages clocks in the always-on power domain,
> ensuring essential services remain functional even when the main system
> power is gated.
> 
> Since the reset controller shares the same register space with the ISO
> clock controller, it is instantiated as an auxiliary device by the core
> clock driver. This patch also includes the corresponding auxiliary reset
> driver to handle the ISO domain resets.
> 
> Signed-off-by: Cheng-Yu Lee <[email-masked]>
> Co-developed-by: Yu-Chun Lin <[email-masked]>
> Signed-off-by: Yu-Chun Lin <[email-masked]>
> ---
> Changes in v6:
> - Add the headers used in c file to follow the "Include What You Use" principle.
> - Move struct rtk_reset_desc arrays from the clock driver to the dedicated reset driver.
> - Implement and register a dedicated reset auxiliary driver.
> ---
>  drivers/clk/realtek/Makefile              |   1 +
>  drivers/clk/realtek/clk-rtd1625-iso.c     | 144 ++++++++++++++++++++++
>  drivers/reset/realtek/Makefile            |   2 +-
>  drivers/reset/realtek/reset-rtd1625-iso.c |  96 +++++++++++++++
>  4 files changed, 242 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clk/realtek/clk-rtd1625-iso.c
>  create mode 100644 drivers/reset/realtek/reset-rtd1625-iso.c
> 
> diff --git a/drivers/clk/realtek/Makefile b/drivers/clk/realtek/Makefile
> index c992f97dfbc7..1680435e1e0f 100644
> --- a/drivers/clk/realtek/Makefile
> +++ b/drivers/clk/realtek/Makefile
> @@ -10,3 +10,4 @@ clk-rtk-y += freq_table.o
>  
>  clk-rtk-$(CONFIG_RTK_CLK_PLL_MMC) += clk-pll-mmc.o
>  obj-$(CONFIG_COMMON_CLK_RTD1625) += clk-rtd1625-crt.o
> +obj-$(CONFIG_COMMON_CLK_RTD1625) += clk-rtd1625-iso.o
> diff --git a/drivers/clk/realtek/clk-rtd1625-iso.c b/drivers/clk/realtek/clk-rtd1625-iso.c
> new file mode 100644
> index 000000000000..027a131363f9
> --- /dev/null
> +++ b/drivers/clk/realtek/clk-rtd1625-iso.c
> @@ -0,0 +1,144 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2024 Realtek Semiconductor Corporation
> + * Author: Cheng-Yu Lee <[email-masked]>
> + */
> +
> +#include <dt-bindings/clock/realtek,rtd1625-clk.h>
> +#include <linux/array_size.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include "clk-regmap-gate.h"
> +
> +#define RTD1625_ISO_CLK_MAX	19
> +#define RTD1625_ISO_RSTN_MAX	29
> +#define RTD1625_ISO_S_CLK_MAX	5
> +#define RTD1625_ISO_S_RSTN_MAX	5
> +
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_usb_p4, 0, 0x4, 0, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_usb_p3, 0, 0x4, 1, 0);
> +static CLK_REGMAP_GATE(clk_en_misc_cec0, "clk_en_misc", 0, 0x4, 2, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_cbusrx_sys, 0, 0x4, 3, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_cbustx_sys, 0, 0x4, 4, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_cbus_sys, 0, 0x4, 5, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_cbus_osc, 0, 0x4, 6, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_i2c0, 0, 0x4, 9, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_i2c1, 0, 0x4, 10, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_etn_250m, 0, 0x4, 11, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_etn_sys, 0, 0x4, 12, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_usb_drd, 0, 0x4, 13, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_usb_host, 0, 0x4, 14, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_usb_u3_host, 0, 0x4, 15, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_usb, 0, 0x4, 16, 0);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_vtc, 0, 0x4, 17, 0);
> +static CLK_REGMAP_GATE(clk_en_misc_vfd, "clk_en_misc", 0, 0x4, 18, 0);
> +
> +static struct clk_regmap *rtd1625_clk_regmap_list[] = {

static const? Same for some others below as well.

> +	&clk_en_usb_p4.clkr,
> +	&clk_en_usb_p3.clkr,
> +	&clk_en_misc_cec0.clkr,
> +	&clk_en_cbusrx_sys.clkr,
> +	&clk_en_cbustx_sys.clkr,
> +	&clk_en_cbus_sys.clkr,
> +	&clk_en_cbus_osc.clkr,
> +	&clk_en_i2c0.clkr,
> +	&clk_en_i2c1.clkr,
> +	&clk_en_etn_250m.clkr,
> +	&clk_en_etn_sys.clkr,
> +	&clk_en_usb_drd.clkr,
> +	&clk_en_usb_host.clkr,
> +	&clk_en_usb_u3_host.clkr,
> +	&clk_en_usb.clkr,
> +	&clk_en_vtc.clkr,
> +	&clk_en_misc_vfd.clkr,
> +};
> +
> +static struct clk_hw_onecell_data rtd1625_iso_clk_data = {
> +	.num = RTD1625_ISO_CLK_MAX,
> +	.hws = {
> +		[RTD1625_ISO_CLK_EN_USB_P4]      = &__clk_regmap_gate_hw(&clk_en_usb_p4),
> +		[RTD1625_ISO_CLK_EN_USB_P3]      = &__clk_regmap_gate_hw(&clk_en_usb_p3),
> +		[RTD1625_ISO_CLK_EN_MISC_CEC0]   = &__clk_regmap_gate_hw(&clk_en_misc_cec0),
> +		[RTD1625_ISO_CLK_EN_CBUSRX_SYS]  = &__clk_regmap_gate_hw(&clk_en_cbusrx_sys),
> +		[RTD1625_ISO_CLK_EN_CBUSTX_SYS]  = &__clk_regmap_gate_hw(&clk_en_cbustx_sys),
> +		[RTD1625_ISO_CLK_EN_CBUS_SYS]    = &__clk_regmap_gate_hw(&clk_en_cbus_sys),
> +		[RTD1625_ISO_CLK_EN_CBUS_OSC]    = &__clk_regmap_gate_hw(&clk_en_cbus_osc),
> +		[RTD1625_ISO_CLK_EN_I2C0]        = &__clk_regmap_gate_hw(&clk_en_i2c0),
> +		[RTD1625_ISO_CLK_EN_I2C1]        = &__clk_regmap_gate_hw(&clk_en_i2c1),
> +		[RTD1625_ISO_CLK_EN_ETN_250M]    = &__clk_regmap_gate_hw(&clk_en_etn_250m),
> +		[RTD1625_ISO_CLK_EN_ETN_SYS]     = &__clk_regmap_gate_hw(&clk_en_etn_sys),
> +		[RTD1625_ISO_CLK_EN_USB_DRD]     = &__clk_regmap_gate_hw(&clk_en_usb_drd),
> +		[RTD1625_ISO_CLK_EN_USB_HOST]    = &__clk_regmap_gate_hw(&clk_en_usb_host),
> +		[RTD1625_ISO_CLK_EN_USB_U3_HOST] = &__clk_regmap_gate_hw(&clk_en_usb_u3_host),
> +		[RTD1625_ISO_CLK_EN_USB]         = &__clk_regmap_gate_hw(&clk_en_usb),
> +		[RTD1625_ISO_CLK_EN_VTC]         = &__clk_regmap_gate_hw(&clk_en_vtc),
> +		[RTD1625_ISO_CLK_EN_MISC_VFD]    = &__clk_regmap_gate_hw(&clk_en_misc_vfd),
> +		[RTD1625_ISO_CLK_MAX] = NULL,
> +	},
> +};
> +
> +static const struct rtk_clk_desc rtd1625_iso_desc = {
> +	.clk_data = &rtd1625_iso_clk_data,
> +	.clks     = rtd1625_clk_regmap_list,
> +	.num_clks = ARRAY_SIZE(rtd1625_clk_regmap_list),
> +};
> +
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_irda, 0, 0x4, 6, 1);
> +static CLK_REGMAP_GATE_NO_PARENT(clk_en_ur10, 0, 0x4, 8, 1);
> +
> +static struct clk_regmap *rtd1625_iso_s_clk_regmap_list[] = {
> +	&clk_en_irda.clkr,
> +	&clk_en_ur10.clkr,
> +};
> +
> +static struct clk_hw_onecell_data rtd1625_iso_s_clk_data = {
> +	.num = RTD1625_ISO_S_CLK_MAX,
> +	.hws = {
> +		[RTD1625_ISO_S_CLK_EN_IRDA] = &__clk_regmap_gate_hw(&clk_en_irda),
> +		[RTD1625_ISO_S_CLK_EN_UR10] = &__clk_regmap_gate_hw(&clk_en_ur10),
> +		[RTD1625_ISO_S_CLK_MAX] = NULL,
> +	},
> +};
> +
> +static const struct rtk_clk_desc rtd1625_iso_s_desc = {
> +	.clk_data = &rtd1625_iso_s_clk_data,
> +	.clks     = rtd1625_iso_s_clk_regmap_list,
> +	.num_clks = ARRAY_SIZE(rtd1625_iso_s_clk_regmap_list),
> +};
> +
> +static int rtd1625_iso_probe(struct platform_device *pdev)
> +{
> +	const struct rtk_clk_desc *desc;
> +
> +	desc = of_device_get_match_data(&pdev->dev);
> +	if (!desc)
> +		return -EINVAL;
> +	return rtk_clk_probe(pdev, desc, "iso_rst");

Add newline before return.

> +}
> +
> +static const struct of_device_id rtd1625_iso_match[] = {
> +	{.compatible = "realtek,rtd1625-iso-clk", .data = &rtd1625_iso_desc},
> +	{.compatible = "realtek,rtd1625-iso-s-clk", .data = &rtd1625_iso_s_desc},
> +	{ /* sentinel */ }
> +};
> +
> +static struct platform_driver rtd1625_iso_driver = {
> +	.probe = rtd1625_iso_probe,
> +	.driver = {
> +		.name = "rtk-rtd1625-iso-clk",
> +		.of_match_table = rtd1625_iso_match,
> +	},
> +};
> +
> +static int __init rtd1625_iso_init(void)
> +{
> +	return platform_driver_register(&rtd1625_iso_driver);
> +}
> +subsys_initcall(rtd1625_iso_init);
> +
> +MODULE_DESCRIPTION("Realtek RTD1625 ISO Controller Driver");
> +MODULE_AUTHOR("Cheng-Yu Lee <[email-masked]>");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS("REALTEK_CLK");
> diff --git a/drivers/reset/realtek/Makefile b/drivers/reset/realtek/Makefile
> index 8ca1fa939f10..26b3ddc75ada 100644
> --- a/drivers/reset/realtek/Makefile
> +++ b/drivers/reset/realtek/Makefile
> @@ -1,2 +1,2 @@
>  # SPDX-License-Identifier: GPL-2.0-only
> -obj-$(CONFIG_RESET_RTK_COMMON) += common.o reset-rtd1625-crt.o
> +obj-$(CONFIG_RESET_RTK_COMMON) += common.o reset-rtd1625-crt.o reset-rtd1625-iso.o

Some comment as the previous patch. CONFIG_RESET_RTK_COMMON is expected
to be common, right? If so, a SoC-specific driver shouldn't be listed
here.

> diff --git a/drivers/reset/realtek/reset-rtd1625-iso.c b/drivers/reset/realtek/reset-rtd1625-iso.c
> new file mode 100644
> index 000000000000..f2a0478382ae
> --- /dev/null
> +++ b/drivers/reset/realtek/reset-rtd1625-iso.c
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2026 Realtek Semiconductor Corporation
> + */
> +
> +#include <dt-bindings/reset/realtek,rtd1625.h>
> +#include <linux/auxiliary_bus.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include "common.h"
> +
> +#define RTD1625_ISO_RSTN_MAX	29
> +#define RTD1625_ISO_S_RSTN_MAX	5
> +
> +static struct rtk_reset_desc rtd1625_iso_reset_descs[] = {

static const?

> +	[RTD1625_ISO_RSTN_VFD]                 = { .ofs = 0x88, .bit = 0 },
> +	[RTD1625_ISO_RSTN_CEC0]                = { .ofs = 0x88, .bit = 2 },
> +	[RTD1625_ISO_RSTN_CEC1]                = { .ofs = 0x88, .bit = 3 },
> +	[RTD1625_ISO_RSTN_CBUSTX]              = { .ofs = 0x88, .bit = 5 },
> +	[RTD1625_ISO_RSTN_CBUSRX]              = { .ofs = 0x88, .bit = 6 },
> +	[RTD1625_ISO_RSTN_USB3_PHY2_XTAL_POW]  = { .ofs = 0x88, .bit = 7 },
> +	[RTD1625_ISO_RSTN_UR0]                 = { .ofs = 0x88, .bit = 8 },
> +	[RTD1625_ISO_RSTN_GMAC]                = { .ofs = 0x88, .bit = 9 },
> +	[RTD1625_ISO_RSTN_GPHY]                = { .ofs = 0x88, .bit = 10 },
> +	[RTD1625_ISO_RSTN_I2C_0]               = { .ofs = 0x88, .bit = 11 },
> +	[RTD1625_ISO_RSTN_I2C_1]               = { .ofs = 0x88, .bit = 12 },
> +	[RTD1625_ISO_RSTN_CBUS]                = { .ofs = 0x88, .bit = 13 },
> +	[RTD1625_ISO_RSTN_USB_DRD]             = { .ofs = 0x88, .bit = 14 },
> +	[RTD1625_ISO_RSTN_USB_HOST]            = { .ofs = 0x88, .bit = 15 },
> +	[RTD1625_ISO_RSTN_USB_PHY_0]           = { .ofs = 0x88, .bit = 16 },
> +	[RTD1625_ISO_RSTN_USB_PHY_1]           = { .ofs = 0x88, .bit = 17 },
> +	[RTD1625_ISO_RSTN_USB_PHY_2]           = { .ofs = 0x88, .bit = 18 },
> +	[RTD1625_ISO_RSTN_USB]                 = { .ofs = 0x88, .bit = 19 },
> +	[RTD1625_ISO_RSTN_TYPE_C]              = { .ofs = 0x88, .bit = 20 },
> +	[RTD1625_ISO_RSTN_USB_U3_HOST]         = { .ofs = 0x88, .bit = 21 },
> +	[RTD1625_ISO_RSTN_USB3_PHY0_POW]       = { .ofs = 0x88, .bit = 22 },
> +	[RTD1625_ISO_RSTN_USB3_P0_MDIO]        = { .ofs = 0x88, .bit = 23 },
> +	[RTD1625_ISO_RSTN_USB3_PHY1_POW]       = { .ofs = 0x88, .bit = 24 },
> +	[RTD1625_ISO_RSTN_USB3_P1_MDIO]        = { .ofs = 0x88, .bit = 25 },
> +	[RTD1625_ISO_RSTN_VTC]                 = { .ofs = 0x88, .bit = 26 },
> +	[RTD1625_ISO_RSTN_USB3_PHY2_POW]       = { .ofs = 0x88, .bit = 27 },
> +	[RTD1625_ISO_RSTN_USB3_P2_MDIO]        = { .ofs = 0x88, .bit = 28 },
> +	[RTD1625_ISO_RSTN_USB_PHY_3]           = { .ofs = 0x88, .bit = 29 },
> +	[RTD1625_ISO_RSTN_USB_PHY_4]           = { .ofs = 0x88, .bit = 30 },
> +};
> +
> +static struct rtk_reset_desc rtd1625_iso_s_reset_descs[] = {
> +	[RTD1625_ISO_S_RSTN_ISOM_MIS] = { .ofs = 0x310, .bit = 0, .write_en = 1 },
> +	[RTD1625_ISO_S_RSTN_GPIOM]    = { .ofs = 0x310, .bit = 2, .write_en = 1 },
> +	[RTD1625_ISO_S_RSTN_TIMER7]   = { .ofs = 0x310, .bit = 4, .write_en = 1 },
> +	[RTD1625_ISO_S_RSTN_IRDA]     = { .ofs = 0x310, .bit = 6, .write_en = 1 },
> +	[RTD1625_ISO_S_RSTN_UR10]     = { .ofs = 0x310, .bit = 8, .write_en = 1 },
> +};
> +
> +static int rtd1625_iso_reset_probe(struct auxiliary_device *adev,
> +				   const struct auxiliary_device_id *id)
> +{
> +	struct device *dev = &adev->dev;
> +	struct device *parent = dev->parent;
> +	struct rtk_reset_data *data;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	if (of_device_is_compatible(parent->of_node, "realtek,rtd1625-iso-s-clk")) {
> +		data->descs           = rtd1625_iso_s_reset_descs;
> +		data->rcdev.nr_resets = RTD1625_ISO_S_RSTN_MAX;
> +	} else {
> +		data->descs           = rtd1625_iso_reset_descs;
> +		data->rcdev.nr_resets = RTD1625_ISO_RSTN_MAX;
> +	}
> +	return rtk_reset_controller_add(dev, data);

Newline before return.

> +}
> +
> +static const struct auxiliary_device_id rtd1625_iso_reset_ids[] = {
> +	{
> +		.name = "clk_rtk.iso_rst",
> +	},

I would combine the { .name } all on one line.

Brian

> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(auxiliary, rtd1625_iso_reset_ids);
> +
> +static struct auxiliary_driver rtd1625_iso_driver = {
> +	.probe = rtd1625_iso_reset_probe,
> +	.id_table = rtd1625_iso_reset_ids,
> +	.driver = {
> +		.name = "rtd1625-iso-reset",
> +	},
> +};
> +module_auxiliary_driver(rtd1625_iso_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS("REALTEK_RESET");
> -- 
> 2.34.1
>