Subject: [PATCH v4 2/6] clocksource: add Marvell Orion SoC timer

From: [email-masked] (Daniel Lezcano)
Date: Mon, 10 Jun 2013 18:04:14 +0200

On 06/10/2013 11:35 AM, Sebastian Hesselbarth wrote:
> This patch add a DT enabled driver for timers found on Marvell Orion SoCs
> (Kirkwood, Dove, Orion5x, and Discovery Innovation). It installs a free-
> running clocksource on timer0 and a clockevent source on timer1.
> Corresponding device tree documentation is also added.
> 
> Signed-off-by: Sebastian Hesselbarth <[email-masked]>

It looks good for me.

Sebastian,

shall I take it through my tree (it will go to Thomas's tree) ?

Thanks
  -- Daniel

> ---
> Changelog:
> v3->v4:
> - export thread-safe access to TIMER_CTRL register to use with watchdog
> - remove IRQF_DISABLED and add .irq to clock event (Suggested by Daniel Lezcano)
> 
> Notes:
> - This is only an update to clocksource driver, the remaining patches are
>   not resent as they have not been changed.
> - I will not rework orion watchdog driver for this patch set. It is written
>   Kirkwood/Orion5x specific although it will also work on Dove and it is messing
>   with shared registers. It has done it before, so I consider it broken anyway.
>   I (or somebody else) will take care of proper watchdog later.
> - An updated branch can be found on
>   git://github.com/shesselba/linux-dove.git orion-irqchip-for-v3.11_v4
> 
> Cc: Grant Likely <[email-masked]>
> Cc: Rob Herring <[email-masked]>
> Cc: Rob Landley <[email-masked]>
> Cc: Thomas Gleixner <[email-masked]>
> Cc: John Stultz <[email-masked]>
> Cc: Russell King <[email-masked]>
> Cc: Jason Cooper <[email-masked]>
> Cc: Andrew Lunn <[email-masked]>
> Cc: Thomas Petazzoni <[email-masked]>
> Cc: Gregory Clement <[email-masked]>
> Cc: Daniel Lezcano <[email-masked]>
> Cc: devicetree-discuss at lists.ozlabs.org
> Cc: linux-doc at vger.kernel.org
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-kernel at vger.kernel.org
> ---
>  .../bindings/timer/marvell,orion-timer.txt         |   17 +++
>  drivers/clocksource/Kconfig                        |    5 +
>  drivers/clocksource/Makefile                       |    1 +
>  drivers/clocksource/time-orion.c                   |  150 ++++++++++++++++++++
>  4 files changed, 173 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/timer/marvell,orion-timer.txt
>  create mode 100644 drivers/clocksource/time-orion.c
> 
> diff --git a/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt b/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt
> new file mode 100644
> index 0000000..62bb826
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt
> @@ -0,0 +1,17 @@
> +Marvell Orion SoC timer
> +
> +Required properties:
> +- compatible: shall be "marvell,orion-timer"
> +- reg: base address of the timer register starting with TIMERS CONTROL register
> +- interrupt-parent: phandle of the bridge interrupt controller
> +- interrupts: should contain the interrupts for Timer0 and Timer1
> +- clocks: phandle of timer reference clock (tclk)
> +
> +Example:
> +	timer: timer {
> +		compatible = "marvell,orion-timer";
> +		reg = <0x20300 0x20>;
> +		interrupt-parent = <&bridge_intc>;
> +		interrupts = <1>, <2>;
> +		clocks = <&core_clk 0>;
> +	};
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index f151c6c..2404869 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -25,6 +25,11 @@ config DW_APB_TIMER_OF
>  config ARMADA_370_XP_TIMER
>  	bool
>  
> +config ORION_TIMER
> +	select CLKSRC_OF
> +	select CLKSRC_MMIO
> +	bool
> +
>  config SUN4I_TIMER
>  	bool
>  
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index 8d979c7..d1e8d68 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_DW_APB_TIMER_OF)	+= dw_apb_timer_of.o
>  obj-$(CONFIG_CLKSRC_NOMADIK_MTU)	+= nomadik-mtu.o
>  obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
>  obj-$(CONFIG_ARMADA_370_XP_TIMER)	+= time-armada-370-xp.o
> +obj-$(CONFIG_ORION_TIMER)	+= time-orion.o
>  obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835_timer.o
>  obj-$(CONFIG_ARCH_MARCO)	+= timer-marco.o
>  obj-$(CONFIG_ARCH_MXS)		+= mxs_timer.o
> diff --git a/drivers/clocksource/time-orion.c b/drivers/clocksource/time-orion.c
> new file mode 100644
> index 0000000..ad7df17
> --- /dev/null
> +++ b/drivers/clocksource/time-orion.c
> @@ -0,0 +1,150 @@
> +/*
> + * Marvell Orion SoC timer handling.
> + *
> + * Sebastian Hesselbarth <[email-masked]>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2.  This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + *
> + * Timer 0 is used as free-running clocksource, while timer 1 is
> + * used as clock_event_device.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/clockchips.h>
> +#include <linux/interrupt.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/spinlock.h>
> +#include <asm/sched_clock.h>
> +
> +#define TIMER_CTRL		0x00
> +#define  TIMER0_EN		BIT(0)
> +#define  TIMER0_RELOAD_EN	BIT(1)
> +#define  TIMER1_EN		BIT(2)
> +#define  TIMER1_RELOAD_EN	BIT(3)
> +#define TIMER0_RELOAD		0x10
> +#define TIMER0_VAL		0x14
> +#define TIMER1_RELOAD		0x18
> +#define TIMER1_VAL		0x1c
> +
> +#define ORION_ONESHOT_MIN	1
> +#define ORION_ONESHOT_MAX	0xfffffffe
> +
> +static void __iomem *timer_base;
> +static DEFINE_SPINLOCK(timer_ctrl_lock);
> +
> +/*
> + * Thread-safe access to TIMER_CTRL register
> + * (shared with watchdog timer)
> + */
> +void orion_timer_ctrl_clrset(u32 clr, u32 set)
> +{
> +	spin_lock(&timer_ctrl_lock);
> +	writel((readl(timer_base + TIMER_CTRL) & ~clr) | set,
> +		timer_base + TIMER_CTRL);
> +	spin_unlock(&timer_ctrl_lock);
> +} 
> +EXPORT_SYMBOL(orion_timer_ctrl_clrset);
> +
> +/*
> + * Free-running clocksource handling.
> + */
> +static u32 notrace orion_read_sched_clock(void)
> +{
> +	return ~readl(timer_base + TIMER0_VAL);
> +}
> +
> +/*
> + * Clockevent handling.
> + */
> +static u32 ticks_per_jiffy;
> +
> +static int orion_clkevt_next_event(unsigned long delta,
> +				   struct clock_event_device *dev)
> +{
> +	/* setup and enable one-shot timer */
> +	writel(delta, timer_base + TIMER1_VAL);
> +	orion_timer_ctrl_clrset(TIMER1_RELOAD_EN, TIMER1_EN);
> +
> +	return 0;
> +}
> +
> +static void orion_clkevt_mode(enum clock_event_mode mode,
> +			      struct clock_event_device *dev)
> +{
> +	if (mode == CLOCK_EVT_MODE_PERIODIC) {
> +		/* setup and enable periodic timer at 1/HZ intervals */
> +		writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD);
> +		writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL);
> +		orion_timer_ctrl_clrset(0, TIMER1_RELOAD_EN | TIMER1_EN);
> +	} else {
> +		/* disable timer */
> +		orion_timer_ctrl_clrset(TIMER1_RELOAD_EN | TIMER1_EN, 0);
> +	}
> +}
> +
> +static struct clock_event_device orion_clkevt = {
> +	.name		= "orion_event",
> +	.features	= CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
> +	.shift		= 32,
> +	.rating		= 300,
> +	.set_next_event	= orion_clkevt_next_event,
> +	.set_mode	= orion_clkevt_mode,
> +};
> +
> +static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id)
> +{
> +	orion_clkevt.event_handler(&orion_clkevt);
> +	return IRQ_HANDLED;
> +}
> +
> +static struct irqaction orion_clkevt_irq = {
> +	.name		= "orion_event",
> +	.flags		= IRQF_TIMER,
> +	.handler	= orion_clkevt_irq_handler,
> +};
> +
> +static void __init orion_timer_init(struct device_node *np)
> +{
> +	struct clk *clk;
> +	int irq;
> +
> +	/* timer registers are shared with watchdog timer */
> +	timer_base = of_iomap(np, 0);
> +	if (!timer_base)
> +		panic("%s: unable to map resource\n", np->name);
> +
> +	clk = of_clk_get(np, 0);
> +	if (IS_ERR(clk))
> +		panic("%s: unable to get clk\n", np->name);
> +	clk_prepare_enable(clk);
> +
> +	/* we are only interested in timer1 irq */
> +	irq = irq_of_parse_and_map(np, 1);
> +	if (irq <= 0)
> +		panic("%s: unable to parse timer1 irq\n", np->name);
> +
> +	/* setup timer0 as free-running clocksource */
> +	writel(~0, timer_base + TIMER0_VAL);
> +	writel(~0, timer_base + TIMER0_RELOAD);
> +	orion_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | TIMER0_EN);
> +	clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
> +			      clk_get_rate(clk), 300, 32,
> +			      clocksource_mmio_readl_down);
> +	setup_sched_clock(orion_read_sched_clock, 32, clk_get_rate(clk));
> +
> +	/* setup timer1 as clockevent timer */
> +	if (setup_irq(irq, &orion_clkevt_irq))
> +		panic("%s: unable to setup irq\n", np->name);
> +
> +	ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
> +	orion_clkevt.cpumask = cpumask_of(0);
> +	orion_clkevt.irq = irq;
> +	clockevents_config_and_register(&orion_clkevt, clk_get_rate(clk),
> +					ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
> +}
> +CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);
> 

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