Commit 5a5056cc authored by Linus Walleij's avatar Linus Walleij
Browse files

ARM: u300: device tree support for the timer 



This adds device tree support for the U300 timer, by making
the memory base offset and IRQ dynamically assigned, then
optionally looking them up from the device tree.

Since the timer needs to be registered before any platform
devices are created, we will go into the device tree and look
up the "/timer@c0014000" node and read our base address and
IRQ from there.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 3c96d8ea

Documentation/devicetree/bindings/timer/stericsson-u300-apptimer.txt

0 → 100644
+18 −0
Original line number Diff line number Diff line 
ST-Ericsson U300 apptimer



Required properties:



- compatible : should be "stericsson,u300-apptimer"

- reg : Specifies base physical address and size of the registers.

- interrupts : A list of 4 interrupts; one for each subtimer. These

  are, in order: OS (operating system), DD (device driver) both

  adopted for EPOC/Symbian with two specific IRQs for these tasks,

  then GP1 and GP2, which are general-purpose timers.



Example:



timer {

	compatible = "stericsson,u300-apptimer";

	reg = <0xc0014000 0x1000>;

	interrupts = <24 25 26 27>;

};

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -821,6 +821,7 @@ config ARCH_U300 
	select ARM_VIC

	select CLKDEV_LOOKUP

	select CLKSRC_MMIO

	select CLKSRC_OF

	select COMMON_CLK

	select CPU_ARM926T

	select GENERIC_CLOCKEVENTS

arch/arm/mach-u300/timer.c

+71 −38
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 
#include <linux/err.h>

#include <linux/irq.h>

#include <linux/delay.h>

#include <linux/of_address.h>

#include <linux/of_irq.h>



#include <mach/hardware.h>

#include <mach/irqs.h>
@@ -190,6 +192,8 @@ 
#define TICKS_PER_JIFFY ((CLOCK_TICK_RATE + (HZ/2)) / HZ)

#define US_PER_TICK ((1000000 + (HZ/2)) / HZ)



static void __iomem *u300_timer_base;



/*

 * The u300_set_mode() function is always called first, if we

 * have oneshot timer active, the oneshot scheduling function
@@ -202,28 +206,28 @@ static void u300_set_mode(enum clock_event_mode mode, 
	case CLOCK_EVT_MODE_PERIODIC:

		/* Disable interrupts on GPT1 */

		writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);

		       u300_timer_base + U300_TIMER_APP_GPT1IE);

		/* Disable GP1 while we're reprogramming it. */

		writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);

		       u300_timer_base + U300_TIMER_APP_DGPT1);

		/*

		 * Set the periodic mode to a certain number of ticks per

		 * jiffy.

		 */

		writel(TICKS_PER_JIFFY,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC);

		       u300_timer_base + U300_TIMER_APP_GPT1TC);

		/*

		 * Set continuous mode, so the timer keeps triggering

		 * interrupts.

		 */

		writel(U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M);

		       u300_timer_base + U300_TIMER_APP_SGPT1M);

		/* Enable timer interrupts */

		writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);

		       u300_timer_base + U300_TIMER_APP_GPT1IE);

		/* Then enable the OS timer again */

		writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1);

		       u300_timer_base + U300_TIMER_APP_EGPT1);

		break;

	case CLOCK_EVT_MODE_ONESHOT:

		/* Just break; here? */
@@ -234,33 +238,33 @@ static void u300_set_mode(enum clock_event_mode mode, 
		 */

		/* Disable interrupts on GPT1 */

		writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);

		       u300_timer_base + U300_TIMER_APP_GPT1IE);

		/* Disable GP1 while we're reprogramming it. */

		writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);

		       u300_timer_base + U300_TIMER_APP_DGPT1);

		/*

		 * Expire far in the future, u300_set_next_event() will be

		 * called soon...

		 */

		writel(0xFFFFFFFF, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC);

		writel(0xFFFFFFFF, u300_timer_base + U300_TIMER_APP_GPT1TC);

		/* We run one shot per tick here! */

		writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M);

		       u300_timer_base + U300_TIMER_APP_SGPT1M);

		/* Enable interrupts for this timer */

		writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);

		       u300_timer_base + U300_TIMER_APP_GPT1IE);

		/* Enable timer */

		writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1);

		       u300_timer_base + U300_TIMER_APP_EGPT1);

		break;

	case CLOCK_EVT_MODE_UNUSED:

	case CLOCK_EVT_MODE_SHUTDOWN:

		/* Disable interrupts on GP1 */

		writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);

		       u300_timer_base + U300_TIMER_APP_GPT1IE);

		/* Disable GP1 */

		writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,

		       U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);

		       u300_timer_base + U300_TIMER_APP_DGPT1);

		break;

	case CLOCK_EVT_MODE_RESUME:

		/* Ignore this call */
@@ -282,27 +286,27 @@ static int u300_set_next_event(unsigned long cycles, 
{

	/* Disable interrupts on GPT1 */

	writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,

	       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);

	       u300_timer_base + U300_TIMER_APP_GPT1IE);

	/* Disable GP1 while we're reprogramming it. */

	writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,

	       U300_TIMER_APP_VBASE + U300_TIMER_APP_DGPT1);

	       u300_timer_base + U300_TIMER_APP_DGPT1);

	/* Reset the General Purpose timer 1. */

	writel(U300_TIMER_APP_RGPT1_TIMER_RESET,

	       U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT1);

	       u300_timer_base + U300_TIMER_APP_RGPT1);

	/* IRQ in n * cycles */

	writel(cycles, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1TC);

	writel(cycles, u300_timer_base + U300_TIMER_APP_GPT1TC);

	/*

	 * We run one shot per tick here! (This is necessary to reconfigure,

	 * the timer will tilt if you don't!)

	 */

	writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,

	       U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT1M);

	       u300_timer_base + U300_TIMER_APP_SGPT1M);

	/* Enable timer interrupts */

	writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,

	       U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IE);

	       u300_timer_base + U300_TIMER_APP_GPT1IE);

	/* Then enable the OS timer again */

	writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,

	       U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT1);

	       u300_timer_base + U300_TIMER_APP_EGPT1);

	return 0;

}
@@ -321,8 +325,9 @@ static irqreturn_t u300_timer_interrupt(int irq, void *dev_id) 
{

	struct clock_event_device *evt = &clockevent_u300_1mhz;

	/* ACK/Clear timer IRQ for the APP GPT1 Timer */



	writel(U300_TIMER_APP_GPT1IA_IRQ_ACK,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT1IA);

		u300_timer_base + U300_TIMER_APP_GPT1IA);

	evt->event_handler(evt);

	return IRQ_HANDLED;

}
@@ -343,12 +348,12 @@ static struct irqaction u300_timer_irq = { 


static u32 notrace u300_read_sched_clock(void)

{

	return readl(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC);

	return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);

}



static unsigned long u300_read_current_timer(void)

{

	return readl(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC);

	return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);

}



static struct delay_timer u300_delay_timer;
@@ -356,11 +361,14 @@ static struct delay_timer u300_delay_timer; 
/*

 * This sets up the system timers, clock source and clock event.

 */

void __init u300_timer_init(void)

static void __init u300_timer_setup(void __iomem *base, int irq)

{

	struct clk *clk;

	unsigned long rate;



	u300_timer_base = base;

	pr_info("U300 GP1 timer @ base: %p, IRQ: %d\n", u300_timer_base, irq);



	/* Clock the interrupt controller */

	clk = clk_get_sys("apptimer", NULL);

	BUG_ON(IS_ERR(clk));
@@ -378,40 +386,40 @@ void __init u300_timer_init(void) 
	 * Example usage in cnh1601578 cpu subsystem pd_timer_app.c

	 */

	writel(U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_CRC);

		u300_timer_base + U300_TIMER_APP_CRC);

	writel(U300_TIMER_APP_ROST_TIMER_RESET,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_ROST);

		u300_timer_base + U300_TIMER_APP_ROST);

	writel(U300_TIMER_APP_DOST_TIMER_DISABLE,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_DOST);

		u300_timer_base + U300_TIMER_APP_DOST);

	writel(U300_TIMER_APP_RDDT_TIMER_RESET,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_RDDT);

		u300_timer_base + U300_TIMER_APP_RDDT);

	writel(U300_TIMER_APP_DDDT_TIMER_DISABLE,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_DDDT);

		u300_timer_base + U300_TIMER_APP_DDDT);



	/* Reset the General Purpose timer 1. */

	writel(U300_TIMER_APP_RGPT1_TIMER_RESET,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT1);

		u300_timer_base + U300_TIMER_APP_RGPT1);



	/* Set up the IRQ handler */

	setup_irq(IRQ_U300_TIMER_APP_GP1, &u300_timer_irq);

	setup_irq(irq, &u300_timer_irq);



	/* Reset the General Purpose timer 2 */

	writel(U300_TIMER_APP_RGPT2_TIMER_RESET,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_RGPT2);

		u300_timer_base + U300_TIMER_APP_RGPT2);

	/* Set this timer to run around forever */

	writel(0xFFFFFFFFU, U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2TC);

	writel(0xFFFFFFFFU, u300_timer_base + U300_TIMER_APP_GPT2TC);

	/* Set continuous mode so it wraps around */

	writel(U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS,

	       U300_TIMER_APP_VBASE + U300_TIMER_APP_SGPT2M);

	       u300_timer_base + U300_TIMER_APP_SGPT2M);

	/* Disable timer interrupts */

	writel(U300_TIMER_APP_GPT2IE_IRQ_DISABLE,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2IE);

		u300_timer_base + U300_TIMER_APP_GPT2IE);

	/* Then enable the GP2 timer to use as a free running us counter */

	writel(U300_TIMER_APP_EGPT2_TIMER_ENABLE,

		U300_TIMER_APP_VBASE + U300_TIMER_APP_EGPT2);

		u300_timer_base + U300_TIMER_APP_EGPT2);



	/* Use general purpose timer 2 as clock source */

	if (clocksource_mmio_init(U300_TIMER_APP_VBASE + U300_TIMER_APP_GPT2CC,

	if (clocksource_mmio_init(u300_timer_base + U300_TIMER_APP_GPT2CC,

			"GPT2", rate, 300, 32, clocksource_mmio_readl_up))

		pr_err("timer: failed to initialize U300 clock source\n");
@@ -424,3 +432,28 @@ void __init u300_timer_init(void) 
	 * used by hrtimers!

	 */

}





void __init u300_timer_init()

{

	u300_timer_setup(U300_TIMER_APP_VBASE, IRQ_U300_TIMER_APP_GP1);

}



#ifdef CONFIG_OF



static void __init u300_timer_init_of(struct device_node *np)

{

	void __iomem *base;

	struct resource irq_res;

	int irq;



	base = of_iomap(np, 0);

	/* Get the IRQ for the GP1 timer */

	irq = of_irq_to_resource(np, 2, &irq_res);

	u300_timer_setup(base, irq);

}



CLOCKSOURCE_OF_DECLARE(u300_timer, "stericsson,u300-apptimer",

		       u300_timer_init_of);



#endif

arch/arm/mach-u300/timer.h

+1 −0
Original line number Diff line number Diff line 
extern void u300_timer_init(void);

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