[PATCH v8 1/9] clocksource: time-armada-370-xp: Marvell Armada 370/XP SoC timer driver

Andrew Lunn andrew at lunn.ch
Wed Jul 4 11:12:55 EDT 2012


On Wed, Jul 04, 2012 at 04:56:38PM +0200, Thomas Petazzoni wrote:
> From: Gregory Clement <gregory.clement at free-electrons.com>
> 
> Timer 0 is used as free-running clocksource, while timer 1 is used as
> clock_event_device.
> 
> Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> Signed-off-by: Lior Amsalem <alior at marvell.com>
> Reviewed-by: Thomas Gleixner <tglx at linutronix.de>
> Tested-by: Yehuda Yitschak <yehuday at marvell.com>
> Tested-by: Lior Amsalem <alior at marvell.com>
> CC: Thomas Gleixner <tglx at linutronix.de>
> CC: John Stultz <johnstul at us.ibm.com>
> ---
>  drivers/clocksource/Kconfig              |    3 +
>  drivers/clocksource/Makefile             |    3 +-
>  drivers/clocksource/time-armada-370-xp.c |  226 ++++++++++++++++++++++++++++++
>  include/linux/time-armada-370-xp.h       |   18 +++
>  4 files changed, 249 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/clocksource/time-armada-370-xp.c
>  create mode 100644 include/linux/time-armada-370-xp.h
> 
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index 99c6b20..b323631 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -16,6 +16,9 @@ config CLKSRC_MMIO
>  config DW_APB_TIMER
>  	bool
>  
> +config ARMADA_370_XP_TIMER
> +	bool
> +
>  config CLKSRC_DBX500_PRCMU
>  	bool "Clocksource PRCMU Timer"
>  	depends on UX500_SOC_DB8500
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index dd3e661..022015c 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -10,4 +10,5 @@ obj-$(CONFIG_EM_TIMER_STI)	+= em_sti.o
>  obj-$(CONFIG_CLKBLD_I8253)	+= i8253.o
>  obj-$(CONFIG_CLKSRC_MMIO)	+= mmio.o
>  obj-$(CONFIG_DW_APB_TIMER)	+= dw_apb_timer.o
> -obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
> \ No newline at end of file
> +obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
> +obj-$(CONFIG_ARMADA_370_XP_TIMER)	+= time-armada-370-xp.o
> diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c
> new file mode 100644
> index 0000000..4674f94
> --- /dev/null
> +++ b/drivers/clocksource/time-armada-370-xp.c
> @@ -0,0 +1,226 @@
> +/*
> + * Marvell Armada 370/XP SoC timer handling.
> + *
> + * Copyright (C) 2012 Marvell
> + *
> + * Lior Amsalem <alior at marvell.com>
> + * Gregory CLEMENT <gregory.clement at free-electrons.com>
> + * Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> + *
> + * 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/init.h>
> +#include <linux/platform_device.h>
> +#include <linux/kernel.h>
> +#include <linux/timer.h>
> +#include <linux/clockchips.h>
> +#include <linux/interrupt.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
> +#include <linux/irq.h>
> +#include <linux/module.h>
> +#include <asm/sched_clock.h>
> +
> +/*
> + * Timer block registers.
> + */
> +#define TIMER_CTRL_OFF		0x0000
> +#define  TIMER0_EN		 0x0001
> +#define  TIMER0_RELOAD_EN	 0x0002
> +#define  TIMER0_25MHZ            0x0800
> +#define  TIMER0_DIV(div)         ((div) << 19)
> +#define  TIMER1_EN		 0x0004
> +#define  TIMER1_RELOAD_EN	 0x0008
> +#define  TIMER1_25MHZ            0x1000
> +#define  TIMER1_DIV(div)         ((div) << 22)
> +#define TIMER_EVENTS_STATUS	0x0004
> +#define  TIMER0_CLR_MASK         (~0x1)
> +#define  TIMER1_CLR_MASK         (~0x100)
> +#define TIMER0_RELOAD_OFF	0x0010
> +#define TIMER0_VAL_OFF		0x0014
> +#define TIMER1_RELOAD_OFF	0x0018
> +#define TIMER1_VAL_OFF		0x001c
> +
> +/* Global timers are connected to the coherency fabric clock, and the
> +   below divider reduces their incrementing frequency. */
> +#define TIMER_DIVIDER_SHIFT     5
> +#define TIMER_DIVIDER           (1 << TIMER_DIVIDER_SHIFT)
> +
> +/*
> + * SoC-specific data.
> + */
> +static void __iomem *timer_base;
> +static int timer_irq;
> +
> +/*
> + * Number of timer ticks per jiffy.
> + */
> +static u32 ticks_per_jiffy;
> +
> +static u32 notrace armada_370_xp_read_sched_clock(void)
> +{
> +	return ~readl(timer_base + TIMER0_VAL_OFF);
> +}
> +
> +/*
> + * Clockevent handling.
> + */
> +static int
> +armada_370_xp_clkevt_next_event(unsigned long delta,
> +				struct clock_event_device *dev)
> +{
> +	u32 u;
> +
> +	/*
> +	 * Clear clockevent timer interrupt.
> +	 */
> +	writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
> +
> +	/*
> +	 * Setup new clockevent timer value.
> +	 */
> +	writel(delta, timer_base + TIMER1_VAL_OFF);
> +
> +	/*
> +	 * Enable the timer.
> +	 */
> +	u = readl(timer_base + TIMER_CTRL_OFF);
> +	u = ((u & ~TIMER1_RELOAD_EN) | TIMER1_EN |
> +	     TIMER1_DIV(TIMER_DIVIDER_SHIFT));
> +	writel(u, timer_base + TIMER_CTRL_OFF);
> +
> +	return 0;
> +}
> +
> +static void
> +armada_370_xp_clkevt_mode(enum clock_event_mode mode,
> +			  struct clock_event_device *dev)
> +{
> +	u32 u;
> +
> +	if (mode == CLOCK_EVT_MODE_PERIODIC) {
> +		/*
> +		 * Setup timer to fire at 1/HZ intervals.
> +		 */
> +		writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD_OFF);
> +		writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL_OFF);
> +
> +		/*
> +		 * Enable timer.
> +		 */
> +		u = readl(timer_base + TIMER_CTRL_OFF);
> +
> +		writel((u | TIMER1_EN | TIMER1_RELOAD_EN |
> +			TIMER1_DIV(TIMER_DIVIDER_SHIFT)),
> +		       timer_base + TIMER_CTRL_OFF);
> +	} else {
> +		/*
> +		 * Disable timer.
> +		 */
> +		u = readl(timer_base + TIMER_CTRL_OFF);
> +		writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF);
> +
> +		/*
> +		 * ACK pending timer interrupt.
> +		 */
> +		writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
> +
> +	}
> +}
> +
> +static struct clock_event_device armada_370_xp_clkevt = {
> +	.name		= "armada_370_xp_tick",
> +	.features	= CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
> +	.shift		= 32,
> +	.rating		= 300,
> +	.set_next_event	= armada_370_xp_clkevt_next_event,
> +	.set_mode	= armada_370_xp_clkevt_mode,
> +};
> +
> +static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
> +{
> +	/*
> +	 * ACK timer interrupt and call event handler.
> +	 */
> +
> +	writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
> +	armada_370_xp_clkevt.event_handler(&armada_370_xp_clkevt);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static struct irqaction armada_370_xp_timer_irq = {
> +	.name		= "armada_370_xp_tick",
> +	.flags		= IRQF_DISABLED | IRQF_TIMER,
> +	.handler	= armada_370_xp_timer_interrupt
> +};
> +
> +void __init armada_370_xp_timer_init(void)
> +{
> +	u32 u;
> +	struct device_node *np;
> +	unsigned int timer_clk;
> +	int ret;
> +	np = of_find_compatible_node(NULL, NULL, "marvell,armada-370-xp-timer")

Acked-by: Andrew Lunn <andrew at lunn.ch>




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