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clocksource/drivers/timer-microchip-pit64b: Add clocksource suspend/r…
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…esume

Add suspend/resume support for clocksource timer.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1611061165-30180-1-git-send-email-claudiu.beznea@microchip.com
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Claudiu Beznea authored and Daniel Lezcano committed Feb 3, 2021
1 parent a8d8023 commit e85c1d2
Showing 1 changed file with 71 additions and 15 deletions.
86 changes: 71 additions & 15 deletions drivers/clocksource/timer-microchip-pit64b.c
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Original file line number Diff line number Diff line change
Expand Up @@ -71,10 +71,24 @@ struct mchp_pit64b_clkevt {
struct clock_event_device clkevt;
};

#define to_mchp_pit64b_timer(x) \
#define clkevt_to_mchp_pit64b_timer(x) \
((struct mchp_pit64b_timer *)container_of(x,\
struct mchp_pit64b_clkevt, clkevt))

/**
* mchp_pit64b_clksrc - PIT64B clocksource data structure
* @timer: PIT64B timer
* @clksrc: clocksource
*/
struct mchp_pit64b_clksrc {
struct mchp_pit64b_timer timer;
struct clocksource clksrc;
};

#define clksrc_to_mchp_pit64b_timer(x) \
((struct mchp_pit64b_timer *)container_of(x,\
struct mchp_pit64b_clksrc, clksrc))

/* Base address for clocksource timer. */
static void __iomem *mchp_pit64b_cs_base;
/* Default cycles for clockevent timer. */
Expand Down Expand Up @@ -116,6 +130,36 @@ static inline void mchp_pit64b_reset(struct mchp_pit64b_timer *timer,
writel_relaxed(MCHP_PIT64B_CR_START, timer->base + MCHP_PIT64B_CR);
}

static void mchp_pit64b_suspend(struct mchp_pit64b_timer *timer)
{
writel_relaxed(MCHP_PIT64B_CR_SWRST, timer->base + MCHP_PIT64B_CR);
if (timer->mode & MCHP_PIT64B_MR_SGCLK)
clk_disable_unprepare(timer->gclk);
clk_disable_unprepare(timer->pclk);
}

static void mchp_pit64b_resume(struct mchp_pit64b_timer *timer)
{
clk_prepare_enable(timer->pclk);
if (timer->mode & MCHP_PIT64B_MR_SGCLK)
clk_prepare_enable(timer->gclk);
}

static void mchp_pit64b_clksrc_suspend(struct clocksource *cs)
{
struct mchp_pit64b_timer *timer = clksrc_to_mchp_pit64b_timer(cs);

mchp_pit64b_suspend(timer);
}

static void mchp_pit64b_clksrc_resume(struct clocksource *cs)
{
struct mchp_pit64b_timer *timer = clksrc_to_mchp_pit64b_timer(cs);

mchp_pit64b_resume(timer);
mchp_pit64b_reset(timer, ULLONG_MAX, MCHP_PIT64B_MR_CONT, 0);
}

static u64 mchp_pit64b_clksrc_read(struct clocksource *cs)
{
return mchp_pit64b_cnt_read(mchp_pit64b_cs_base);
Expand All @@ -128,7 +172,7 @@ static u64 mchp_pit64b_sched_read_clk(void)

static int mchp_pit64b_clkevt_shutdown(struct clock_event_device *cedev)
{
struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);

writel_relaxed(MCHP_PIT64B_CR_SWRST, timer->base + MCHP_PIT64B_CR);

Expand All @@ -137,7 +181,7 @@ static int mchp_pit64b_clkevt_shutdown(struct clock_event_device *cedev)

static int mchp_pit64b_clkevt_set_periodic(struct clock_event_device *cedev)
{
struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);

mchp_pit64b_reset(timer, mchp_pit64b_ce_cycles, MCHP_PIT64B_MR_CONT,
MCHP_PIT64B_IER_PERIOD);
Expand All @@ -148,7 +192,7 @@ static int mchp_pit64b_clkevt_set_periodic(struct clock_event_device *cedev)
static int mchp_pit64b_clkevt_set_next_event(unsigned long evt,
struct clock_event_device *cedev)
{
struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);

mchp_pit64b_reset(timer, evt, MCHP_PIT64B_MR_ONE_SHOT,
MCHP_PIT64B_IER_PERIOD);
Expand All @@ -158,21 +202,16 @@ static int mchp_pit64b_clkevt_set_next_event(unsigned long evt,

static void mchp_pit64b_clkevt_suspend(struct clock_event_device *cedev)
{
struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);

writel_relaxed(MCHP_PIT64B_CR_SWRST, timer->base + MCHP_PIT64B_CR);
if (timer->mode & MCHP_PIT64B_MR_SGCLK)
clk_disable_unprepare(timer->gclk);
clk_disable_unprepare(timer->pclk);
mchp_pit64b_suspend(timer);
}

static void mchp_pit64b_clkevt_resume(struct clock_event_device *cedev)
{
struct mchp_pit64b_timer *timer = to_mchp_pit64b_timer(cedev);
struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);

clk_prepare_enable(timer->pclk);
if (timer->mode & MCHP_PIT64B_MR_SGCLK)
clk_prepare_enable(timer->gclk);
mchp_pit64b_resume(timer);
}

static irqreturn_t mchp_pit64b_interrupt(int irq, void *dev_id)
Expand Down Expand Up @@ -296,20 +335,37 @@ static int __init mchp_pit64b_init_mode(struct mchp_pit64b_timer *timer,
static int __init mchp_pit64b_init_clksrc(struct mchp_pit64b_timer *timer,
u32 clk_rate)
{
struct mchp_pit64b_clksrc *cs;
int ret;

cs = kzalloc(sizeof(*cs), GFP_KERNEL);
if (!cs)
return -ENOMEM;

mchp_pit64b_reset(timer, ULLONG_MAX, MCHP_PIT64B_MR_CONT, 0);

mchp_pit64b_cs_base = timer->base;

ret = clocksource_mmio_init(timer->base, MCHP_PIT64B_NAME, clk_rate,
210, 64, mchp_pit64b_clksrc_read);
cs->timer.base = timer->base;
cs->timer.pclk = timer->pclk;
cs->timer.gclk = timer->gclk;
cs->timer.mode = timer->mode;
cs->clksrc.name = MCHP_PIT64B_NAME;
cs->clksrc.mask = CLOCKSOURCE_MASK(64);
cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
cs->clksrc.rating = 210;
cs->clksrc.read = mchp_pit64b_clksrc_read;
cs->clksrc.suspend = mchp_pit64b_clksrc_suspend;
cs->clksrc.resume = mchp_pit64b_clksrc_resume;

ret = clocksource_register_hz(&cs->clksrc, clk_rate);
if (ret) {
pr_debug("clksrc: Failed to register PIT64B clocksource!\n");

/* Stop timer. */
writel_relaxed(MCHP_PIT64B_CR_SWRST,
timer->base + MCHP_PIT64B_CR);
kfree(cs);

return ret;
}
Expand Down

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