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pwm: pwm-tiecap: Low power sleep support

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In low power modes of AM33XX platforms, peripherals power is cut off.
This patch supports low power sleep transition support for ECAP driver.

Signed-off-by: Philip Avinash <avinashphilip@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
This commit is contained in:
Philip Avinash 2013-01-17 14:50:03 +05:30 committed by Thierry Reding
parent 0e2feb17de
commit 0d75c203ef
1 changed files with 53 additions and 0 deletions
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53
drivers/pwm/pwm-tiecap.c
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@ -41,10 +41,17 @@
#define ECCTL2_SYNC_SEL_DISA (BIT(7) | BIT(6))
#define ECCTL2_TSCTR_FREERUN BIT(4)
struct ecap_context {
u32 cap3;
u32 cap4;
u16 ecctl2;
};
struct ecap_pwm_chip {
struct pwm_chip chip;
unsigned int clk_rate;
void __iomem *mmio_base;
struct ecap_context ctx;
};
static inline struct ecap_pwm_chip *to_ecap_pwm_chip(struct pwm_chip *chip)
@ -288,11 +295,57 @@ static int ecap_pwm_remove(struct platform_device *pdev)
return pwmchip_remove(&pc->chip);
}
void ecap_pwm_save_context(struct ecap_pwm_chip *pc)
{
pm_runtime_get_sync(pc->chip.dev);
pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2);
pc->ctx.cap4 = readl(pc->mmio_base + CAP4);
pc->ctx.cap3 = readl(pc->mmio_base + CAP3);
pm_runtime_put_sync(pc->chip.dev);
}
void ecap_pwm_restore_context(struct ecap_pwm_chip *pc)
{
writel(pc->ctx.cap3, pc->mmio_base + CAP3);
writel(pc->ctx.cap4, pc->mmio_base + CAP4);
writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2);
}
static int ecap_pwm_suspend(struct device *dev)
{
struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
struct pwm_device *pwm = pc->chip.pwms;
ecap_pwm_save_context(pc);
/* Disable explicitly if PWM is running */
if (test_bit(PWMF_ENABLED, &pwm->flags))
pm_runtime_put_sync(dev);
return 0;
}
static int ecap_pwm_resume(struct device *dev)
{
struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
struct pwm_device *pwm = pc->chip.pwms;
/* Enable explicitly if PWM was running */
if (test_bit(PWMF_ENABLED, &pwm->flags))
pm_runtime_get_sync(dev);
ecap_pwm_restore_context(pc);
return 0;
}
static SIMPLE_DEV_PM_OPS(ecap_pwm_pm_ops, ecap_pwm_suspend, ecap_pwm_resume);
static struct platform_driver ecap_pwm_driver = {
.driver = {
.name = "ecap",
.owner = THIS_MODULE,
.of_match_table = ecap_of_match,
.pm = &ecap_pwm_pm_ops,
},
.probe = ecap_pwm_probe,
.remove = ecap_pwm_remove,