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authorPhilip Avinash <avinashphilip@ti.com>2013-01-17 14:50:03 +0530
committerThierry Reding <thierry.reding@avionic-design.de>2013-01-17 16:52:59 +0100
commit0d75c203effefa4f62ca4d30bf52bd9ec246717f (patch)
tree1584cc1c0f5fc3fb374f006a2cd1a5ede9053629 /drivers/pwm
parent0e2feb17dec9d97f6b44d5af872633f7ffba9ffb (diff)
downloadvexpress-lsk-0d75c203effefa4f62ca4d30bf52bd9ec246717f.tar.gz
pwm: pwm-tiecap: Low power sleep support
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>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-tiecap.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 5cf016dd982..05b676db88e 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -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,