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authorPhilip Avinash <avinashphilip@ti.com>2013-01-17 14:50:02 +0530
committerThierry Reding <thierry.reding@avionic-design.de>2013-01-17 16:52:58 +0100
commit0e2feb17dec9d97f6b44d5af872633f7ffba9ffb (patch)
tree65288a11f9cedc298d87adf7b36d64da5062b77f /drivers/pwm
parent0074b49b3fa0886047413dbca0508594b1d80c61 (diff)
downloadvexpress-lsk-0e2feb17dec9d97f6b44d5af872633f7ffba9ffb.tar.gz
pwm: pwm-tiehrpwm: 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 EHRPWM 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-tiehrpwm.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index 4fcafbfba60..33e15c4fba0 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -113,6 +113,17 @@
#define NUM_PWM_CHANNEL 2 /* EHRPWM channels */
+struct ehrpwm_context {
+ u16 tbctl;
+ u16 tbprd;
+ u16 cmpa;
+ u16 cmpb;
+ u16 aqctla;
+ u16 aqctlb;
+ u16 aqsfrc;
+ u16 aqcsfrc;
+};
+
struct ehrpwm_pwm_chip {
struct pwm_chip chip;
unsigned int clk_rate;
@@ -120,6 +131,7 @@ struct ehrpwm_pwm_chip {
unsigned long period_cycles[NUM_PWM_CHANNEL];
enum pwm_polarity polarity[NUM_PWM_CHANNEL];
struct clk *tbclk;
+ struct ehrpwm_context ctx;
};
static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
@@ -127,6 +139,11 @@ static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
return container_of(chip, struct ehrpwm_pwm_chip, chip);
}
+static u16 ehrpwm_read(void *base, int offset)
+{
+ return readw(base + offset);
+}
+
static void ehrpwm_write(void *base, int offset, unsigned int val)
{
writew(val & 0xFFFF, base + offset);
@@ -516,11 +533,77 @@ static int ehrpwm_pwm_remove(struct platform_device *pdev)
return pwmchip_remove(&pc->chip);
}
+void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
+{
+ pm_runtime_get_sync(pc->chip.dev);
+ pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
+ pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
+ pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
+ pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
+ pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
+ pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
+ pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
+ pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
+ pm_runtime_put_sync(pc->chip.dev);
+}
+
+void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
+{
+ ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
+ ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
+ ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
+ ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
+ ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
+ ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
+ ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
+ ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
+}
+
+static int ehrpwm_pwm_suspend(struct device *dev)
+{
+ struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
+ int i;
+
+ ehrpwm_pwm_save_context(pc);
+ for (i = 0; i < pc->chip.npwm; i++) {
+ struct pwm_device *pwm = &pc->chip.pwms[i];
+
+ if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ continue;
+
+ /* Disable explicitly if PWM is running */
+ pm_runtime_put_sync(dev);
+ }
+ return 0;
+}
+
+static int ehrpwm_pwm_resume(struct device *dev)
+{
+ struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < pc->chip.npwm; i++) {
+ struct pwm_device *pwm = &pc->chip.pwms[i];
+
+ if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ continue;
+
+ /* Enable explicitly if PWM was running */
+ pm_runtime_get_sync(dev);
+ }
+ ehrpwm_pwm_restore_context(pc);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
+ ehrpwm_pwm_resume);
+
static struct platform_driver ehrpwm_pwm_driver = {
.driver = {
.name = "ehrpwm",
.owner = THIS_MODULE,
.of_match_table = ehrpwm_of_match,
+ .pm = &ehrpwm_pwm_pm_ops,
},
.probe = ehrpwm_pwm_probe,
.remove = ehrpwm_pwm_remove,