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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>
This commit is contained in:
Philip Avinash 2013-01-17 14:50:02 +05:30 committed by Thierry Reding
parent 0074b49b3f
commit 0e2feb17de
1 changed files with 83 additions and 0 deletions
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83
drivers/pwm/pwm-tiehrpwm.c
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@ -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,