From 0e2feb17dec9d97f6b44d5af872633f7ffba9ffb Mon Sep 17 00:00:00 2001 From: Philip Avinash Date: Thu, 17 Jan 2013 14:50:02 +0530 Subject: 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 Signed-off-by: Thierry Reding --- drivers/pwm/pwm-tiehrpwm.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c index 4fcafbfba60e..33e15c4fba02 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, -- cgit v1.2.3