Commit 0e2feb17 authored by Philip Avinash's avatar Philip Avinash Committed by Thierry Reding
Browse files

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: default avatarPhilip Avinash <avinashphilip@ti.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
parent 0074b49b

drivers/pwm/pwm-tiehrpwm.c

+83 −0
Original line number Diff line number Diff line
@@ -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,