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Commit 0d75c203 authored by Philip Avinash's avatar Philip Avinash Committed by Thierry Reding
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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: default avatarPhilip Avinash <avinashphilip@ti.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
parent 0e2feb17

drivers/pwm/pwm-tiecap.c

+53 −0
Original line number Diff line number Diff line
@@ -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,