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Commit 6ad6b838 authored by Ajit Pal Singh's avatar Ajit Pal Singh Committed by Thierry Reding
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pwm: sti: Sync between enable/disable calls 



ST PWM IP has a common enable/disable control for all the PWM
channels on a PWM cell. Disables PWM output on the PWM HW only
when disable is called for the last channel.

Signed-off-by: default avatarAjit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent 5165166e

drivers/pwm/pwm-sti.c

+30 −14
Original line number Diff line number Diff line
@@ -59,6 +59,8 @@ struct sti_pwm_chip { 
	unsigned long *pwm_periods;

	struct pwm_chip chip;

	struct pwm_device *cur;

	unsigned int en_count;

	struct mutex sti_pwm_lock; /* To sync between enable/disable calls */

	void __iomem *mmio;

};
@@ -236,32 +238,44 @@ static int sti_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) 
{

	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);

	struct device *dev = pc->dev;

	int ret;

	int ret = 0;



	/*

	 * Since we have a common enable for all PWM channels,

	 * do not enable if already enabled.

	 */

	mutex_lock(&pc->sti_pwm_lock);

	if (!pc->en_count) {

		ret = clk_enable(pc->clk);

		if (ret)

		return ret;

			goto out;



		ret = regmap_field_write(pc->pwm_en, 1);

	if (ret)

		dev_err(dev, "%s,pwm_en write failed\n", __func__);



		if (ret) {

			dev_err(dev, "failed to enable PWM device:%d\n",

				pwm->hwpwm);

			goto out;

		}

	}

	pc->en_count++;

out:

	mutex_unlock(&pc->sti_pwm_lock);

	return ret;

}



static void sti_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)

{

	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);

	struct device *dev = pc->dev;

	unsigned int val;



	mutex_lock(&pc->sti_pwm_lock);

	if (--pc->en_count) {

		mutex_unlock(&pc->sti_pwm_lock);

		return;

	}

	regmap_field_write(pc->pwm_en, 0);



	regmap_read(pc->regmap, STI_CNT, &val);



	dev_dbg(dev, "pwm counter :%u\n", val);



	clk_disable(pc->clk);

	mutex_unlock(&pc->sti_pwm_lock);

}



static const struct pwm_ops sti_pwm_ops = {
@@ -352,6 +366,8 @@ static int sti_pwm_probe(struct platform_device *pdev) 


	pc->cdata = cdata;

	pc->dev = dev;

	pc->en_count = 0;

	mutex_init(&pc->sti_pwm_lock);



	ret = sti_pwm_probe_dt(pc);

	if (ret)