Commit cd264b6a authored by Ajit Pal Singh's avatar Ajit Pal Singh Committed by Thierry Reding
Browse files

pwm: sti: Maintain a bitmap of configured devices 



This patch introduces a bitmap which is used to keep track of the
pwm channels which have been configured in a pwm chip.

The method used earlier to find the number of configured channels,
was to count the pwmdevices with PWMF_REQUESTED field set
and period value configured. This was not correct and failed
when of_pwm_get()/pwm_get() and then pwm_config() was used.

Signed-off-by: default avatarAjit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent ed735985

drivers/pwm/pwm-sti.c

+11 −19
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ struct sti_pwm_chip { 
	struct regmap_field *pwm_int_en;

	struct pwm_chip chip;

	struct pwm_device *cur;

	unsigned long configured;

	unsigned int en_count;

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

	void __iomem *mmio;
@@ -102,24 +103,6 @@ static int sti_pwm_get_prescale(struct sti_pwm_chip *pc, unsigned long period, 
	return 0;

}



/* Calculate the number of PWM devices configured with a period. */

static unsigned int sti_pwm_count_configured(struct pwm_chip *chip)

{

	struct pwm_device *pwm;

	unsigned int ncfg = 0;

	unsigned int i;



	for (i = 0; i < chip->npwm; i++) {

		pwm = &chip->pwms[i];

		if (test_bit(PWMF_REQUESTED, &pwm->flags)) {

			if (pwm_get_period(pwm))

				ncfg++;

		}

	}



	return ncfg;

}



/*

 * For STiH4xx PWM IP, the PWM period is fixed to 256 local clock cycles.

 * The only way to change the period (apart from changing the PWM input clock)
@@ -141,7 +124,7 @@ static int sti_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 
	unsigned int ncfg;

	bool period_same = false;



	ncfg = sti_pwm_count_configured(chip);

	ncfg = hweight_long(pc->configured);

	if (ncfg)

		period_same = (period_ns == pwm_get_period(cur));
@@ -197,6 +180,7 @@ static int sti_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 


		ret = regmap_field_write(pc->pwm_int_en, 0);



		set_bit(pwm->hwpwm, &pc->configured);

		pc->cur = pwm;



		dev_dbg(dev, "prescale:%u, period:%i, duty:%i, pwmvalx:%u\n",
@@ -254,10 +238,18 @@ static void sti_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) 
	mutex_unlock(&pc->sti_pwm_lock);

}



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

{

	struct sti_pwm_chip *pc = to_sti_pwmchip(chip);



	clear_bit(pwm->hwpwm, &pc->configured);

}



static const struct pwm_ops sti_pwm_ops = {

	.config = sti_pwm_config,

	.enable = sti_pwm_enable,

	.disable = sti_pwm_disable,

	.free = sti_pwm_free,

	.owner = THIS_MODULE,

};

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