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: Ajit Pal Singh <ajitpal.singh@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c
index b95115cdaea7ba813a9c42a8da10c8e8db51279e..92abbd56b9f7183810eb222b8b194f3817838367 100644 (file)
--- a/drivers/pwm/pwm-sti.c
+++ b/drivers/pwm/pwm-sti.c
@@ -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,
 };