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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2021-11-02 12:28:03 +0300
committerThierry Reding <thierry.reding@gmail.com>2021-11-17 19:13:29 +0300
commit14d8956548ad48574138d8fd377d434083c3c3cd (patch)
tree082be0ba87769dc36d56d1ed320990dbb5a2021f /drivers/pwm/pwm-vt8500.c
parent0ee11b87c38b64c693881a53969056e16a03fcd1 (diff)
downloadlinux-14d8956548ad48574138d8fd377d434083c3c3cd.tar.xz
pwm: vt8500: Implement .apply() callback
To eventually get rid of all legacy drivers convert this driver to the modern world implementing .apply(). This just pushes down a slightly optimized variant of how legacy drivers are handled in the core. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm/pwm-vt8500.c')
-rw-r--r--drivers/pwm/pwm-vt8500.c57
1 files changed, 50 insertions, 7 deletions
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index 480bfc29782f..7170a315535b 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -70,7 +70,7 @@ static inline void vt8500_pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 b
}
static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+ u64 duty_ns, u64 period_ns)
{
struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
unsigned long long c;
@@ -102,8 +102,8 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
}
c = (unsigned long long)pv * duty_ns;
- do_div(c, period_ns);
- dc = c;
+
+ dc = div64_u64(c, period_ns);
writel(prescale, vt8500->base + REG_SCALAR(pwm->hwpwm));
vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
@@ -176,11 +176,54 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip,
return 0;
}
+static int vt8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int err;
+ bool enabled = pwm->state.enabled;
+
+ if (state->polarity != pwm->state.polarity) {
+ /*
+ * Changing the polarity of a running PWM is only allowed when
+ * the PWM driver implements ->apply().
+ */
+ if (enabled) {
+ vt8500_pwm_disable(chip, pwm);
+
+ enabled = false;
+ }
+
+ err = vt8500_pwm_set_polarity(chip, pwm, state->polarity);
+ if (err)
+ return err;
+ }
+
+ if (!state->enabled) {
+ if (enabled)
+ vt8500_pwm_disable(chip, pwm);
+
+ return 0;
+ }
+
+ /*
+ * We cannot skip calling ->config even if state->period ==
+ * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
+ * because we might have exited early in the last call to
+ * pwm_apply_state because of !state->enabled and so the two values in
+ * pwm->state might not be configured in hardware.
+ */
+ err = vt8500_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);
+ if (err)
+ return err;
+
+ if (!enabled)
+ err = vt8500_pwm_enable(chip, pwm);
+
+ return err;
+}
+
static const struct pwm_ops vt8500_pwm_ops = {
- .enable = vt8500_pwm_enable,
- .disable = vt8500_pwm_disable,
- .config = vt8500_pwm_config,
- .set_polarity = vt8500_pwm_set_polarity,
+ .apply = vt8500_pwm_apply,
.owner = THIS_MODULE,
};