diff options
author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2021-11-02 10:28:03 +0100 |
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committer | Thierry Reding <thierry.reding@gmail.com> | 2021-11-17 17:13:29 +0100 |
commit | 14d8956548ad48574138d8fd377d434083c3c3cd (patch) | |
tree | 082be0ba87769dc36d56d1ed320990dbb5a2021f | |
parent | 0ee11b87c38b64c693881a53969056e16a03fcd1 (diff) | |
download | linux-stable-14d8956548ad48574138d8fd377d434083c3c3cd.tar.gz linux-stable-14d8956548ad48574138d8fd377d434083c3c3cd.tar.bz2 linux-stable-14d8956548ad48574138d8fd377d434083c3c3cd.zip |
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>
-rw-r--r-- | drivers/pwm/pwm-vt8500.c | 57 |
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, }; |