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hwmon: (pwm-fan) stop using legacy PWM functions and some cleanups

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pwm_apply_state() does what the legacy functions pwm_config() and
pwm_{en,dis}able() do in a single function call. This simplifies error
handling and is more efficient for new-style PWM hardware drivers.

Instead of repeatedly querying the PWM framework about the initial PWM
configuration, cache the settings in driver data.

Also use __set_pwm() in .probe() to have the algorithm calculating the PWM
state in a single place.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210112191314.124686-1-u.kleine-koenig@pengutronix.de
[groeck: Added missing empty line after declaration]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Uwe Kleine-König 2021-01-12 20:13:14 +01:00 committed by Guenter Roeck
parent 8c78f0dee4
commit 86585c6197
1 changed files with 20 additions and 28 deletions
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48
drivers/hwmon/pwm-fan.c
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@ -31,6 +31,7 @@ struct pwm_fan_tach {
struct pwm_fan_ctx {
struct mutex lock;
struct pwm_device *pwm;
struct pwm_state pwm_state;
struct regulator *reg_en;
int tach_count;
@ -95,18 +96,17 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
{
unsigned long period;
int ret = 0;
struct pwm_state state = { };
struct pwm_state *state = &ctx->pwm_state;
mutex_lock(&ctx->lock);
if (ctx->pwm_value == pwm)
goto exit_set_pwm_err;
pwm_init_state(ctx->pwm, &state);
period = ctx->pwm->args.period;
state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
state.enabled = pwm ? true : false;
period = state->period;
state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
state->enabled = pwm ? true : false;
ret = pwm_apply_state(ctx->pwm, &state);
ret = pwm_apply_state(ctx->pwm, state);
if (!ret)
ctx->pwm_value = pwm;
exit_set_pwm_err:
@ -288,7 +288,9 @@ static void pwm_fan_regulator_disable(void *data)
static void pwm_fan_pwm_disable(void *__ctx)
{
struct pwm_fan_ctx *ctx = __ctx;
pwm_disable(ctx->pwm);
ctx->pwm_state.enabled = false;
pwm_apply_state(ctx->pwm, &ctx->pwm_state);
del_timer_sync(&ctx->rpm_timer);
}
@ -299,7 +301,6 @@ static int pwm_fan_probe(struct platform_device *pdev)
struct pwm_fan_ctx *ctx;
struct device *hwmon;
int ret;
struct pwm_state state = { };
const struct hwmon_channel_info **channels;
u32 *fan_channel_config;
int channel_count = 1; /* We always have a PWM channel. */
@ -337,22 +338,20 @@ static int pwm_fan_probe(struct platform_device *pdev)
ctx->pwm_value = MAX_PWM;
pwm_init_state(ctx->pwm, &state);
pwm_init_state(ctx->pwm, &ctx->pwm_state);
/*
* __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
* long. Check this here to prevent the fan running at a too low
* frequency.
*/
if (state.period > ULONG_MAX / MAX_PWM + 1) {
if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) {
dev_err(dev, "Configured period too big\n");
return -EINVAL;
}
/* Set duty cycle to maximum allowed and enable PWM output */
state.duty_cycle = ctx->pwm->args.period - 1;
state.enabled = true;
ret = pwm_apply_state(ctx->pwm, &state);
ret = __set_pwm(ctx, MAX_PWM);
if (ret) {
dev_err(dev, "Failed to configure PWM: %d\n", ret);
return ret;
@ -468,17 +467,17 @@ static int pwm_fan_probe(struct platform_device *pdev)
static int pwm_fan_disable(struct device *dev)
{
struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
struct pwm_args args;
int ret;
pwm_get_args(ctx->pwm, &args);
if (ctx->pwm_value) {
ret = pwm_config(ctx->pwm, 0, args.period);
/* keep ctx->pwm_state unmodified for pwm_fan_resume() */
struct pwm_state state = ctx->pwm_state;
state.duty_cycle = 0;
state.enabled = false;
ret = pwm_apply_state(ctx->pwm, &state);
if (ret < 0)
return ret;
pwm_disable(ctx->pwm);
}
if (ctx->reg_en) {
@ -506,8 +505,6 @@ static int pwm_fan_suspend(struct device *dev)
static int pwm_fan_resume(struct device *dev)
{
struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
struct pwm_args pargs;
unsigned long duty;
int ret;
if (ctx->reg_en) {
@ -521,12 +518,7 @@ static int pwm_fan_resume(struct device *dev)
if (ctx->pwm_value == 0)
return 0;
pwm_get_args(ctx->pwm, &pargs);
duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
ret = pwm_config(ctx->pwm, duty, pargs.period);
if (ret)
return ret;
return pwm_enable(ctx->pwm);
return pwm_apply_state(ctx->pwm, &ctx->pwm_state);
}
#endif