[PATCH v3 10/14] regulator: pwm: Switch to the atomic PWM API

Boris Brezillon
2016-06-14T09:13:18Z

Use the atomic API wherever appropriate and get rid of pwm_apply_args()
call (the reference period and polarity are now explicitly set when
calling pwm_apply_state()).

We also make use of the pwm_set_relative_duty_cycle() helper to ease
relative to absolute duty_cycle conversion.

Note that changes introduced by commit fd786fb0276a ("regulator: pwm:
Try to avoid voltage error in duty cycle calculation") are no longer
needed because pwm_set_relative_duty_cycle() takes care of all rounding
approximation for us.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Reviewed-by: Brian Norris <briannorris-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Tested-by: Brian Norris <briannorris-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Acked-by: Laxman Dewangan <ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
---
drivers/regulator/pwm-regulator.c | 38 ++++++++++----------------------------
1 file changed, 10 insertions(+), 28 deletions(-)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 524b43f..ad75360 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -59,16 +59,14 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
unsigned selector)
{
struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
- struct pwm_args pargs;
- int dutycycle;
+ struct pwm_state pstate;
int ret;

- pwm_get_args(drvdata->pwm, &pargs);
+ pwm_init_state(drvdata->pwm, &pstate);
+ pwm_set_relative_duty_cycle(&pstate,
+ drvdata->duty_cycle_table[selector].dutycycle, 100);

- dutycycle = (pargs.period *
- drvdata->duty_cycle_table[selector].dutycycle) / 100;
-
- ret = pwm_config(drvdata->pwm, dutycycle, pargs.period);
+ ret = pwm_apply_state(drvdata->pwm, &pstate);
if (ret) {
dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
return ret;
@@ -126,34 +124,18 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
{
struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
unsigned int ramp_delay = rdev->constraints->ramp_delay;
- struct pwm_args pargs;
unsigned int req_diff = min_uV - rdev->constraints->min_uV;
+ struct pwm_state pstate;
unsigned int diff;
- unsigned int duty_pulse;
- u64 req_period;
- u32 rem;
int ret;

- pwm_get_args(drvdata->pwm, &pargs);
+ pwm_init_state(drvdata->pwm, &pstate);
diff = rdev->constraints->max_uV - rdev->constraints->min_uV;

- /* First try to find out if we get the iduty cycle time which is
- * factor of PWM period time. If (request_diff_to_min * pwm_period)
- * is perfect divided by voltage_range_diff then it is possible to
- * get duty cycle time which is factor of PWM period. This will help
- * to get output voltage nearer to requested value as there is no
- * calculation loss.
- */
- req_period = req_diff * pargs.period;
- div_u64_rem(req_period, diff, &rem);
- if (!rem) {
- do_div(req_period, diff);
- duty_pulse = (unsigned int)req_period;
- } else {
- duty_pulse = (pargs.period / 100) * ((req_diff * 100) / diff);
- }
+ /* We pass diff as the scale to get a uV precision. */
+ pwm_set_relative_duty_cycle(&pstate, req_diff, diff);

- ret = pwm_config(drvdata->pwm, duty_pulse, pargs.period);
+ ret = pwm_apply_state(drvdata->pwm, &pstate);
if (ret) {
dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
return ret;
--
2.7.4