regulator: pwm: Switch to the atomic PWM API
authorBoris Brezillon <boris.brezillon@free-electrons.com>
Tue, 14 Jun 2016 09:13:18 +0000 (11:13 +0200)
committerThierry Reding <thierry.reding@gmail.com>
Mon, 11 Jul 2016 06:43:21 +0000 (08:43 +0200)
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@free-electrons.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
drivers/regulator/pwm-regulator.c

index cb2f22c02469000de2eb9f94c67c0ef29cceef14..7920411057af301a25b6c0a0d6a686c11e871935 100644 (file)
@@ -63,16 +63,14 @@ 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;
@@ -139,35 +137,19 @@ 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 old_uV = pwm_regulator_get_voltage(rdev);
        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;
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