[PATCH v6] backlight: lp855x: Switch to atomic PWM API

From: Maíra Canal
Date: Thu Nov 04 2021 - 13:59:01 EST


Remove legacy PWM interface (pwm_config, pwm_enable, pwm_disable) and
replace it for the atomic PWM API.

Signed-off-by: Maíra Canal <maira.canal@xxxxxx>
---
V1 -> V2: Initialize variable and simplify conditional loop
V2 -> V3: Fix assignment of NULL variable
V3 -> V4: Replace division for pwm_set_relative_duty_cycle
V4 -> V5: Fix overwrite of state.period
V5 -> V6: Fix duty cycle rounding and set period outside conditional loop
---
drivers/video/backlight/lp855x_bl.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c
index e94932c69f54..8f893cf0cfde 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -233,9 +233,8 @@ static int lp855x_configure(struct lp855x *lp)

static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
{
- unsigned int period = lp->pdata->period_ns;
- unsigned int duty = br * period / max_br;
struct pwm_device *pwm;
+ struct pwm_state state;

/* request pwm device with the consumer name */
if (!lp->pwm) {
@@ -245,18 +244,16 @@ static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)

lp->pwm = pwm;

- /*
- * FIXME: pwm_apply_args() should be removed when switching to
- * the atomic PWM API.
- */
- pwm_apply_args(pwm);
+ pwm_init_state(lp->pwm, &state);
+ } else {
+ pwm_get_state(lp->pwm, &state);
}

- pwm_config(lp->pwm, duty, period);
- if (duty)
- pwm_enable(lp->pwm);
- else
- pwm_disable(lp->pwm);
+ state.period = lp->pdata->period_ns;
+ state.duty_cycle = div_u64(br * state.period, max_br);
+ state.enabled = state.duty_cycle;
+
+ pwm_apply_state(lp->pwm, &state);
}

static int lp855x_bl_update_status(struct backlight_device *bl)
--
2.31.1