The "atomic" API allows us to configure PWM period and duty_cycle and enable it in one call.
The patch also moves the pwm_init_state just before any use of the pwm_state struct, this fixes a potential bug where pwm_get_state can be called before pwm_init_state.
Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com ---
drivers/video/backlight/pwm_bl.c | 48 ++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 18 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index bdfcc0a71db1..2c734d55d607 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -46,7 +46,8 @@ struct pwm_bl_data { void (*exit)(struct device *); };
-static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) +static void pwm_backlight_power_on(struct pwm_bl_data *pb, + struct pwm_state *state) { int err;
@@ -57,7 +58,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) if (err < 0) dev_err(pb->dev, "failed to enable power supply\n");
- pwm_enable(pb->pwm); + state->enabled = true; + pwm_apply_state(pb->pwm, state);
if (pb->post_pwm_on_delay) msleep(pb->post_pwm_on_delay); @@ -70,6 +72,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
static void pwm_backlight_power_off(struct pwm_bl_data *pb) { + struct pwm_state state; + if (!pb->enabled) return;
@@ -79,8 +83,11 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb) if (pb->pwm_off_delay) msleep(pb->pwm_off_delay);
- pwm_config(pb->pwm, 0, pb->period); - pwm_disable(pb->pwm); + pwm_get_state(pb->pwm, &state); + state.enabled = false; + state.period = pb->period; + state.duty_cycle = 0; + pwm_apply_state(pb->pwm, &state);
regulator_disable(pb->power_supply); pb->enabled = false; @@ -106,6 +113,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) { struct pwm_bl_data *pb = bl_get_data(bl); int brightness = bl->props.brightness; + struct pwm_state state; int duty_cycle;
if (bl->props.power != FB_BLANK_UNBLANK || @@ -118,8 +126,13 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
if (brightness > 0) { duty_cycle = compute_duty_cycle(pb, brightness); - pwm_config(pb->pwm, duty_cycle, pb->period); - pwm_backlight_power_on(pb, brightness); + pwm_get_state(pb->pwm, &state); + state.duty_cycle = duty_cycle; + state.period = pb->period; + if (!state.enabled) + pwm_backlight_power_on(pb, &state); + else + pwm_apply_state(pb->pwm, &state); } else pwm_backlight_power_off(pb);
@@ -447,7 +460,6 @@ static int pwm_backlight_probe(struct platform_device *pdev) struct device_node *node = pdev->dev.of_node; struct pwm_bl_data *pb; struct pwm_state state; - struct pwm_args pargs; unsigned int i; int ret;
@@ -539,10 +551,17 @@ static int pwm_backlight_probe(struct platform_device *pdev)
dev_dbg(&pdev->dev, "got pwm for backlight\n");
- if (!data->levels) { - /* Get the PWM period (in nanoseconds) */ - pwm_get_state(pb->pwm, &state); + /* Sync up PWM state and ensure it is off. */ + pwm_init_state(pb->pwm, &state); + state.enabled = false; + ret = pwm_apply_state(pb->pwm, &state); + if (ret) { + dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n", + ret); + goto err_alloc; + }
+ if (!data->levels) { ret = pwm_backlight_brightness_default(&pdev->dev, data, state.period); if (ret < 0) { @@ -559,20 +578,13 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->levels = data->levels; }
- /* - * FIXME: pwm_apply_args() should be removed when switching to - * the atomic PWM API. - */ - pwm_apply_args(pb->pwm); - /* * The DT case will set the pwm_period_ns field to 0 and store the * period, parsed from the DT, in the PWM device. For the non-DT case, * set the period from platform data if it has not already been set * via the PWM lookup table. */ - pwm_get_args(pb->pwm, &pargs); - pb->period = pargs.period; + pb->period = state.period; if (!pb->period && (data->pwm_period_ns > 0)) pb->period = data->pwm_period_ns;