Commit 7835ed6a authored by Linus Walleij's avatar Linus Walleij
Browse files

drm/panel-sony-acx424akp: Modernize backlight handling 



This converts the internal backlight in the Sony ACX424AKP
driver to do it the canonical way:

- Assign the panel->backlight during probe.
- Let the panel framework handle the backlight.
- Make the backlight .set_brightness() turn the backlight
  off completely if blank.
- Fix some dev_err_probe() use cases along the way.

Tested on the U8500 HREF520 reference design.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210715092808.1100106-1-linus.walleij@linaro.org
parent 28be2405

drivers/gpu/drm/panel/panel-sony-acx424akp.c

+26 −56
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ 
struct acx424akp {

	struct drm_panel panel;

	struct device *dev;

	struct backlight_device *bl;

	struct regulator *supply;

	struct gpio_desc *reset_gpio;

	bool video_mode;
@@ -102,6 +101,18 @@ static int acx424akp_set_brightness(struct backlight_device *bl) 
	u8 par;

	int ret;



	if (backlight_is_blank(bl)) {

		/* Disable backlight */

		par = 0x00;

		ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,

					 &par, 1);

		if (ret) {

			dev_err(acx->dev, "failed to disable display backlight (%d)\n", ret);

			return ret;

		}

		return 0;

	}



	/* Calculate the PWM duty cycle in n/256's */

	pwm_ratio = max(((duty_ns * 256) / period_ns) - 1, 1);

	pwm_div = max(1,
@@ -172,6 +183,12 @@ static const struct backlight_ops acx424akp_bl_ops = { 
	.update_status = acx424akp_set_brightness,

};



static const struct backlight_properties acx424akp_bl_props = {

	.type = BACKLIGHT_RAW,

	.brightness = 512,

	.max_brightness = 1023,

};



static int acx424akp_read_id(struct acx424akp *acx)

{

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(acx->dev);
@@ -310,8 +327,6 @@ static int acx424akp_prepare(struct drm_panel *panel) 
		}

	}



	acx->bl->props.power = FB_BLANK_NORMAL;



	return 0;



err_power_off:
@@ -323,18 +338,8 @@ static int acx424akp_unprepare(struct drm_panel *panel) 
{

	struct acx424akp *acx = panel_to_acx424akp(panel);

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(acx->dev);

	u8 par;

	int ret;



	/* Disable backlight */

	par = 0x00;

	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,

				 &par, 1);

	if (ret) {

		dev_err(acx->dev, "failed to disable display backlight (%d)\n", ret);

		return ret;

	}



	ret = mipi_dsi_dcs_set_display_off(dsi);

	if (ret) {

		dev_err(acx->dev, "failed to turn display off (%d)\n", ret);
@@ -350,36 +355,10 @@ static int acx424akp_unprepare(struct drm_panel *panel) 
	msleep(85);



	acx424akp_power_off(acx);

	acx->bl->props.power = FB_BLANK_POWERDOWN;



	return 0;

}



static int acx424akp_enable(struct drm_panel *panel)

{

	struct acx424akp *acx = panel_to_acx424akp(panel);



	/*

	 * The backlight is on as long as the display is on

	 * so no use to call backlight_enable() here.

	 */

	acx->bl->props.power = FB_BLANK_UNBLANK;



	return 0;

}



static int acx424akp_disable(struct drm_panel *panel)

{

	struct acx424akp *acx = panel_to_acx424akp(panel);



	/*

	 * The backlight is on as long as the display is on

	 * so no use to call backlight_disable() here.

	 */

	acx->bl->props.power = FB_BLANK_NORMAL;



	return 0;

}



static int acx424akp_get_modes(struct drm_panel *panel,

			       struct drm_connector *connector)
@@ -409,10 +388,8 @@ static int acx424akp_get_modes(struct drm_panel *panel, 
}



static const struct drm_panel_funcs acx424akp_drm_funcs = {

	.disable = acx424akp_disable,

	.unprepare = acx424akp_unprepare,

	.prepare = acx424akp_prepare,

	.enable = acx424akp_enable,

	.get_modes = acx424akp_get_modes,

};
@@ -458,25 +435,18 @@ static int acx424akp_probe(struct mipi_dsi_device *dsi) 
	/* This asserts RESET by default */

	acx->reset_gpio = devm_gpiod_get_optional(dev, "reset",

						  GPIOD_OUT_HIGH);

	if (IS_ERR(acx->reset_gpio)) {

		ret = PTR_ERR(acx->reset_gpio);

		if (ret != -EPROBE_DEFER)

			dev_err(dev, "failed to request GPIO (%d)\n", ret);

		return ret;

	}

	if (IS_ERR(acx->reset_gpio))

		return dev_err_probe(dev, PTR_ERR(acx->reset_gpio),

				     "failed to request GPIO\n");



	drm_panel_init(&acx->panel, dev, &acx424akp_drm_funcs,

		       DRM_MODE_CONNECTOR_DSI);



	acx->bl = devm_backlight_device_register(dev, "acx424akp", dev, acx,

						 &acx424akp_bl_ops, NULL);

	if (IS_ERR(acx->bl)) {

		dev_err(dev, "failed to register backlight device\n");

		return PTR_ERR(acx->bl);

	}

	acx->bl->props.max_brightness = 1023;

	acx->bl->props.brightness = 512;

	acx->bl->props.power = FB_BLANK_POWERDOWN;

	acx->panel.backlight = devm_backlight_device_register(dev, "acx424akp", dev, acx,

					&acx424akp_bl_ops, &acx424akp_bl_props);

	if (IS_ERR(acx->panel.backlight))

		return dev_err_probe(dev, PTR_ERR(acx->panel.backlight),

				     "failed to register backlight device\n");



	drm_panel_add(&acx->panel);