drm/panel: kingdisplay-kd097d04: Stop tracking prepared/enabled

As talked about in commit d2aacaf0 ("drm/panel: Check for already
prepared/enabled in drm_panel"), we want to remove needless code from
panel drivers that was storing and double-checking the
prepared/enabled state. Even if someone was relying on the
double-check before, that double-check is now in the core and not
needed in individual drivers.

Cc: Brian Norris <briannorris@chromium.org>
Cc: Chris Zhong <zyw@rock-chips.com>
Cc: Nickey Yang <nickey.yang@rock-chips.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240503143327.RFT.v2.12.I711d07c4f4738df199697fd534c452cdfa46a21f@changeid

drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c

@@ -23,9 +23,6 @@ struct kingdisplay_panel {
 
 	struct regulator *supply;
 	struct gpio_desc *enable_gpio;
-
-	bool prepared;
-	bool enabled;
 };
 
 struct kingdisplay_panel_cmd {
@@ -185,15 +182,10 @@ static int kingdisplay_panel_disable(struct drm_panel *panel)
 	struct kingdisplay_panel *kingdisplay = to_kingdisplay_panel(panel);
 	int err;
 
-	if (!kingdisplay->enabled)
-		return 0;
-
 	err = mipi_dsi_dcs_set_display_off(kingdisplay->link);
 	if (err < 0)
 		dev_err(panel->dev, "failed to set display off: %d\n", err);
 
-	kingdisplay->enabled = false;
-
 	return 0;
 }
 
@@ -202,9 +194,6 @@ static int kingdisplay_panel_unprepare(struct drm_panel *panel)
 	struct kingdisplay_panel *kingdisplay = to_kingdisplay_panel(panel);
 	int err;
 
-	if (!kingdisplay->prepared)
-		return 0;
-
 	err = mipi_dsi_dcs_enter_sleep_mode(kingdisplay->link);
 	if (err < 0) {
 		dev_err(panel->dev, "failed to enter sleep mode: %d\n", err);
@@ -220,8 +209,6 @@ static int kingdisplay_panel_unprepare(struct drm_panel *panel)
 	if (err < 0)
 		return err;
 
-	kingdisplay->prepared = false;
-
 	return 0;
 }
 
@@ -231,9 +218,6 @@ static int kingdisplay_panel_prepare(struct drm_panel *panel)
 	int err, regulator_err;
 	unsigned int i;
 
-	if (kingdisplay->prepared)
-		return 0;
-
 	gpiod_set_value_cansleep(kingdisplay->enable_gpio, 0);
 
 	err = regulator_enable(kingdisplay->supply);
@@ -275,8 +259,6 @@ static int kingdisplay_panel_prepare(struct drm_panel *panel)
 	/* T7: 10ms */
 	usleep_range(10000, 11000);
 
-	kingdisplay->prepared = true;
-
 	return 0;
 
 poweroff:
@@ -289,18 +271,6 @@ static int kingdisplay_panel_prepare(struct drm_panel *panel)
 	return err;
 }
 
-static int kingdisplay_panel_enable(struct drm_panel *panel)
-{
-	struct kingdisplay_panel *kingdisplay = to_kingdisplay_panel(panel);
-
-	if (kingdisplay->enabled)
-		return 0;
-
-	kingdisplay->enabled = true;
-
-	return 0;
-}
-
 static const struct drm_display_mode default_mode = {
 	.clock = 229000,
 	.hdisplay = 1536,
@@ -341,7 +311,6 @@ static const struct drm_panel_funcs kingdisplay_panel_funcs = {
 	.disable = kingdisplay_panel_disable,
 	.unprepare = kingdisplay_panel_unprepare,
 	.prepare = kingdisplay_panel_prepare,
-	.enable = kingdisplay_panel_enable,
 	.get_modes = kingdisplay_panel_get_modes,
 };