MLK-17389: drm/panel: rm67191: Fix power on/off logic

On remove, the panel driver was only calling rad_panel_disable, which
only updates the brightness. During a reboot, the panel may remain
powered which will cause the whole screen to be bright white (sometimes
flashing).
This patch also calls the rad_panel_unprepare, which puts the panel to
sleep and also sets the DSI_EN gpio to LOW (which is the proper power
off sequence).
While powering on the sleeps are too high, so reduce them according to
the sample driver received from vendor.
Also, fixed the reading of display-timings property: this property is
optional, but will dump some error messages into the console log by
directly calling of_get_videomode() when this property is missing. To
avoid the error messages, first check if we really have this property
first.

Signed-off-by: Robert Chiras <robert.chiras@nxp.com>

diff --git a/drivers/gpu/drm/panel/panel-raydium-rm67191.c b/drivers/gpu/drm/panel/panel-raydium-rm67191.c
index 4f41fd3..07b0bd4 100644 (file)
--- a/drivers/gpu/drm/panel/panel-raydium-rm67191.c
+++ b/drivers/gpu/drm/panel/panel-raydium-rm67191.c
@@ -229,11 +229,11 @@ static int rad_panel_prepare(struct drm_panel *panel)
 
        if (rad->reset != NULL) {
                gpiod_set_value(rad->reset, 1);
-               msleep(100);
+               usleep_range(10000, 15000);
                gpiod_set_value(rad->reset, 0);
-               msleep(100);
+               usleep_range(5000, 10000);
                gpiod_set_value(rad->reset, 1);
-               msleep(100);
+               usleep_range(20000, 25000);
        }
 
        dsi->mode_flags |= MIPI_DSI_MODE_LPM;
@@ -256,7 +256,7 @@ static int rad_panel_prepare(struct drm_panel *panel)
                goto fail;
        }
 
-       msleep(100);
+       usleep_range(10000, 15000);
 
        /* Set DSI mode */
        ret = mipi_dsi_generic_write(dsi, (u8[]){ 0xC2, 0x0B }, 2);
@@ -296,6 +296,8 @@ static int rad_panel_prepare(struct drm_panel *panel)
                goto fail;
        }
 
+       usleep_range(5000, 10000);
+
        ret = mipi_dsi_dcs_set_display_on(dsi);
        if (ret < 0) {
                DRM_DEV_ERROR(dev, "Failed to set display ON (%d)\n", ret);
@@ -509,6 +511,7 @@ static int rad_panel_probe(struct mipi_dsi_device *dsi)
 {
        struct device *dev = &dsi->dev;
        struct device_node *np = dev->of_node;
+       struct device_node *timings;
        struct rad_panel *panel;
        struct backlight_properties bl_props;
        int ret;
@@ -531,9 +534,20 @@ static int rad_panel_probe(struct mipi_dsi_device *dsi)
                return ret;
        }
 
-       ret = of_get_videomode(np, &panel->vm, 0);
-       if (ret < 0)
+       /*
+        * 'display-timings' is optional, so verify if the node is present
+        * before calling of_get_videomode so we won't get console error
+        * messages
+        */
+       timings = of_get_child_by_name(np, "display-timings");
+       if (timings) {
+               of_node_put(timings);
+               ret = of_get_videomode(np, &panel->vm, 0);
+       } else {
                videomode_from_timing(&rad_default_timing, &panel->vm);
+       }
+       if (ret < 0)
+               return ret;
 
        of_property_read_u32(np, "panel-width-mm", &panel->width_mm);
        of_property_read_u32(np, "panel-height-mm", &panel->height_mm);
@@ -583,7 +597,8 @@ static int rad_panel_remove(struct mipi_dsi_device *dsi)
        struct device *dev = &dsi->dev;
        int ret;
 
-       ret = rad_panel_disable(&rad->base);
+       ret = rad_panel_unprepare(&rad->base);
+       ret |= rad_panel_disable(&rad->base);
        if (ret < 0)
                DRM_DEV_ERROR(dev, "Failed to disable panel (%d)\n", ret);
 
@@ -604,6 +619,7 @@ static void rad_panel_shutdown(struct mipi_dsi_device *dsi)
 {
        struct rad_panel *rad = mipi_dsi_get_drvdata(dsi);
 
+       rad_panel_unprepare(&rad->base);
        rad_panel_disable(&rad->base);
 }