[RFC PATCH 06/10] drm/panel: synaptics-r63353: don't re-activate the panel if already setup

[Dario Binacchi]

The patch does not re-execute the hardware initialization/activation
procedure for the panel if it is already operational.
This feature is crucial when supporting the simple framebuffer, as the
controller has already been initialized by the bootloader.

Co-developed-by: Michael Trimarchi <mich...@amarulasolutions.com>
Signed-off-by: Michael Trimarchi <mich...@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binac...@amarulasolutions.com>
---

 drivers/gpu/drm/panel/panel-synaptics-r63353.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-synaptics-r63353.c 
b/drivers/gpu/drm/panel/panel-synaptics-r63353.c
index 169c629746c7..93e3ed545b34 100644
--- a/drivers/gpu/drm/panel/panel-synaptics-r63353.c
+++ b/drivers/gpu/drm/panel/panel-synaptics-r63353.c
@@ -258,6 +258,8 @@ static int r63353_panel_probe(struct mipi_dsi_device *dsi)
        int ret = 0;
        struct device *dev = &dsi->dev;
        struct r63353_panel *panel;
+       bool initialized;
+       enum gpiod_flags rflags;
 
        panel = devm_kzalloc(&dsi->dev, sizeof(*panel), GFP_KERNEL);
        if (!panel)
@@ -282,7 +284,9 @@ static int r63353_panel_probe(struct mipi_dsi_device *dsi)
        if (IS_ERR(panel->avdd))
                return PTR_ERR(panel->avdd);
 
-       panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+       initialized = of_property_read_bool(dev->of_node, "syna,boot-on");
+       rflags = initialized ? GPIOD_ASIS : GPIOD_OUT_LOW;
+       panel->reset_gpio = devm_gpiod_get(dev, "reset", rflags);
        if (IS_ERR(panel->reset_gpio)) {
                dev_err(dev, "failed to get RESET GPIO\n");
                return PTR_ERR(panel->reset_gpio);
@@ -297,6 +301,10 @@ static int r63353_panel_probe(struct mipi_dsi_device *dsi)
                return ret;
 
        drm_panel_add(&panel->base);
+       if (initialized) {
+               r63353_panel_power_on(panel);
+               panel->base.prepared = true;
+       }
 
        ret = mipi_dsi_attach(dsi);
        if (ret < 0) {
-- 
2.43.0