drm/stm: ltdc: add pinctrl for DPI encoder mode

The implementation of functions encoder_enable and encoder_disable
make possible to control the pinctrl according to the encoder type.
The pinctrl must be activated only if the encoder type is DPI.
This helps to move the DPI-related pinctrl configuration from
all the panel or bridge to the LTDC dt node.

Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1567761708-31777-1-git-send-email-yannick.fertre@st.com

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 7cdab685b527e65866668d45cb26ec9acc73edd1..5b51298921cf18675c70f7a624fba8921719001b 100644 (file)
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_graph.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
@@ -1040,6 +1041,36 @@ static const struct drm_encoder_funcs ltdc_encoder_funcs = {
        .destroy = drm_encoder_cleanup,
 };
 
+static void ltdc_encoder_disable(struct drm_encoder *encoder)
+{
+       struct drm_device *ddev = encoder->dev;
+
+       DRM_DEBUG_DRIVER("\n");
+
+       /* Set to sleep state the pinctrl whatever type of encoder */
+       pinctrl_pm_select_sleep_state(ddev->dev);
+}
+
+static void ltdc_encoder_enable(struct drm_encoder *encoder)
+{
+       struct drm_device *ddev = encoder->dev;
+
+       DRM_DEBUG_DRIVER("\n");
+
+       /*
+        * Set to default state the pinctrl only with DPI type.
+        * Others types like DSI, don't need pinctrl due to
+        * internal bridge (the signals do not come out of the chipset).
+        */
+       if (encoder->encoder_type == DRM_MODE_ENCODER_DPI)
+               pinctrl_pm_select_default_state(ddev->dev);
+}
+
+static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = {
+       .disable = ltdc_encoder_disable,
+       .enable = ltdc_encoder_enable,
+};
+
 static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
 {
        struct drm_encoder *encoder;
@@ -1055,6 +1086,8 @@ static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
        drm_encoder_init(ddev, encoder, &ltdc_encoder_funcs,
                         DRM_MODE_ENCODER_DPI, NULL);
 
+       drm_encoder_helper_add(encoder, &ltdc_encoder_helper_funcs);
+
        ret = drm_bridge_attach(encoder, bridge, NULL);
        if (ret) {
                drm_encoder_cleanup(encoder);
@@ -1280,6 +1313,8 @@ int ltdc_load(struct drm_device *ddev)
 
        clk_disable_unprepare(ldev->pixel_clk);
 
+       pinctrl_pm_select_sleep_state(ddev->dev);
+
        pm_runtime_enable(ddev->dev);
 
        return 0;