drm/dsi: Implement some standard DCS commands

Add helpers for the {enter,exit}_sleep_mode, set_display_{on,off} and
set_tear_{on,off} DCS commands.
Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
[treding: kerneldoc and other minor cleanup]
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/drm_mipi_dsi.c

@@ -556,6 +556,124 @@ ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
 }
 EXPORT_SYMBOL(mipi_dsi_dcs_read);
 
+/**
+ * mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
+ *    display module except interface communication
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int mipi_dsi_dcs_enter_sleep_mode(struct mipi_dsi_device *dsi)
+{
+	ssize_t err;
+
+	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_ENTER_SLEEP_MODE, NULL, 0);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_enter_sleep_mode);
+
+/**
+ * mipi_dsi_dcs_exit_sleep_mode() - enable all blocks inside the display
+ *    module
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int mipi_dsi_dcs_exit_sleep_mode(struct mipi_dsi_device *dsi)
+{
+	ssize_t err;
+
+	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_EXIT_SLEEP_MODE, NULL, 0);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_exit_sleep_mode);
+
+/**
+ * mipi_dsi_dcs_set_display_off() - stop displaying the image data on the
+ *    display device
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int mipi_dsi_dcs_set_display_off(struct mipi_dsi_device *dsi)
+{
+	ssize_t err;
+
+	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_OFF, NULL, 0);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_set_display_off);
+
+/**
+ * mipi_dsi_dcs_set_display_on() - start displaying the image data on the
+ *    display device
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure
+ */
+int mipi_dsi_dcs_set_display_on(struct mipi_dsi_device *dsi)
+{
+	ssize_t err;
+
+	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_ON, NULL, 0);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_set_display_on);
+
+/**
+ * mipi_dsi_dcs_set_tear_off() - turn off the display module's Tearing Effect
+ *    output signal on the TE signal line
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure
+ */
+int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi)
+{
+	ssize_t err;
+
+	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_OFF, NULL, 0);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_off);
+
+/**
+ * mipi_dsi_dcs_set_tear_on() - turn on the display module's Tearing Effect
+ *    output signal on the TE signal line.
+ * @dsi: DSI peripheral device
+ * @mode: the Tearing Effect Output Line mode
+ *
+ * Return: 0 on success or a negative error code on failure
+ */
+int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
+			     enum mipi_dsi_dcs_tear_mode mode)
+{
+	u8 value = mode;
+	ssize_t err;
+
+	err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_TEAR_ON, &value,
+				 sizeof(value));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_set_tear_on);
+
 static int mipi_dsi_drv_probe(struct device *dev)
 {
 	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);

include/drm/drm_mipi_dsi.h

@@ -161,12 +161,31 @@ ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
 ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
 			      size_t num_params, void *data, size_t size);
 
+/**
+ * enum mipi_dsi_dcs_tear_mode - Tearing Effect Output Line mode
+ * @MIPI_DSI_DCS_TEAR_MODE_VBLANK: the TE output line consists of V-Blanking
+ *    information only
+ * @MIPI_DSI_DCS_TEAR_MODE_VHBLANK : the TE output line consists of both
+ *    V-Blanking and H-Blanking information
+ */
+enum mipi_dsi_dcs_tear_mode {
+	MIPI_DSI_DCS_TEAR_MODE_VBLANK,
+	MIPI_DSI_DCS_TEAR_MODE_VHBLANK,
+};
+
 ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
 				  const void *data, size_t len);
 ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
 			   const void *data, size_t len);
 ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
 			  size_t len);
+int mipi_dsi_dcs_enter_sleep_mode(struct mipi_dsi_device *dsi);
+int mipi_dsi_dcs_exit_sleep_mode(struct mipi_dsi_device *dsi);
+int mipi_dsi_dcs_set_display_off(struct mipi_dsi_device *dsi);
+int mipi_dsi_dcs_set_display_on(struct mipi_dsi_device *dsi);
+int mipi_dsi_dcs_set_tear_off(struct mipi_dsi_device *dsi);
+int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
+			     enum mipi_dsi_dcs_tear_mode mode);
 
 /**
  * struct mipi_dsi_driver - DSI driver