drm/dsi: Implement DCS nop command
Provide a small convenience wrapper that transmits a DCS nop command.
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 431e96f..d953b7f 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -567,6 +567,24 @@
EXPORT_SYMBOL(mipi_dsi_dcs_read);
/**
+ * mipi_dsi_dcs_nop() - send DCS nop packet
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int mipi_dsi_dcs_nop(struct mipi_dsi_device *dsi)
+{
+ ssize_t err;
+
+ err = mipi_dsi_dcs_write(dsi, MIPI_DCS_NOP, NULL, 0);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_nop);
+
+/**
* mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
* display module except interface communication
* @dsi: DSI peripheral device
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 31678ce..cbf4486 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -191,6 +191,7 @@
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_nop(struct mipi_dsi_device *dsi);
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);