drm/dsi: Implement DCS soft_reset command

Provide a small convenience wrapper that transmits a DCS soft_reset
command.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index d953b7fe5013..b3c28feff650 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -585,6 +585,24 @@ int mipi_dsi_dcs_nop(struct mipi_dsi_device *dsi)
 EXPORT_SYMBOL(mipi_dsi_dcs_nop);
 
 /**
+ * mipi_dsi_dcs_soft_reset() - perform a software reset of the display module
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int mipi_dsi_dcs_soft_reset(struct mipi_dsi_device *dsi)
+{
+        ssize_t err;
+
+        err = mipi_dsi_dcs_write(dsi, MIPI_DCS_SOFT_RESET, NULL, 0);
+        if (err < 0)
+                return err;
+
+        return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_soft_reset);
+
+/**
  * mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
  *    display module except interface communication
  * @dsi: DSI peripheral device