drm/dsi: Implement DCS get_power_mode command

Provide a small convenience wrapper that transmits a DCS get_power_mode
command. A set of bitmasks for the mode bits is also provided.

Acked-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index b3c28feff650..80d930191ce7 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -603,6 +603,31 @@ int mipi_dsi_dcs_soft_reset(struct mipi_dsi_device *dsi)
 EXPORT_SYMBOL(mipi_dsi_dcs_soft_reset);
 
 /**
+ * mipi_dsi_dcs_get_power_mode() - query the display module's current power
+ *    mode
+ * @dsi: DSI peripheral device
+ * @mode: return location for the current power mode
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int mipi_dsi_dcs_get_power_mode(struct mipi_dsi_device *dsi, u8 *mode)
+{
+        ssize_t err;
+
+        err = mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_POWER_MODE, mode,
+                                sizeof(*mode));
+        if (err <= 0) {
+                if (err == 0)
+                        err = -ENODATA;
+
+                return err;
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL(mipi_dsi_dcs_get_power_mode);
+
+/**
  * mipi_dsi_dcs_enter_sleep_mode() - disable all unnecessary blocks inside the
  *    display module except interface communication
  * @dsi: DSI peripheral device