[PATCH v4 12/16] drm/dsi: Implement DCS get_power_mode command

[Thierry Reding]

From: Thierry Reding <treding at nvidia.com>

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 at samsung.com>
Signed-off-by: Thierry Reding <treding at nvidia.com>
---
Changes in v4:
- return -ENODATA when no data could be read

 drivers/gpu/drm/drm_mipi_dsi.c | 25 +++++++++++++++++++++++++
 include/drm/drm_mipi_dsi.h     |  7 +++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index acfaaa37b905..da34469b9b98 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -528,6 +528,31 @@ 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
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index c72838679136..4cbf8e658a3a 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -182,6 +182,12 @@ enum mipi_dsi_dcs_tear_mode {
 	MIPI_DSI_DCS_TEAR_MODE_VHBLANK,
 };
 
+#define MIPI_DSI_DCS_POWER_MODE_DISPLAY (1 << 2)
+#define MIPI_DSI_DCS_POWER_MODE_NORMAL  (1 << 3)
+#define MIPI_DSI_DCS_POWER_MODE_SLEEP   (1 << 4)
+#define MIPI_DSI_DCS_POWER_MODE_PARTIAL (1 << 5)
+#define MIPI_DSI_DCS_POWER_MODE_IDLE    (1 << 6)
+
 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,
@@ -190,6 +196,7 @@ 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_soft_reset(struct mipi_dsi_device *dsi);
+int mipi_dsi_dcs_get_power_mode(struct mipi_dsi_device *dsi, u8 *mode);
 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);
-- 
2.1.2