drm/mipi-dsi: Add a mipi_dsi_dcs_write_seq() macro

Many panel drivers define dsi_dcs_write_seq() and dsi_generic_write_seq()
macros to send DCS commands and generic write packets respectively, with
the payload specified as a list of parameters instead of using arrays.

There's already a macro for the former, introduced by commit 2a9e9daf
("drm/mipi-dsi: Introduce mipi_dsi_dcs_write_seq macro") so drivers can be
changed to use that. But there isn't one yet for the latter, let's add it.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230102202542.3494677-2-javierm@redhat.com

include/drm/drm_mipi_dsi.h

@@ -297,6 +297,24 @@ int mipi_dsi_dcs_set_display_brightness(struct mipi_dsi_device *dsi,
 int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi,
 					u16 *brightness);
 
+/**
+ * mipi_dsi_generic_write_seq - transmit data using a generic write packet
+ * @dsi: DSI peripheral device
+ * @seq: buffer containing the payload
+ */
+#define mipi_dsi_generic_write_seq(dsi, seq...)                                \
+	do {                                                                   \
+		static const u8 d[] = { seq };                                 \
+		struct device *dev = &dsi->dev;                                \
+		int ret;                                                       \
+		ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d));           \
+		if (ret < 0) {                                                 \
+			dev_err_ratelimited(dev, "transmit data failed: %d\n", \
+					    ret);                              \
+			return ret;                                            \
+		}                                                              \
+	} while (0)
+
 /**
  * mipi_dsi_dcs_write_seq - transmit a DCS command with payload
  * @dsi: DSI peripheral device