[PATCH 4/7] drm: mipi: add mipi_dsi_generic_write_multi_type()

[Caleb Connolly <caleb@xxxxxxxxxxxxxxxx>]

Some panels like the Samsung AMB655X use long write commands for all
non-standard messages and do not work when trying to use the appropriate
command type.

Support these panels by introducing a new helper to send commands of a
specific type, overriding the normal rules.

Signed-off-by: Caleb Connolly <caleb@xxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/drm_mipi_dsi.c | 40 ++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_mipi_dsi.h     | 16 ++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index a471c46f5ca6..d0fee0498d91 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -819,8 +819,48 @@ void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx,
 	}
 }
 EXPORT_SYMBOL(mipi_dsi_generic_write_multi);
 
+/**
+ * mipi_dsi_generic_write_type() - transmit data using a generic write packet of
+ * a specific type
+ * @dsi: DSI peripheral device
+ * @type: data type of the packet
+ * @payload: buffer containing the payload
+ * @size: size of payload buffer
+ *
+ * This function will automatically choose the right data type depending on
+ * the payload length.
+ *
+ * Return: The number of bytes transmitted on success or a negative error code
+ * on failure.
+ */
+ssize_t mipi_dsi_generic_write_multi_type(struct mipi_dsi_multi_context *ctx,
+					  u8 type, const void *payload, size_t size)
+{
+	struct mipi_dsi_device *dsi = ctx->dsi;
+	struct mipi_dsi_msg msg = {
+		.channel = dsi->channel,
+		.tx_buf = payload,
+		.tx_len = size,
+		.type = type,
+	};
+	ssize_t ret;
+
+	if (ctx->accum_err)
+		return 0;
+
+	ret = mipi_dsi_device_transfer(dsi, &msg);
+	if (ret < 0) {
+		ctx->accum_err = ret;
+		dev_err(&dsi->dev, "sending generic data %*ph failed: %zd\n",
+			(int)size, payload, ret);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(mipi_dsi_generic_write_multi_type);
+
 /**
  * mipi_dsi_generic_read() - receive data using a generic read packet
  * @dsi: DSI peripheral device
  * @params: buffer containing the request parameters
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 71d121aeef24..a5d949e695d4 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -287,8 +287,10 @@ ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload,
 int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi,
 				  const void *payload, size_t size);
 void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx,
 				  const void *payload, size_t size);
+ssize_t mipi_dsi_generic_write_multi_type(struct mipi_dsi_multi_context *ctx, u8 type,
+				    const void *payload, size_t size);
 ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params,
 			      size_t num_params, void *data, size_t size);
 
 #define mipi_dsi_msleep(ctx, delay)	\
@@ -432,8 +434,22 @@ void mipi_dsi_dcs_set_tear_on_multi(struct mipi_dsi_multi_context *ctx,
 		static const u8 d[] = { cmd, seq };                     \
 		mipi_dsi_dcs_write_buffer_multi(ctx, d, ARRAY_SIZE(d)); \
 	} while (0)
 
+/**
+ * mipi_dsi_dcs_write_long - transmit a DCS long command with payload
+ * @dsi: DSI peripheral device
+ * @cmd: Commands
+ * @seq: buffer containing data to be transmitted
+ */
+#define mipi_dsi_dcs_write_long(ctx, cmd, seq...)                          \
+	do {                                                               \
+		static const u8 d[] = { cmd, seq };                        \
+		mipi_dsi_generic_write_multi_type(ctx,                     \
+						  MIPI_DSI_DCS_LONG_WRITE, \
+						  d, ARRAY_SIZE(d));       \
+	} while (0)
+
 /**
  * struct mipi_dsi_driver - DSI driver
  * @driver: device driver model driver
  * @probe: callback for device binding

-- 
2.45.0