drm: Create mipi_dsi_dual* macros

Create mipi_dsi_dual, mipi_dsi_dual_dcs_write_seq_multi, and
mipi_dsi_dual_generic_write_seq_multi macros for panels which are driven
by two parallel serial interfaces. This allows for the reduction of code
duplication in drivers for these panels.

Remove mipi_dsi_dual_dcs_write_seq_multi definition from
panel-novatek-nt36523.c to avoid the duplicate definition. Make novatek
driver pass mipi_dsi_context struct as a pointer.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Brigham Campbell <me@brighamcampbell.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250722015313.561966-2-me@brighamcampbell.com

1 files changed, 95 insertions, 0 deletions

diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index 369b0d8830c3..f1dc822f69d6 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -289,6 +289,10 @@ 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);
+void mipi_dsi_dual_generic_write_multi(struct mipi_dsi_multi_context *ctx,
+				       struct mipi_dsi_device *dsi1,
+				       struct mipi_dsi_device *dsi2,
+				       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);
 u32 drm_mipi_dsi_get_input_bus_fmt(enum mipi_dsi_pixel_format dsi_format);
@@ -329,6 +333,10 @@ int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi,
 				     const void *data, size_t len);
 void mipi_dsi_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx,
 				     const void *data, size_t len);
+void mipi_dsi_dual_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx,
+					  struct mipi_dsi_device *dsi1,
+					  struct mipi_dsi_device *dsi2,
+					  const void *data, size_t len);
 ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
 			   const void *data, size_t len);
 ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
@@ -432,6 +440,93 @@ void mipi_dsi_dcs_set_tear_off_multi(struct mipi_dsi_multi_context *ctx);
 	} while (0)
 
 /**
+ * mipi_dsi_dual - send the same MIPI DSI command to two interfaces
+ *
+ * This macro will send the specified MIPI DSI command twice, once per each of
+ * the two interfaces supplied. This is useful for reducing duplication of code
+ * in panel drivers which use two parallel serial interfaces.
+ *
+ * Note that the _func parameter cannot accept a macro such as
+ * mipi_dsi_generic_write_multi() or mipi_dsi_dcs_write_buffer_multi(). See
+ * mipi_dsi_dual_generic_write_multi() and
+ * mipi_dsi_dual_dcs_write_buffer_multi() instead.
+ *
+ * WARNING: This macro reuses the _func argument and the optional trailing
+ * arguments twice each, which may cause unintended side effects. For example,
+ * adding the postfix increment ++ operator to one of the arguments to be
+ * passed to _func will cause the variable to be incremented twice instead of
+ * once and the variable will be its original value + 1 when sent to _dsi2.
+ *
+ * @_func: MIPI DSI function to pass context and arguments into
+ * @_ctx: Context for multiple DSI transactions
+ * @_dsi1: First DSI interface to act as recipient of the MIPI DSI command
+ * @_dsi2: Second DSI interface to act as recipient of the MIPI DSI command
+ * @...: Arguments to pass to MIPI DSI function or macro
+ */
+
+#define mipi_dsi_dual(_func, _ctx, _dsi1, _dsi2, ...)		 \
+	do {							 \
+		struct mipi_dsi_multi_context *_ctxcpy = (_ctx); \
+		_ctxcpy->dsi = (_dsi1);				 \
+		(_func)(_ctxcpy, ##__VA_ARGS__);		 \
+		_ctxcpy->dsi = (_dsi2);				 \
+		(_func)(_ctxcpy, ##__VA_ARGS__);		 \
+	} while (0)
+
+/**
+ * mipi_dsi_dual_generic_write_seq_multi - transmit data using a generic write
+ * packet to two dsi interfaces, one after the other
+ *
+ * This macro will send the specified generic packet twice, once per each of
+ * the two interfaces supplied. This is useful for reducing duplication of code
+ * in panel drivers which use two parallel serial interfaces.
+ *
+ * Note that if an error occurs while transmitting the packet to the first DSI
+ * interface, the packet will not be sent to the second DSI interface.
+ *
+ * This macro will print errors for you and error handling is optimized for
+ * callers that call this multiple times in a row.
+ *
+ * @_ctx: Context for multiple DSI transactions
+ * @_dsi1: First DSI interface to act as recipient of packet
+ * @_dsi2: Second DSI interface to act as recipient of packet
+ * @_seq: buffer containing the payload
+ */
+#define mipi_dsi_dual_generic_write_seq_multi(_ctx, _dsi1, _dsi2, _seq...) \
+	do {								   \
+		static const u8 d[] = { _seq };				   \
+		mipi_dsi_dual_generic_write_multi(_ctx, _dsi1, _dsi2, d,   \
+						  ARRAY_SIZE(d));	   \
+	} while (0)
+
+/**
+ * mipi_dsi_dual_dcs_write_seq_multi - transmit a DCS command with payload to
+ * two dsi interfaces, one after the other
+ *
+ * This macro will send the specified DCS command with payload twice, once per
+ * each of the two interfaces supplied. This is useful for reducing duplication
+ * of code in panel drivers which use two parallel serial interfaces.
+ *
+ * Note that if an error occurs while transmitting the payload to the first DSI
+ * interface, the payload will not be sent to the second DSI interface.
+ *
+ * This macro will print errors for you and error handling is optimized for
+ * callers that call this multiple times in a row.
+ *
+ * @_ctx: Context for multiple DSI transactions
+ * @_dsi1: First DSI interface to act as recipient of packet
+ * @_dsi2: Second DSI interface to act as recipient of packet
+ * @_cmd: Command
+ * @_seq: buffer containing the payload
+ */
+#define mipi_dsi_dual_dcs_write_seq_multi(_ctx, _dsi1, _dsi2, _cmd, _seq...) \
+	do {								     \
+		static const u8 d[] = { _cmd, _seq };			     \
+		mipi_dsi_dual_dcs_write_buffer_multi(_ctx, _dsi1, _dsi2, d,  \
+						     ARRAY_SIZE(d));	     \
+	} while (0)
+
+/**
  * struct mipi_dsi_driver - DSI driver
  * @driver: device driver model driver
  * @probe: callback for device binding