[PATCH v2] drm/bridge: tc358762: Use mipi_dsi_generic_write_multi()

[PATCH v2] drm/bridge: tc358762: Use mipi_dsi_generic_write_multi()

[Hussain Qadri]

Replace the driver-local error accumulation around
mipi_dsi_generic_write() with mipi_dsi_generic_write_multi()
and struct mipi_dsi_multi_context.

Signed-off-by: Hussain Qadri <hussain.bqadri@gmail.com>
---

Changes in v2:
- Remove extra blank line in tc358762_write().
- Rebase onto current master.

 drivers/gpu/drm/bridge/tc358762.c | 47 +++++++++++--------------------
 1 file changed, 16 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358762.c b/drivers/gpu/drm/bridge/tc358762.c
index 98df3e667d4a..739283fc51db 100644
--- a/drivers/gpu/drm/bridge/tc358762.c
+++ b/drivers/gpu/drm/bridge/tc358762.c
@@ -76,26 +76,12 @@ struct tc358762 {
 	struct gpio_desc *reset_gpio;
 	struct drm_display_mode mode;
 	bool pre_enabled;
-	int error;
 };
 
-static int tc358762_clear_error(struct tc358762 *ctx)
+static void tc358762_write(struct mipi_dsi_multi_context *dsi_ctx, u16 addr, u32 val)
 {
-	int ret = ctx->error;
-
-	ctx->error = 0;
-	return ret;
-}
-
-static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
-{
-	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
-	ssize_t ret;
 	u8 data[6];
 
-	if (ctx->error)
-		return;
-
 	data[0] = addr;
 	data[1] = addr >> 8;
 	data[2] = val;
@@ -103,9 +89,7 @@ static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
 	data[4] = val >> 16;
 	data[5] = val >> 24;
 
-	ret = mipi_dsi_generic_write(dsi, data, sizeof(data));
-	if (ret < 0)
-		ctx->error = ret;
+	mipi_dsi_generic_write_multi(dsi_ctx, data, sizeof(data));
 }
 
 static inline struct tc358762 *bridge_to_tc358762(struct drm_bridge *bridge)
@@ -115,17 +99,19 @@ static inline struct tc358762 *bridge_to_tc358762(struct drm_bridge *bridge)
 
 static int tc358762_init(struct tc358762 *ctx)
 {
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
 	u32 lcdctrl;
 
-	tc358762_write(ctx, DSI_LANEENABLE,
+	tc358762_write(&dsi_ctx, DSI_LANEENABLE,
 		       LANEENABLE_L0EN | LANEENABLE_CLEN);
-	tc358762_write(ctx, PPI_D0S_CLRSIPOCOUNT, 5);
-	tc358762_write(ctx, PPI_D1S_CLRSIPOCOUNT, 5);
-	tc358762_write(ctx, PPI_D0S_ATMR, 0);
-	tc358762_write(ctx, PPI_D1S_ATMR, 0);
-	tc358762_write(ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
+	tc358762_write(&dsi_ctx, PPI_D0S_CLRSIPOCOUNT, 5);
+	tc358762_write(&dsi_ctx, PPI_D1S_CLRSIPOCOUNT, 5);
+	tc358762_write(&dsi_ctx, PPI_D0S_ATMR, 0);
+	tc358762_write(&dsi_ctx, PPI_D1S_ATMR, 0);
+	tc358762_write(&dsi_ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
 
-	tc358762_write(ctx, SPICMR, 0x00);
+	tc358762_write(&dsi_ctx, SPICMR, 0x00);
 
 	lcdctrl = LCDCTRL_VSDELAY(1) | LCDCTRL_RGB888 |
 		  LCDCTRL_UNK6 | LCDCTRL_VTGEN;
@@ -136,17 +122,16 @@ static int tc358762_init(struct tc358762 *ctx)
 	if (ctx->mode.flags & DRM_MODE_FLAG_NVSYNC)
 		lcdctrl |= LCDCTRL_VSPOL;
 
-	tc358762_write(ctx, LCDCTRL, lcdctrl);
+	tc358762_write(&dsi_ctx, LCDCTRL, lcdctrl);
 
-	tc358762_write(ctx, SYSCTRL, 0x040f);
+	tc358762_write(&dsi_ctx, SYSCTRL, 0x040f);
 	msleep(100);
 
-	tc358762_write(ctx, PPI_STARTPPI, PPI_START_FUNCTION);
-	tc358762_write(ctx, DSI_STARTDSI, DSI_RX_START);
+	tc358762_write(&dsi_ctx, PPI_STARTPPI, PPI_START_FUNCTION);
+	tc358762_write(&dsi_ctx, DSI_STARTDSI, DSI_RX_START);
 
 	msleep(100);
-
-	return tc358762_clear_error(ctx);
+	return dsi_ctx.accum_err;
 }
 
 static void tc358762_post_disable(struct drm_bridge *bridge,
-- 
2.54.0

Claude review: drm/bridge: tc358762: Use mipi_dsi_generic_write_multi()

[Claude Code Review Bot]

Overall Series Review

Subject: drm/bridge: tc358762: Use mipi_dsi_generic_write_multi()
Author: Hussain Qadri <hussain.bqadri@gmail.com>
Patches: 1
Reviewed: 2026-05-05T08:59:34.716883

---

This is a single-patch series that converts the tc358762 DSI/DPI bridge driver from a hand-rolled error accumulation pattern (using `ctx->error` and `tc358762_clear_error()`) to the standard `mipi_dsi_multi_context` / `mipi_dsi_generic_write_multi()` framework provided by the DRM subsystem.

The conversion is straightforward, correct, and follows established patterns used across numerous other DSI drivers. It reduces code by ~15 lines, removes the `error` field from the driver struct, and eliminates two helper functions (`tc358762_clear_error` and the old error-checking logic in `tc358762_write`). The `mipi_dsi_generic_write_multi()` API already handles error accumulation internally via `accum_err`, providing identical semantics.

**Verdict: Looks good.** This is a clean mechanical conversion with no functional change in behavior.

---
Generated by Claude Code Patch Reviewer

Claude review: drm/bridge: tc358762: Use mipi_dsi_generic_write_multi()

[Claude Code Review Bot]

Patch Review

**Correctness:**

The conversion is correct. The old pattern:
```c
static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
{
    ...
    if (ctx->error)
        return;
    ...
    ret = mipi_dsi_generic_write(dsi, data, sizeof(data));
    if (ret < 0)
        ctx->error = ret;
}
```
is functionally equivalent to the new pattern:
```c
static void tc358762_write(struct mipi_dsi_multi_context *dsi_ctx, u16 addr, u32 val)
{
    ...
    mipi_dsi_generic_write_multi(dsi_ctx, data, sizeof(data));
}
```
because `mipi_dsi_generic_write_multi()` internally checks and sets `ctx->accum_err`, providing the same early-return-on-error and error-capture semantics.

The removal of the `int error` field from `struct tc358762` is correct — no other code references it outside the removed functions.

The return value change from `tc358762_clear_error(ctx)` to `dsi_ctx.accum_err` at the end of `tc358762_init()` is correct. The old `tc358762_clear_error()` returned the accumulated error and reset it to zero; since `dsi_ctx` is a local variable that goes out of scope immediately after the return, clearing is unnecessary.

The `struct mipi_dsi_device *dsi` lookup moved from `tc358762_write()` into `tc358762_init()` where it's used to initialize `dsi_ctx` — this is appropriate since the multi-context carries the device pointer.

**Style:** The removal of the extra blank line before the final `return` (noted in the v2 changelog) is correct; the result matches typical kernel style.

**No issues found.** 

Reviewed-by worthy as-is.

---
Generated by Claude Code Patch Reviewer