Claude review: drm/panel: Add Ilitek ILI9488 controller driver

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

**Structure and patterns — good:**
- Uses `devm_drm_panel_alloc()` (modern pattern, matches ILI9805).
- Uses `mipi_dsi_multi_context` for the init sequence (correct modern approach).
- Uses `drm_connector_helper_get_modes_fixed()` instead of manual `drm_mode_duplicate` + `drm_mode_probed_add` (cleaner than ILI9805).
- Panel descriptor pattern allows future ILI9488-based panels with different timings to be added easily.

**Mode timing — correct:**
```c
.clock = 14400,
.htotal = 320 + 60 + 20 + 42,   /* = 442 */
.vtotal = 480 + 20 + 10 + 33,   /* = 543 */
```
14400000 / (442 × 543) = ~59.97 Hz. Sensible for a 60 Hz panel.

**Init sequence — minor observation on command 0x21:**
```c
mipi_dsi_dcs_write_seq_multi(ctx, 0x21, 0x00);
```
DCS command 0x21 (`set_display_inversion_on`) is defined as a no-parameter command per the MIPI DCS spec. The extra `0x00` data byte is likely harmless (the panel probably ignores it), but could be simplified to just the command byte. This is likely copied from the vendor's reference init code, so it's fine to leave as-is.

**Reset sequence — correct:**
```c
gpiod_set_value_cansleep(ili->reset, 0);   /* deassert */
usleep_range(1000, 5000);
gpiod_set_value_cansleep(ili->reset, 1);   /* assert reset */
usleep_range(1000, 5000);
gpiod_set_value_cansleep(ili->reset, 0);   /* deassert */
usleep_range(5000, 10000);
```
Standard reset pulse pattern — deassert, pulse assert, deassert. Uses `_cansleep` variant which is safer than the ILI9805's non-cansleep version (since the GPIO controller might be on an I2C/SPI bus).

**Unprepare — deactivate error ignored:**
```c
static int ili9488_unprepare(struct drm_panel *panel)
{
	struct ili9488 *ili = panel_to_ili9488(panel);
	struct mipi_dsi_device *dsi = ili->dsi;
	int ret;

	ili9488_deactivate(ili);
	ret = ili9488_power_off(ili);
```
The return value from `ili9488_deactivate()` is silently discarded. This is reasonable — you still want to power off even if the display-off/sleep-in commands fail — but a `dev_warn` on failure would be helpful for debugging. Not a blocking issue.

**Probe ordering — correct:**
```c
ili->panel.prepare_prev_first = true;
drm_panel_add(&ili->panel);

ret = mipi_dsi_attach(dsi);
if (ret < 0) {
	dev_err_probe(dev, ret, "failed to attach to DSI host\n");
	drm_panel_remove(&ili->panel);
	return ret;
}
```
The `drm_panel_add` before `mipi_dsi_attach` with rollback on failure is the correct ordering.

**MAINTAINERS entry — correct:**
```
+DRM DRIVER FOR ILITEK ILI9488 PANELS
+M:	Igor Reznichenko <igor@reznichenko.net>
+S:	Maintained
+F:	Documentation/devicetree/bindings/display/panel/ilitek,ili9488.yaml
+F:	drivers/gpu/drm/panel/panel-ilitek-ili9488.c
```
Missing a `T:` (git tree) line, but this is common for new drivers that go through drm-misc. Not required.

**Overall for patch 2:** Clean driver, no correctness bugs found. Ready for merge with the minor nits above optionally addressed.

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Generated by Claude Code Patch Reviewer