drm/panel: Support Rocktech jh057n00900 DSI panel

+#include <video/display_timing.h>

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +37 -0

+
+static int jh057n_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct jh057n *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		DRM_DEV_ERROR(dev, "cannot get reset gpio");
+		return PTR_ERR(ctx->reset_gpio);
+	}
+
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	ctx->dev = dev;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+		MIPI_DSI_MODE_VIDEO_BURST | MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+
+	ctx->backlight = devm_of_find_backlight(dev);
+	if (IS_ERR(ctx->backlight))
+		return PTR_ERR(ctx->backlight);
+
+	drm_panel_init(&ctx->panel);
+	ctx->panel.dev = dev;
+	ctx->panel.funcs = &jh057n_drm_funcs;
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);

Hi Guido.

Thanks for addressing review comments in first round. Just a few nits in this follow-up.
With these nits addressed:

Reviewed-by Sam Ravnborg <[email protected]>

Quoted 2 lines

+#include <video/display_timing.h>

This include file is, as far as I could tell, no longer used and can be dropped.

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 217

Quoted 11 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +11 -0

+
+static int jh057n_get_modes(struct drm_panel *panel)
+{
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &default_mode);
+	if (!mode) {
+		DRM_ERROR("Failed to add mode %ux%u@%u",
+			  default_mode.hdisplay, default_mode.vdisplay,
+			  default_mode.vrefresh);
+		return -ENOMEM;

Use DRM_DEV_ERROR()
You can find dev via: panel->base.drm-dev

Quoted 37 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +37 -0

+
+static int jh057n_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct jh057n *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		DRM_DEV_ERROR(dev, "cannot get reset gpio");
+		return PTR_ERR(ctx->reset_gpio);
+	}
+
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	ctx->dev = dev;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+		MIPI_DSI_MODE_VIDEO_BURST | MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+
+	ctx->backlight = devm_of_find_backlight(dev);
+	if (IS_ERR(ctx->backlight))
+		return PTR_ERR(ctx->backlight);
+
+	drm_panel_init(&ctx->panel);
+	ctx->panel.dev = dev;
+	ctx->panel.funcs = &jh057n_drm_funcs;
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 325

Quoted 10 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +10 -0

+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed. Is host ready?");
+		drm_panel_remove(&ctx->panel);
+		return ret;
+	}
+
+	DRM_INFO(DRV_NAME "_panel %ux%u@%u %ubpp dsi %udl - ready",
+		 default_mode.hdisplay, default_mode.vdisplay,
+		 default_mode.vrefresh,
+		 mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);

You already have dev, so use DRM_DEV_INFO() and drop DRV_NAME

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 368

Quoted 4 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +4 -0

+
+static const struct of_device_id jh057n_of_match[] = {
+	{ .compatible = "rocktech,jh057n00900" },
+	{ /* Sentinel */ }

Lower case 's' (sorry, likely my bad)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 377

Quoted 5 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +5 -0

+	.probe	= jh057n_probe,
+	.remove = jh057n_remove,
+	.shutdown = jh057n_shutdown,
+	.driver = {
+		.name = DRV_NAME "_panel",

Drop "_panel" postfix. Other drivers do not use it.

Sam