drm/panel: Support Rocktech jh057n00900 DSI panel

Support Rocktech jh057n00900 5.5" 720x1440 TFT LCD panel. It is a MIPI DSI video mode panel.

The panel seems to use a Sitronix ST7703 look alike (most of the commands look similar to the ST7703's data sheet but use a different number of parameters). The initial version of the DSI init sequence (including sleeps) were provided by the vendor. Sleeps were reduced considerably though to speed up initialization.

Signed-off-by Guido Günther <[email protected]>

---
+++ b/drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c

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

@@ -0,0 +1,414 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Rockteck jh057n00900 5.5" MIPI-DSI panel driver
+ *

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +21 -0

+
+#define DRV_NAME "jh057n00900"
+
+/* Manufacturer specific Commands send via DSI */
+#define ST7703_CMD_ALL_PIXEL_OFF 0x22
+#define ST7703_CMD_ALL_PIXEL_ON	 0x23
+#define ST7703_CMD_SETDISP	 0xB2
+#define ST7703_CMD_SETRGBIF	 0xB3
+#define ST7703_CMD_SETCYC	 0xB4
+#define ST7703_CMD_SETBGP	 0xB5
+#define ST7703_CMD_SETVCOM	 0xB6
+#define ST7703_CMD_SETOTP	 0xB7
+#define ST7703_CMD_SETPOWER_EXT	 0xB8
+#define ST7703_CMD_SETEXTC	 0xB9
+#define ST7703_CMD_SETMIPI	 0xBA
+#define ST7703_CMD_SETVDC	 0xBC
+#define ST7703_CMD_SETSCR	 0xC0
+#define ST7703_CMD_SETPOWER	 0xC1
+#define ST7703_CMD_SETPANEL	 0xCC
+#define ST7703_CMD_SETGAMMA	 0xE0
+#define ST7703_CMD_SETEQ	 0xE3

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +95 -0

+
+	struct dentry *debugfs;
+};
+
+static inline struct jh057n *panel_to_jh057n(struct drm_panel *panel)
+{
+	return container_of(panel, struct jh057n, panel);
+}
+
+#define dsi_generic_write_seq(dsi, seq...) do {				\
+		static const u8 d[] = { seq };				\
+		int ret;						\
+		ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d));	\
+		if (ret < 0)						\
+			return ret;					\
+	} while (0)
+
+static int jh057n_init_sequence(struct jh057n *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	struct device *dev = ctx->dev;
+	int ret;
+
+	/*
+	 * Init sequence was supplied by the panel vendor. Most of the commands
+	 * resemble the ST7703 but the number of parameters often don't match
+	 * so it's likely a clone.
+	 */
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETEXTC,
+			      0xF1, 0x12, 0x83);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETRGBIF,
+			      0x10, 0x10, 0x05, 0x05, 0x03, 0xFF, 0x00, 0x00,
+			      0x00, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETSCR,
+			      0x73, 0x73, 0x50, 0x50, 0x00, 0x00, 0x08, 0x70,
+			      0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETVDC, 0x4E);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETPANEL, 0x0B);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETCYC, 0x80);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETDISP, 0xF0, 0x12, 0x30);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETEQ,
+			      0x07, 0x07, 0x0B, 0x0B, 0x03, 0x0B, 0x00, 0x00,
+			      0x00, 0x00, 0xFF, 0x00, 0xC0, 0x10);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETBGP, 0x08, 0x08);
+	msleep(20);
+
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETVCOM, 0x3F, 0x3F);
+	dsi_generic_write_seq(dsi, 0xBF, 0x02, 0x11, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETGIP1,
+			      0x82, 0x10, 0x06, 0x05, 0x9E, 0x0A, 0xA5, 0x12,
+			      0x31, 0x23, 0x37, 0x83, 0x04, 0xBC, 0x27, 0x38,
+			      0x0C, 0x00, 0x03, 0x00, 0x00, 0x00, 0x0C, 0x00,
+			      0x03, 0x00, 0x00, 0x00, 0x75, 0x75, 0x31, 0x88,
+			      0x88, 0x88, 0x88, 0x88, 0x88, 0x13, 0x88, 0x64,
+			      0x64, 0x20, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
+			      0x02, 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETGIP2,
+			      0x02, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x02, 0x46, 0x02, 0x88,
+			      0x88, 0x88, 0x88, 0x88, 0x88, 0x64, 0x88, 0x13,
+			      0x57, 0x13, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
+			      0x75, 0x88, 0x23, 0x14, 0x00, 0x00, 0x02, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x0A,
+			      0xA5, 0x00, 0x00, 0x00, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETGAMMA,
+			      0x00, 0x09, 0x0E, 0x29, 0x2D, 0x3C, 0x41, 0x37,
+			      0x07, 0x0B, 0x0D, 0x10, 0x11, 0x0F, 0x10, 0x11,
+			      0x18, 0x00, 0x09, 0x0E, 0x29, 0x2D, 0x3C, 0x41,
+			      0x37, 0x07, 0x0B, 0x0D, 0x10, 0x11, 0x0F, 0x10,
+			      0x11, 0x18);
+	msleep(20);
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "Failed to exit sleep mode");
+		return ret;
+	}
+	/* Panel is operational 120 msec after reset */
+	msleep(60);
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret)
+		return ret;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done");
+	return 0;
+}
+
+static int jh057n_disable(struct drm_panel *panel)
+{
+	struct jh057n *ctx = panel_to_jh057n(panel);
+	int ret;
+
+	if (!ctx->enabled)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +23 -0

+static int jh057n_disable(struct drm_panel *panel)
+{
+	struct jh057n *ctx = panel_to_jh057n(panel);
+
+	backlight_disable(ctx->backlight);
+
+	return 0;
+}
 
 
 
+static const struct drm_display_mode default_mode = {
+	.hdisplay    = 720,
+	.hsync_start = 720 + 90,
+	.hsync_end   = 720 + 90 + 20,
+	.htotal	     = 720 + 90 + 20 + 20,
+	.vdisplay    = 1440,
+	.vsync_start = 1440 + 20,
+	.vsync_end   = 1440 + 20 + 4,
+	.vtotal	     = 1440 + 20 + 4 + 12,
+	.vrefresh    = 60,
+	.clock	     = 75276,
+	.flags	     = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.width_mm    = 65,
+	.height_mm   = 130,
+};

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +7 -0

+	if (ret)
+		return ret;
+
+	drm_mode_probed_add(panel->connector, mode);
+
+	return 1;
+}

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +77 -0

+	/* Reset the panel to get video back */
+	drm_panel_disable(&ctx->panel);
+	drm_panel_unprepare(&ctx->panel);
+	drm_panel_prepare(&ctx->panel);
+	drm_panel_enable(&ctx->panel);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(allpixelson_fops, NULL,
+			allpixelson_set, "%llu\n");
+
+static int jh057n_debugfs_init(struct jh057n *ctx)
+{
+	struct dentry *f;
+
+	ctx->debugfs = debugfs_create_dir(DRV_NAME, NULL);
+	if (!ctx->debugfs)
+		return -ENOMEM;
+
+	f = debugfs_create_file("allpixelson", 0600,
+				ctx->debugfs, ctx, &allpixelson_fops);
+	if (!f)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void jh057n_debugfs_remove(struct jh057n *ctx)
+{
+	debugfs_remove_recursive(ctx->debugfs);
+	ctx->debugfs = NULL;
+}
+
+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);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed. Is host ready?");
+		drm_panel_remove(&ctx->panel);
+		goto err;
+	}
+
+	DRM_INFO(DRV_NAME "_panel %ux%u@%u %ubpp dsi %udl - ready",

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +26 -0

+	return ret;
+
+}
+
+static void jh057n_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct jh057n *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = jh057n_unprepare(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to unprepare panel: %d\n",
+			      ret);
+
+	ret = jh057n_disable(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to disable panel: %d\n",
+			      ret);
+}
+
+static int jh057n_remove(struct mipi_dsi_device *dsi)
+{
+	struct jh057n *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	jh057n_shutdown(dsi);

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +7 -0

+};
+MODULE_DEVICE_TABLE(of, jh057n_of_match);
+
+static struct mipi_dsi_driver jh057n_driver = {
+	.probe	= jh057n_probe,
+	.remove = jh057n_remove,
+	.shutdown = jh057n_shutdown,

+// SPDX-License-Identifier: GPL-2.0+

Hi Guido.

Thanks for this patch.
See below for some review feedback.

The driver includes the "allpixelson_set" debugfs feature. Is this a debug leftover, or is there a real need for this? If this is a debug feature that is no logner needed then no need to add it to the mainline driver.

Sam

Quoted 17 lines · Guido Günther

Support Rocktech jh057n00900 5.5" 720x1440 TFT LCD panel. It is a MIPI DSI video mode panel.

The panel seems to use a Sitronix ST7703 look alike (most of the commands look similar to the ST7703's data sheet but use a different number of parameters). The initial version of the DSI init sequence (including sleeps) were provided by the vendor. Sleeps were reduced considerably though to speed up initialization.

Signed-off-by Guido Günther <[email protected]>

---
+++ b/drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c

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

@@ -0,0 +1,414 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Rockteck jh057n00900 5.5" MIPI-DSI panel driver
+ *

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 14

Quoted 10 lines

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

+ * Copyright (C) Purism SPC 2019
+ */
+#include <drm/drmP.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <video/mipi_display.h>
+#include <video/display_timing.h>
+#include <linux/debugfs.h>

1) Drop use of drmP.h - it is dreprecated and shall not be used for new drivers
2) Group the include files, and within each group sort them alphabetically

Quoted 21 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +21 -0

+
+#define DRV_NAME "jh057n00900"
+
+/* Manufacturer specific Commands send via DSI */
+#define ST7703_CMD_ALL_PIXEL_OFF 0x22
+#define ST7703_CMD_ALL_PIXEL_ON	 0x23
+#define ST7703_CMD_SETDISP	 0xB2
+#define ST7703_CMD_SETRGBIF	 0xB3
+#define ST7703_CMD_SETCYC	 0xB4
+#define ST7703_CMD_SETBGP	 0xB5
+#define ST7703_CMD_SETVCOM	 0xB6
+#define ST7703_CMD_SETOTP	 0xB7
+#define ST7703_CMD_SETPOWER_EXT	 0xB8
+#define ST7703_CMD_SETEXTC	 0xB9
+#define ST7703_CMD_SETMIPI	 0xBA
+#define ST7703_CMD_SETVDC	 0xBC
+#define ST7703_CMD_SETSCR	 0xC0
+#define ST7703_CMD_SETPOWER	 0xC1
+#define ST7703_CMD_SETPANEL	 0xCC
+#define ST7703_CMD_SETGAMMA	 0xE0
+#define ST7703_CMD_SETEQ	 0xE3

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 45

Quoted 10 lines

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

+#define ST7703_CMD_SETGIP1	 0xE9
+#define ST7703_CMD_SETGIP2	 0xEA
+
+struct jh057n {
+	struct device *dev;
+	struct drm_panel panel;
+	struct gpio_desc *reset_gpio;
+	struct backlight_device *backlight;
+	bool prepared;
+	bool enabled;

enabled is used only to protect from calling backlight_disable() again. There is nothing (as far as I can see) that should make calling backlight_disbale() bad if already disabled. So consider if this can be dropped.

Quoted 95 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +95 -0

+
+	struct dentry *debugfs;
+};
+
+static inline struct jh057n *panel_to_jh057n(struct drm_panel *panel)
+{
+	return container_of(panel, struct jh057n, panel);
+}
+
+#define dsi_generic_write_seq(dsi, seq...) do {				\
+		static const u8 d[] = { seq };				\
+		int ret;						\
+		ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d));	\
+		if (ret < 0)						\
+			return ret;					\
+	} while (0)
+
+static int jh057n_init_sequence(struct jh057n *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	struct device *dev = ctx->dev;
+	int ret;
+
+	/*
+	 * Init sequence was supplied by the panel vendor. Most of the commands
+	 * resemble the ST7703 but the number of parameters often don't match
+	 * so it's likely a clone.
+	 */
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETEXTC,
+			      0xF1, 0x12, 0x83);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETRGBIF,
+			      0x10, 0x10, 0x05, 0x05, 0x03, 0xFF, 0x00, 0x00,
+			      0x00, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETSCR,
+			      0x73, 0x73, 0x50, 0x50, 0x00, 0x00, 0x08, 0x70,
+			      0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETVDC, 0x4E);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETPANEL, 0x0B);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETCYC, 0x80);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETDISP, 0xF0, 0x12, 0x30);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETEQ,
+			      0x07, 0x07, 0x0B, 0x0B, 0x03, 0x0B, 0x00, 0x00,
+			      0x00, 0x00, 0xFF, 0x00, 0xC0, 0x10);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETBGP, 0x08, 0x08);
+	msleep(20);
+
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETVCOM, 0x3F, 0x3F);
+	dsi_generic_write_seq(dsi, 0xBF, 0x02, 0x11, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETGIP1,
+			      0x82, 0x10, 0x06, 0x05, 0x9E, 0x0A, 0xA5, 0x12,
+			      0x31, 0x23, 0x37, 0x83, 0x04, 0xBC, 0x27, 0x38,
+			      0x0C, 0x00, 0x03, 0x00, 0x00, 0x00, 0x0C, 0x00,
+			      0x03, 0x00, 0x00, 0x00, 0x75, 0x75, 0x31, 0x88,
+			      0x88, 0x88, 0x88, 0x88, 0x88, 0x13, 0x88, 0x64,
+			      0x64, 0x20, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
+			      0x02, 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETGIP2,
+			      0x02, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x02, 0x46, 0x02, 0x88,
+			      0x88, 0x88, 0x88, 0x88, 0x88, 0x64, 0x88, 0x13,
+			      0x57, 0x13, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
+			      0x75, 0x88, 0x23, 0x14, 0x00, 0x00, 0x02, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x0A,
+			      0xA5, 0x00, 0x00, 0x00, 0x00);
+	dsi_generic_write_seq(dsi, ST7703_CMD_SETGAMMA,
+			      0x00, 0x09, 0x0E, 0x29, 0x2D, 0x3C, 0x41, 0x37,
+			      0x07, 0x0B, 0x0D, 0x10, 0x11, 0x0F, 0x10, 0x11,
+			      0x18, 0x00, 0x09, 0x0E, 0x29, 0x2D, 0x3C, 0x41,
+			      0x37, 0x07, 0x0B, 0x0D, 0x10, 0x11, 0x0F, 0x10,
+			      0x11, 0x18);
+	msleep(20);
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "Failed to exit sleep mode");
+		return ret;
+	}
+	/* Panel is operational 120 msec after reset */
+	msleep(60);
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret)
+		return ret;
+
+	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done");
+	return 0;
+}
+
+static int jh057n_disable(struct drm_panel *panel)
+{
+	struct jh057n *ctx = panel_to_jh057n(panel);
+	int ret;
+
+	if (!ctx->enabled)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 150

Quoted 10 lines

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

+		return 0;
+
+	ret = backlight_disable(ctx->backlight);
+	if (ret < 0)
+		return ret;
+
+	ctx->enabled = false;
+
+	return 0;
+}

If ctx->enable is dropped then this function becomes:

Quoted 26 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +23 -0

+static int jh057n_disable(struct drm_panel *panel)
+{
+	struct jh057n *ctx = panel_to_jh057n(panel);
+
+	backlight_disable(ctx->backlight);
+
+	return 0;
+}
 
 
 
+static const struct drm_display_mode default_mode = {
+	.hdisplay    = 720,
+	.hsync_start = 720 + 90,
+	.hsync_end   = 720 + 90 + 20,
+	.htotal	     = 720 + 90 + 20 + 20,
+	.vdisplay    = 1440,
+	.vsync_start = 1440 + 20,
+	.vsync_end   = 1440 + 20 + 4,
+	.vtotal	     = 1440 + 20 + 4 + 12,
+	.vrefresh    = 60,
+	.clock	     = 75276,
+	.flags	     = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.width_mm    = 65,
+	.height_mm   = 130,
+};

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 229

Quoted 10 lines

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

+
+static int jh057n_get_modes(struct drm_panel *panel)
+{
+	struct drm_display_mode *mode;
+	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+	int ret;
+
+	mode = drm_mode_duplicate(panel->drm, &default_mode);
+	if (!mode) {
+		DRM_ERROR("Failed to add mode %ux%ux@%u",

Should this be?

Review

Quoted 1 line

(quoted diff) +1 -0

+		DRM_ERROR("Failed to add mode %ux%u@%u",

(Note the second 'x' was dropped.

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 241

Quoted 12 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +12 -0

+			  default_mode.hdisplay, default_mode.vdisplay,
+			  default_mode.vrefresh);
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	panel->connector->display_info.width_mm = mode->width_mm;
+	panel->connector->display_info.height_mm = mode->height_mm;
+	ret = drm_display_info_set_bus_formats(&panel->connector->display_info,
+					       &bus_format, 1);

It is my understanding that for spi controlled displays there is no need to set the bus_format.

Quoted 7 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +7 -0

+	if (ret)
+		return ret;
+
+	drm_mode_probed_add(panel->connector, mode);
+
+	return 1;
+}

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 265

Quoted 10 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +9 -0

+
 
+static int allpixelson_set(void *data, u64 val)
+{
+	struct jh057n *ctx = data;
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Setting all pixels on");
+	dsi_generic_write_seq(dsi, ST7703_CMD_ALL_PIXEL_ON);
+	msleep(val*1000);

If this is kept, then add spaces around operator '*'

Quoted 77 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +77 -0

+	/* Reset the panel to get video back */
+	drm_panel_disable(&ctx->panel);
+	drm_panel_unprepare(&ctx->panel);
+	drm_panel_prepare(&ctx->panel);
+	drm_panel_enable(&ctx->panel);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(allpixelson_fops, NULL,
+			allpixelson_set, "%llu\n");
+
+static int jh057n_debugfs_init(struct jh057n *ctx)
+{
+	struct dentry *f;
+
+	ctx->debugfs = debugfs_create_dir(DRV_NAME, NULL);
+	if (!ctx->debugfs)
+		return -ENOMEM;
+
+	f = debugfs_create_file("allpixelson", 0600,
+				ctx->debugfs, ctx, &allpixelson_fops);
+	if (!f)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void jh057n_debugfs_remove(struct jh057n *ctx)
+{
+	debugfs_remove_recursive(ctx->debugfs);
+	ctx->debugfs = NULL;
+}
+
+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);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed. Is host ready?");
+		drm_panel_remove(&ctx->panel);
+		goto err;
+	}
+
+	DRM_INFO(DRV_NAME "_panel %ux%u@%u %ubpp dsi %udl - ready",

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 352

Quoted 10 lines

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

+		 default_mode.hdisplay, default_mode.vdisplay,
+		 default_mode.vrefresh,
+		 mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
+
+	jh057n_debugfs_init(ctx);
+	return 0;
+
+err:
+	if (ctx->backlight)
+		put_device(&ctx->backlight->dev);

No need for this check, it is handled by the devm_ infrastructure

Quoted 26 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +26 -0

+	return ret;
+
+}
+
+static void jh057n_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct jh057n *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = jh057n_unprepare(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to unprepare panel: %d\n",
+			      ret);
+
+	ret = jh057n_disable(&ctx->panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to disable panel: %d\n",
+			      ret);
+}
+
+static int jh057n_remove(struct mipi_dsi_device *dsi)
+{
+	struct jh057n *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	jh057n_shutdown(dsi);

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 388

Quoted 10 lines

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

+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		DRM_DEV_ERROR(&dsi->dev, "Failed to detach from DSI host: %d\n",
+			      ret);
+
+	drm_panel_remove(&ctx->panel);
+
+	if (ctx->backlight)
+		put_device(&ctx->backlight->dev);

No need for this check, it is handled by the devm_ infrastructure

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 397

Quoted 9 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +9 -0

+
+	jh057n_debugfs_remove(ctx);
+
+	return 0;
+}
+
+static const struct of_device_id jh057n_of_match[] = {
+	{ .compatible = "rocktech,jh057n00900" },
+	{ }

Consider replacing { } with

	{ /* Sentinel */ }

This is how it looks in many other drivers.

Quoted 7 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c new file +7 -0

+};
+MODULE_DEVICE_TABLE(of, jh057n_of_match);
+
+static struct mipi_dsi_driver jh057n_driver = {
+	.probe	= jh057n_probe,
+	.remove = jh057n_remove,
+	.shutdown = jh057n_shutdown,

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c line 414

Quoted 10 lines

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

+	.driver = {
+		.name = DRV_NAME "_panel",
+		.of_match_table = jh057n_of_match,
+	},
+};
+module_mipi_dsi_driver(jh057n_driver);
+
+MODULE_AUTHOR("Guido Günther <[email protected]>");
+MODULE_DESCRIPTION("DRM driver for Rocktech JH057N00900 MIPI DSI panel");
+MODULE_LICENSE("GPL v2");

SPDX says this:

Quoted 1 line

+// SPDX-License-Identifier: GPL-2.0+

As far as I can tell this is not the same license.