From: Kamil Trzciński <ayufan@ayufan.eu>

The driver is for panels based on the Himax HX8394 controller, such as the
HannStar HSD060BHW4 720x1440 TFT LCD panel that uses a MIPI-DSI interface.

Signed-off-by: Kamil Trzciński <ayufan@ayufan.eu>
Co-developed-by: Ondrej Jirman <megi@xff.cz>
Signed-off-by: Ondrej Jirman <megi@xff.cz>
Co-developed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

 drivers/gpu/drm/panel/Kconfig              |  12 +
 drivers/gpu/drm/panel/Makefile             |   1 +
 drivers/gpu/drm/panel/panel-himax-hx8394.c | 460 +++++++++++++++++++++
 3 files changed, 473 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-himax-hx8394.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 737edcdf9eef..7ee9c83f09a7 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -154,6 +154,18 @@ config DRM_PANEL_FEIYANG_FY07024DI26A30D
 	  Say Y if you want to enable support for panels based on the
 	  Feiyang FY07024DI26A30-D MIPI-DSI interface.
 
+config DRM_PANEL_HIMAX_HX8394
+	tristate "HIMAX HX8394 MIPI-DSI LCD panels"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y if you want to enable support for panels based on the
+	  Himax HX8394 controller, such as the HannStar HSD060BHW4
+	  720x1440 TFT LCD panel that uses a MIPI-DSI interface.
+
+	  If M is selected the module will be called panel-himax-hx8394.
+
 config DRM_PANEL_ILITEK_IL9322
 	tristate "Ilitek ILI9322 320x240 QVGA panels"
 	depends on OF && SPI
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index f8f9d9f6a307..84c01adafd4c 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_DRM_PANEL_EBBG_FT8719) += panel-ebbg-ft8719.o
 obj-$(CONFIG_DRM_PANEL_ELIDA_KD35T133) += panel-elida-kd35t133.o
 obj-$(CONFIG_DRM_PANEL_FEIXIN_K101_IM2BA02) += panel-feixin-k101-im2ba02.o
 obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) += panel-feiyang-fy07024di26a30d.o
+obj-$(CONFIG_DRM_PANEL_HIMAX_HX8394) += panel-himax-hx8394.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
diff --git a/drivers/gpu/drm/panel/panel-himax-hx8394.c b/drivers/gpu/drm/panel/panel-himax-hx8394.c
new file mode 100644
index 000000000000..b22eec0674b5
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-himax-hx8394.c
@@ -0,0 +1,460 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for panels based on Himax HX8394 controller, such as:
+ *
+ * - HannStar HSD060BHW4 5.99" MIPI-DSI panel
+ *
+ * Copyright (C) Kamil Trzciński
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/display_timing.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+#define DRV_NAME "panel-himax-hx8394"
+
+/* Manufacturer specific commands sent via DSI, listed in HX8394-F datasheet */
+#define HX8394_CMD_SETSEQUENCE	  0xb0
+#define HX8394_CMD_SETPOWER	  0xb1
+#define HX8394_CMD_SETDISP	  0xb2
+#define HX8394_CMD_SETCYC	  0xb4
+#define HX8394_CMD_SETVCOM	  0xb6
+#define HX8394_CMD_SETTE	  0xb7
+#define HX8394_CMD_SETSENSOR	  0xb8
+#define HX8394_CMD_SETEXTC	  0xb9
+#define HX8394_CMD_SETMIPI	  0xba
+#define HX8394_CMD_SETOTP	  0xbb
+#define HX8394_CMD_SETREGBANK	  0xbd
+#define HX8394_CMD_UNKNOWN1	  0xc0
+#define HX8394_CMD_SETDGCLUT	  0xc1
+#define HX8394_CMD_SETID	  0xc3
+#define HX8394_CMD_SETDDB	  0xc4
+#define HX8394_CMD_UNKNOWN2	  0xc6
+#define HX8394_CMD_SETCABC	  0xc9
+#define HX8394_CMD_SETCABCGAIN	  0xca
+#define HX8394_CMD_SETPANEL	  0xcc
+#define HX8394_CMD_SETOFFSET	  0xd2
+#define HX8394_CMD_SETGIP0	  0xd3
+#define HX8394_CMD_UNKNOWN3	  0xd4
+#define HX8394_CMD_SETGIP1	  0xd5
+#define HX8394_CMD_SETGIP2	  0xd6
+#define HX8394_CMD_SETGPO	  0xd6
+#define HX8394_CMD_SETSCALING	  0xdd
+#define HX8394_CMD_SETIDLE	  0xdf
+#define HX8394_CMD_SETGAMMA	  0xe0
+#define HX8394_CMD_SETCHEMODE_DYN 0xe4
+#define HX8394_CMD_SETCHE	  0xe5
+#define HX8394_CMD_SETCESEL	  0xe6
+#define HX8394_CMD_SET_SP_CMD	  0xe9
+#define HX8394_CMD_SETREADINDEX	  0xfe
+#define HX8394_CMD_GETSPIREAD	  0xff
+
+struct hx8394 {
+	struct device *dev;
+	struct drm_panel panel;
+	struct gpio_desc *reset_gpio;
+	struct regulator *vcc;
+	struct regulator *iovcc;
+	bool prepared;
+
+	const struct hx8394_panel_desc *desc;
+};
+
+struct hx8394_panel_desc {
+	const struct drm_display_mode *mode;
+	unsigned int lanes;
+	unsigned long mode_flags;
+	enum mipi_dsi_pixel_format format;
+	int (*init_sequence)(struct hx8394 *ctx);
+};
+
+static inline struct hx8394 *panel_to_hx8394(struct drm_panel *panel)
+{
+	return container_of(panel, struct hx8394, panel);
+}
+
+#define dsi_dcs_write_seq(dsi, cmd, seq...) do {			\
+		static const u8 d[] = { seq };				\
+		int ret;						\
+		ret = mipi_dsi_dcs_write(dsi, cmd, d, ARRAY_SIZE(d));	\
+		if (ret < 0)						\
+			return ret;					\
+	} while (0)
+
+static int hsd060bhw4_init_sequence(struct hx8394 *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+
+	/* 5.19.8 SETEXTC: Set extension command (B9h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETEXTC,
+			  0xff, 0x83, 0x94);
+
+	/* 5.19.2 SETPOWER: Set power (B1h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETPOWER,
+			  0x48, 0x11, 0x71, 0x09, 0x32, 0x24, 0x71, 0x31, 0x55, 0x30);
+
+	/* 5.19.9 SETMIPI: Set MIPI control (BAh) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETMIPI,
+			  0x63, 0x03, 0x68, 0x6b, 0xb2, 0xc0);
+
+	/* 5.19.3 SETDISP: Set display related register (B2h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETDISP,
+			  0x00, 0x80, 0x78, 0x0c, 0x07);
+
+	/* 5.19.4 SETCYC: Set display waveform cycles (B4h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETCYC,
+			  0x12, 0x63, 0x12, 0x63, 0x12, 0x63, 0x01, 0x0c, 0x7c, 0x55,
+			  0x00, 0x3f, 0x12, 0x6b, 0x12, 0x6b, 0x12, 0x6b, 0x01, 0x0c,
+			  0x7c);
+
+	/* 5.19.19 SETGIP0: Set GIP Option0 (D3h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGIP0,
+			  0x00, 0x00, 0x00, 0x00, 0x3c, 0x1c, 0x00, 0x00, 0x32, 0x10,
+			  0x09, 0x00, 0x09, 0x32, 0x15, 0xad, 0x05, 0xad, 0x32, 0x00,
+			  0x00, 0x00, 0x00, 0x37, 0x03, 0x0b, 0x0b, 0x37, 0x00, 0x00,
+			  0x00, 0x0c, 0x40);
+
+	/* 5.19.20 Set GIP Option1 (D5h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGIP1,
+			  0x19, 0x19, 0x18, 0x18, 0x1b, 0x1b, 0x1a, 0x1a, 0x00, 0x01,
+			  0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x20, 0x21, 0x18, 0x18,
+			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
+			  0x24, 0x25, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
+			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18);
+
+	/* 5.19.21 Set GIP Option2 (D6h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGIP2,
+			  0x18, 0x18, 0x19, 0x19, 0x1b, 0x1b, 0x1a, 0x1a, 0x07, 0x06,
+			  0x05, 0x04, 0x03, 0x02, 0x01, 0x00, 0x25, 0x24, 0x18, 0x18,
+			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
+			  0x21, 0x20, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
+			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18);
+
+	/* 5.19.25 SETGAMMA: Set gamma curve related setting (E0h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGAMMA,
+			  0x00, 0x04, 0x0c, 0x12, 0x14, 0x18, 0x1a, 0x18, 0x31, 0x3f,
+			  0x4d, 0x4c, 0x54, 0x65, 0x6b, 0x70, 0x7f, 0x82, 0x7e, 0x8a,
+			  0x99, 0x4a, 0x48, 0x49, 0x4b, 0x4a, 0x4c, 0x4b, 0x7f, 0x00,
+			  0x04, 0x0c, 0x11, 0x13, 0x17, 0x1a, 0x18, 0x31,
+			  0x3f, 0x4d, 0x4c, 0x54, 0x65, 0x6b, 0x70, 0x7f,
+			  0x82, 0x7e, 0x8a, 0x99, 0x4a, 0x48, 0x49, 0x4b,
+			  0x4a, 0x4c, 0x4b, 0x7f);
+
+	/* 5.19.17 SETPANEL (CCh) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETPANEL, 0x0b);
+
+	/* Unknown command, not listed in the HX8394-F datasheet */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_UNKNOWN1, 0x1f, 0x31);
+
+	/* 5.19.5 SETVCOM: Set VCOM voltage (B6h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETVCOM,
+			  0x7d, 0x7d);
+
+	/* Unknown command, not listed in the HX8394-F datasheet */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_UNKNOWN3,
+			  0x02);
+
+	/* 5.19.11 Set register bank (BDh) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETREGBANK, 0x01);
+
+	/* 5.19.2 SETPOWER: Set power (B1h) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETPOWER, 0x00);
+
+	/* 5.19.11 Set register bank (BDh) */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_SETREGBANK, 0x00);
+
+	/* Unknown command, not listed in the HX8394-F datasheet */
+	dsi_dcs_write_seq(dsi, HX8394_CMD_UNKNOWN3,
+			  0xed);
+
+	return 0;
+}
+
+static const struct drm_display_mode hsd060bhw4_mode = {
+	.hdisplay    = 720,
+	.hsync_start = 720 + 40,
+	.hsync_end   = 720 + 40 + 46,
+	.htotal	     = 720 + 40 + 46 + 40,
+	.vdisplay    = 1440,
+	.vsync_start = 1440 + 9,
+	.vsync_end   = 1440 + 9 + 7,
+	.vtotal	     = 1440 + 9 + 7 + 7,
+	.clock	     = 74250,
+	.flags	     = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.width_mm    = 68,
+	.height_mm   = 136,
+};
+
+static const struct hx8394_panel_desc hsd060bhw4_desc = {
+	.mode = &hsd060bhw4_mode,
+	.lanes = 4,
+	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST,
+	.format = MIPI_DSI_FMT_RGB888,
+	.init_sequence = hsd060bhw4_init_sequence,
+};
+
+static int hx8394_enable(struct drm_panel *panel)
+{
+	struct hx8394 *ctx = panel_to_hx8394(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	dev_info(ctx->dev, "enable\n");
+
+	ret = ctx->desc->init_sequence(ctx);
+	if (ret) {
+		dev_err(ctx->dev, "Panel init sequence failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret) {
+		dev_err(ctx->dev, "Failed to exit sleep mode: %d\n", ret);
+		return ret;
+	}
+
+	/* Panel is operational 120 msec after reset */
+	msleep(120);
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret) {
+		dev_err(ctx->dev, "Failed to turn on the display: %d\n", ret);
+		goto sleep_in;
+	}
+
+	return 0;
+
+sleep_in:
+	/* This will probably fail, but let's try orderly power off anyway. */
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (!ret)
+		msleep(50);
+
+	return ret;
+}
+
+static int hx8394_disable(struct drm_panel *panel)
+{
+	struct hx8394 *ctx = panel_to_hx8394(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	dev_info(ctx->dev, "disable\n");
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret) {
+		dev_err(ctx->dev, "Failed to enter sleep mode: %d\n", ret);
+		return ret;
+	}
+
+	msleep(50); /* about 3 frames */
+
+	return 0;
+}
+
+static int hx8394_unprepare(struct drm_panel *panel)
+{
+	struct hx8394 *ctx = panel_to_hx8394(panel);
+
+	if (!ctx->prepared)
+		return 0;
+
+	dev_info(ctx->dev, "unprepare\n");
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+	regulator_disable(ctx->iovcc);
+	regulator_disable(ctx->vcc);
+
+	ctx->prepared = false;
+
+	return 0;
+}
+
+static int hx8394_prepare(struct drm_panel *panel)
+{
+	struct hx8394 *ctx = panel_to_hx8394(panel);
+	int ret;
+
+	if (ctx->prepared)
+		return 0;
+
+	dev_info(ctx->dev, "prepare\n");
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+	ret = regulator_enable(ctx->vcc);
+	if (ret) {
+		dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
+		return ret;
+	}
+
+	ret = regulator_enable(ctx->iovcc);
+	if (ret) {
+		dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
+		goto disable_vcc;
+	}
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+
+	msleep(180);
+
+	ctx->prepared = true;
+
+	return 0;
+
+disable_vcc:
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	regulator_disable(ctx->vcc);
+	return ret;
+}
+
+static int hx8394_get_modes(struct drm_panel *panel,
+			    struct drm_connector *connector)
+{
+	struct hx8394 *ctx = panel_to_hx8394(panel);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, ctx->desc->mode);
+	if (!mode) {
+		dev_err(ctx->dev, "Failed to add mode %ux%u@%u\n",
+			ctx->desc->mode->hdisplay, ctx->desc->mode->vdisplay,
+			drm_mode_vrefresh(ctx->desc->mode));
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	connector->display_info.width_mm = mode->width_mm;
+	connector->display_info.height_mm = mode->height_mm;
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_panel_funcs hx8394_drm_funcs = {
+	.disable   = hx8394_disable,
+	.unprepare = hx8394_unprepare,
+	.prepare   = hx8394_prepare,
+	.enable	   = hx8394_enable,
+	.get_modes = hx8394_get_modes,
+};
+
+static int hx8394_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct hx8394 *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_HIGH);
+	if (IS_ERR(ctx->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+				     "Failed to get reset gpio\n");
+
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	ctx->dev = dev;
+	ctx->desc = of_device_get_match_data(dev);
+
+	dsi->mode_flags = ctx->desc->mode_flags;
+	dsi->format = ctx->desc->format;
+	dsi->lanes = ctx->desc->lanes;
+
+	ctx->vcc = devm_regulator_get(dev, "vcc");
+	if (IS_ERR(ctx->vcc))
+		return dev_err_probe(dev, PTR_ERR(ctx->vcc),
+				     "Failed to request vcc regulator\n");
+
+	ctx->iovcc = devm_regulator_get(dev, "iovcc");
+	if (IS_ERR(ctx->iovcc))
+		return dev_err_probe(dev, PTR_ERR(ctx->iovcc),
+				     "Failed to request iovcc regulator\n");
+
+	drm_panel_init(&ctx->panel, dev, &hx8394_drm_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret)
+		return ret;
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		dev_err_probe(dev, ret, "mipi_dsi_attach failed\n");
+		drm_panel_remove(&ctx->panel);
+		return ret;
+	}
+
+	dev_info(dev, "%ux%u@%u %ubpp dsi %udl - ready\n",
+		 ctx->desc->mode->hdisplay, ctx->desc->mode->vdisplay,
+		 drm_mode_vrefresh(ctx->desc->mode),
+		 mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
+
+	return 0;
+}
+
+static void hx8394_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct hx8394 *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = drm_panel_disable(&ctx->panel);
+	if (ret < 0)
+		dev_err(&dsi->dev, "Failed to disable panel: %d\n", ret);
+
+	ret = drm_panel_unprepare(&ctx->panel);
+	if (ret < 0)
+		dev_err(&dsi->dev, "Failed to unprepare panel: %d\n", ret);
+}
+
+static void hx8394_remove(struct mipi_dsi_device *dsi)
+{
+	struct hx8394 *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	hx8394_shutdown(dsi);
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
+
+	drm_panel_remove(&ctx->panel);
+}
+
+static const struct of_device_id hx8394_of_match[] = {
+	{ .compatible = "hannstar,hsd060bhw4", .data = &hsd060bhw4_desc },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, hx8394_of_match);
+
+static struct mipi_dsi_driver hx8394_driver = {
+	.probe	= hx8394_probe,
+	.remove = hx8394_remove,
+	.shutdown = hx8394_shutdown,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = hx8394_of_match,
+	},
+};
+module_mipi_dsi_driver(hx8394_driver);
+
+MODULE_AUTHOR("Kamil Trzciński <ayufan@ayufan.eu>");
+MODULE_DESCRIPTION("DRM driver for Himax HX8394 based MIPI DSI panels");
+MODULE_LICENSE("GPL");
-- 
2.38.1

Hi Javier.

On Thu, Dec 22, 2022 at 11:38:27PM +0100, Javier Martinez Canillas wrote:
> From: Kamil Trzciński <ayufan@ayufan.eu>
> 
> The driver is for panels based on the Himax HX8394 controller, such as the
> HannStar HSD060BHW4 720x1440 TFT LCD panel that uses a MIPI-DSI interface.

A few comments/nitpicks in the following.
I have been away for a while, and paged out most of my panel knowledge,
so read it all with that in mind.

In general - very nicely written driver.

	Sam

> 
> Signed-off-by: Kamil Trzciński <ayufan@ayufan.eu>
> Co-developed-by: Ondrej Jirman <megi@xff.cz>
> Signed-off-by: Ondrej Jirman <megi@xff.cz>
> Co-developed-by: Javier Martinez Canillas <javierm@redhat.com>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
> 
>  drivers/gpu/drm/panel/Kconfig              |  12 +
>  drivers/gpu/drm/panel/Makefile             |   1 +
>  drivers/gpu/drm/panel/panel-himax-hx8394.c | 460 +++++++++++++++++++++
>  3 files changed, 473 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-himax-hx8394.c
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 737edcdf9eef..7ee9c83f09a7 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -154,6 +154,18 @@ config DRM_PANEL_FEIYANG_FY07024DI26A30D
>  	  Say Y if you want to enable support for panels based on the
>  	  Feiyang FY07024DI26A30-D MIPI-DSI interface.
>  
> +config DRM_PANEL_HIMAX_HX8394
> +	tristate "HIMAX HX8394 MIPI-DSI LCD panels"
> +	depends on OF
> +	depends on DRM_MIPI_DSI
> +	depends on BACKLIGHT_CLASS_DEVICE
> +	help
> +	  Say Y if you want to enable support for panels based on the
> +	  Himax HX8394 controller, such as the HannStar HSD060BHW4
> +	  720x1440 TFT LCD panel that uses a MIPI-DSI interface.
> +
> +	  If M is selected the module will be called panel-himax-hx8394.
> +
>  config DRM_PANEL_ILITEK_IL9322
>  	tristate "Ilitek ILI9322 320x240 QVGA panels"
>  	depends on OF && SPI
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index f8f9d9f6a307..84c01adafd4c 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_DRM_PANEL_EBBG_FT8719) += panel-ebbg-ft8719.o
>  obj-$(CONFIG_DRM_PANEL_ELIDA_KD35T133) += panel-elida-kd35t133.o
>  obj-$(CONFIG_DRM_PANEL_FEIXIN_K101_IM2BA02) += panel-feixin-k101-im2ba02.o
>  obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) += panel-feiyang-fy07024di26a30d.o
> +obj-$(CONFIG_DRM_PANEL_HIMAX_HX8394) += panel-himax-hx8394.o
>  obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
>  obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
>  obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
> diff --git a/drivers/gpu/drm/panel/panel-himax-hx8394.c b/drivers/gpu/drm/panel/panel-himax-hx8394.c
> new file mode 100644
> index 000000000000..b22eec0674b5
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-himax-hx8394.c
> @@ -0,0 +1,460 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for panels based on Himax HX8394 controller, such as:
> + *
> + * - HannStar HSD060BHW4 5.99" MIPI-DSI panel
> + *
> + * Copyright (C) Kamil Trzciński
Needs year

> + */
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/media-bus-format.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regulator/consumer.h>
> +

> +#include <video/display_timing.h>
I do not think this include is used.

> +#include <video/mipi_display.h>
> +
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +
> +#define DRV_NAME "panel-himax-hx8394"
> +
> +/* Manufacturer specific commands sent via DSI, listed in HX8394-F datasheet */
> +#define HX8394_CMD_SETSEQUENCE	  0xb0
> +#define HX8394_CMD_SETPOWER	  0xb1
> +#define HX8394_CMD_SETDISP	  0xb2
> +#define HX8394_CMD_SETCYC	  0xb4
> +#define HX8394_CMD_SETVCOM	  0xb6
> +#define HX8394_CMD_SETTE	  0xb7
> +#define HX8394_CMD_SETSENSOR	  0xb8
> +#define HX8394_CMD_SETEXTC	  0xb9
> +#define HX8394_CMD_SETMIPI	  0xba
> +#define HX8394_CMD_SETOTP	  0xbb
> +#define HX8394_CMD_SETREGBANK	  0xbd
> +#define HX8394_CMD_UNKNOWN1	  0xc0
> +#define HX8394_CMD_SETDGCLUT	  0xc1
> +#define HX8394_CMD_SETID	  0xc3
> +#define HX8394_CMD_SETDDB	  0xc4
> +#define HX8394_CMD_UNKNOWN2	  0xc6
> +#define HX8394_CMD_SETCABC	  0xc9
> +#define HX8394_CMD_SETCABCGAIN	  0xca
> +#define HX8394_CMD_SETPANEL	  0xcc
> +#define HX8394_CMD_SETOFFSET	  0xd2
> +#define HX8394_CMD_SETGIP0	  0xd3
> +#define HX8394_CMD_UNKNOWN3	  0xd4
> +#define HX8394_CMD_SETGIP1	  0xd5
> +#define HX8394_CMD_SETGIP2	  0xd6
> +#define HX8394_CMD_SETGPO	  0xd6
> +#define HX8394_CMD_SETSCALING	  0xdd
> +#define HX8394_CMD_SETIDLE	  0xdf
> +#define HX8394_CMD_SETGAMMA	  0xe0
> +#define HX8394_CMD_SETCHEMODE_DYN 0xe4
> +#define HX8394_CMD_SETCHE	  0xe5
> +#define HX8394_CMD_SETCESEL	  0xe6
> +#define HX8394_CMD_SET_SP_CMD	  0xe9
> +#define HX8394_CMD_SETREADINDEX	  0xfe
> +#define HX8394_CMD_GETSPIREAD	  0xff
> +
> +struct hx8394 {
> +	struct device *dev;
> +	struct drm_panel panel;
> +	struct gpio_desc *reset_gpio;
> +	struct regulator *vcc;
> +	struct regulator *iovcc;
> +	bool prepared;
> +
> +	const struct hx8394_panel_desc *desc;
> +};
> +
> +struct hx8394_panel_desc {
> +	const struct drm_display_mode *mode;
> +	unsigned int lanes;
> +	unsigned long mode_flags;
> +	enum mipi_dsi_pixel_format format;
> +	int (*init_sequence)(struct hx8394 *ctx);
> +};
> +
> +static inline struct hx8394 *panel_to_hx8394(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct hx8394, panel);
> +}
> +
> +#define dsi_dcs_write_seq(dsi, cmd, seq...) do {			\
> +		static const u8 d[] = { seq };				\
> +		int ret;						\
> +		ret = mipi_dsi_dcs_write(dsi, cmd, d, ARRAY_SIZE(d));	\
> +		if (ret < 0)						\
> +			return ret;					\
> +	} while (0)
Use mipi_dsi_dcs_write_seq()

> +
> +static int hsd060bhw4_init_sequence(struct hx8394 *ctx)
> +{
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +
> +	/* 5.19.8 SETEXTC: Set extension command (B9h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETEXTC,
> +			  0xff, 0x83, 0x94);
> +
> +	/* 5.19.2 SETPOWER: Set power (B1h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETPOWER,
> +			  0x48, 0x11, 0x71, 0x09, 0x32, 0x24, 0x71, 0x31, 0x55, 0x30);
> +
> +	/* 5.19.9 SETMIPI: Set MIPI control (BAh) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETMIPI,
> +			  0x63, 0x03, 0x68, 0x6b, 0xb2, 0xc0);
> +
> +	/* 5.19.3 SETDISP: Set display related register (B2h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETDISP,
> +			  0x00, 0x80, 0x78, 0x0c, 0x07);
> +
> +	/* 5.19.4 SETCYC: Set display waveform cycles (B4h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETCYC,
> +			  0x12, 0x63, 0x12, 0x63, 0x12, 0x63, 0x01, 0x0c, 0x7c, 0x55,
> +			  0x00, 0x3f, 0x12, 0x6b, 0x12, 0x6b, 0x12, 0x6b, 0x01, 0x0c,
> +			  0x7c);
> +
> +	/* 5.19.19 SETGIP0: Set GIP Option0 (D3h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGIP0,
> +			  0x00, 0x00, 0x00, 0x00, 0x3c, 0x1c, 0x00, 0x00, 0x32, 0x10,
> +			  0x09, 0x00, 0x09, 0x32, 0x15, 0xad, 0x05, 0xad, 0x32, 0x00,
> +			  0x00, 0x00, 0x00, 0x37, 0x03, 0x0b, 0x0b, 0x37, 0x00, 0x00,
> +			  0x00, 0x0c, 0x40);
> +
> +	/* 5.19.20 Set GIP Option1 (D5h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGIP1,
> +			  0x19, 0x19, 0x18, 0x18, 0x1b, 0x1b, 0x1a, 0x1a, 0x00, 0x01,
> +			  0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x20, 0x21, 0x18, 0x18,
> +			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
> +			  0x24, 0x25, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
> +			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18);
> +
> +	/* 5.19.21 Set GIP Option2 (D6h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGIP2,
> +			  0x18, 0x18, 0x19, 0x19, 0x1b, 0x1b, 0x1a, 0x1a, 0x07, 0x06,
> +			  0x05, 0x04, 0x03, 0x02, 0x01, 0x00, 0x25, 0x24, 0x18, 0x18,
> +			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
> +			  0x21, 0x20, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
> +			  0x18, 0x18, 0x18, 0x18, 0x18, 0x18);
> +
> +	/* 5.19.25 SETGAMMA: Set gamma curve related setting (E0h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETGAMMA,
> +			  0x00, 0x04, 0x0c, 0x12, 0x14, 0x18, 0x1a, 0x18, 0x31, 0x3f,
> +			  0x4d, 0x4c, 0x54, 0x65, 0x6b, 0x70, 0x7f, 0x82, 0x7e, 0x8a,
> +			  0x99, 0x4a, 0x48, 0x49, 0x4b, 0x4a, 0x4c, 0x4b, 0x7f, 0x00,
> +			  0x04, 0x0c, 0x11, 0x13, 0x17, 0x1a, 0x18, 0x31,
> +			  0x3f, 0x4d, 0x4c, 0x54, 0x65, 0x6b, 0x70, 0x7f,
> +			  0x82, 0x7e, 0x8a, 0x99, 0x4a, 0x48, 0x49, 0x4b,
> +			  0x4a, 0x4c, 0x4b, 0x7f);
> +
> +	/* 5.19.17 SETPANEL (CCh) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETPANEL, 0x0b);
> +
> +	/* Unknown command, not listed in the HX8394-F datasheet */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_UNKNOWN1, 0x1f, 0x31);
> +
> +	/* 5.19.5 SETVCOM: Set VCOM voltage (B6h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETVCOM,
> +			  0x7d, 0x7d);
> +
> +	/* Unknown command, not listed in the HX8394-F datasheet */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_UNKNOWN3,
> +			  0x02);
> +
> +	/* 5.19.11 Set register bank (BDh) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETREGBANK, 0x01);
> +
> +	/* 5.19.2 SETPOWER: Set power (B1h) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETPOWER, 0x00);
> +
> +	/* 5.19.11 Set register bank (BDh) */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_SETREGBANK, 0x00);
> +
> +	/* Unknown command, not listed in the HX8394-F datasheet */
> +	dsi_dcs_write_seq(dsi, HX8394_CMD_UNKNOWN3,
> +			  0xed);
> +
> +	return 0;
> +}
> +
> +static const struct drm_display_mode hsd060bhw4_mode = {
> +	.hdisplay    = 720,
> +	.hsync_start = 720 + 40,
> +	.hsync_end   = 720 + 40 + 46,
> +	.htotal	     = 720 + 40 + 46 + 40,
> +	.vdisplay    = 1440,
> +	.vsync_start = 1440 + 9,
> +	.vsync_end   = 1440 + 9 + 7,
> +	.vtotal	     = 1440 + 9 + 7 + 7,
> +	.clock	     = 74250,
> +	.flags	     = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
> +	.width_mm    = 68,
> +	.height_mm   = 136,
> +};
> +
> +static const struct hx8394_panel_desc hsd060bhw4_desc = {
> +	.mode = &hsd060bhw4_mode,
> +	.lanes = 4,
> +	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST,
> +	.format = MIPI_DSI_FMT_RGB888,
> +	.init_sequence = hsd060bhw4_init_sequence,
> +};
> +
> +static int hx8394_enable(struct drm_panel *panel)
> +{
> +	struct hx8394 *ctx = panel_to_hx8394(panel);
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +	int ret;
> +
> +	dev_info(ctx->dev, "enable\n");
Drop this - or at least move to debug level
> +
> +	ret = ctx->desc->init_sequence(ctx);
> +	if (ret) {
> +		dev_err(ctx->dev, "Panel init sequence failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
> +	if (ret) {
> +		dev_err(ctx->dev, "Failed to exit sleep mode: %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Panel is operational 120 msec after reset */
> +	msleep(120);
> +
> +	ret = mipi_dsi_dcs_set_display_on(dsi);
> +	if (ret) {
> +		dev_err(ctx->dev, "Failed to turn on the display: %d\n", ret);
> +		goto sleep_in;
> +	}
> +
> +	return 0;
> +
> +sleep_in:
> +	/* This will probably fail, but let's try orderly power off anyway. */
> +	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
> +	if (!ret)
> +		msleep(50);
> +
> +	return ret;
> +}
> +
> +static int hx8394_disable(struct drm_panel *panel)
> +{
> +	struct hx8394 *ctx = panel_to_hx8394(panel);
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +	int ret;
> +
> +	dev_info(ctx->dev, "disable\n");
debug

> +
> +	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
> +	if (ret) {
> +		dev_err(ctx->dev, "Failed to enter sleep mode: %d\n", ret);
> +		return ret;
> +	}
> +
> +	msleep(50); /* about 3 frames */
> +
> +	return 0;
> +}
> +
> +static int hx8394_unprepare(struct drm_panel *panel)
> +{
> +	struct hx8394 *ctx = panel_to_hx8394(panel);
> +
> +	if (!ctx->prepared)
> +		return 0;
> +
> +	dev_info(ctx->dev, "unprepare\n");
debug

> +
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +
> +	regulator_disable(ctx->iovcc);
> +	regulator_disable(ctx->vcc);
> +
> +	ctx->prepared = false;
> +
> +	return 0;
> +}
> +
> +static int hx8394_prepare(struct drm_panel *panel)
> +{
> +	struct hx8394 *ctx = panel_to_hx8394(panel);
> +	int ret;
> +
> +	if (ctx->prepared)
> +		return 0;
> +
> +	dev_info(ctx->dev, "prepare\n");
debug
> +
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +
> +	ret = regulator_enable(ctx->vcc);
> +	if (ret) {
> +		dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = regulator_enable(ctx->iovcc);
> +	if (ret) {
> +		dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
> +		goto disable_vcc;
> +	}
> +
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +
> +	msleep(180);
> +
> +	ctx->prepared = true;
> +
> +	return 0;
> +
> +disable_vcc:
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +	regulator_disable(ctx->vcc);
> +	return ret;
> +}
> +
> +static int hx8394_get_modes(struct drm_panel *panel,
> +			    struct drm_connector *connector)
> +{
> +	struct hx8394 *ctx = panel_to_hx8394(panel);
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(connector->dev, ctx->desc->mode);
> +	if (!mode) {
> +		dev_err(ctx->dev, "Failed to add mode %ux%u@%u\n",
> +			ctx->desc->mode->hdisplay, ctx->desc->mode->vdisplay,
> +			drm_mode_vrefresh(ctx->desc->mode));
> +		return -ENOMEM;
> +	}
> +
> +	drm_mode_set_name(mode);
> +
> +	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> +	connector->display_info.width_mm = mode->width_mm;
> +	connector->display_info.height_mm = mode->height_mm;
> +	drm_mode_probed_add(connector, mode);
> +
> +	return 1;
> +}
> +
> +static const struct drm_panel_funcs hx8394_drm_funcs = {
> +	.disable   = hx8394_disable,
> +	.unprepare = hx8394_unprepare,
> +	.prepare   = hx8394_prepare,
> +	.enable	   = hx8394_enable,
> +	.get_modes = hx8394_get_modes,
> +};
> +
> +static int hx8394_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct device *dev = &dsi->dev;
> +	struct hx8394 *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_HIGH);
> +	if (IS_ERR(ctx->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
> +				     "Failed to get reset gpio\n");
> +
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	ctx->dev = dev;
> +	ctx->desc = of_device_get_match_data(dev);
> +
> +	dsi->mode_flags = ctx->desc->mode_flags;
> +	dsi->format = ctx->desc->format;
> +	dsi->lanes = ctx->desc->lanes;
> +
> +	ctx->vcc = devm_regulator_get(dev, "vcc");
> +	if (IS_ERR(ctx->vcc))
> +		return dev_err_probe(dev, PTR_ERR(ctx->vcc),
> +				     "Failed to request vcc regulator\n");
> +
> +	ctx->iovcc = devm_regulator_get(dev, "iovcc");
> +	if (IS_ERR(ctx->iovcc))
> +		return dev_err_probe(dev, PTR_ERR(ctx->iovcc),
> +				     "Failed to request iovcc regulator\n");
> +
> +	drm_panel_init(&ctx->panel, dev, &hx8394_drm_funcs,
> +		       DRM_MODE_CONNECTOR_DSI);
> +
> +	ret = drm_panel_of_backlight(&ctx->panel);
> +	if (ret)
> +		return ret;
> +
> +	drm_panel_add(&ctx->panel);
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret < 0) {
> +		dev_err_probe(dev, ret, "mipi_dsi_attach failed\n");
> +		drm_panel_remove(&ctx->panel);
> +		return ret;
> +	}
> +
> +	dev_info(dev, "%ux%u@%u %ubpp dsi %udl - ready\n",
> +		 ctx->desc->mode->hdisplay, ctx->desc->mode->vdisplay,
> +		 drm_mode_vrefresh(ctx->desc->mode),
> +		 mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
debug
> +
> +	return 0;
> +}
> +
> +static void hx8394_shutdown(struct mipi_dsi_device *dsi)
> +{
> +	struct hx8394 *ctx = mipi_dsi_get_drvdata(dsi);
> +	int ret;
> +
> +	ret = drm_panel_disable(&ctx->panel);
> +	if (ret < 0)
> +		dev_err(&dsi->dev, "Failed to disable panel: %d\n", ret);
> +
> +	ret = drm_panel_unprepare(&ctx->panel);
> +	if (ret < 0)
> +		dev_err(&dsi->dev, "Failed to unprepare panel: %d\n", ret);
> +}
> +
> +static void hx8394_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct hx8394 *ctx = mipi_dsi_get_drvdata(dsi);
> +	int ret;
> +
> +	hx8394_shutdown(dsi);
> +
> +	ret = mipi_dsi_detach(dsi);
> +	if (ret < 0)
> +		dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
> +
> +	drm_panel_remove(&ctx->panel);
> +}
> +
> +static const struct of_device_id hx8394_of_match[] = {
> +	{ .compatible = "hannstar,hsd060bhw4", .data = &hsd060bhw4_desc },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, hx8394_of_match);
> +
> +static struct mipi_dsi_driver hx8394_driver = {
> +	.probe	= hx8394_probe,
> +	.remove = hx8394_remove,
> +	.shutdown = hx8394_shutdown,
> +	.driver = {
> +		.name = DRV_NAME,
> +		.of_match_table = hx8394_of_match,
> +	},
> +};
> +module_mipi_dsi_driver(hx8394_driver);
> +
> +MODULE_AUTHOR("Kamil Trzciński <ayufan@ayufan.eu>");
> +MODULE_DESCRIPTION("DRM driver for Himax HX8394 based MIPI DSI panels");
> +MODULE_LICENSE("GPL");
> -- 
> 2.38.1

Hello Sam,

On 12/23/22 10:17, Sam Ravnborg wrote:
> Hi Javier.
> 
> On Thu, Dec 22, 2022 at 11:38:27PM +0100, Javier Martinez Canillas wrote:
>> From: Kamil Trzciński <ayufan@ayufan.eu>
>>
>> The driver is for panels based on the Himax HX8394 controller, such as the
>> HannStar HSD060BHW4 720x1440 TFT LCD panel that uses a MIPI-DSI interface.
> 
> A few comments/nitpicks in the following.
> I have been away for a while, and paged out most of my panel knowledge,
> so read it all with that in mind.
>

Thanks a lot for your feedback! I agree with your comments and will address
those in the next iteration.
 
> In general - very nicely written driver.
> 
> 	Sam
> 

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat