Re: [PATCH v4 3/7] drm/panel: Add LG LH400WV3-SD04 MIPI DBI Type B panel driver

[Neil Armstrong <neil.armstrong@linaro.org>]

On 10/22/26 15:22, Svyatoslav Ryhel wrote:
> Add a driver for panel used in LG Optimus 2X P990. Panel is 4" WVGA MIPI
> DBI Type B linked to DRM encoder via RGB to DBI bridge.
> 
> Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> ---
>   drivers/gpu/drm/panel/Kconfig             |  13 ++
>   drivers/gpu/drm/panel/Makefile            |   1 +
>   drivers/gpu/drm/panel/panel-lg-lh400wv3.c | 236 ++++++++++++++++++++++
>   3 files changed, 250 insertions(+)
>   create mode 100644 drivers/gpu/drm/panel/panel-lg-lh400wv3.c
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 5f68b78526c3e..f29b63ad8ba0f 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -554,6 +554,19 @@ config DRM_PANEL_LG_LG4573
>   	  Say Y here if you want to enable support for LG4573 RGB panel.
>   	  To compile this driver as a module, choose M here.
>   
> +config DRM_PANEL_LG_LH400WV3
> +	tristate "LG LH400WV3 MIPI DBI Type B panel"
> +	depends on OF
> +	depends on BACKLIGHT_CLASS_DEVICE
> +	select DRM_MIPI_DBI
> +	select VIDEOMODE_HELPERS
> +	help
> +	  Say Y here if you want to enable support for the LG LH400WV3 MIPI
> +	  DBI Type B panel found in the LG Optimus 2X P990 smartphone.
> +
> +	  To compile this driver as a module, choose M here: the module will
> +	  be called panel-lg-lh400wv3.
> +
>   config DRM_PANEL_LG_SW43408
>   	tristate "LG SW43408 panel"
>   	depends on GPIOLIB
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index 414267a49d922..842a2a973777f 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -54,6 +54,7 @@ obj-$(CONFIG_DRM_PANEL_LINCOLNTECH_LCD197) += panel-lincolntech-lcd197.o
>   obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
>   obj-$(CONFIG_DRM_PANEL_LG_LD070WX3) += panel-lg-ld070wx3.o
>   obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
> +obj-$(CONFIG_DRM_PANEL_LG_LH400WV3) += panel-lg-lh400wv3.o
>   obj-$(CONFIG_DRM_PANEL_LG_SW43408) += panel-lg-sw43408.o
>   obj-$(CONFIG_DRM_PANEL_LXD_M9189A) += panel-lxd-m9189a.o
>   obj-$(CONFIG_DRM_PANEL_MAGNACHIP_D53E6EA8966) += panel-magnachip-d53e6ea8966.o
> diff --git a/drivers/gpu/drm/panel/panel-lg-lh400wv3.c b/drivers/gpu/drm/panel/panel-lg-lh400wv3.c
> new file mode 100644
> index 0000000000000..557bcb6f2ca70
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-lg-lh400wv3.c
> @@ -0,0 +1,236 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <linux/array_size.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/media-bus-format.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <video/mipi_display.h>
> +
> +#include <drm/drm_mipi_dbi.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_probe_helper.h>
> +
> +static const struct regulator_bulk_data lg_lh400wv3_supplies[] = {
> +	{ .supply = "avci" }, { .supply = "iovcc" },
> +};
> +
> +struct lg_lh400wv3 {
> +	struct drm_panel panel;
> +	struct mipi_dbi *dbi;
> +
> +	struct regulator_bulk_data *supplies;
> +	struct gpio_desc *reset_gpio;
> +};
> +
> +static inline struct lg_lh400wv3 *to_lg_lh400wv3(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct lg_lh400wv3, panel);
> +}
> +
> +#define panel_dbi_command(priv, cmd, seq...) \
> +({ \
> +	const u8 d[] = { seq }; \
> +	struct drm_panel *panel = &(priv)->panel; \
> +	struct device *dev = panel->dev; \
> +	int ret; \
> +	ret = mipi_dbi_command_stackbuf((priv)->dbi, cmd, d, ARRAY_SIZE(d)); \
> +	if (ret) \
> +		dev_err_ratelimited(dev, "error %d when sending command %#02x\n", ret, cmd); \
> +	ret; \
> +})
> +
> +static int lg_lh400wv3_prepare(struct drm_panel *panel)
> +{
> +	struct lg_lh400wv3 *priv = to_lg_lh400wv3(panel);
> +	struct device *dev = panel->dev;
> +	int ret;
> +
> +	priv->dbi = dev_get_drvdata(dev->parent);
> +	if (!priv->dbi)
> +		return -ENODEV;
> +
> +	gpiod_set_value_cansleep(priv->reset_gpio, 1);
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(lg_lh400wv3_supplies), priv->supplies);
> +	if (ret) {
> +		dev_err(dev, "failed to enable power supplies: %d\n", ret);
> +		return ret;
> +	}
> +
> +	usleep_range(1000, 2000);
> +
> +	gpiod_set_value_cansleep(priv->reset_gpio, 0);
> +
> +	usleep_range(10000, 11000);
> +
> +	return 0;
> +};
> +
> +static int lg_lh400wv3_enable(struct drm_panel *panel)
> +{
> +	struct lg_lh400wv3 *priv = to_lg_lh400wv3(panel);
> +
> +	panel_dbi_command(priv, MIPI_DCS_EXIT_INVERT_MODE);
> +	panel_dbi_command(priv, MIPI_DCS_SET_TEAR_ON);
> +
> +	panel_dbi_command(priv, MIPI_DCS_SET_PIXEL_FORMAT, MIPI_DCS_PIXEL_FMT_24BIT |
> +			  MIPI_DCS_PIXEL_FMT_24BIT << 4);
> +
> +	panel_dbi_command(priv, 0xb2, 0x00, 0xc8);
> +	panel_dbi_command(priv, 0xb3, 0x00);
> +	panel_dbi_command(priv, 0xb4, 0x04);
> +	panel_dbi_command(priv, 0xb5, 0x42, 0x10, 0x10, 0x00, 0x20);
> +	panel_dbi_command(priv, 0xb6, 0x0b, 0x0f, 0x3c, 0x13, 0x13, 0xe8);
> +	panel_dbi_command(priv, 0xb7, 0x4c, 0x06, 0x0c, 0x00, 0x00);
> +
> +	panel_dbi_command(priv, 0xc0, 0x01, 0x11);
> +	panel_dbi_command(priv, 0xc3, 0x07, 0x03, 0x04, 0x04, 0x04);
> +	panel_dbi_command(priv, 0xc4, 0x12, 0x24, 0x18, 0x18, 0x02, 0x49);
> +	panel_dbi_command(priv, 0xc5, 0x65);
> +	panel_dbi_command(priv, 0xc6, 0x41, 0x63);
> +
> +	panel_dbi_command(priv, 0xd0, 0x00, 0x46, 0x74, 0x32, 0x1d, 0x03, 0x51, 0x15, 0x04);
> +	panel_dbi_command(priv, 0xd1, 0x00, 0x46, 0x74, 0x32, 0x1d, 0x03, 0x51, 0x15, 0x04);
> +	panel_dbi_command(priv, 0xd2, 0x00, 0x46, 0x74, 0x32, 0x1f, 0x03, 0x51, 0x15, 0x04);
> +	panel_dbi_command(priv, 0xd3, 0x00, 0x46, 0x74, 0x32, 0x1f, 0x03, 0x51, 0x15, 0x04);
> +	panel_dbi_command(priv, 0xd4, 0x01, 0x46, 0x74, 0x25, 0x00, 0x03, 0x51, 0x15, 0x04);
> +	panel_dbi_command(priv, 0xd5, 0x01, 0x46, 0x74, 0x25, 0x00, 0x03, 0x51, 0x15, 0x04);
> +
> +	panel_dbi_command(priv, MIPI_DCS_SET_COLUMN_ADDRESS, 0x00, 0x00, 0x01, 0xdf);
> +	panel_dbi_command(priv, MIPI_DCS_SET_PAGE_ADDRESS, 0x00, 0x00, 0x03, 0x1f);
> +
> +	panel_dbi_command(priv, MIPI_DCS_EXIT_SLEEP_MODE);
> +	msleep(120);
> +
> +	panel_dbi_command(priv, MIPI_DCS_WRITE_MEMORY_START);
> +	panel_dbi_command(priv, MIPI_DCS_SET_DISPLAY_ON);
> +
> +	return 0;
> +}
> +
> +static int lg_lh400wv3_disable(struct drm_panel *panel)
> +{
> +	struct lg_lh400wv3 *priv = to_lg_lh400wv3(panel);
> +
> +	panel_dbi_command(priv, MIPI_DCS_SET_DISPLAY_OFF);
> +	panel_dbi_command(priv, MIPI_DCS_ENTER_SLEEP_MODE);
> +	msleep(150);
> +
> +	panel_dbi_command(priv, 0xc1, 0x01);
> +	usleep_range(10000, 11000);
> +
> +	return 0;
> +};
> +
> +static int lg_lh400wv3_unprepare(struct drm_panel *panel)
> +{
> +	struct lg_lh400wv3 *priv = to_lg_lh400wv3(panel);
> +
> +	gpiod_set_value_cansleep(priv->reset_gpio, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(lg_lh400wv3_supplies), priv->supplies);
> +
> +	msleep(50);
> +
> +	return 0;
> +}
> +
> +static const struct drm_display_mode lg_lh400wv3_mode = {
> +	.clock = (480 + 10 + 10 + 10) * (800 + 4 + 4 + 4) * 60 / 1000,
> +	.hdisplay = 480,
> +	.hsync_start = 480 + 10,
> +	.hsync_end = 480 + 10 + 10,
> +	.htotal = 480 + 10 + 10 + 10,
> +	.vdisplay = 800,
> +	.vsync_start = 800 + 4,
> +	.vsync_end = 800 + 4 + 4,
> +	.vtotal = 800 + 4 + 4 + 4,
> +	.width_mm = 52,
> +	.height_mm = 86,
> +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +};
> +
> +static int lg_lh400wv3_get_modes(struct drm_panel *panel,
> +				 struct drm_connector *connector)
> +{
> +	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
> +
> +	drm_display_info_set_bus_formats(&connector->display_info,
> +					 &bus_format, 1);
> +
> +	connector->display_info.bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE |
> +					    DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE |
> +					    DRM_BUS_FLAG_DE_HIGH |
> +					    DRM_BUS_FLAG_DATA_LSB_TO_MSB;
> +
> +	return drm_connector_helper_get_modes_fixed(connector, &lg_lh400wv3_mode);
> +}
> +
> +static const struct drm_panel_funcs lg_lh400wv3_panel_funcs = {
> +	.prepare = lg_lh400wv3_prepare,
> +	.enable = lg_lh400wv3_enable,
> +	.disable = lg_lh400wv3_disable,
> +	.unprepare = lg_lh400wv3_unprepare,
> +	.get_modes = lg_lh400wv3_get_modes,
> +};
> +
> +static int lg_lh400wv3_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct lg_lh400wv3 *priv;
> +	int ret;
> +
> +	priv = devm_drm_panel_alloc(dev, struct lg_lh400wv3, panel,
> +				    &lg_lh400wv3_panel_funcs, DRM_MODE_CONNECTOR_DPI);
> +	if (IS_ERR(priv))
> +		return PTR_ERR(priv);
> +
> +	ret = devm_regulator_bulk_get_const(dev, ARRAY_SIZE(lg_lh400wv3_supplies),
> +					    lg_lh400wv3_supplies, &priv->supplies);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get supplies\n");
> +
> +	priv->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(priv->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(priv->reset_gpio),
> +				     "Failed to get reset gpio\n");
> +
> +	ret = drm_panel_of_backlight(&priv->panel);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get backlight\n");
> +
> +	ret = devm_drm_panel_add(dev, &priv->panel);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to add panel\n");
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id lg_lh400wv3_of_match[] = {
> +	{ .compatible = "lg,lh400wv3-sd04" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, lg_lh400wv3_of_match);
> +
> +static struct platform_driver lg_lh400wv3_driver = {
> +	.driver = {
> +		.name = "panel-lg-lh400wv3",
> +		.of_match_table = lg_lh400wv3_of_match,
> +	},
> +	.probe = lg_lh400wv3_probe,
> +};
> +module_platform_driver(lg_lh400wv3_driver);
> +
> +MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
> +MODULE_DESCRIPTION("LG LH400WV3-SD04 MIPI DBI Type B panel driver");
> +MODULE_LICENSE("GPL");

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Thanks,
Neil