Re: [PATCH v3 2/2] drm/panel: add Ilitek ILI7807S panel driver

[Dmitry Baryshkov]

On Wed, Jun 24, 2026 at 02:23:52PM +0530, Arpit Saini wrote:
> Add a DRM panel driver for the DLC DLC0697 1080x1920@60Hz MIPI DSI
> panel based on the Ilitek ILI7807S display controller.
> 
> The panel operates in video burst mode with four data lanes using
> RGB888 pixel format.
> 
> Signed-off-by: Arpit Saini <arpit.saini@xxxxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/panel/Kconfig                 |  12 ++
>  drivers/gpu/drm/panel/Makefile                |   1 +
>  drivers/gpu/drm/panel/panel-ilitek-ili7807s.c | 293 ++++++++++++++++++++++++++
>  3 files changed, 306 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 7450b27622a2..1cbaac1bf545 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -264,6 +264,18 @@ config DRM_PANEL_HYDIS_HV101HD1
>  
>  	  If M is selected the module will be called panel-hydis-hv101hd1
>  
> +config DRM_PANEL_ILITEK_ILI7807S
> +	tristate "Ilitek ILI7807S-based 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
> +	  Ilitek ILI7807S display controller, such as the DLC DLC0697
> +	  1080x1920 MIPI DSI panel.
> +
> +	  If M is selected the module will be called panel-ilitek-ili7807s.
> +
>  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 c2c5cf817116..c3002b351cb8 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_DRM_PANEL_HIMAX_HX83112B) += panel-himax-hx83112b.o
>  obj-$(CONFIG_DRM_PANEL_HIMAX_HX83121A) += panel-himax-hx83121a.o
>  obj-$(CONFIG_DRM_PANEL_HIMAX_HX8394) += panel-himax-hx8394.o
>  obj-$(CONFIG_DRM_PANEL_HYDIS_HV101HD1) += panel-hydis-hv101hd1.o
> +obj-$(CONFIG_DRM_PANEL_ILITEK_ILI7807S) += panel-ilitek-ili7807s.o
>  obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
>  obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
>  obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9805) += panel-ilitek-ili9805.o
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c b/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c
> new file mode 100644
> index 000000000000..8ddfab2693ec
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c
> @@ -0,0 +1,293 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +#include <linux/backlight.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_probe_helper.h>
> +
> +struct panel_desc {
> +	const struct drm_display_mode *mode;
> +	unsigned int lanes;
> +	enum mipi_dsi_pixel_format format;
> +	unsigned long mode_flags;
> +	void (*init)(struct mipi_dsi_multi_context *dsi_ctx);
> +};
> +
> +struct ili7807s {
> +	struct drm_panel panel;
> +	struct mipi_dsi_device *dsi;
> +	const struct panel_desc *desc;
> +
> +	struct regulator_bulk_data *supplies;
> +	struct gpio_desc *reset_gpio;
> +};
> +
> +static const struct regulator_bulk_data ili7807s_supplies[] = {
> +	{ .supply = "vddi" },
> +	{ .supply = "avdd" },
> +	{ .supply = "avee" },
> +};
> +
> +static inline struct ili7807s *to_ili7807s(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct ili7807s, panel);
> +}
> +
> +static void ili7807s_reset(struct ili7807s *ctx)
> +{
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +	usleep_range(10000, 11000);
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +	usleep_range(10000, 11000);
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +	usleep_range(10000, 11000);

This looks like the reset being active-low. Please define it as is in
the DT and use normal (hold = 1, drop = 0) semantics in the driver.

> +}
> +
> +static void dlc0697_init_sequence(struct mipi_dsi_multi_context *dsi_ctx)
> +{
> +	mipi_dsi_dcs_soft_reset_multi(dsi_ctx);
> +	mipi_dsi_msleep(dsi_ctx, 120);
> +
> +	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0xff, 0x78, 0x07, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x35, 0x00);

mipi_dsi_dcs_set_tear_on_multi()

> +	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x5e, 0x09, 0x99);

MIPI_DCS_SET_CABC_MIN_BRIGHTNESS

> +	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x53, 0x24);

MIPI_DCS_WRITE_CONTROL_DISPLAY

> +	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x55, 0x01);

MIPI_DCS_WRITE_POWER_SAVE

> +	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x51, 0x3f, 0xff);

mipi_dsi_dcs_set_display_brightness_large_multi(). Also please use
0x1fff instead of the full brightness.

> +
> +	mipi_dsi_dcs_exit_sleep_mode_multi(dsi_ctx);
> +	mipi_dsi_msleep(dsi_ctx, 120);
> +
> +	mipi_dsi_dcs_set_display_on_multi(dsi_ctx);
> +	mipi_dsi_msleep(dsi_ctx, 20);
> +}
> +
> +static int ili7807s_on(struct ili7807s *ctx)
> +{
> +	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
> +
> +	ctx->dsi->mode_flags |= MIPI_DSI_MODE_LPM;

Drop, set it in probe()

> +
> +	ctx->desc->init(&dsi_ctx);
> +
> +	ctx->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;

Drop

> +
> +	return dsi_ctx.accum_err;
> +}
> +
> +static int ili7807s_off(struct ili7807s *ctx)
> +{
> +	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
> +
> +	ctx->dsi->mode_flags |= MIPI_DSI_MODE_LPM;

Drop

> +
> +	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
> +	mipi_dsi_msleep(&dsi_ctx, 20);
> +
> +	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
> +	mipi_dsi_msleep(&dsi_ctx, 120);
> +
> +	ctx->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;

Drop

> +
> +	return dsi_ctx.accum_err;
> +}
> +
> +static int ili7807s_prepare(struct drm_panel *panel)
> +{
> +	struct ili7807s *ctx = to_ili7807s(panel);
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
> +	if (ret < 0) {
> +		dev_err(ctx->panel.dev, "failed to enable regulators: %d\n", ret);
> +		return ret;
> +	}
> +
> +	msleep(20);
> +
> +	ili7807s_reset(ctx);
> +
> +	ret = ili7807s_on(ctx);
> +	if (ret < 0) {
> +		dev_err(ctx->panel.dev, "failed to initialise panel: %d\n", ret);
> +		goto err;
> +	}
> +
> +	return 0;
> +
> +err:
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +
> +	regulator_bulk_disable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
> +	return ret;
> +}
> +
> +static int ili7807s_unprepare(struct drm_panel *panel)
> +{
> +	struct ili7807s *ctx = to_ili7807s(panel);
> +	int ret;
> +
> +	ret = ili7807s_off(ctx);
> +	if (ret < 0)
> +		dev_err(ctx->panel.dev, "failed to disable panel: %d\n", ret);
> +
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +
> +	regulator_bulk_disable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
> +
> +	return 0;
> +}
> +
> +static int ili7807s_get_modes(struct drm_panel *panel,
> +			      struct drm_connector *connector)
> +{
> +	struct ili7807s *ctx = to_ili7807s(panel);
> +
> +	return drm_connector_helper_get_modes_fixed(connector, ctx->desc->mode);
> +}
> +
> +static const struct drm_panel_funcs ili7807s_panel_funcs = {
> +	.prepare = ili7807s_prepare,
> +	.unprepare = ili7807s_unprepare,
> +	.get_modes = ili7807s_get_modes,
> +};
> +
> +static int ili7807s_bl_update_status(struct backlight_device *bl)
> +{
> +	struct mipi_dsi_device *dsi = bl_get_data(bl);
> +	u16 brightness = backlight_get_brightness(bl);
> +	int ret;
> +
> +	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> +	ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
> +
> +	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> +
> +	return ret;
> +}
> +
> +static const struct backlight_ops ili7807s_bl_ops = {
> +	.update_status = ili7807s_bl_update_status,
> +};
> +
> +static struct backlight_device *ili7807s_create_backlight(struct mipi_dsi_device *dsi)
> +{
> +	struct device *dev = &dsi->dev;
> +	const struct backlight_properties props = {
> +		.type           = BACKLIGHT_RAW,
> +		.brightness     = 0x3fff,
> +		.max_brightness = 0x3fff,
> +	};
> +
> +	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
> +					      &ili7807s_bl_ops, &props);
> +}
> +
> +static const struct drm_display_mode dlc0697_mode = {
> +	.clock = 131911,

= (1080 + 18 + 2 + 16) * (1920 + 26 + 4 + 20) * 60 / 1000

> +
> +	.hdisplay    = 1080,
> +	.hsync_start = 1080 + 18,
> +	.hsync_end   = 1080 + 18 + 2,
> +	.htotal      = 1080 + 18 + 2 + 16,
> +
> +	.vdisplay    = 1920,
> +	.vsync_start = 1920 + 26,
> +	.vsync_end   = 1920 + 26 + 4,
> +	.vtotal      = 1920 + 26 + 4 + 20,
> +
> +	.width_mm  = 0,
> +	.height_mm = 0,

Do you really don't know the dimensions of the panel you are
contributing?

> +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +};
> +

-- 
With best wishes
Dmitry