On Fri, Oct 10, 2025 at 05:37:51PM +0800, Langyan Ye wrote:
> Add a DRM panel driver for the Ilitek IL79900A MIPI-DSI LCD controller.
>
> The controller is used in panels such as the Tianma TL121BVMS07-00.
> It requires multiple power supplies (AVDD, AVEE, 1.8V logic), an enable
> GPIO, and a backlight device.
>
> Signed-off-by: Langyan Ye <[email protected]>
> ---
> drivers/gpu/drm/panel/panel-ilitek-il79900a.c | 394 ++++++++++++++++++
> 1 file changed, 394 insertions(+)
> create mode 100644 drivers/gpu/drm/panel/panel-ilitek-il79900a.c
>
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
> b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
> new file mode 100644
> index 000000000000..2134f8af673e
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
> @@ -0,0 +1,394 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Panels based on the Ilitek IL79900A display controller.
> + */
> +#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_connector.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_panel.h>
> +
> +#include <video/mipi_display.h>
> +
> +struct il79900a;
> +
> +/*
> + * Use this descriptor struct to describe different panels using the
> + * Ilitek IL79900A display controller.
> + */
> +struct panel_desc {
> + const struct drm_display_mode *modes;
> + unsigned int bpc;
> +
> + /**
> + * @width_mm: width of the panel's active display area
> + * @height_mm: height of the panel's active display area
> + */
> + struct {
> + unsigned int width_mm;
> + unsigned int height_mm;
> + } size;
Move these to the mode
> +
> + unsigned long mode_flags;
> + enum mipi_dsi_pixel_format format;
> + int (*init)(struct il79900a *boe);
> + unsigned int lanes;
> +};
> +
> +struct il79900a {
> + struct drm_panel base;
> + struct mipi_dsi_device *dsi;
> +
> + const struct panel_desc *desc;
> +
> + enum drm_panel_orientation orientation;
> + struct regulator *pp1800;
> + struct regulator *avee;
> + struct regulator *avdd;
> + struct gpio_desc *enable_gpio;
> +};
> +
> +/* IL79900A-specific commands, add new commands as you decode them */
> +#define IL79900A_DCS_SWITCH_PAGE 0xFF
> +
> +#define il79900a_switch_page(ctx, page) \
> + mipi_dsi_dcs_write_seq_multi(ctx, IL79900A_DCS_SWITCH_PAGE, \
> + 0x5a, 0xa5, (page))
> +
> +static int tianma_il79900a_init(struct il79900a *ili)
> +{
> + struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
> +
> + usleep_range(5000, 5100);
mipi_dsi_usleep_range
> +
> + il79900a_switch_page(&ctx, 0x06);
> + mipi_dsi_dcs_write_seq_multi(&ctx, 0x3e, 0x62);
> +
> + il79900a_switch_page(&ctx, 0x02);
> + mipi_dsi_dcs_write_seq_multi(&ctx, 0x1b, 0x20);
> + mipi_dsi_dcs_write_seq_multi(&ctx, 0x5d, 0x00);
> + mipi_dsi_dcs_write_seq_multi(&ctx, 0x5e, 0x40);
> +
> + il79900a_switch_page(&ctx, 0x07);
> + mipi_dsi_dcs_write_seq_multi(&ctx, 0X29, 0x00);
> +
> + il79900a_switch_page(&ctx, 0x06);
> + mipi_dsi_dcs_write_seq_multi(&ctx, 0x92, 0x22);
> +
> + il79900a_switch_page(&ctx, 0x00);
> + mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_EXIT_SLEEP_MODE);
> + if (ctx.accum_err)
> + return ctx.accum_err;
Drop
> +
> + msleep(120);
mipi_dsi_msleep
> +
> + mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_SET_DISPLAY_ON);
> + if (ctx.accum_err)
> + return ctx.accum_err;
drop
> +
> + msleep(80);
mipi_dsi_msleep
> +
> + return 0;
> +};
> +
> +static inline struct il79900a *to_il79900a(struct drm_panel *panel)
> +{
> + return container_of(panel, struct il79900a, base);
> +}
> +
> +static int il79900a_enter_sleep_mode(struct il79900a *ili)
> +{
> + struct mipi_dsi_device *dsi = ili->dsi;
> + int ret;
> +
> + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> + ret = mipi_dsi_dcs_set_display_off(dsi);
_multi
> + if (ret < 0)
> + return ret;
> +
> + ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
_multi
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int il79900a_disable(struct drm_panel *panel)
> +{
> + struct il79900a *ili = to_il79900a(panel);
> + struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
> + int ret;
> +
> + il79900a_switch_page(&ctx, 0x00);
> + if (ctx.accum_err)
> + return ctx.accum_err;
> +
> + ret = il79900a_enter_sleep_mode(ili);
Pass context to that function
> + if (ret < 0) {
> + dev_err(panel->dev, "failed to set panel off: %d\n", ret);
> + return ret;
> + }
> +
> + msleep(150);
mipi_dsi_msleep
> +
> + return 0;
> +}
> +
> +static int il79900a_unprepare(struct drm_panel *panel)
> +{
> + struct il79900a *ili = to_il79900a(panel);
> +
> + gpiod_set_value(ili->enable_gpio, 0);
> + usleep_range(1000, 2000);
> + regulator_disable(ili->avee);
> + regulator_disable(ili->avdd);
> + usleep_range(5000, 7000);
> + regulator_disable(ili->pp1800);
> +
> + return 0;
> +}
> +
> +static int il79900a_prepare(struct drm_panel *panel)
> +{
> + struct il79900a *ili = to_il79900a(panel);
> + int ret;
> +
> + gpiod_set_value(ili->enable_gpio, 0);
> + usleep_range(1000, 1500);
> +
> + ret = regulator_enable(ili->pp1800);
> + if (ret < 0)
> + return ret;
> +
> + usleep_range(3000, 5000);
> +
> + ret = regulator_enable(ili->avdd);
> + if (ret < 0)
> + goto poweroff1v8;
> + ret = regulator_enable(ili->avee);
> + if (ret < 0)
> + goto poweroffavdd;
> +
> + usleep_range(10000, 11000);
> +
> + // MIPI needs to keep the LP11 state before the lcm_reset pin is pulled
> high
> + ret = mipi_dsi_dcs_nop(ili->dsi);
> + if (ret < 0) {
> + dev_err(&ili->dsi->dev, "Failed to send NOP: %d\n", ret);
> + goto poweroff;
> + }
> + usleep_range(1000, 2000);
> +
> + gpiod_set_value(ili->enable_gpio, 1);
> + usleep_range(1000, 2000);
> + gpiod_set_value(ili->enable_gpio, 0);
> + usleep_range(10000, 11000);
> + gpiod_set_value(ili->enable_gpio, 1);
> + usleep_range(20000, 21000);
> +
> + ret = ili->desc->init(ili);
> + if (ret < 0)
> + goto poweroff;
> +
> + return 0;
> +
> +poweroff:
> + gpiod_set_value(ili->enable_gpio, 0);
> + regulator_disable(ili->avee);
> +poweroffavdd:
> + regulator_disable(ili->avdd);
> +poweroff1v8:
> + usleep_range(5000, 7000);
> + regulator_disable(ili->pp1800);
> +
> + return ret;
> +}
> +
> +static int il79900a_enable(struct drm_panel *panel)
> +{
> + msleep(130);
Why?
> + return 0;
> +}
> +
> +static const struct drm_display_mode tianma_il79900a_default_mode = {
> + .clock = 264355,
> + .hdisplay = 1600,
> + .hsync_start = 1600 + 20,
> + .hsync_end = 1600 + 20 + 4,
> + .htotal = 1600 + 20 + 4 + 20,
> + .vdisplay = 2560,
> + .vsync_start = 2560 + 82,
> + .vsync_end = 2560 + 82 + 2,
> + .vtotal = 2560 + 82 + 2 + 36,
> +};
> +
> +static const struct panel_desc tianma_il79900a_desc = {
> + .modes = &tianma_il79900a_default_mode,
> + .bpc = 8,
> + .size = {
> + .width_mm = 163,
> + .height_mm = 260,
> + },
> + .lanes = 3,
> + .format = MIPI_DSI_FMT_RGB888,
> + .mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
> + MIPI_DSI_MODE_LPM,
> + .init = tianma_il79900a_init,
> +};
> +
> +static int il79900a_get_modes(struct drm_panel *panel,
> + struct drm_connector *connector)
> +{
> + struct il79900a *ili = to_il79900a(panel);
> + const struct drm_display_mode *m = ili->desc->modes;
> + struct drm_display_mode *mode;
> +
> + mode = drm_mode_duplicate(connector->dev, m);
> + if (!mode) {
> + dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
> + m->hdisplay, m->vdisplay, drm_mode_vrefresh(m));
> + return -ENOMEM;
> + }
> +
> + mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> + drm_mode_set_name(mode);
> + drm_mode_probed_add(connector, mode);
> +
> + connector->display_info.width_mm = ili->desc->size.width_mm;
> + connector->display_info.height_mm = ili->desc->size.height_mm;
drm_connector_helper_get_modes_fixed()
> + connector->display_info.bpc = ili->desc->bpc;
> +
> + return 1;
> +}
> +
> +static enum drm_panel_orientation il79900a_get_orientation(struct drm_panel
> *panel)
> +{
> + struct il79900a *ili = to_il79900a(panel);
> +
> + return ili->orientation;
> +}
> +
> +static const struct drm_panel_funcs il79900a_funcs = {
> + .disable = il79900a_disable,
> + .unprepare = il79900a_unprepare,
> + .prepare = il79900a_prepare,
> + .enable = il79900a_enable,
> + .get_modes = il79900a_get_modes,
> + .get_orientation = il79900a_get_orientation,
> +};
> +
> +static int il79900a_add(struct il79900a *ili)
> +{
> + struct device *dev = &ili->dsi->dev;
> + int err;
> +
> + ili->avdd = devm_regulator_get(dev, "avdd");
> + if (IS_ERR(ili->avdd))
> + return PTR_ERR(ili->avdd);
> +
> + ili->avee = devm_regulator_get(dev, "avee");
> + if (IS_ERR(ili->avee))
> + return PTR_ERR(ili->avee);
> +
> + ili->pp1800 = devm_regulator_get(dev, "pp1800");
> + if (IS_ERR(ili->pp1800))
> + return PTR_ERR(ili->pp1800);
> +
> + ili->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> + if (IS_ERR(ili->enable_gpio)) {
> + dev_err(dev, "cannot get reset-gpios %ld\n",
> + PTR_ERR(ili->enable_gpio));
> + return PTR_ERR(ili->enable_gpio);
> + }
> +
> + gpiod_set_value(ili->enable_gpio, 0);
> +
> + drm_panel_init(&ili->base, dev, &il79900a_funcs,
> + DRM_MODE_CONNECTOR_DSI);
> + err = of_drm_get_panel_orientation(dev->of_node, &ili->orientation);
> + if (err < 0) {
> + dev_err(dev, "%pOF: failed to get orientation %d\n",
> dev->of_node, err);
> + return err;
> + }
> +
> + err = drm_panel_of_backlight(&ili->base);
> + if (err)
> + return err;
> +
> + ili->base.funcs = &il79900a_funcs;
> + ili->base.dev = &ili->dsi->dev;
> +
> + drm_panel_add(&ili->base);
> +
> + return 0;
> +}
> +
> +static int il79900a_probe(struct mipi_dsi_device *dsi)
> +{
> + struct il79900a *ili;
> + int ret;
> + const struct panel_desc *desc;
> +
> + ili = devm_kzalloc(&dsi->dev, sizeof(*ili), GFP_KERNEL);
> + if (!ili)
> + return -ENOMEM;
> +
> + desc = of_device_get_match_data(&dsi->dev);
> + dsi->lanes = desc->lanes;
> + dsi->format = desc->format;
> + dsi->mode_flags = desc->mode_flags;
> + ili->desc = desc;
> + ili->dsi = dsi;
> + ret = il79900a_add(ili);
> + if (ret < 0)
> + return ret;
> +
> + mipi_dsi_set_drvdata(dsi, ili);
> +
> + ret = mipi_dsi_attach(dsi);
> + if (ret)
> + drm_panel_remove(&ili->base);
> +
> + return ret;
> +}
> +
> +static void il79900a_remove(struct mipi_dsi_device *dsi)
> +{
> + struct il79900a *ili = mipi_dsi_get_drvdata(dsi);
> + int ret;
> +
> + ret = mipi_dsi_detach(dsi);
> + if (ret < 0)
> + dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", ret);
> +
> + if (ili->base.dev)
> + drm_panel_remove(&ili->base);
> +}
> +
> +static const struct of_device_id il79900a_of_match[] = {
> + { .compatible = "tianma,il79900a",
> + .data = &tianma_il79900a_desc
> + },
Single line
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, il79900a_of_match);
> +
> +static struct mipi_dsi_driver il79900a_driver = {
> + .driver = {
> + .name = "panel-il79900a",
> + .of_match_table = il79900a_of_match,
> + },
> + .probe = il79900a_probe,
> + .remove = il79900a_remove,
> +};
> +module_mipi_dsi_driver(il79900a_driver);
> +
> +MODULE_AUTHOR("Langyan Ye <[email protected]>");
> +MODULE_DESCRIPTION("Ilitek IL79900A-based panels driver");
> +MODULE_LICENSE("GPL");
> --
> 2.34.1
>
--
With best wishes
Dmitry
