Hi,

just some random remarks, not a complete review.

On Wed Mar 11, 2026 at 4:55 PM CET, Bartholomäus Steinmayr wrote:
> Add Densitron DMT050WVNMCMI-1A to ILI9806E DSI
> Add i2c-frag to allow probe deferral until Goodix touchpanel chip in the
> display is initialized. Make reset-gpios optional to allow delegation of
> reset to Goodix driver.
>
> Signed-off-by: Bart Steinmayr <[email protected]>
> ---
>  drivers/gpu/drm/panel/panel-ilitek-ili9806e.c | 202 +++++++++++++++++-
>  1 file changed, 201 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9806e.c 
> b/drivers/gpu/drm/panel/panel-ilitek-ili9806e.c
> index 18aa6222b0c5..ce77ee7cbc10 100644
> --- a/drivers/gpu/drm/panel/panel-ilitek-ili9806e.c
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9806e.c
> @@ -10,6 +10,9 @@
>  #include <linux/module.h>
>  #include <linux/property.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/of.h>
> +
> +#include <linux/i2c.h>
>
>  #include <drm/drm_mipi_dsi.h>
>  #include <drm/drm_modes.h>
> @@ -166,6 +169,22 @@ static int ili9806e_dsi_probe(struct mipi_dsi_device 
> *dsi)
>       struct ili9806e_panel *ctx;
>       int i, ret;
>
> +     struct device_node *i2c_frag = of_parse_phandle(dev->of_node, 
> "i2c-frag", 0);
> +
> +     if (i2c_frag) {
> +             void *i2c_driver_data = NULL;
> +
> +             struct i2c_client *i2c_frag_client = 
> of_find_i2c_device_by_node(i2c_frag);
> +
> +             of_node_put(i2c_frag);
> +             if (i2c_frag_client) {
> +                     i2c_driver_data = 
> dev_get_drvdata(&i2c_frag_client->dev);
> +                     put_device(&i2c_frag_client->dev);
> +             }
> +             if (!i2c_driver_data)
> +                     return dev_err_probe(dev, -EPROBE_DEFER, "failed to get 
> i2c-frag\n");
> +     }
> +
>       ctx = devm_drm_panel_alloc(dev, struct ili9806e_panel, panel, 
> &ili9806e_funcs,
>                                  DRM_MODE_CONNECTOR_DSI);
>       if (IS_ERR(ctx))
> @@ -181,7 +200,7 @@ static int ili9806e_dsi_probe(struct mipi_dsi_device *dsi)
>       if (ret < 0)
>               return ret;
>
> -     ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +     ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);

As mentioned in my previous reply. I'm not really sure this will
work. Do you have a regulator attached and described in the device
tree? First, that will still be disabled and not having a reset
then is bad. Also I guess the init sequeuce will still be run if the
panel is turned off and on again. And then there will be no reset to
defaults.

>       if (IS_ERR(ctx->reset_gpio))
>               return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
>                                    "Failed to get reset-gpios\n");
> @@ -542,8 +561,188 @@ static const struct panel_desc dmt028vghmcmi_1d_desc = {
>       .lanes = 2,
>  };
>
> +static u8 dsi_read(struct mipi_dsi_multi_context *ctx, u8 command)
> +{
> +     struct mipi_dsi_device *dsi = ctx->dsi;
> +
> +     u8 len = 1;
> +     u8 result_data = 0xFF;

Use lower case, as you've already did below.

> +
> +     mipi_dsi_set_maximum_return_packet_size(dsi, 1);
> +     mipi_dsi_dcs_read(dsi, command, &result_data, len);
> +
> +     return result_data;
> +}
> +
> +static void dmt050wvnmcmi_1a_init(struct mipi_dsi_multi_context *ctx)
> +{
> +     // Try to read pixel format to check display connection

Use C comments /* */

> +     u8 pixel_format = dsi_read(ctx, 0x0c);

Also this is just used once. You could just use the two commands
here. "dsi_read" is a pretty common name which might cause aliasing
issues in the future.

> +
> +     if (pixel_format != 0x70)
> +             dev_err(&ctx->dsi->dev, "Read pixel format failed: %d\n", 
> pixel_format);

So? No return? Just an error message? Also if you happen to know
what 0x70 is, please either add a define or a comment.

> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xff, 0xff, 0x98, 0x06, 0x04, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x08, 0x10);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x20, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x21, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x30, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x31, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x40, 0x16);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x41, 0x33);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x42, 0x03);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x43, 0x09);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x44, 0x06);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x50, 0x88);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x51, 0x88);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x52, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x53, 0x49);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x55, 0x49);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x60, 0x07);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x61, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x62, 0x07);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x63, 0x00);
> +
> +     //Positive Gamma
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA0, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA1, 0x09);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA2, 0x11);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA3, 0x0B);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA4, 0x05);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA5, 0x08);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA6, 0x06);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA7, 0x04);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA8, 0x09);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xA9, 0x0C);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xAA, 0x15);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xAB, 0x08);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xAC, 0x0F);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xAD, 0x12);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xAE, 0x09);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xAF, 0x00);
> +
> +     //Negative Gamma
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC0, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC1, 0x09);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC2, 0x10);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC3, 0x0C);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC4, 0x05);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC5, 0x08);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC6, 0x06);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC7, 0x04);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC8, 0x08);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xC9, 0x0C);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xCA, 0x14);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xCB, 0x08);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xCC, 0x0F);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xCD, 0x11);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xCE, 0x09);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xCF, 0x00);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xff, 0xff, 0x98, 0x06, 0x04, 0x6);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x00, 0x20);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x01, 0x0A);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x02, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x03, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x04, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x05, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x06, 0x98);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x07, 0x06);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x08, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x09, 0x80);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x0A, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x0B, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x0C, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x0D, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x0E, 0x05);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x0F, 0x00);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x10, 0xF0);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x11, 0xF4);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x12, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x13, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x14, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x15, 0xC0);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x16, 0x08);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x17, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x18, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x19, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x1A, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x1B, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x1C, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x1D, 0x00);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x20, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x21, 0x23);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x22, 0x45);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x23, 0x67);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x24, 0x01);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x25, 0x23);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x26, 0x45);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x27, 0x67);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x30, 0x11);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x31, 0x11);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x32, 0x00);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x33, 0xEE);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x34, 0xFF);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x35, 0xBB);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x36, 0xAA);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x37, 0xDD);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x38, 0xCC);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x39, 0x66);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x3A, 0x77);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x3B, 0x22);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x3C, 0x22);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x3D, 0x22);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x3E, 0x22);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x3F, 0x22);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x40, 0x22);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xff, 0xff, 0x98, 0x06, 0x04, 0x07);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x17, 0x22);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x02, 0x77);
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x26, 0xB2);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0xff, 0xff, 0x98, 0x06, 0x04, 0x00);
> +
> +     mipi_dsi_dcs_write_seq_multi(ctx, 0x3A, 0x70); //Data format RGB24

For all the numbers above, please use lower case to match the style
of this file.

-michael

> +};
> +
> +static const struct drm_display_mode dmt050wvnmcmi_1a_default_mode = {
> +     .clock          = 41666,
> +
> +     .hdisplay       = 480,
> +     .hsync_start    = 480 + 100,
> +     .hsync_end      = 480 + 100 + 10,
> +     .htotal         = 480 + 100 + 10 + 50,
> +
> +     .vdisplay       = 854,
> +     .vsync_start    = 854 + 20,
> +     .vsync_end      = 854 + 20 + 4,
> +     .vtotal         = 854 + 20 + 4 + 20,
> +
> +     .width_mm       = 61,
> +     .height_mm      = 109,
> +
> +     .flags          = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
> +     .type           = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +};
> +
> +static const struct panel_desc dmt050wvnmcmi_1a_desc = {
> +     .init_sequence = dmt050wvnmcmi_1a_init,
> +     .display_mode = &dmt050wvnmcmi_1a_default_mode,
> +     .mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
> +                   MIPI_DSI_MODE_LPM | MIPI_DSI_CLOCK_NON_CONTINUOUS,
> +     .format = MIPI_DSI_FMT_RGB888,
> +     .lanes = 2,
> +};
> +
>  static const struct of_device_id ili9806e_of_match[] = {
>       { .compatible = "densitron,dmt028vghmcmi-1d", .data = 
> &dmt028vghmcmi_1d_desc },
> +     { .compatible = "densitron,dmt050wvnmcmi-1a", .data = 
> &dmt050wvnmcmi_1a_desc },
>       { .compatible = "ortustech,com35h3p70ulc", .data = &com35h3p70ulc_desc 
> },
>       { }
>  };
> @@ -561,5 +760,6 @@ module_mipi_dsi_driver(ili9806e_dsi_driver);
>
>  MODULE_AUTHOR("Gunnar Dibbern <[email protected]>");
>  MODULE_AUTHOR("Michael Walle <[email protected]>");
> +MODULE_AUTHOR("Bart Steinmayr <[email protected]>");
>  MODULE_DESCRIPTION("Ilitek ILI9806E Controller Driver");
>  MODULE_LICENSE("GPL");

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