On Wed 26 Jun 2024 at 07:41, Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> wrote:
> On Tue, Jun 25, 2024 at 04:25:50PM GMT, Jerome Brunet wrote:
>> Add support for the Lincoln LCD197 1080x1920 DSI panel.
>>
>> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
>> ---
>> drivers/gpu/drm/panel/Kconfig | 11 +
>> drivers/gpu/drm/panel/Makefile | 1 +
>> drivers/gpu/drm/panel/panel-lincoln-lcd197.c | 333 +++++++++++++++++++
>> 3 files changed, 345 insertions(+)
>> create mode 100644 drivers/gpu/drm/panel/panel-lincoln-lcd197.c
>>
>
> [...]
>
>> +
>> + mipi_dsi_dcs_write_seq(lcd->dsi, 0xB9, 0xFF, 0x83, 0x99);
>
> - Please use lowercase hex instead
> - Please consider switching to _multi() functions.
Could you be a bit more specific about these '_multi' function ?
I've looked at 'drm_mipi_dsi.h' and can't really make what you mean.
Maybe I'm not looking in the right place.
>
>
>> + usleep_range(200, 300);
>
> This will require new helper msm_dsi_usleep_range(ctx, 200, 300);
I don't really understand why I would need something else to just sleep
? Could you add some context please ?
Isn't 'msm_' usually something Qcom specific ?
>
>> + mipi_dsi_dcs_write_seq(lcd->dsi, 0xB6, 0x92, 0x92);
>> + mipi_dsi_dcs_write_seq(lcd->dsi, 0xCC, 0x00);
>> + mipi_dsi_dcs_write_seq(lcd->dsi, 0xBF, 0x40, 0x41, 0x50, 0x49);
>> + mipi_dsi_dcs_write_seq(lcd->dsi, 0xC6, 0xFF, 0xF9);
>> + mipi_dsi_dcs_write_seq(lcd->dsi, 0xC0, 0x25, 0x5A);
>> + mipi_dsi_dcs_write_seq(lcd->dsi, MIPI_DCS_SET_ADDRESS_MODE, 0x02);
>> +
>> + err = mipi_dsi_dcs_exit_sleep_mode(lcd->dsi);
>> + if (err < 0) {
>> + dev_err(panel->dev, "failed to exit sleep mode: %d\n", err);
>> + goto poweroff;
>> + }
>> + msleep(120);
>> +
>> + err = mipi_dsi_dcs_read(lcd->dsi, MIPI_DCS_GET_DISPLAY_ID, display_id, 3);
>
> This probably needs new _multi helper too.
>
>> + if (err < 0) {
>> + dev_err(panel->dev, "Failed to read display id: %d\n", err);
>> + } else {
>> + dev_dbg(panel->dev, "Display id: 0x%02x-0x%02x-0x%02x\n",
>> + display_id[0], display_id[1], display_id[2]);
>> + }
>> +
>> + lcd->prepared = true;
>
> Should not be required anymore.
The whole driver is heavily inspired by what is already in
drivers/gpu/drm/panel/ and a lot are doing something similar.
Maybe there has been a change since then and the existing have been
reworked yet. Would you mind pointing me that change if that is
the case ?
>
>> +
>> + return 0;
>> +
>> +poweroff:
>> + gpiod_set_value_cansleep(lcd->enable_gpio, 0);
>> + gpiod_set_value_cansleep(lcd->reset_gpio, 1);
>> + regulator_disable(lcd->supply);
>> +
>> + return err;
>> +}
>> +
>
>> +
>> +static const struct drm_display_mode default_mode = {
>> + .clock = 154002,
>> + .hdisplay = 1080,
>> + .hsync_start = 1080 + 20,
>> + .hsync_end = 1080 + 20 + 6,
>> + .htotal = 1080 + 204,
>> + .vdisplay = 1920,
>> + .vsync_start = 1920 + 4,
>> + .vsync_end = 1920 + 4 + 4,
>> + .vtotal = 1920 + 79,
>> + .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
>> +};
>> +
>> +static int lincoln_lcd197_panel_get_modes(struct drm_panel *panel,
>> + struct drm_connector *connector)
>> +{
>> + struct drm_display_mode *mode;
>> +
>> + mode = drm_mode_duplicate(connector->dev, &default_mode);
>> + if (!mode) {
>> + dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
>> + default_mode.hdisplay, default_mode.vdisplay,
>> + drm_mode_vrefresh(&default_mode));
>> + return -ENOMEM;
>> + }
>> +
>> + drm_mode_set_name(mode);
>> + drm_mode_probed_add(connector, mode);
>> + connector->display_info.width_mm = 79;
>> + connector->display_info.height_mm = 125;
>
> drm_connector_helper_get_modes_fixed()
Thanks for the hint
>
>> +
>> + return 1;
>> +}
>> +
>
>
>> +
>> +static void lincoln_lcd197_panel_shutdown(struct mipi_dsi_device *dsi)
>> +{
>> + struct lincoln_lcd197_panel *lcd = mipi_dsi_get_drvdata(dsi);
>> +
>> + drm_panel_disable(&lcd->panel);
>> + drm_panel_unprepare(&lcd->panel);
>> +}
>
> I think the agreement was that there should be no need for the panel's
> shutdown, the DRM driver should shutdown the panel.
I'm happy to drop that if there is such agreement. Again, most panel
drivers do implement that callback so I just did the same.
Could you point me to this 'agreement' please, so I can get a better
understanding of it ?
--
Jerome
