[PATCH v2 3/5] drm: panel: Add a panel driver for the Summit display

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Sat Nov 30 01:29:07 PST 2024


On Tue, Nov 26, 2024 at 05:34:22PM +0100, Sasha Finkelstein via B4 Relay wrote:
> From: Sasha Finkelstein <fnkl.kernel at gmail.com>
> 
> This is the display panel used for the touchbar on laptops that have it.
> 
> Co-developed-by: Nick Chan <towinchenmi at gmail.com>
> Signed-off-by: Nick Chan <towinchenmi at gmail.com>
> Signed-off-by: Sasha Finkelstein <fnkl.kernel at gmail.com>
> ---
>  drivers/gpu/drm/panel/Kconfig        |   9 +++
>  drivers/gpu/drm/panel/Makefile       |   1 +
>  drivers/gpu/drm/panel/panel-summit.c | 143 +++++++++++++++++++++++++++++++++++
>  3 files changed, 153 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index d7469c565d1db8b8e974dd6c45d03d9352d99d63..5085a82e4bc695e85cabbc3200859bbe10cb0f91 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -925,6 +925,15 @@ config DRM_PANEL_SIMPLE
>  	  that it can be automatically turned off when the panel goes into a
>  	  low power state.
>  
> +config DRM_PANEL_SUMMIT
> +	tristate "Apple Summit display panel"
> +	depends on OF
> +	depends on DRM_MIPI_DSI
> +	depends on BACKLIGHT_CLASS_DEVICE
> +	help
> +	  Say Y if you want to enable support for the "Summit" display panel
> +	  used as a touchbar on certain Apple laptops.
> +
>  config DRM_PANEL_SYNAPTICS_R63353
>  	tristate "Synaptics R63353-based panels"
>  	depends on OF
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index 7dcf72646cacff11bab90c78e3b8b1f357e5f14a..10ac2e850f5cd6d6546439de75483466e4015d1a 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -89,6 +89,7 @@ obj-$(CONFIG_DRM_PANEL_SHARP_LS060T1SX01) += panel-sharp-ls060t1sx01.o
>  obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7701) += panel-sitronix-st7701.o
>  obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7703) += panel-sitronix-st7703.o
>  obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
> +obj-$(CONFIG_DRM_PANEL_SUMMIT) += panel-summit.o
>  obj-$(CONFIG_DRM_PANEL_SYNAPTICS_R63353) += panel-synaptics-r63353.o
>  obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
>  obj-$(CONFIG_DRM_PANEL_SONY_TD4353_JDI) += panel-sony-td4353-jdi.o
> diff --git a/drivers/gpu/drm/panel/panel-summit.c b/drivers/gpu/drm/panel/panel-summit.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..16bd9fa1213d7bc3f022b878ea5cfeadbd468995
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-summit.c
> @@ -0,0 +1,143 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <linux/backlight.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_mode.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +#include <video/mipi_display.h>
> +
> +struct summit_data {
> +	struct mipi_dsi_device *dsi;
> +	struct backlight_device *bl;
> +	struct drm_panel panel;
> +};
> +
> +static int summit_set_brightness(struct device *dev)
> +{
> +	struct summit_data *s_data = dev_get_drvdata(dev);
> +	int level = backlight_get_brightness(s_data->bl);
> +
> +	return mipi_dsi_dcs_set_display_brightness(s_data->dsi, level);
> +}

Inline this function.

> +
> +static int summit_bl_update_status(struct backlight_device *dev)
> +{
> +	return summit_set_brightness(&dev->dev);
> +}
> +
> +static int summit_bl_get_brightness(struct backlight_device *dev)
> +{
> +	return backlight_get_brightness(dev);
> +}

Should not be necessary, please drop. Moreover
backlight_get_brightness() uses blanking information to override
brightness. As such it is not suitable for the .get_brightness()
callback.

> +
> +static const struct backlight_ops summit_bl_ops = {
> +	.get_brightness = summit_bl_get_brightness,
> +	.update_status	= summit_bl_update_status,
> +};
> +
> +static int summit_get_modes(struct drm_panel *panel,
> +			    struct drm_connector *connector)
> +{
> +	struct drm_display_mode *mode = drm_mode_create(connector->dev);
> +
> +	connector->display_info.non_desktop = true;
> +	drm_object_property_set_value(&connector->base,
> +				      connector->dev->mode_config.non_desktop_property,
> +				      connector->display_info.non_desktop);
> +
> +	mode->vdisplay = 2008;
> +	mode->hdisplay = 60;
> +	mode->hsync_start = mode->hdisplay + 8;
> +	mode->hsync_end = mode->hsync_start + 80;
> +	mode->htotal = mode->hsync_end + 40;
> +	mode->vsync_start = mode->vdisplay + 1;
> +	mode->vsync_end = mode->vsync_start + 15;
> +	mode->vtotal = mode->vsync_end + 6;
> +	mode->clock = (mode->vtotal * mode->htotal * 60) / 1000;
> +	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> +	mode->flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NVSYNC;
> +	drm_mode_set_name(mode);
> +	drm_mode_probed_add(connector, mode);
> +	return 1;
> +}
> +
> +static const struct drm_panel_funcs summit_panel_funcs = {
> +	.get_modes = summit_get_modes,
> +};
> +
> +static int summit_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct backlight_properties props = { 0 };
> +	struct device *dev = &dsi->dev;
> +	struct summit_data *s_data;
> +	int ret;
> +
> +	s_data = devm_kzalloc(dev, sizeof(*s_data), GFP_KERNEL);
> +	if (!s_data)
> +		return -ENOMEM;
> +
> +	mipi_dsi_set_drvdata(dsi, s_data);
> +	s_data->dsi = dsi;
> +
> +	ret = device_property_read_u32(dev, "max-brightness", &props.max_brightness);
> +	if (ret)
> +		return ret;
> +	props.type = BACKLIGHT_RAW;
> +
> +	s_data->bl = devm_backlight_device_register(dev, dev_name(dev),
> +						   dev, s_data, &summit_bl_ops, &props);
> +	if (IS_ERR(s_data->bl))
> +		return PTR_ERR(s_data->bl);
> +
> +	drm_panel_init(&s_data->panel, dev, &summit_panel_funcs,
> +		       DRM_MODE_CONNECTOR_DSI);
> +	drm_panel_add(&s_data->panel);
> +
> +	return mipi_dsi_attach(dsi);
> +}
> +
> +static void summit_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct summit_data *s_data = mipi_dsi_get_drvdata(dsi);
> +
> +	mipi_dsi_detach(dsi);
> +	drm_panel_remove(&s_data->panel);
> +}
> +
> +static int summit_resume(struct device *dev)
> +{
> +	return summit_set_brightness(dev);

Doesn't the generic code already handle that for you?

> +}
> +
> +static int summit_suspend(struct device *dev)
> +{
> +	struct summit_data *s_data = dev_get_drvdata(dev);
> +
> +	return mipi_dsi_dcs_set_display_brightness(s_data->dsi, 0);

And here too.

> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(summit_pm_ops, summit_suspend,
> +				summit_resume);
> +
> +static const struct of_device_id summit_of_match[] = {
> +	{ .compatible = "apple,summit" },
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(of, summit_of_match);
> +
> +static struct mipi_dsi_driver summit_driver = {
> +	.probe = summit_probe,
> +	.remove = summit_remove,
> +	.driver = {
> +		.name = "panel-summit",
> +		.of_match_table = summit_of_match,
> +		.pm = pm_sleep_ptr(&summit_pm_ops),
> +	},
> +};
> +module_mipi_dsi_driver(summit_driver);
> +
> +MODULE_DESCRIPTION("Summit Display Panel Driver");
> +MODULE_LICENSE("GPL");
> 
> -- 
> 2.47.1
> 
> 

-- 
With best wishes
Dmitry



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