drm: panel: Add a panel driver for the Summit display

This is the display panel used for the touchbar on laptops that have it.

Co-developed-by: Nick Chan <towinchenmi@gmail.com>
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Link: https://lore.kernel.org/r/20250217-adpdrm-v7-3-ca2e44b3c7d8@gmail.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250217-adpdrm-v7-3-ca2e44b3c7d8@gmail.com

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

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

drivers/gpu/drm/panel/panel-summit.c

@@ -0,0 +1,132 @@
+// 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 <drm/drm_probe_helper.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);
+}
+
+static int summit_bl_update_status(struct backlight_device *dev)
+{
+	return summit_set_brightness(&dev->dev);
+}
+
+static const struct backlight_ops summit_bl_ops = {
+	.update_status	= summit_bl_update_status,
+};
+
+static struct drm_display_mode summit_mode = {
+	.vdisplay = 2008,
+	.hdisplay = 60,
+	.hsync_start = 60 + 8,
+	.hsync_end = 60 + 8 + 80,
+	.htotal = 60 + 8 + 80 + 40,
+	.vsync_start = 2008 + 1,
+	.vsync_end = 2008 + 1 + 15,
+	.vtotal = 2008 + 1 + 15 + 6,
+	.clock = ((60 + 8 + 80 + 40) * (2008 + 1 + 15 + 6) * 60) / 1000,
+	.type = DRM_MODE_TYPE_DRIVER,
+	.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NVSYNC,
+};
+
+static int summit_get_modes(struct drm_panel *panel,
+			    struct drm_connector *connector)
+{
+	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);
+
+	return drm_connector_helper_get_modes_fixed(connector, &summit_mode);
+}
+
+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_suspend(struct device *dev)
+{
+	struct summit_data *s_data = dev_get_drvdata(dev);
+
+	return mipi_dsi_dcs_set_display_brightness(s_data->dsi, 0);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(summit_pm_ops, summit_suspend,
+				summit_set_brightness);
+
+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");