From 7dae9f51796a57f9b308fd08275b082b3822bde9 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Fri, 14 Apr 2023 13:50:08 +0100
Subject: [PATCH 0438/1085] drm/panel: Add panel driver for Waveshare DSI
 touchscreens

Waveshare sell a range of DSI panels of varying sizes, all
using a common MCU to control the panel and backlight.

Add a panel driver that supports these panels.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/panel/Kconfig               |  10 +
 drivers/gpu/drm/panel/Makefile              |   1 +
 drivers/gpu/drm/panel/panel-waveshare-dsi.c | 410 ++++++++++++++++++++
 3 files changed, 421 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-waveshare-dsi.c

--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -838,6 +838,16 @@ config DRM_PANEL_VISIONOX_R66451
 	  Say Y here if you want to enable support for Visionox
 	  R66451 1080x2340 AMOLED DSI panel.
 
+config DRM_PANEL_WAVESHARE_TOUCHSCREEN
+	tristate "Waveshare touchscreen panels"
+	depends on DRM_MIPI_DSI
+	depends on I2C
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for the Waveshare
+	  DSI Touchscreens.  To compile this driver as a module,
+	  choose M here.
+
 config DRM_PANEL_WIDECHIPS_WS2401
 	tristate "Widechips WS2401 DPI panel driver"
 	depends on SPI && GPIOLIB
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -85,5 +85,6 @@ obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQX
 obj-$(CONFIG_DRM_PANEL_VISIONOX_RM69299) += panel-visionox-rm69299.o
 obj-$(CONFIG_DRM_PANEL_VISIONOX_VTDR6130) += panel-visionox-vtdr6130.o
 obj-$(CONFIG_DRM_PANEL_VISIONOX_R66451) += panel-visionox-r66451.o
+obj-$(CONFIG_DRM_PANEL_WAVESHARE_TOUCHSCREEN) += panel-waveshare-dsi.o
 obj-$(CONFIG_DRM_PANEL_WIDECHIPS_WS2401) += panel-widechips-ws2401.o
 obj-$(CONFIG_DRM_PANEL_XINPENG_XPP055C272) += panel-xinpeng-xpp055c272.o
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-waveshare-dsi.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright © 2023 Raspberry Pi Ltd
+ *
+ * Based on panel-raspberrypi-touchscreen by Broadcom
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/pm.h>
+
+#include <drm/drm_crtc.h>
+#include <drm/drm_device.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#define WS_DSI_DRIVER_NAME "ws-ts-dsi"
+
+struct ws_panel {
+	struct drm_panel base;
+	struct mipi_dsi_device *dsi;
+	struct i2c_client *i2c;
+	const struct drm_display_mode *mode;
+	enum drm_panel_orientation orientation;
+};
+
+/* 2.8inch 480x640
+ * https://www.waveshare.com/product/raspberry-pi/displays/2.8inch-dsi-lcd.htm
+ */
+static const struct drm_display_mode ws_panel_2_8_mode = {
+	.clock = 50000,
+	.hdisplay = 480,
+	.hsync_start = 480 + 150,
+	.hsync_end = 480 + 150 + 50,
+	.htotal = 480 + 150 + 50 + 150,
+	.vdisplay = 640,
+	.vsync_start = 640 + 150,
+	.vsync_end = 640 + 150 + 50,
+	.vtotal = 640 + 150 + 50 + 150,
+};
+
+/* 3.4inch 800x800 Round
+ * https://www.waveshare.com/product/displays/lcd-oled/3.4inch-dsi-lcd-c.htm
+ */
+static const struct drm_display_mode ws_panel_3_4_mode = {
+	.clock = 50000,
+	.hdisplay = 800,
+	.hsync_start = 800 + 32,
+	.hsync_end = 800 + 32 + 6,
+	.htotal = 800 + 32 + 6 + 120,
+	.vdisplay = 800,
+	.vsync_start = 800 + 8,
+	.vsync_end = 800 + 8 + 4,
+	.vtotal = 800 + 8 + 4 + 16,
+};
+
+/* 4.0inch 480x800
+ * https://www.waveshare.com/product/raspberry-pi/displays/4inch-dsi-lcd.htm
+ */
+static const struct drm_display_mode ws_panel_4_0_mode = {
+	.clock = 50000,
+	.hdisplay = 480,
+	.hsync_start = 480 + 150,
+	.hsync_end = 480 + 150 + 100,
+	.htotal = 480 + 150 + 100 + 150,
+	.vdisplay = 800,
+	.vsync_start = 800 + 20,
+	.vsync_end = 800 + 20 + 100,
+	.vtotal = 800 + 20 + 100 + 20,
+};
+
+/* 7.0inch C 1024x600
+ * https://www.waveshare.com/product/raspberry-pi/displays/lcd-oled/7inch-dsi-lcd-c-with-case-a.htm
+ */
+static const struct drm_display_mode ws_panel_7_0_c_mode = {
+	.clock = 50000,
+	.hdisplay = 1024,
+	.hsync_start = 1024 + 100,
+	.hsync_end = 1024 + 100 + 100,
+	.htotal = 1024 + 100 + 100 + 100,
+	.vdisplay = 600,
+	.vsync_start = 600 + 10,
+	.vsync_end = 600 + 10 + 10,
+	.vtotal = 600 + 10 + 10 + 10,
+};
+
+/* 7.9inch 400x1280
+ * https://www.waveshare.com/product/raspberry-pi/displays/7.9inch-dsi-lcd.htm
+ */
+static const struct drm_display_mode ws_panel_7_9_mode = {
+	.clock = 50000,
+	.hdisplay = 400,
+	.hsync_start = 400 + 40,
+	.hsync_end = 400 + 40 + 30,
+	.htotal = 400 + 40 + 30 + 40,
+	.vdisplay = 1280,
+	.vsync_start = 1280 + 20,
+	.vsync_end = 1280 + 20 + 10,
+	.vtotal = 1280 + 20 + 10 + 20,
+};
+
+/* 8.0inch or 10.1inch 1280x800
+ * https://www.waveshare.com/product/raspberry-pi/displays/8inch-dsi-lcd-c.htm
+ * https://www.waveshare.com/product/raspberry-pi/displays/10.1inch-dsi-lcd-c.htm
+ */
+static const struct drm_display_mode ws_panel_10_1_mode = {
+	.clock = 76800,
+	.hdisplay = 1280,
+	.hsync_start = 1280 + 40,
+	.hsync_end = 1280 + 40 + 20,
+	.htotal = 1280 + 40 + 20 + 40,
+	.vdisplay = 800,
+	.vsync_start = 800 + 40,
+	.vsync_end = 800 + 40 + 48,
+	.vtotal = 800 + 40 + 48 + 40,
+};
+
+/* 11.9inch 320x1480
+ * https://www.waveshare.com/product/raspberry-pi/displays/11.9inch-dsi-lcd.htm
+ */
+static const struct drm_display_mode ws_panel_11_9_mode = {
+	.clock = 50000,
+	.hdisplay = 320,
+	.hsync_start = 320 + 60,
+	.hsync_end = 320 + 60 + 60,
+	.htotal = 320 + 60 + 60 + 120,
+	.vdisplay = 1480,
+	.vsync_start = 1480 + 60,
+	.vsync_end = 1480 + 60 + 60,
+	.vtotal = 1480 + 60 + 60 + 60,
+};
+
+static struct ws_panel *panel_to_ts(struct drm_panel *panel)
+{
+	return container_of(panel, struct ws_panel, base);
+}
+
+static void ws_panel_i2c_write(struct ws_panel *ts, u8 reg, u8 val)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
+	if (ret)
+		dev_err(&ts->i2c->dev, "I2C write failed: %d\n", ret);
+}
+
+static int ws_panel_disable(struct drm_panel *panel)
+{
+	struct ws_panel *ts = panel_to_ts(panel);
+
+	ws_panel_i2c_write(ts, 0xad, 0x00);
+
+	return 0;
+}
+
+static int ws_panel_unprepare(struct drm_panel *panel)
+{
+	return 0;
+}
+
+static int ws_panel_prepare(struct drm_panel *panel)
+{
+	return 0;
+}
+
+static int ws_panel_enable(struct drm_panel *panel)
+{
+	struct ws_panel *ts = panel_to_ts(panel);
+
+	ws_panel_i2c_write(ts, 0xad, 0x01);
+
+	return 0;
+}
+
+static int ws_panel_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+	struct ws_panel *ts = panel_to_ts(panel);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, ts->mode);
+	if (!mode) {
+		dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
+			ts->mode->hdisplay,
+			ts->mode->vdisplay,
+			drm_mode_vrefresh(ts->mode));
+	}
+
+	mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+
+	drm_mode_set_name(mode);
+
+	drm_mode_probed_add(connector, mode);
+
+	connector->display_info.bpc = 8;
+	connector->display_info.width_mm = 154;
+	connector->display_info.height_mm = 86;
+	drm_display_info_set_bus_formats(&connector->display_info,
+					 &bus_format, 1);
+
+	/*
+	 * TODO: Remove once all drm drivers call
+	 * drm_connector_set_orientation_from_panel()
+	 */
+	drm_connector_set_panel_orientation(connector, ts->orientation);
+
+	return 1;
+}
+
+static enum drm_panel_orientation ws_panel_get_orientation(struct drm_panel *panel)
+{
+	struct ws_panel *ts = panel_to_ts(panel);
+
+	return ts->orientation;
+}
+
+static const struct drm_panel_funcs ws_panel_funcs = {
+	.disable = ws_panel_disable,
+	.unprepare = ws_panel_unprepare,
+	.prepare = ws_panel_prepare,
+	.enable = ws_panel_enable,
+	.get_modes = ws_panel_get_modes,
+	.get_orientation = ws_panel_get_orientation,
+};
+
+static int ws_panel_bl_update_status(struct backlight_device *bl)
+{
+	struct ws_panel *ts = bl_get_data(bl);
+
+	ws_panel_i2c_write(ts, 0xab, 0xff - backlight_get_brightness(bl));
+	ws_panel_i2c_write(ts, 0xaa, 0x01);
+
+	return 0;
+}
+
+static const struct backlight_ops ws_panel_bl_ops = {
+	.update_status = ws_panel_bl_update_status,
+};
+
+static struct backlight_device *
+ws_panel_create_backlight(struct ws_panel *ts)
+{
+	struct device *dev = ts->base.dev;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 255,
+		.max_brightness = 255,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, ts,
+					      &ws_panel_bl_ops, &props);
+}
+
+static int ws_panel_probe(struct i2c_client *i2c)
+{
+	struct device *dev = &i2c->dev;
+	struct ws_panel *ts;
+	struct device_node *endpoint, *dsi_host_node;
+	struct mipi_dsi_host *host;
+	struct mipi_dsi_device_info info = {
+		.type = WS_DSI_DRIVER_NAME,
+		.channel = 0,
+		.node = NULL,
+	};
+	int ret;
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	ts->mode = of_device_get_match_data(dev);
+	if (!ts->mode)
+		return -EINVAL;
+
+	i2c_set_clientdata(i2c, ts);
+
+	ts->i2c = i2c;
+
+	ws_panel_i2c_write(ts, 0xc0, 0x01);
+	ws_panel_i2c_write(ts, 0xc2, 0x01);
+	ws_panel_i2c_write(ts, 0xac, 0x01);
+
+	ret = of_drm_get_panel_orientation(dev->of_node, &ts->orientation);
+	if (ret) {
+		dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, ret);
+		return ret;
+	}
+
+	/* Look up the DSI host.  It needs to probe before we do. */
+	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
+	if (!endpoint)
+		return -ENODEV;
+
+	dsi_host_node = of_graph_get_remote_port_parent(endpoint);
+	if (!dsi_host_node)
+		goto error;
+
+	host = of_find_mipi_dsi_host_by_node(dsi_host_node);
+	of_node_put(dsi_host_node);
+	if (!host) {
+		of_node_put(endpoint);
+		return -EPROBE_DEFER;
+	}
+
+	info.node = of_graph_get_remote_port(endpoint);
+	if (!info.node)
+		goto error;
+
+	of_node_put(endpoint);
+
+	ts->dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
+	if (IS_ERR(ts->dsi)) {
+		dev_err(dev, "DSI device registration failed: %ld\n",
+			PTR_ERR(ts->dsi));
+		return PTR_ERR(ts->dsi);
+	}
+
+	drm_panel_init(&ts->base, dev, &ws_panel_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	ts->base.backlight = ws_panel_create_backlight(ts);
+	if (IS_ERR(ts->base.backlight)) {
+		ret = PTR_ERR(ts->base.backlight);
+		dev_err(dev, "Failed to create backlight: %d\n", ret);
+		return ret;
+	}
+
+	/* This appears last, as it's what will unblock the DSI host
+	 * driver's component bind function.
+	 */
+	drm_panel_add(&ts->base);
+
+	ts->dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
+			   MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+			   MIPI_DSI_MODE_LPM);
+	ts->dsi->format = MIPI_DSI_FMT_RGB888;
+	ts->dsi->lanes = 2;
+
+	ret = devm_mipi_dsi_attach(dev, ts->dsi);
+
+	if (ret)
+		dev_err(dev, "failed to attach dsi to host: %d\n", ret);
+
+	return 0;
+
+error:
+	of_node_put(endpoint);
+	return -ENODEV;
+}
+
+static void ws_panel_remove(struct i2c_client *i2c)
+{
+	struct ws_panel *ts = i2c_get_clientdata(i2c);
+
+	drm_panel_remove(&ts->base);
+}
+
+static const struct of_device_id ws_panel_of_ids[] = {
+	{
+		.compatible = "waveshare,2.8inch-panel",
+		.data = &ws_panel_2_8_mode,
+	}, {
+		.compatible = "waveshare,3.4inch-panel",
+		.data = &ws_panel_3_4_mode,
+	}, {
+		.compatible = "waveshare,4.0inch-panel",
+		.data = &ws_panel_4_0_mode,
+	}, {
+		.compatible = "waveshare,7.0inch-c-panel",
+		.data = &ws_panel_7_0_c_mode,
+	}, {
+		.compatible = "waveshare,7.9inch-panel",
+		.data = &ws_panel_7_9_mode,
+	}, {
+		.compatible = "waveshare,8.0inch-panel",
+		.data = &ws_panel_10_1_mode,
+	}, {
+		.compatible = "waveshare,10.1inch-panel",
+		.data = &ws_panel_10_1_mode,
+	}, {
+		.compatible = "waveshare,11.9inch-panel",
+		.data = &ws_panel_11_9_mode,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, ws_panel_of_ids);
+
+static struct i2c_driver ws_panel_driver = {
+	.driver = {
+		.name = "ws_touchscreen",
+		.of_match_table = ws_panel_of_ids,
+	},
+	.probe = ws_panel_probe,
+	.remove = ws_panel_remove,
+};
+module_i2c_driver(ws_panel_driver);
+
+MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.com>");
+MODULE_DESCRIPTION("Waveshare DSI panel driver");
+MODULE_LICENSE("GPL");
