openwrt/target/linux/brcm2708/patches-4.4/0444-drm-panel-Add-support-...

391 lines
11 KiB
Diff

From 4557de6d23737cf44fa5ddf1379be59d4bca2df7 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Tue, 26 Apr 2016 13:46:13 -0700
Subject: [PATCH] drm/panel: Add support for the Raspberry Pi 7" Touchscreen.
Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/gpu/drm/panel/Kconfig | 9 +
drivers/gpu/drm/panel/Makefile | 1 +
.../gpu/drm/panel/panel-raspberrypi-touchscreen.c | 347 +++++++++++++++++++++
3 files changed, 357 insertions(+)
create mode 100644 drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -31,6 +31,15 @@ config DRM_PANEL_LG_LG4573
Say Y here if you want to enable support for LG4573 RGB panel.
To compile this driver as a module, choose M here.
+config DRM_PANEL_RASPBERRYPI_TOUCHSCREEN
+ tristate "Raspberry Pi 7-inch touchscreen panel"
+ depends on DRM_MIPI_DSI
+ depends on BACKLIGHT_CLASS_DEVICE
+ help
+ Say Y here if you want to enable support for the Raspberry
+ Pi 7" Touchscreen. To compile this driver as a module,
+ choose M here.
+
config DRM_PANEL_SAMSUNG_S6E8AA0
tristate "Samsung S6E8AA0 DSI video mode panel"
depends on OF
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
+obj-$(CONFIG_DRM_PANEL_RASPBERRYPI_TOUCHSCREEN) += panel-raspberrypi-touchscreen.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -0,0 +1,347 @@
+/*
+ * Copyright © 2016 Broadcom Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Portions of this file (derived from panel-simple.c) are:
+ *
+ * Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * DOC: Raspberry Pi 7" touchscreen panel driver.
+ *
+ * The 7" touchscreen consists of a DPI LCD panel, a Toshiba
+ * TC358762XBG DSI-DPI bridge, and an I2C-connected Atmel ATTINY88-MUR
+ * controlling power management, the LCD PWM, and the touchscreen.
+ *
+ * This driver presents this device as a MIPI DSI panel to the DRM
+ * driver, and should expose the touchscreen as a HID device.
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.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_panel.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+struct rpi_touchscreen {
+ struct drm_panel base;
+ struct mipi_dsi_device *dsi;
+ struct i2c_client *bridge_i2c;
+ struct backlight_device *backlight;
+
+ bool prepared;
+ bool enabled;
+
+ /* Version of the firmware on the bridge chip */
+ int atmel_ver;
+};
+
+static const struct drm_display_mode rpi_touchscreen_modes[] = {
+ {
+ /* This is assuming that we'll be running the DSI PLL
+ * at 2Ghz / 3 (since we only get integer dividers),
+ * so a pixel clock of 2Ghz / 3 / 8.
+ */
+ .clock = 83333,
+ .hdisplay = 800,
+ .hsync_start = 800 + 61,
+ .hsync_end = 800 + 61 + 2,
+ .htotal = 800 + 61 + 2 + 44,
+ .vdisplay = 480,
+ .vsync_start = 480 + 7,
+ .vsync_end = 480 + 7 + 2,
+ .vtotal = 480 + 7 + 2 + 21,
+ .vrefresh = 60,
+ },
+};
+
+static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
+{
+ return container_of(panel, struct rpi_touchscreen, base);
+}
+
+struct regdump {
+ const char *reg;
+ u32 offset;
+};
+
+#define REGDUMP(reg) { #reg, reg }
+
+static int rpi_touchscreen_disable(struct drm_panel *panel)
+{
+ struct rpi_touchscreen *ts = panel_to_ts(panel);
+ pr_err("disable\n");
+
+ if (!ts->enabled)
+ return 0;
+
+ if (ts->backlight) {
+ ts->backlight->props.power = FB_BLANK_POWERDOWN;
+ backlight_update_status(ts->backlight);
+ }
+
+ ts->enabled = false;
+
+ return 0;
+}
+
+static int rpi_touchscreen_unprepare(struct drm_panel *panel)
+{
+ struct rpi_touchscreen *ts = panel_to_ts(panel);
+
+ if (!ts->prepared)
+ return 0;
+
+ ts->prepared = false;
+
+ return 0;
+}
+
+static int rpi_touchscreen_prepare(struct drm_panel *panel)
+{
+ struct rpi_touchscreen *ts = panel_to_ts(panel);
+
+ if (ts->prepared)
+ return 0;
+
+ ts->prepared = true;
+
+ return 0;
+}
+
+/*
+ * Powers on the panel once the DSI link is up.
+ *
+ * The TC358762 is run in PLLOFF mode, where it usees the MIPI DSI
+ * byte clock instead of an external reference clock. This means that
+ * we need the DSI host to be on and transmitting before we start
+ * talking to it.
+ */
+static int rpi_touchscreen_enable(struct drm_panel *panel)
+{
+ struct rpi_touchscreen *ts = panel_to_ts(panel);
+
+ if (ts->enabled)
+ return 0;
+
+ if (ts->backlight) {
+ ts->backlight->props.power = FB_BLANK_UNBLANK;
+ backlight_update_status(ts->backlight);
+ }
+
+ ts->enabled = true;
+
+ return 0;
+}
+
+static int rpi_touchscreen_get_modes(struct drm_panel *panel)
+{
+ struct drm_connector *connector = panel->connector;
+ struct drm_device *drm = panel->drm;
+ unsigned int i, num = 0;
+
+ for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
+ const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
+ struct drm_display_mode *mode;
+
+ mode = drm_mode_duplicate(drm, m);
+ if (!mode) {
+ dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
+ m->hdisplay, m->vdisplay, m->vrefresh);
+ continue;
+ }
+
+ mode->type |= DRM_MODE_TYPE_DRIVER;
+
+ if (i == 0)
+ mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+ drm_mode_set_name(mode);
+
+ drm_mode_probed_add(connector, mode);
+ num++;
+ }
+
+ connector->display_info.bpc = 8;
+ connector->display_info.width_mm = 217; /* XXX */
+ connector->display_info.height_mm = 136; /* XXX */
+
+ return num;
+}
+
+static int rpi_touchscreen_backlight_update(struct backlight_device *bl)
+{
+ int brightness = bl->props.brightness;
+
+ if (bl->props.power != FB_BLANK_UNBLANK ||
+ bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
+ brightness = 0;
+
+ return 0;
+}
+
+static const struct backlight_ops rpi_touchscreen_backlight_ops = {
+ .update_status = rpi_touchscreen_backlight_update,
+};
+
+static const struct drm_panel_funcs rpi_touchscreen_funcs = {
+ .disable = rpi_touchscreen_disable,
+ .unprepare = rpi_touchscreen_unprepare,
+ .prepare = rpi_touchscreen_prepare,
+ .enable = rpi_touchscreen_enable,
+ .get_modes = rpi_touchscreen_get_modes,
+};
+
+static struct i2c_client *rpi_touchscreen_get_i2c(struct device *dev,
+ const char *name)
+{
+ struct device_node *node;
+ struct i2c_client *client;
+
+ node = of_parse_phandle(dev->of_node, name, 0);
+ if (!node)
+ return ERR_PTR(-ENODEV);
+
+ client = of_find_i2c_device_by_node(node);
+
+ of_node_put(node);
+
+ return client;
+}
+
+static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
+{
+ struct device *dev = &dsi->dev;
+ struct rpi_touchscreen *ts;
+ int ret;
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, ts);
+
+ ts->dsi = dsi;
+ dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
+ MIPI_DSI_MODE_VIDEO_SYNC_PULSE);
+ dsi->format = MIPI_DSI_FMT_RGB888;
+ dsi->lanes = 1;
+
+ ts->bridge_i2c =
+ rpi_touchscreen_get_i2c(dev, "raspberrypi,touchscreen-bridge");
+ if (!ts->bridge_i2c) {
+ ret = -EPROBE_DEFER;
+ return ret;
+ }
+
+#if 0
+ ts->backlight =
+ devm_backlight_device_register(dev,
+ "raspberrypi-touchscreen-backlight",
+ dev, ts,
+ &rpi_touchscreen_backlight_ops,
+ NULL);
+ if (IS_ERR(ts->backlight)) {
+ DRM_ERROR("failed to register backlight\n");
+ return PTR_ERR(ts->backlight);
+ }
+ ts->backlight->props.max_brightness = RPI_TOUCHSCREEN_MAX_BRIGHTNESS;
+ ts->backlight->props.brightness = RPI_TOUCHSCREEN_MAX_BRIGHTNESS;
+#endif
+
+ drm_panel_init(&ts->base);
+ ts->base.dev = dev;
+ ts->base.funcs = &rpi_touchscreen_funcs;
+
+ ret = drm_panel_add(&ts->base);
+ if (ret < 0)
+ goto err_release_bridge;
+
+ return mipi_dsi_attach(dsi);
+
+err_release_bridge:
+ put_device(&ts->bridge_i2c->dev);
+ return ret;
+}
+
+static int rpi_touchscreen_dsi_remove(struct mipi_dsi_device *dsi)
+{
+ struct device *dev = &dsi->dev;
+ struct rpi_touchscreen *ts = dev_get_drvdata(dev);
+ int ret;
+
+ ret = mipi_dsi_detach(dsi);
+ if (ret < 0) {
+ dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", ret);
+ return ret;
+ }
+
+ drm_panel_detach(&ts->base);
+ drm_panel_remove(&ts->base);
+
+ put_device(&ts->bridge_i2c->dev);
+
+ return 0;
+}
+
+static void rpi_touchscreen_dsi_shutdown(struct mipi_dsi_device *dsi)
+{
+ /* XXX: poweroff */
+}
+
+static const struct of_device_id rpi_touchscreen_of_match[] = {
+ { .compatible = "raspberrypi,touchscreen" },
+ { } /* sentinel */
+};
+MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_match);
+
+static struct mipi_dsi_driver rpi_touchscreen_driver = {
+ .driver = {
+ .name = "raspberrypi-touchscreen",
+ .of_match_table = rpi_touchscreen_of_match,
+ },
+ .probe = rpi_touchscreen_dsi_probe,
+ .remove = rpi_touchscreen_dsi_remove,
+ .shutdown = rpi_touchscreen_dsi_shutdown,
+};
+module_mipi_dsi_driver(rpi_touchscreen_driver);
+
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
+MODULE_LICENSE("GPL v2");