This driver communicates with the Atmel microcontroller for sequencing the poweron of the TC358762 DSI-DPI bridge and controlling the backlight PWM.
The following lines are required in config.txt, to keep the firmware from trying to bash our I2C lines and steal the DSI interrupts: disable_touchscreen=1 ignore_lcd=2 mask_gpu_interrupt1=0x1000 This means that the firmware won't power on the panel at boot time (no rainbow) and the touchscreen input won't work. A native input driver for the touchscreen still needs to be written. Signed-off-by: Eric Anholt <e...@anholt.net> --- drivers/gpu/drm/bridge/Kconfig | 9 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/raspberrypi-touchscreen.c | 460 +++++++++++++++++++++++ 3 files changed, 470 insertions(+) create mode 100644 drivers/gpu/drm/bridge/raspberrypi-touchscreen.c diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index c4daca38743c..9adda62f45df 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -76,6 +76,15 @@ config DRM_SIL_SII8620 help Silicon Image SII8620 HDMI/MHL bridge chip driver. +config DRM_RASPBERRYPI_TOUCHSCREEN_BRIDGE + tristate "Raspberry Pi 7-inch touchscreen bridge" + depends on OF + select DRM_KMS_HELPER + 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_SII902X tristate "Silicon Image sii902x RGB/HDMI bridge" depends on OF diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index 3fe2226ee2f2..6226ed41f4d1 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o +obj-$(CONFIG_DRM_RASPBERRYPI_TOUCHSCREEN_BRIDGE) += raspberrypi-touchscreen.o obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o obj-$(CONFIG_DRM_SII902X) += sii902x.o obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o diff --git a/drivers/gpu/drm/bridge/raspberrypi-touchscreen.c b/drivers/gpu/drm/bridge/raspberrypi-touchscreen.c new file mode 100644 index 000000000000..b19b5a83f210 --- /dev/null +++ b/drivers/gpu/drm/bridge/raspberrypi-touchscreen.c @@ -0,0 +1,460 @@ +/* + * Copyright © 2016-2017 Broadcom + * + * 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. + */ + +/** + * Raspberry Pi 7" touchscreen panel bridge 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 initial register + * setup of the Tohsiba. + * + * This driver controls the TC358762 and ATTINY88, bridging between + * the DSI host and the LCD panel. The panel-simple driver has the + * actual panel. + */ + +#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/drmP.h> +#include <drm/drm_atomic_helper.h> +#include <drm/drm_crtc.h> +#include <drm/drm_crtc_helper.h> +#include <drm/drm_mipi_dsi.h> +#include <drm/drm_of.h> +#include <drm/drm_panel.h> + +/* I2C registers of the Atmel microcontroller. */ +enum REG_ADDR { + REG_ID = 0x80, + REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */ + REG_PORTB, + REG_PORTC, + REG_PORTD, + REG_POWERON, + REG_PWM, + REG_DDRA, + REG_DDRB, + REG_DDRC, + REG_DDRD, + REG_TEST, + REG_WR_ADDRL, + REG_WR_ADDRH, + REG_READH, + REG_READL, + REG_WRITEH, + REG_WRITEL, + REG_ID2, +}; + +/* We only turn the PWM on or off, without varying values. */ +#define RPI_TOUCHSCREEN_MAX_BRIGHTNESS 1 + +/* DSI D-PHY Layer Registers */ +#define D0W_DPHYCONTTX 0x0004 +#define CLW_DPHYCONTRX 0x0020 +#define D0W_DPHYCONTRX 0x0024 +#define D1W_DPHYCONTRX 0x0028 +#define COM_DPHYCONTRX 0x0038 +#define CLW_CNTRL 0x0040 +#define D0W_CNTRL 0x0044 +#define D1W_CNTRL 0x0048 +#define DFTMODE_CNTRL 0x0054 + +/* DSI PPI Layer Registers */ +#define PPI_STARTPPI 0x0104 +#define PPI_BUSYPPI 0x0108 +#define PPI_LINEINITCNT 0x0110 +#define PPI_LPTXTIMECNT 0x0114 +#define PPI_LANEENABLE 0x0134 +#define PPI_TX_RX_TA 0x013C +#define PPI_CLS_ATMR 0x0140 +#define PPI_D0S_ATMR 0x0144 +#define PPI_D1S_ATMR 0x0148 +#define PPI_D0S_CLRSIPOCOUNT 0x0164 +#define PPI_D1S_CLRSIPOCOUNT 0x0168 +#define CLS_PRE 0x0180 +#define D0S_PRE 0x0184 +#define D1S_PRE 0x0188 +#define CLS_PREP 0x01A0 +#define D0S_PREP 0x01A4 +#define D1S_PREP 0x01A8 +#define CLS_ZERO 0x01C0 +#define D0S_ZERO 0x01C4 +#define D1S_ZERO 0x01C8 +#define PPI_CLRFLG 0x01E0 +#define PPI_CLRSIPO 0x01E4 +#define HSTIMEOUT 0x01F0 +#define HSTIMEOUTENABLE 0x01F4 + +/* DSI Protocol Layer Registers */ +#define DSI_STARTDSI 0x0204 +#define DSI_BUSYDSI 0x0208 +#define DSI_LANEENABLE 0x0210 +# define DSI_LANEENABLE_CLOCK BIT(0) +# define DSI_LANEENABLE_D0 BIT(1) +# define DSI_LANEENABLE_D1 BIT(2) + +#define DSI_LANESTATUS0 0x0214 +#define DSI_LANESTATUS1 0x0218 +#define DSI_INTSTATUS 0x0220 +#define DSI_INTMASK 0x0224 +#define DSI_INTCLR 0x0228 +#define DSI_LPTXTO 0x0230 +#define DSI_MODE 0x0260 +#define DSI_PAYLOAD0 0x0268 +#define DSI_PAYLOAD1 0x026C +#define DSI_SHORTPKTDAT 0x0270 +#define DSI_SHORTPKTREQ 0x0274 +#define DSI_BTASTA 0x0278 +#define DSI_BTACLR 0x027C + +/* DSI General Registers */ +#define DSIERRCNT 0x0300 +#define DSISIGMOD 0x0304 + +/* DSI Application Layer Registers */ +#define APLCTRL 0x0400 +#define APLSTAT 0x0404 +#define APLERR 0x0408 +#define PWRMOD 0x040C +#define RDPKTLN 0x0410 +#define PXLFMT 0x0414 +#define MEMWRCMD 0x0418 + +/* LCDC/DPI Host Registers */ +#define LCDCTRL 0x0420 +#define HSR 0x0424 +#define HDISPR 0x0428 +#define VSR 0x042C +#define VDISPR 0x0430 +#define VFUEN 0x0434 + +/* DBI-B Host Registers */ +#define DBIBCTRL 0x0440 + +/* SPI Master Registers */ +#define SPICMR 0x0450 +#define SPITCR 0x0454 + +/* System Controller Registers */ +#define SYSSTAT 0x0460 +#define SYSCTRL 0x0464 +#define SYSPLL1 0x0468 +#define SYSPLL2 0x046C +#define SYSPLL3 0x0470 +#define SYSPMCTRL 0x047C + +/* GPIO Registers */ +#define GPIOC 0x0480 +#define GPIOO 0x0484 +#define GPIOI 0x0488 + +/* I2C Registers */ +#define I2CCLKCTRL 0x0490 + +/* Chip/Rev Registers */ +#define IDREG 0x04A0 + +/* Debug Registers */ +#define WCMDQUEUE 0x0500 +#define RCMDQUEUE 0x0504 + +struct rpi_touchscreen { + struct drm_bridge base; + struct drm_bridge *panel_bridge; + struct mipi_dsi_device *dsi; + struct i2c_client *bridge_i2c; +}; + +static struct rpi_touchscreen *bridge_to_ts(struct drm_bridge *bridge) +{ + return container_of(bridge, struct rpi_touchscreen, base); +} + +static u8 rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg) +{ + return i2c_smbus_read_byte_data(ts->bridge_i2c, reg); +} + +static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts, + u8 reg, u8 val) +{ + int ret; + + ret = i2c_smbus_write_byte_data(ts->bridge_i2c, reg, val); + if (ret) + dev_err(&ts->dsi->dev, "I2C write failed: %d\n", ret); +} + +static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val) +{ +#if 0 + /* The firmware uses LP DSI transactions like this to bring up + * the hardware, which should be faster than using I2C to then + * pass to the Toshiba. However, I was unable to get it to + * work. + */ + u8 msg[] = { + reg, + reg >> 8, + val, + val >> 8, + val >> 16, + val >> 24, + }; + + mipi_dsi_dcs_write_buffer(ts->dsi, msg, sizeof(msg)); +#else + rpi_touchscreen_i2c_write(ts, REG_WR_ADDRH, reg >> 8); + rpi_touchscreen_i2c_write(ts, REG_WR_ADDRL, reg); + rpi_touchscreen_i2c_write(ts, REG_WRITEH, val >> 8); + rpi_touchscreen_i2c_write(ts, REG_WRITEL, val); +#endif + + return 0; +} + +static void rpi_bridge_disable(struct drm_bridge *bridge) +{ + struct rpi_touchscreen *ts = bridge_to_ts(bridge); + + rpi_touchscreen_i2c_write(ts, REG_PWM, 0); + + rpi_touchscreen_i2c_write(ts, REG_POWERON, 0); + udelay(1); +} + +static void rpi_bridge_enable(struct drm_bridge *bridge) +{ + struct rpi_touchscreen *ts = bridge_to_ts(bridge); + int i; + + rpi_touchscreen_i2c_write(ts, REG_POWERON, 1); + /* Wait for nPWRDWN to go low to indicate poweron is done. */ + for (i = 0; i < 100; i++) { + if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1) + break; + } + + rpi_touchscreen_write(ts, DSI_LANEENABLE, + DSI_LANEENABLE_CLOCK | + DSI_LANEENABLE_D0); + rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05); + rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05); + rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00); + rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00); + rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03); + + rpi_touchscreen_write(ts, SPICMR, 0x00); + rpi_touchscreen_write(ts, LCDCTRL, 0x00100150); + rpi_touchscreen_write(ts, SYSCTRL, 0x040f); + msleep(100); + + rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01); + rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01); + msleep(100); + + /* Turn on the backlight. */ + rpi_touchscreen_i2c_write(ts, REG_PWM, 255); + + /* Default to the same orientation as the closed source + * firmware used for the panel. Runtime rotation + * configuration will be supported using VC4's plane + * orientation bits. + */ + rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2)); +} + +static int rpi_bridge_attach(struct drm_bridge *bridge) +{ + struct rpi_touchscreen *ts = bridge_to_ts(bridge); + + return drm_bridge_attach(bridge->encoder, ts->panel_bridge, bridge); +} + +static struct drm_bridge_funcs rpi_bridge_funcs = { + .enable = rpi_bridge_enable, + .disable = rpi_bridge_disable, + .attach = rpi_bridge_attach, +}; + +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); + if (!client) + return ERR_PTR(-ENODEV); + + return client; +} + +static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi) +{ + struct device *dev = &dsi->dev; + struct drm_panel *panel; + struct rpi_touchscreen *ts; + int ret, ver; + + 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 | + MIPI_DSI_MODE_LPM); + dsi->format = MIPI_DSI_FMT_RGB888; + dsi->lanes = 1; + + ts->bridge_i2c = + rpi_touchscreen_get_i2c(dev, "raspberrypi,touchscreen-bridge"); + if (IS_ERR(ts->bridge_i2c)) { + ret = -EPROBE_DEFER; + return ret; + } + + ver = rpi_touchscreen_i2c_read(ts, REG_ID); + if (ver < 0) { + dev_err(dev, "Atmel I2C read failed: %d\n", ver); + return -ENODEV; + } + + switch (ver) { + case 0xde: /* ver 1 */ + case 0xc3: /* ver 2 */ + break; + default: + dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver); + ret = -ENODEV; + goto err_release_i2c; + } + + drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &panel, NULL); + if (!panel) + return -EPROBE_DEFER; + + ts->panel_bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI); + if (IS_ERR(ts->panel_bridge)) { + dev_err(dev, "Failed to create panel bridge\n"); + ret = PTR_ERR(ts->panel_bridge); + goto err_release_i2c; + } + + /* Turn off at boot, so we can cleanly sequence powering on. */ + rpi_touchscreen_i2c_write(ts, REG_POWERON, 0); + + ts->base.funcs = &rpi_bridge_funcs; + ts->base.of_node = dev->of_node; + + ret = drm_bridge_add(&ts->base); + if (ret) { + dev_err(dev, "Failed to add bridge\n"); + goto err_remove_bridge; + } + + return mipi_dsi_attach(dsi); + +err_remove_bridge: + drm_panel_bridge_remove(ts->panel_bridge); +err_release_i2c: + 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_bridge_remove(ts->panel_bridge); + drm_bridge_remove(&ts->base); + + put_device(&ts->bridge_i2c->dev); + + return 0; +} + +static void rpi_touchscreen_dsi_shutdown(struct mipi_dsi_device *dsi) +{ + struct device *dev = &dsi->dev; + struct rpi_touchscreen *ts = dev_get_drvdata(dev); + + rpi_touchscreen_i2c_write(ts, REG_POWERON, 0); +} + +static const struct of_device_id rpi_touchscreen_of_match[] = { + { .compatible = "raspberrypi,7inch-touchscreen-bridge" }, + { } /* sentinel */ +}; +MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_match); + +static struct mipi_dsi_driver rpi_touchscreen_driver = { + .driver = { + .name = "raspberrypi-touchscreen-bridge", + .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 <e...@anholt.net>"); +MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver"); +MODULE_LICENSE("GPL v2"); -- 2.11.0