]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/commitdiff
drm/panel: Add support for the Raspberry Pi 7" Touchscreen.
authorEric Anholt <eric@anholt.net>
Tue, 26 Apr 2016 20:46:13 +0000 (13:46 -0700)
committerKleber Sacilotto de Souza <kleber.souza@canonical.com>
Tue, 19 Sep 2017 10:07:54 +0000 (12:07 +0200)
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.  The native input
driver for the touchscreen still needs to be written.

v2: Set the same default orientation as the closed source firmware
    used, which is the best for viewing angle.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
drivers/gpu/drm/panel/Kconfig
drivers/gpu/drm/panel/Makefile
drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c [new file with mode: 0644]

index 62aba976e744c146c26d7fedf44c54cdd480361e..de7a56ab758b8f043194391f9b9e43df65c06d0a 100644 (file)
@@ -52,6 +52,14 @@ config DRM_PANEL_PANASONIC_VVX10F034N00
          WUXGA (1920x1200) Novatek NT1397-based DSI panel as found in some
          Xperia Z2 tablets
 
+config DRM_PANEL_RASPBERRYPI_TOUCHSCREEN
+       tristate "Raspberry Pi 7-inch touchscreen panel"
+       depends on DRM_MIPI_DSI
+       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
index a5c7ec0236e0174079cce0f07d46372967e9cf3b..e8a7ed280fff907e5a730a13ae9a3e5e34cacce4 100644 (file)
@@ -2,6 +2,7 @@ obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(CONFIG_DRM_PANEL_PANASONIC_VVX10F034N00) += panel-panasonic-vvx10f034n00.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
diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
new file mode 100644 (file)
index 0000000..1a536fe
--- /dev/null
@@ -0,0 +1,514 @@
+/*
+ * Copyright © 2016 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.
+ */
+
+/**
+ * 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/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>
+
+/* 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_panel base;
+       struct mipi_dsi_device *dsi;
+       struct i2c_client *bridge_i2c;
+
+       /* Version of the firmware on the bridge chip */
+       int atmel_ver;
+};
+
+static const struct drm_display_mode rpi_touchscreen_modes[] = {
+       {
+               /* The DSI PLL can only integer divide from the 2Ghz
+                * PLLD, giving us few choices.  We pick a divide by 3
+                * as our DSI HS clock, giving us a pixel clock of
+                * that divided by 24 bits.  Pad out HFP to get our
+                * panel to refresh at 60Hz, even if that doesn't
+                * match the datasheet.
+                */
+#define PIXEL_CLOCK ((2000000000 / 3) / 24)
+#define VREFRESH    60
+#define VTOTAL      (480 + 7 + 2 + 21)
+#define HACT        800
+#define HSW         2
+#define HBP         46
+#define HFP         ((PIXEL_CLOCK / (VTOTAL * VREFRESH)) - (HACT + HSW + HBP))
+
+               .clock = PIXEL_CLOCK / 1000,
+               .hdisplay = HACT,
+               .hsync_start = HACT + HFP,
+               .hsync_end = HACT + HFP + HSW,
+               .htotal = HACT + HFP + HSW + HBP,
+               .vdisplay = 480,
+               .vsync_start = 480 + 7,
+               .vsync_end = 480 + 7 + 2,
+               .vtotal = VTOTAL,
+               .vrefresh = 60,
+       },
+};
+
+static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
+{
+       return container_of(panel, 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 int rpi_touchscreen_disable(struct drm_panel *panel)
+{
+       struct rpi_touchscreen *ts = panel_to_ts(panel);
+
+       rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
+
+       rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
+       udelay(1);
+
+       return 0;
+}
+
+static int rpi_touchscreen_noop(struct drm_panel *panel)
+{
+       return 0;
+}
+
+static int rpi_touchscreen_enable(struct drm_panel *panel)
+{
+       struct rpi_touchscreen *ts = panel_to_ts(panel);
+       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 |
+                             (ts->dsi->lanes > 1 ? DSI_LANEENABLE_D1 : 0));
+       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));
+
+       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 = 154;
+       connector->display_info.height_mm = 86;
+
+       return num;
+}
+
+static const struct drm_panel_funcs rpi_touchscreen_funcs = {
+       .disable = rpi_touchscreen_disable,
+       .unprepare = rpi_touchscreen_noop,
+       .prepare = rpi_touchscreen_noop,
+       .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, 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:
+               ts->atmel_ver = 1;
+               break;
+       case 0xc3:
+               ts->atmel_ver = 2;
+               break;
+       default:
+               dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
+               return -ENODEV;
+       }
+
+       /* Turn off at boot, so we can cleanly sequence powering on. */
+       rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
+
+       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)
+{
+       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,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");