Adds support to Raspberry Pi's 7" touchscreen device. Instead of using a conventional bus all information is copied into a memory mapped area by RPi's VC4 firmware.
Based on the driver found in RPi's downstream kernel repository. Signed-off-by: Nicolas Saenz Julienne <[email protected]> --- drivers/input/touchscreen/Kconfig | 12 + drivers/input/touchscreen/Makefile | 1 + drivers/input/touchscreen/raspberrypi-ts.c | 252 +++++++++++++++++++++ 3 files changed, 265 insertions(+) create mode 100644 drivers/input/touchscreen/raspberrypi-ts.c diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig index 2a80675cfd94..8d0fcb3dc8a8 100644 --- a/drivers/input/touchscreen/Kconfig +++ b/drivers/input/touchscreen/Kconfig @@ -696,6 +696,18 @@ config TOUCHSCREEN_EDT_FT5X06 To compile this driver as a module, choose M here: the module will be called edt-ft5x06. +config TOUCHSCREEN_RASPBERRYPI_TS + tristate "Raspberry Pi's firmware base touch screen support" + depends on OF + help + Say Y here if you have the official Raspberry Pi 7' touchscren + connected on your system. + + If unsure, say N. + + To compile this driver as a module, choose M here: the + module will be called raspberrypi-ts. + config TOUCHSCREEN_MIGOR tristate "Renesas MIGO-R touchscreen" depends on (SH_MIGOR || COMPILE_TEST) && I2C diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile index 5911a4190cd2..3eccb1925e89 100644 --- a/drivers/input/touchscreen/Makefile +++ b/drivers/input/touchscreen/Makefile @@ -109,3 +109,4 @@ obj-$(CONFIG_TOUCHSCREEN_ZET6223) += zet6223.o obj-$(CONFIG_TOUCHSCREEN_ZFORCE) += zforce_ts.o obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o +obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_TS) += raspberrypi-ts.o diff --git a/drivers/input/touchscreen/raspberrypi-ts.c b/drivers/input/touchscreen/raspberrypi-ts.c new file mode 100644 index 000000000000..9d29411a5674 --- /dev/null +++ b/drivers/input/touchscreen/raspberrypi-ts.c @@ -0,0 +1,252 @@ +/* + * Raspberry Pi 3 firmware based touchscreen driver + * + * Copyright (C) 2015, 2017 Raspberry Pi + * Copyright (C) 2018 Nicolas Saenz Julienne <[email protected]> + * + * 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. + */ + +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/bitops.h> +#include <linux/dma-mapping.h> +#include <linux/platform_device.h> +#include <linux/input.h> +#include <linux/input/mt.h> +#include <linux/input/touchscreen.h> +#include <soc/bcm2835/raspberrypi-firmware.h> + +#define RPI_TS_DEFAULT_WIDTH 800 +#define RPI_TS_DEFAULT_HEIGHT 480 + +#define RPI_TS_MAX_SUPPORTED_POINTS 10 + +#define RPI_TS_FTS_TOUCH_DOWN 0 +#define RPI_TS_FTS_TOUCH_CONTACT 2 + +struct rpi_ts { + struct input_dev *input; + struct touchscreen_properties prop; + + void __iomem *ts_base; + dma_addr_t bus_addr; + + struct delayed_work work; + int known_ids; +}; + +struct rpi_ts_regs { + uint8_t device_mode; + uint8_t gesture_id; + uint8_t num_points; + struct rpi_ts_touch { + uint8_t xh; + uint8_t xl; + uint8_t yh; + uint8_t yl; + uint8_t pressure; /* Not supported */ + uint8_t area; /* Not supported */ + } point[RPI_TS_MAX_SUPPORTED_POINTS]; +}; + +/* + * This process polls the memory based register copy of the touch screen chip + * registers using the number of points register to know whether the copy has + * been updated (we write 99 to the memory copy, the GPU will write between 0 - + * 10 points) + */ +static void rpi_ts_work(struct work_struct *work) +{ + struct rpi_ts *ts = container_of(work, struct rpi_ts, work.work); + struct input_dev *input = ts->input; + struct rpi_ts_regs regs; + int modified_ids = 0; + int released_ids; + int event_type; + int touchid; + int x, y; + int i; + + memcpy_fromio(®s, ts->ts_base, sizeof(struct rpi_ts_regs)); + iowrite8(99, ts->ts_base + offsetof(struct rpi_ts_regs, num_points)); + + if (regs.num_points == 99 || + (regs.num_points == 0 && ts->known_ids == 0)) + goto out; + + for (i = 0; i < regs.num_points; i++) { + x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl; + y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl; + touchid = (regs.point[i].yh >> 4) & 0xf; + event_type = (regs.point[i].xh >> 6) & 0x03; + + modified_ids |= BIT(touchid); + + if (event_type == RPI_TS_FTS_TOUCH_DOWN || + event_type == RPI_TS_FTS_TOUCH_CONTACT) { + input_mt_slot(input, touchid); + input_mt_report_slot_state(input, MT_TOOL_FINGER, 1); + touchscreen_report_pos(input, &ts->prop, x, y, true); + } + } + + released_ids = ts->known_ids & ~modified_ids; + for (i = 0; released_ids && i < RPI_TS_MAX_SUPPORTED_POINTS; i++) { + if (released_ids & BIT(i)) { + input_mt_slot(input, i); + input_mt_report_slot_state(input, MT_TOOL_FINGER, 0); + modified_ids &= ~(BIT(i)); + } + } + ts->known_ids = modified_ids; + + input_mt_report_pointer_emulation(ts->input, true); + input_sync(ts->input); + +out: + schedule_delayed_work(&ts->work, msecs_to_jiffies(17)); /* 60 fps */ +} + +static int rpi_ts_open(struct input_dev *dev) +{ + struct rpi_ts *ts = input_get_drvdata(dev); + + schedule_delayed_work(&ts->work, 0); + + return 0; +} + +static void rpi_ts_close(struct input_dev *dev) +{ + struct rpi_ts *ts = input_get_drvdata(dev); + + cancel_delayed_work_sync(&ts->work); +} + +static int rpi_ts_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct device_node *fw_node; + struct input_dev *input; + struct rpi_firmware *fw; + struct rpi_ts *ts; + u32 touchbuf; + int err = 0; + + fw_node = of_get_parent(np); + if (!fw_node) { + dev_err(dev, "Missing firmware node\n"); + return -ENOENT; + } + + fw = rpi_firmware_get(fw_node); + if (!fw) + return -EPROBE_DEFER; + + ts = devm_kzalloc(dev, sizeof(struct rpi_ts), GFP_KERNEL); + if (!ts) { + dev_err(dev, "Failed to allocate memory\n"); + return -ENOMEM; + } + + input = input_allocate_device(); + if (!input) { + dev_err(dev, "Failed to allocate input device\n"); + return -ENOMEM; + } + ts->input = input; + + ts->ts_base = dma_zalloc_coherent(dev, PAGE_SIZE, &ts->bus_addr, + GFP_KERNEL); + if (!ts->ts_base) { + dev_err(dev, "failed to dma_alloc_coherent\n"); + err = -ENOMEM; + goto undegister_input_device; + } + + touchbuf = (u32)ts->bus_addr; + err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF, + &touchbuf, sizeof(touchbuf)); + + if (err || touchbuf != 0) { + dev_warn(dev, "Failed to set touchbuf, trying to get err:%x\n", + err); + goto clean_dma_buf; + } + + INIT_DELAYED_WORK(&ts->work, rpi_ts_work); + platform_set_drvdata(pdev, ts); + + input->name = "raspberrypi-ts"; + input->id.bustype = BUS_HOST; + input->open = rpi_ts_open; + input->close = rpi_ts_close; + input->dev.parent = &pdev->dev; + + __set_bit(EV_KEY, input->evbit); + __set_bit(EV_SYN, input->evbit); + __set_bit(EV_ABS, input->evbit); + + input_set_abs_params(input, ABS_MT_POSITION_X, 0, + RPI_TS_DEFAULT_WIDTH, 0, 0); + input_set_abs_params(input, ABS_MT_POSITION_Y, 0, + RPI_TS_DEFAULT_HEIGHT, 0, 0); + touchscreen_parse_properties(input, true, &ts->prop); + + input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS, + INPUT_MT_DIRECT); + + input_set_drvdata(input, ts); + + err = input_register_device(input); + if (err) { + dev_err(dev, "could not register input device, %d\n", + err); + goto clean_dma_buf; + } + return 0; + +clean_dma_buf: + dma_free_coherent(dev, PAGE_SIZE, ts->ts_base, ts->bus_addr); +undegister_input_device: + input_unregister_device(ts->input); + + return err; +} + +static int rpi_ts_remove(struct platform_device *pdev) +{ + struct rpi_ts *ts = (struct rpi_ts *)platform_get_drvdata(pdev); + + input_unregister_device(ts->input); + dma_free_coherent(&pdev->dev, PAGE_SIZE, ts->ts_base, ts->bus_addr); + return 0; +} + +static const struct of_device_id rpi_ts_match[] = { + { .compatible = "raspberrypi,firmware-ts", }, + {}, +}; +MODULE_DEVICE_TABLE(of, rpi_ts_match); + +static struct platform_driver rpi_ts_driver = { + .driver = { + .name = "raspberrypi-ts", + .owner = THIS_MODULE, + .of_match_table = rpi_ts_match, + }, + .probe = rpi_ts_probe, + .remove = rpi_ts_remove, +}; + +module_platform_driver(rpi_ts_driver); + +MODULE_AUTHOR("Gordon Hollingworth"); +MODULE_AUTHOR("Nicolas Saenz Julienne <[email protected]>"); +MODULE_DESCRIPTION("Raspberry Pi 3 firmware based touchscreen driver"); +MODULE_LICENSE("GPL"); -- 2.19.2
