Hi Nicolas,
On Wed, Dec 05, 2018 at 11:09:03PM +0100, Nicolas Saenz Julienne wrote:
> 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 <nsaenzjulie...@suse.de>
> ---
> 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
I think "depends on ASPBERRYPI_FIRMWARE || COMPILE_TEST" is more
precise dependency.
> + 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 <nsaenzjulie...@suse.de>
> + *
> + * 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.
Please use SPDX tag for the license.
> + */
> +
> +#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;
Since the only way is to poll, please use polled input device instead of
standard one. It will take care of scheduling polling, stopping it when
needed, etc.
> + 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;
Simply u8 in kernel.
> + 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 you make released_ids long instead of int you can use
for_each_set_bit() here.
> + 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_mt_sync_frame() and then you would not need to call
input_mt_report_pointer_emulation() if you passed right flags to
input_mt_init_slots().
> + 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);
> +}
Not needed if using polled input device.
> +
> +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);
You are leaking node here I believe. Stick of_node_put() after
rpi_firmware_get() and before "if".
> + if (!fw)
> + return -EPROBE_DEFER;
> +
> + ts = devm_kzalloc(dev, sizeof(struct rpi_ts), GFP_KERNEL);
sizeof(*ts)
> + if (!ts) {
> + dev_err(dev, "Failed to allocate memory\n");
> + return -ENOMEM;
> + }
> +
> + input = input_allocate_device();
devm.
> + 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);
I wild make freeing this area a devm custom action
(devm_add_action_or_reset). Then you can get rid of rpi_ts_remove().
> +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,
I am pretty sure we no longer need to set owner explicitly.
> + .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 <nsaenzjulie...@suse.de>");
> +MODULE_DESCRIPTION("Raspberry Pi 3 firmware based touchscreen driver");
> +MODULE_LICENSE("GPL");
This should be "GPL v2" to math the license notice at the top of the
file.
Thanks.
--
Dmitry
