Re: [PATCH 1/2] input: add official Raspberry Pi's touchscreen driver
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2018-12-10 19:02:18
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Hi Nicolas, On Mon, Dec 10, 2018 at 05:30:20PM +0100, Nicolas Saenz Julienne wrote:
Add's support to Raspberry Pi's 7" Touch device. Instead of using a conventional bus all information is copied into a memory mapped area by RPi's firmware. Based on the driver found in RPi's kernel repository.
I believe we are almost there, just a couple of nits.
quoted hunk ↗ jump to hunk
Signed-off-by: Nicolas Saenz Julienne <redacted> --- drivers/input/touchscreen/Kconfig | 12 ++ drivers/input/touchscreen/Makefile | 1 + drivers/input/touchscreen/raspberrypi-ts.c | 223 +++++++++++++++++++++ 3 files changed, 236 insertions(+) create mode 100644 drivers/input/touchscreen/raspberrypi-ts.cdiff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig index 2a80675cfd94..a9be434de738 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 RASPBERRYPI_FIRMWARE || COMPILE_TEST + help + Say Y here if you have the offitial Raspberry Pi 7' scren 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) && I2Cdiff --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.odiff --git a/drivers/input/touchscreen/raspberrypi-ts.c b/drivers/input/touchscreen/raspberrypi-ts.c new file mode 100644 index 000000000000..edc92018687e --- /dev/null +++ b/drivers/input/touchscreen/raspberrypi-ts.c@@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Raspberry Pi 3 firmware based touchscreen driver + * + * Copyright (C) 2015, 2017 Raspberry Pi + * Copyright (C) 2018 Nicolas Saenz Julienne <nsaenzjulienne@suse.de> + */ + +#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-polldev.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 + +#define RPI_TS_POLL_INTERVAL 17 /* 60fps */ + +struct rpi_ts { + struct platform_device *pdev; + struct input_polled_dev *poll_dev; + struct touchscreen_properties prop; + + void __iomem *fw_regs_va; + dma_addr_t fw_regs_phys; + + int known_ids; +}; + +struct rpi_ts_regs { + u8 device_mode; + u8 gesture_id; + u8 num_points; + struct rpi_ts_touch { + u8 xh; + u8 xl; + u8 yh; + u8 yl; + u8 pressure; /* Not supported */ + u8 area; /* Not supported */ + } point[RPI_TS_MAX_SUPPORTED_POINTS]; +}; + +/* + * We poll the memory based register copy of the touchscreen chip 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_poll(struct input_polled_dev *dev) +{ + struct input_dev *input = dev->input; + struct rpi_ts *ts = dev->private; + struct rpi_ts_regs regs; + int modified_ids = 0; + long released_ids; + int event_type; + int touchid; + int x, y; + int i; + + memcpy_fromio(®s, ts->fw_regs_va, sizeof(regs)); + iowrite8(99, ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points)); + + if (regs.num_points == 99 || + (regs.num_points == 0 && ts->known_ids == 0)) + return; + + 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_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) { + 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_sync_frame(input); + input_sync(input); +} + +static void rpi_ts_dma_cleanup(void *data) +{ + struct rpi_ts *ts = data; + struct device *dev = &ts->pdev->dev; + + if(ts->fw_regs_va)
Drop the condition.
+ dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va,
+ ts->fw_regs_phys);
+}
+
+static int rpi_ts_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct input_polled_dev *poll_dev;
+ struct device_node *fw_node;
+ struct rpi_firmware *fw;
+ struct input_dev *input;
+ struct rpi_ts *ts;
+ u32 touchbuf;
+ int ret;
+
+ fw_node = of_get_parent(np);
+ if (!fw_node) {
+ dev_err(dev, "Missing firmware node\n");
+ return -ENOENT;
+ }
+
+ fw = rpi_firmware_get(fw_node);
+ of_node_put(fw_node);
+ if (!fw)
+ return -EPROBE_DEFER;
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts) {
+ dev_err(dev, "Failed to allocate memory\n");
+ return -ENOMEM;
+ }
+ ts->pdev = pdev;
+
+ ret = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts);
+ if (ret)
+ return ret;This call needs to be after dma_zalloc_coherent(). Also (my personal preference) can we please call this variable "error"? Then we can write "if (error) ...".
+
+ ts->fw_regs_va = dma_zalloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys,
+ GFP_KERNEL);
+ if (!ts->fw_regs_va) {
+ dev_err(dev, "failed to dma_alloc_coherent\n");
+ return -ENOMEM;
+ }
+
+ touchbuf = (u32)ts->fw_regs_phys;
+ ret = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,
+ &touchbuf, sizeof(touchbuf));
+
+ if (ret || touchbuf != 0) {
+ dev_warn(dev, "Failed to set touchbuf, trying to get err:%x\n",
+ ret);
+ return ret;
+ }
+
+ poll_dev = devm_input_allocate_polled_device(dev);
+ if (!poll_dev) {
+ dev_err(dev, "Failed to allocate input device\n");
+ return -ENOMEM;
+ }
+ ts->poll_dev = poll_dev;
+ input = poll_dev->input;
+
+ input->name = "raspberrypi-ts";
+ input->id.bustype = BUS_HOST;
+ poll_dev->poll_interval = RPI_TS_POLL_INTERVAL;
+ poll_dev->poll = rpi_ts_poll;
+ poll_dev->private = ts;
+
+ __set_bit(EV_SYN, input->evbit);
+ __set_bit(EV_KEY, input->evbit);
+ __set_bit(EV_ABS, input->evbit);No need to set these, EV_SYN is set by the input core, and KEY/ABS are by input_set_abs_params() and input_mt_init_slots().
+ + 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_MT_POINTER);
Error handling here please. Also, for touchscreens you do not need to set INPUT_MT_POINTER, just INPUT_MT_DIRECT.
+
+ ret = input_register_polled_device(poll_dev);
+ if (ret) {
+ dev_err(dev, "could not register input device, %d\n", ret);
+ return ret;
+ }
+
+ 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",
+ .of_match_table = rpi_ts_match,
+ },
+ .probe = rpi_ts_probe,
+};
+module_platform_driver(rpi_ts_driver);
+
+MODULE_AUTHOR("Gordon Hollingworth");
+MODULE_AUTHOR("Nicolas Saenz Julienne [off-list ref]");
+MODULE_DESCRIPTION("Raspberry Pi 3 firmware based touchscreen driver");
+MODULE_LICENSE("GPL v2");
--
2.19.2Thanks. -- Dmitry