// SPDX-License-Identifier: GPL-2.0/* * Raspberry Pi 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/of.h>#include <linux/slab.h>#include <linux/device.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 #define RPI_TS_POLL_INTERVAL		17	/* 60fps */ #define RPI_TS_NPOINTS_REG_INVALIDATE	99 struct rpi_ts {	struct platform_device *pdev;	struct input_dev *input;	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];}; static void rpi_ts_poll(struct input_dev *input){	struct rpi_ts *ts = input_get_drvdata(input);	struct rpi_ts_regs regs;	int modified_ids = 0;	long released_ids;	int event_type;	int touchid;	int x, y;	int i; 	memcpy_fromio(&regs, ts->fw_regs_va, sizeof(regs));	/*	 * 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)	 */	iowrite8(RPI_TS_NPOINTS_REG_INVALIDATE,		 ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points)); 	if (regs.num_points == RPI_TS_NPOINTS_REG_INVALIDATE ||	    (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_inactive(input);		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; 	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_dev *input;	struct rpi_firmware *fw;	struct rpi_ts *ts;	u32 touchbuf;	int error; 	struct device_node *fw_node __free(device_node) = of_get_parent(np);	if (!fw_node) {		dev_err(dev, "Missing firmware node\n");		return -ENOENT;	} 	fw = devm_rpi_firmware_get(&pdev->dev, fw_node);	if (!fw)		return -EPROBE_DEFER; 	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);	if (!ts)		return -ENOMEM;	ts->pdev = pdev; 	ts->fw_regs_va = dma_alloc_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;	} 	error = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts);	if (error) {		dev_err(dev, "failed to devm_add_action_or_reset, %d\n", error);		return error;	} 	touchbuf = (u32)ts->fw_regs_phys;	error = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,				      &touchbuf, sizeof(touchbuf));	if (error || touchbuf != 0) {		dev_warn(dev, "Failed to set touchbuf, %d\n", error);		return error;	} 	input = devm_input_allocate_device(dev);	if (!input) {		dev_err(dev, "Failed to allocate input device\n");		return -ENOMEM;	} 	ts->input = input;	input_set_drvdata(input, ts); 	input->name = "raspberrypi-ts";	input->id.bustype = BUS_HOST; 	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); 	error = input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS,				    INPUT_MT_DIRECT);	if (error) {		dev_err(dev, "could not init mt slots, %d\n", error);		return error;	} 	error = input_setup_polling(input, rpi_ts_poll);	if (error) {		dev_err(dev, "could not set up polling mode, %d\n", error);		return error;	} 	input_set_poll_interval(input, RPI_TS_POLL_INTERVAL); 	error = input_register_device(input);	if (error) {		dev_err(dev, "could not register input device, %d\n", error);		return error;	} 	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 <nsaenzjulienne@suse.de>");MODULE_DESCRIPTION("Raspberry Pi firmware based touchscreen driver");MODULE_LICENSE("GPL v2");