path: root/drivers/input/touchscreen/edt-ft5x06.c

/*
 * Copyright (C) 2012 Simon Budig, <simon.budig@kernelconcepts.de>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*
 * This is a driver for the EDT "Polytouch" family of touch controllers
 * based on the FocalTech FT5x06 line of chips.
 *
 * Development of this driver has been sponsored by Glyn:
 *    http://www.glyn.com/Products/Displays
 */

#include <linux/module.h>
#include <linux/ratelimit.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/i2c.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/input/mt.h>
#include <linux/input/edt-ft5x06.h>

#define MAX_SUPPORT_POINTS		5

#define WORK_REGISTER_THRESHOLD		0x00
#define WORK_REGISTER_REPORT_RATE	0x08
#define WORK_REGISTER_GAIN		0x30
#define WORK_REGISTER_OFFSET		0x31
#define WORK_REGISTER_NUM_X		0x33
#define WORK_REGISTER_NUM_Y		0x34

#define WORK_REGISTER_OPMODE		0x3c
#define FACTORY_REGISTER_OPMODE		0x01

#define TOUCH_EVENT_DOWN		0x00
#define TOUCH_EVENT_UP			0x01
#define TOUCH_EVENT_ON			0x02
#define TOUCH_EVENT_RESERVED		0x03

#define EDT_NAME_LEN			23
#define EDT_SWITCH_MODE_RETRIES		10
#define EDT_SWITCH_MODE_DELAY		5 /* msec */
#define EDT_RAW_DATA_RETRIES		100
#define EDT_RAW_DATA_DELAY		1 /* msec */

struct edt_ft5x06_ts_data {
	struct i2c_client *client;
	struct input_dev *input;
	u16 num_x;
	u16 num_y;

#if defined(CONFIG_DEBUG_FS)
	struct dentry *debug_dir;
	u8 *raw_buffer;
	size_t raw_bufsize;
#endif

	struct mutex mutex;
	bool factory_mode;
	int threshold;
	int gain;
	int offset;
	int report_rate;

	char name[EDT_NAME_LEN];
};

static int edt_ft5x06_ts_readwrite(struct i2c_client *client,
				   u16 wr_len, u8 *wr_buf,
				   u16 rd_len, u8 *rd_buf)
{
	struct i2c_msg wrmsg[2];
	int i = 0;
	int ret;

	if (wr_len) {
		wrmsg[i].addr  = client->addr;
		wrmsg[i].flags = 0;
		wrmsg[i].len = wr_len;
		wrmsg[i].buf = wr_buf;
		i++;
	}
	if (rd_len) {
		wrmsg[i].addr  = client->addr;
		wrmsg[i].flags = I2C_M_RD;
		wrmsg[i].len = rd_len;
		wrmsg[i].buf = rd_buf;
		i++;
	}

	ret = i2c_transfer(client->adapter, wrmsg, i);
	if (ret < 0)
		return ret;
	if (ret != i)
		return -EIO;

	return 0;
}

static bool edt_ft5x06_ts_check_crc(struct edt_ft5x06_ts_data *tsdata,
				    u8 *buf, int buflen)
{
	int i;
	u8 crc = 0;

	for (i = 0; i < buflen - 1; i++)
		crc ^= buf[i];

	if (crc != buf[buflen-1]) {
		dev_err_ratelimited(&tsdata->client->dev,
				    "crc error: 0x%02x expected, got 0x%02x\n",
				    crc, buf[buflen-1]);
		return false;
	}

	return true;
}

static irqreturn_t edt_ft5x06_ts_isr(int irq, void *dev_id)
{
	struct edt_ft5x06_ts_data *tsdata = dev_id;
	struct device *dev = &tsdata->client->dev;
	u8 cmd = 0xf9;
	u8 rdbuf[26];
	int i, type, x, y, id;
	int error;

	memset(rdbuf, 0, sizeof(rdbuf));

	error = edt_ft5x06_ts_readwrite(tsdata->client,
					sizeof(cmd), &cmd,
					sizeof(rdbuf), rdbuf);
	if (error) {
		dev_err_ratelimited(dev, "Unable to fetch data, error: %d\n",
				    error);
		goto out;
	}

	if (rdbuf[0] != 0xaa || rdbuf[1] != 0xaa || rdbuf[2] != 26) {
		dev_err_ratelimited(dev, "Unexpected header: %02x%02x%02x!\n",
				    rdbuf[0], rdbuf[1], rdbuf[2]);
		goto out;
	}

	if (!edt_ft5x06_ts_check_crc(tsdata, rdbuf, 26))
		goto out;

	for (i = 0; i < MAX_SUPPORT_POINTS; i++) {
		u8 *buf = &rdbuf[i * 4 + 5];
		bool down;

		type = buf[0] >> 6;
		/* ignore Reserved events */
		if (type == TOUCH_EVENT_RESERVED)
			continue;

		x = ((buf[0] << 8) | buf[1]) & 0x0fff;
		y = ((buf[2] << 8) | buf[3]) & 0x0fff;
		id = (buf[2] >> 4) & 0x0f;
		down = (type != TOUCH_EVENT_UP);

		input_mt_slot(tsdata->input, id);
		input_mt_report_slot_state(tsdata->input, MT_TOOL_FINGER, down);

		if (!down)
			continue;

		input_report_abs(tsdata->input