Input: add driver for FT5x06 based EDT displays

This is a driver for the EDT "Polytouch" family of touch controllers
based on the FocalTech FT5x06 line of chips.

Signed-off-by: Simon Budig <simon.budig@kernelconcepts.de>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

3 files changed, 912 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 73bd2f6b82ec..1ba232cbc09d 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -472,6 +472,19 @@ config TOUCHSCREEN_PENMOUNT
           To compile this driver as a module, choose M here: the
           module will be called penmount.
 
+config TOUCHSCREEN_EDT_FT5X06
+        tristate "EDT FocalTech FT5x06 I2C Touchscreen support"
+        depends on I2C
+        help
+          Say Y here if you have an EDT "Polytouch" touchscreen based
+          on the FocalTech FT5x06 family of controllers connected to
+          your system.
+
+          If unsure, say N.
+
+          To compile this driver as a module, choose M here: the
+          module will be called edt-ft5x06.
+
 config TOUCHSCREEN_MIGOR
         tristate "Renesas MIGO-R touchscreen"
         depends on SH_MIGOR && I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 5920c60f999d..178eb128d90f 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_TOUCHSCREEN_CYTTSP_SPI)	+= cyttsp_spi.o
 obj-$(CONFIG_TOUCHSCREEN_DA9034)        += da9034-ts.o
 obj-$(CONFIG_TOUCHSCREEN_DA9052)        += da9052_tsi.o
 obj-$(CONFIG_TOUCHSCREEN_DYNAPRO)       += dynapro.o
+obj-$(CONFIG_TOUCHSCREEN_EDT_FT5X06)    += edt-ft5x06.o
 obj-$(CONFIG_TOUCHSCREEN_HAMPSHIRE)     += hampshire.o
 obj-$(CONFIG_TOUCHSCREEN_GUNZE)         += gunze.o
 obj-$(CONFIG_TOUCHSCREEN_EETI)          += eeti_ts.o
diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
new file mode 100644
index 000000000000..9afc777a40a7
--- /dev/null
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -0,0 +1,898 @@
+/*
+ * 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, ABS_MT_POSITION_X, x);
+                input_report_abs(tsdata->input, ABS_MT_POSITION_Y, y);
+        }
+
+        input_mt_report_pointer_emulation(tsdata->input, true);
+        input_sync(tsdata->input);
+
+out:
+        return IRQ_HANDLED;
+}
+
+static int edt_ft5x06_register_write(struct edt_ft5x06_ts_data *tsdata,
+                                     u8 addr, u8 value)
+{
+        u8 wrbuf[4];
+
+        wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
+        wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
+        wrbuf[2] = value;
+        wrbuf[3] = wrbuf[0] ^ wrbuf[1] ^ wrbuf[2];
+
+        return edt_ft5x06_ts_readwrite(tsdata->client, 4, wrbuf, 0, NULL);
+}
+
+static int edt_ft5x06_register_read(struct edt_ft5x06_ts_data *tsdata,
+                                    u8 addr)
+{
+        u8 wrbuf[2], rdbuf[2];
+        int error;
+
+        wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
+        wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
+        wrbuf[1] |= tsdata->factory_mode ? 0x80 : 0x40;
+
+        error = edt_ft5x06_ts_readwrite(tsdata->client, 2, wrbuf, 2, rdbuf);
+        if (error)
+                return error;
+
+        if ((wrbuf[0] ^ wrbuf[1] ^ rdbuf[0]) != rdbuf[1]) {
+                dev_err(&tsdata->client->dev,
+                        "crc error: 0x%02x expected, got 0x%02x\n",
+                        wrbuf[0] ^ wrbuf[1] ^ rdbuf[0], rdbuf[1]);
+                return -EIO;
+        }
+
+        return rdbuf[0];
+}
+
+struct edt_ft5x06_attribute {
+        struct device_attribute dattr;
+        size_t field_offset;
+        u8 limit_low;
+        u8 limit_high;
+        u8 addr;
+};
+
+#define EDT_ATTR(_field, _mode, _addr, _limit_low, _limit_high)         \
+        struct edt_ft5x06_attribute edt_ft5x06_attr_##_field = {        \
+                .dattr = __ATTR(_field, _mode,                          \
+                                edt_ft5x06_setting_show,                \
+                                edt_ft5x06_setting_store),              \
+                .field_offset =                                         \
+                        offsetof(struct edt_ft5x06_ts_data, _field),    \
+                .limit_low = _limit_low,                                \
+                .limit_high = _limit_high,                              \
+                .addr = _addr,                                          \
+        }
+
+static ssize_t edt_ft5x06_setting_show(struct device *dev,
+                                       struct device_attribute *dattr,
+                                       char *buf)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
+        struct edt_ft5x06_attribute *attr =
+                        container_of(dattr, struct edt_ft5x06_attribute, dattr);
+        u8 *field = (u8 *)((char *)tsdata + attr->field_offset);
+        int val;
+        size_t count = 0;
+        int error = 0;
+
+        mutex_lock(&tsdata->mutex);
+
+        if (tsdata->factory_mode) {
+                error = -EIO;
+                goto out;
+        }
+
+        val = edt_ft5x06_register_read(tsdata, attr->addr);
+        if (val < 0) {
+                error = val;
+                dev_err(&tsdata->client->dev,
+                        "Failed to fetch attribute %s, error %d\n",
+                        dattr->attr.name, error);
+                goto out;
+        }
+
+        if (val != *field) {
+                dev_warn(&tsdata->client->dev,
+                         "%s: read (%d) and stored value (%d) differ\n",
+                         dattr->attr.name, val, *field);
+                *field = val;
+        }
+
+        count = scnprintf(buf, PAGE_SIZE, "%d\n", val);
+out:
+        mutex_unlock(&tsdata->mutex);
+        return error ?: count;
+}
+
+static ssize_t edt_ft5x06_setting_store(struct device *dev,
+                                        struct device_attribute *dattr,
+                                        const char *buf, size_t count)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
+        struct edt_ft5x06_attribute *attr =
+                        container_of(dattr, struct edt_ft5x06_attribute, dattr);
+        u8 *field = (u8 *)((char *)tsdata + attr->field_offset);
+        unsigned int val;
+        int error;
+
+        mutex_lock(&tsdata->mutex);
+
+        if (tsdata->factory_mode) {
+                error = -EIO;
+                goto out;
+        }
+
+        error = kstrtouint(buf, 0, &val);
+        if (error)
+                goto out;
+
+        if (val < attr->limit_low || val > attr->limit_high) {
+                error = -ERANGE;
+                goto out;
+        }
+
+        error = edt_ft5x06_register_write(tsdata, attr->addr, val);
+        if (error) {
+                dev_err(&tsdata->client->dev,
+                        "Failed to update attribute %s, error: %d\n",
+                        dattr->attr.name, error);
+                goto out;
+        }
+
+        *field = val;
+
+out:
+        mutex_unlock(&tsdata->mutex);
+        return error ?: count;
+}
+
+static EDT_ATTR(gain, S_IWUSR | S_IRUGO, WORK_REGISTER_GAIN, 0, 31);
+static EDT_ATTR(offset, S_IWUSR | S_IRUGO, WORK_REGISTER_OFFSET, 0, 31);
+static EDT_ATTR(threshold, S_IWUSR | S_IRUGO,
+                WORK_REGISTER_THRESHOLD, 20, 80);
+static EDT_ATTR(report_rate, S_IWUSR | S_IRUGO,
+                WORK_REGISTER_REPORT_RATE, 3, 14);
+
+static struct attribute *edt_ft5x06_attrs[] = {
+        &edt_ft5x06_attr_gain.dattr.attr,
+        &edt_ft5x06_attr_offset.dattr.attr,
+        &edt_ft5x06_attr_threshold.dattr.attr,
+        &edt_ft5x06_attr_report_rate.dattr.attr,
+        NULL
+};
+
+static const struct attribute_group edt_ft5x06_attr_group = {
+        .attrs = edt_ft5x06_attrs,
+};
+
+#ifdef CONFIG_DEBUG_FS
+static int edt_ft5x06_factory_mode(struct edt_ft5x06_ts_data *tsdata)
+{
+        struct i2c_client *client = tsdata->client;
+        int retries = EDT_SWITCH_MODE_RETRIES;
+        int ret;
+        int error;
+
+        disable_irq(client->irq);
+
+        if (!tsdata->raw_buffer) {
+                tsdata->raw_bufsize = tsdata->num_x * tsdata->num_y *
+                                      sizeof(u16);
+                tsdata->raw_buffer = kzalloc(tsdata->raw_bufsize, GFP_KERNEL);
+                if (!tsdata->raw_buffer) {
+                        error = -ENOMEM;
+                        goto err_out;
+                }
+        }
+
+        /* mode register is 0x3c when in the work mode */
+        error = edt_ft5x06_register_write(tsdata, WORK_REGISTER_OPMODE, 0x03);
+        if (error) {
+                dev_err(&client->dev,
+                        "failed to switch to factory mode, error %d\n", error);
+                goto err_out;
+        }
+
+        tsdata->factory_mode = true;
+        do {
+                mdelay(EDT_SWITCH_MODE_DELAY);
+                /* mode register is 0x01 when in factory mode */
+                ret = edt_ft5x06_register_read(tsdata, FACTORY_REGISTER_OPMODE);
+                if (ret == 0x03)
+                        break;
+        } while (--retries > 0);
+
+        if (retries == 0) {
+                dev_err(&client->dev, "not in factory mode after %dms.\n",
+                        EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
+                error = -EIO;
+                goto err_out;
+        }
+
+        return 0;
+
+err_out:
+        kfree(tsdata->raw_buffer);
+        tsdata->raw_buffer = NULL;
+        tsdata->factory_mode = false;
+        enable_irq(client->irq);
+
+        return error;
+}
+
+static int edt_ft5x06_work_mode(struct edt_ft5x06_ts_data *tsdata)
+{
+        struct i2c_client *client = tsdata->client;
+        int retries = EDT_SWITCH_MODE_RETRIES;
+        int ret;
+        int error;
+
+        /* mode register is 0x01 when in the factory mode */
+        error = edt_ft5x06_register_write(tsdata, FACTORY_REGISTER_OPMODE, 0x1);
+        if (error) {
+                dev_err(&client->dev,
+                        "failed to switch to work mode, error: %d\n", error);
+                return error;
+        }
+
+        tsdata->factory_mode = false;
+
+        do {
+                mdelay(EDT_SWITCH_MODE_DELAY);
+                /* mode register is 0x01 when in factory mode */
+                ret = edt_ft5x06_register_read(tsdata, WORK_REGISTER_OPMODE);
+                if (ret == 0x01)
+                        break;
+        } while (--retries > 0);
+
+        if (retries == 0) {
+                dev_err(&client->dev, "not in work mode after %dms.\n",
+                        EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
+                tsdata->factory_mode = true;
+                return -EIO;
+        }
+
+        if (tsdata->raw_buffer)
+                kfree(tsdata->raw_buffer);
+        tsdata->raw_buffer = NULL;
+
+        /* restore parameters */
+        edt_ft5x06_register_write(tsdata, WORK_REGISTER_THRESHOLD,
+                                  tsdata->threshold);
+        edt_ft5x06_register_write(tsdata, WORK_REGISTER_GAIN,
+                                  tsdata->gain);
+        edt_ft5x06_register_write(tsdata, WORK_REGISTER_OFFSET,
+                                  tsdata->offset);
+        edt_ft5x06_register_write(tsdata, WORK_REGISTER_REPORT_RATE,
+                                  tsdata->report_rate);
+
+        enable_irq(client->irq);
+
+        return 0;
+}
+
+static int edt_ft5x06_debugfs_mode_get(void *data, u64 *mode)
+{
+        struct edt_ft5x06_ts_data *tsdata = data;
+
+        *mode = tsdata->factory_mode;
+
+        return 0;
+};
+
+static int edt_ft5x06_debugfs_mode_set(void *data, u64 mode)
+{
+        struct edt_ft5x06_ts_data *tsdata = data;
+        int retval = 0;
+
+        if (mode > 1)
+                return -ERANGE;
+
+        mutex_lock(&tsdata->mutex);
+
+        if (mode != tsdata->factory_mode) {
+                retval = mode ? edt_ft5x06_factory_mode(tsdata) :
+                                edt_ft5x06_work_mode(tsdata);
+        }
+
+        mutex_unlock(&tsdata->mutex);
+
+        return retval;
+};
+
+DEFINE_SIMPLE_ATTRIBUTE(debugfs_mode_fops, edt_ft5x06_debugfs_mode_get,
+                        edt_ft5x06_debugfs_mode_set, "%llu\n");
+
+static int edt_ft5x06_debugfs_raw_data_open(struct inode *inode,
+                                            struct file *file)
+{
+        file->private_data = inode->i_private;
+
+        return 0;
+}
+
+static ssize_t edt_ft5x06_debugfs_raw_data_read(struct file *file,
+                                char __user *buf, size_t count, loff_t *off)
+{
+        struct edt_ft5x06_ts_data *tsdata = file->private_data;
+        struct i2c_client *client = tsdata->client;
+        int retries  = EDT_RAW_DATA_RETRIES;
+        int val, i, error;
+        size_t read = 0;
+        int colbytes;
+        char wrbuf[3];
+        u8 *rdbuf;
+
+        if (*off < 0 || *off >= tsdata->raw_bufsize)
+                return 0;
+
+        mutex_lock(&tsdata->mutex);
+
+        if (!tsdata->factory_mode || !tsdata->raw_buffer) {
+                error = -EIO;
+                goto out;
+        }
+
+        error = edt_ft5x06_register_write(tsdata, 0x08, 0x01);
+        if (error) {
+                dev_dbg(&client->dev,
+                        "failed to write 0x08 register, error %d\n", error);
+                goto out;
+        }
+
+        do {
+                msleep(EDT_RAW_DATA_DELAY);
+                val = edt_ft5x06_register_read(tsdata, 0x08);
+                if (val < 1)
+                        break;
+        } while (--retries > 0);
+
+        if (val < 0) {
+                error = val;
+                dev_dbg(&client->dev,
+                        "failed to read 0x08 register, error %d\n", error);
+                goto out;
+        }
+
+        if (retries == 0) {
+                dev_dbg(&client->dev,
+                        "timed out waiting for register to settle\n");
+                error = -ETIMEDOUT;
+                goto out;
+        }
+
+        rdbuf = tsdata->raw_buffer;
+        colbytes = tsdata->num_y * sizeof(u16);
+
+        wrbuf[0] = 0xf5;
+        wrbuf[1] = 0x0e;
+        for (i = 0; i < tsdata->num_x; i++) {
+                wrbuf[2] = i;  /* column index */
+                error = edt_ft5x06_ts_readwrite(tsdata->client,
+                                                sizeof(wrbuf), wrbuf,
+                                                colbytes, rdbuf);
+                if (error)
+                        goto out;
+
+                rdbuf += colbytes;
+        }
+
+        read = min_t(size_t, count, tsdata->raw_bufsize - *off);
+        error = copy_to_user(buf, tsdata->raw_buffer + *off, read);
+        if (!error)
+                *off += read;
+out:
+        mutex_unlock(&tsdata->mutex);
+        return error ?: read;
+};
+
+
+static const struct file_operations debugfs_raw_data_fops = {
+        .open = edt_ft5x06_debugfs_raw_data_open,
+        .read = edt_ft5x06_debugfs_raw_data_read,
+};
+
+static void __devinit
+edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
+                              const char *debugfs_name)
+{
+        tsdata->debug_dir = debugfs_create_dir(debugfs_name, NULL);
+        if (!tsdata->debug_dir)
+                return;
+
+        debugfs_create_u16("num_x", S_IRUSR, tsdata->debug_dir, &tsdata->num_x);
+        debugfs_create_u16("num_y", S_IRUSR, tsdata->debug_dir, &tsdata->num_y);
+
+        debugfs_create_file("mode", S_IRUSR | S_IWUSR,
+                            tsdata->debug_dir, tsdata, &debugfs_mode_fops);
+        debugfs_create_file("raw_data", S_IRUSR,
+                            tsdata->debug_dir, tsdata, &debugfs_raw_data_fops);
+}
+
+static void __devexit
+edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
+{
+        if (tsdata->debug_dir)
+                debugfs_remove_recursive(tsdata->debug_dir);
+}
+
+#else
+
+static inline void
+edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
+                              const char *debugfs_name)
+{
+}
+
+static inline void
+edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
+{
+}
+
+#endif /* CONFIG_DEBUGFS */
+
+
+
+static int __devinit edt_ft5x06_ts_reset(struct i2c_client *client,
+                                         int reset_pin)
+{
+        int error;
+
+        if (gpio_is_valid(reset_pin)) {
+                /* this pulls reset down, enabling the low active reset */
+                error = gpio_request_one(reset_pin, GPIOF_OUT_INIT_LOW,
+                                         "edt-ft5x06 reset");
+                if (error) {
+                        dev_err(&client->dev,
+                                "Failed to request GPIO %d as reset pin, error %d\n",
+                                reset_pin, error);
+                        return error;
+                }
+
+                mdelay(50);
+                gpio_set_value(reset_pin, 1);
+                mdelay(100);
+        }
+
+        return 0;
+}
+
+static int __devinit edt_ft5x06_ts_identify(struct i2c_client *client,
+                                            char *model_name,
+                                            char *fw_version)
+{
+        u8 rdbuf[EDT_NAME_LEN];
+        char *p;
+        int error;
+
+        error = edt_ft5x06_ts_readwrite(client, 1, "\xbb",
+                                        EDT_NAME_LEN - 1, rdbuf);
+        if (error)
+                return error;
+
+        /* remove last '$' end marker */
+        rdbuf[EDT_NAME_LEN - 1] = '\0';
+        if (rdbuf[EDT_NAME_LEN - 2] == '$')
+                rdbuf[EDT_NAME_LEN - 2] = '\0';
+
+        /* look for Model/Version separator */
+        p = strchr(rdbuf, '*');
+        if (p)
+                *p++ = '\0';
+
+        strlcpy(model_name, rdbuf + 1, EDT_NAME_LEN);
+        strlcpy(fw_version, p ? p : "", EDT_NAME_LEN);
+
+        return 0;
+}
+
+#define EDT_ATTR_CHECKSET(name, reg) \
+        if (pdata->name >= edt_ft5x06_attr_##name.limit_low &&          \
+            pdata->name <= edt_ft5x06_attr_##name.limit_high)           \
+                edt_ft5x06_register_write(tsdata, reg, pdata->name)
+
+static void __devinit
+edt_ft5x06_ts_get_defaults(struct edt_ft5x06_ts_data *tsdata,
+                           const struct edt_ft5x06_platform_data *pdata)
+{
+        if (!pdata->use_parameters)
+                return;
+
+        /* pick up defaults from the platform data */
+        EDT_ATTR_CHECKSET(threshold, WORK_REGISTER_THRESHOLD);
+        EDT_ATTR_CHECKSET(gain, WORK_REGISTER_GAIN);
+        EDT_ATTR_CHECKSET(offset, WORK_REGISTER_OFFSET);
+        EDT_ATTR_CHECKSET(report_rate, WORK_REGISTER_REPORT_RATE);
+}
+
+static void __devinit
+edt_ft5x06_ts_get_parameters(struct edt_ft5x06_ts_data *tsdata)
+{
+        tsdata->threshold = edt_ft5x06_register_read(tsdata,
+                                                     WORK_REGISTER_THRESHOLD);
+        tsdata->gain = edt_ft5x06_register_read(tsdata, WORK_REGISTER_GAIN);
+        tsdata->offset = edt_ft5x06_register_read(tsdata, WORK_REGISTER_OFFSET);
+        tsdata->report_rate = edt_ft5x06_register_read(tsdata,
+                                                WORK_REGISTER_REPORT_RATE);
+        tsdata->num_x = edt_ft5x06_register_read(tsdata, WORK_REGISTER_NUM_X);
+        tsdata->num_y = edt_ft5x06_register_read(tsdata, WORK_REGISTER_NUM_Y);
+}
+
+static int __devinit edt_ft5x06_ts_probe(struct i2c_client *client,
+                                         const struct i2c_device_id *id)
+{
+        const struct edt_ft5x06_platform_data *pdata =
+                                                client->dev.platform_data;
+        struct edt_ft5x06_ts_data *tsdata;
+        struct input_dev *input;
+        int error;
+        char fw_version[EDT_NAME_LEN];
+
+        dev_dbg(&client->dev, "probing for EDT FT5x06 I2C\n");
+
+        if (!pdata) {
+                dev_err(&client->dev, "no platform data?\n");
+                return -EINVAL;
+        }
+
+        error = edt_ft5x06_ts_reset(client, pdata->reset_pin);
+        if (error)
+                return error;
+
+        if (gpio_is_valid(pdata->irq_pin)) {
+                error = gpio_request_one(pdata->irq_pin,
+                                         GPIOF_IN, "edt-ft5x06 irq");
+                if (error) {
+                        dev_err(&client->dev,
+                                "Failed to request GPIO %d, error %d\n",
+                                pdata->irq_pin, error);
+                        return error;
+                }
+        }
+
+        tsdata = kzalloc(sizeof(*tsdata), GFP_KERNEL);
+        input = input_allocate_device();
+        if (!tsdata || !input) {
+                dev_err(&client->dev, "failed to allocate driver data.\n");
+                error = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        mutex_init(&tsdata->mutex);
+        tsdata->client = client;
+        tsdata->input = input;
+        tsdata->factory_mode = false;
+
+        error = edt_ft5x06_ts_identify(client, tsdata->name, fw_version);
+        if (error) {
+                dev_err(&client->dev, "touchscreen probe failed\n");
+                goto err_free_mem;
+        }
+
+        edt_ft5x06_ts_get_defaults(tsdata, pdata);
+        edt_ft5x06_ts_get_parameters(tsdata);
+
+        dev_dbg(&client->dev,
+                "Model \"%s\", Rev. \"%s\", %dx%d sensors\n",
+                tsdata->name, fw_version, tsdata->num_x, tsdata->num_y);
+
+        input->name = tsdata->name;
+        input->id.bustype = BUS_I2C;
+        input->dev.parent = &client->dev;
+
+        __set_bit(EV_SYN, input->evbit);
+        __set_bit(EV_KEY, input->evbit);
+        __set_bit(EV_ABS, input->evbit);
+        __set_bit(BTN_TOUCH, input->keybit);
+        input_set_abs_params(input, ABS_X, 0, tsdata->num_x * 64 - 1, 0, 0);
+        input_set_abs_params(input, ABS_Y, 0, tsdata->num_y * 64 - 1, 0, 0);
+        input_set_abs_params(input, ABS_MT_POSITION_X,
+                             0, tsdata->num_x * 64 - 1, 0, 0);
+        input_set_abs_params(input, ABS_MT_POSITION_Y,
+                             0, tsdata->num_y * 64 - 1, 0, 0);
+        error = input_mt_init_slots(input, MAX_SUPPORT_POINTS);
+        if (error) {
+                dev_err(&client->dev, "Unable to init MT slots.\n");
+                goto err_free_mem;
+        }
+
+        input_set_drvdata(input, tsdata);
+        i2c_set_clientdata(client, tsdata);
+
+        error = request_threaded_irq(client->irq, NULL, edt_ft5x06_ts_isr,
+                                     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+                                     client->name, tsdata);
+        if (error) {
+                dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
+                goto err_free_mem;
+        }
+
+        error = sysfs_create_group(&client->dev.kobj, &edt_ft5x06_attr_group);
+        if (error)
+                goto err_free_irq;
+
+        error = input_register_device(input);
+        if (error)
+                goto err_remove_attrs;
+
+        edt_ft5x06_ts_prepare_debugfs(tsdata, dev_driver_string(&client->dev));
+        device_init_wakeup(&client->dev, 1);
+
+        dev_dbg(&client->dev,
+                "EDT FT5x06 initialized: IRQ pin %d, Reset pin %d.\n",
+                pdata->irq_pin, pdata->reset_pin);
+
+        return 0;
+
+err_remove_attrs:
+        sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
+err_free_irq:
+        free_irq(client->irq, tsdata);
+err_free_mem:
+        input_free_device(input);
+        kfree(tsdata);
+
+        if (gpio_is_valid(pdata->irq_pin))
+                gpio_free(pdata->irq_pin);
+
+        return error;
+}
+
+static int __devexit edt_ft5x06_ts_remove(struct i2c_client *client)
+{
+        const struct edt_ft5x06_platform_data *pdata =
+                                                dev_get_platdata(&client->dev);
+        struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
+
+        edt_ft5x06_ts_teardown_debugfs(tsdata);
+        sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
+
+        free_irq(client->irq, tsdata);
+        input_unregister_device(tsdata->input);
+
+        if (gpio_is_valid(pdata->irq_pin))
+                gpio_free(pdata->irq_pin);
+        if (gpio_is_valid(pdata->reset_pin))
+                gpio_free(pdata->reset_pin);
+
+        kfree(tsdata->raw_buffer);
+        kfree(tsdata);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int edt_ft5x06_ts_suspend(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+
+        if (device_may_wakeup(dev))
+                enable_irq_wake(client->irq);
+
+        return 0;
+}
+
+static int edt_ft5x06_ts_resume(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+
+        if (device_may_wakeup(dev))
+                disable_irq_wake(client->irq);
+
+        return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(edt_ft5x06_ts_pm_ops,
+                         edt_ft5x06_ts_suspend, edt_ft5x06_ts_resume);
+
+static const struct i2c_device_id edt_ft5x06_ts_id[] = {
+        { "edt-ft5x06", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, edt_ft5x06_ts_id);
+
+static struct i2c_driver edt_ft5x06_ts_driver = {
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = "edt_ft5x06",
+                .pm = &edt_ft5x06_ts_pm_ops,
+        },
+        .id_table = edt_ft5x06_ts_id,
+        .probe    = edt_ft5x06_ts_probe,
+        .remove   = __devexit_p(edt_ft5x06_ts_remove),
+};
+
+module_i2c_driver(edt_ft5x06_ts_driver);
+
+MODULE_AUTHOR("Simon Budig <simon.budig@kernelconcepts.de>");
+MODULE_DESCRIPTION("EDT FT5x06 I2C Touchscreen Driver");
+MODULE_LICENSE("GPL");