Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / input / touchscreen / zforce_ts.c
diff --git a/kernel/drivers/input/touchscreen/zforce_ts.c b/kernel/drivers/input/touchscreen/zforce_ts.c
new file mode 100644 (file)
index 0000000..19880c7
--- /dev/null
@@ -0,0 +1,934 @@
+/*
+ * Copyright (C) 2012-2013 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko@sntech.de>
+ *
+ * based in parts on Nook zforce driver
+ *
+ * Copyright (C) 2010 Barnes & Noble, Inc.
+ * Author: Pieter Truter<ptruter@intrinsyc.com>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/hrtimer.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/input/mt.h>
+#include <linux/platform_data/zforce_ts.h>
+#include <linux/regulator/consumer.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+
+#define WAIT_TIMEOUT           msecs_to_jiffies(1000)
+
+#define FRAME_START            0xee
+#define FRAME_MAXSIZE          257
+
+/* Offsets of the different parts of the payload the controller sends */
+#define PAYLOAD_HEADER         0
+#define PAYLOAD_LENGTH         1
+#define PAYLOAD_BODY           2
+
+/* Response offsets */
+#define RESPONSE_ID            0
+#define RESPONSE_DATA          1
+
+/* Commands */
+#define COMMAND_DEACTIVATE     0x00
+#define COMMAND_INITIALIZE     0x01
+#define COMMAND_RESOLUTION     0x02
+#define COMMAND_SETCONFIG      0x03
+#define COMMAND_DATAREQUEST    0x04
+#define COMMAND_SCANFREQ       0x08
+#define COMMAND_STATUS         0X1e
+
+/*
+ * Responses the controller sends as a result of
+ * command requests
+ */
+#define RESPONSE_DEACTIVATE    0x00
+#define RESPONSE_INITIALIZE    0x01
+#define RESPONSE_RESOLUTION    0x02
+#define RESPONSE_SETCONFIG     0x03
+#define RESPONSE_SCANFREQ      0x08
+#define RESPONSE_STATUS                0X1e
+
+/*
+ * Notifications are sent by the touch controller without
+ * being requested by the driver and include for example
+ * touch indications
+ */
+#define NOTIFICATION_TOUCH             0x04
+#define NOTIFICATION_BOOTCOMPLETE      0x07
+#define NOTIFICATION_OVERRUN           0x25
+#define NOTIFICATION_PROXIMITY         0x26
+#define NOTIFICATION_INVALID_COMMAND   0xfe
+
+#define ZFORCE_REPORT_POINTS           2
+#define ZFORCE_MAX_AREA                        0xff
+
+#define STATE_DOWN                     0
+#define STATE_MOVE                     1
+#define STATE_UP                       2
+
+#define SETCONFIG_DUALTOUCH            (1 << 0)
+
+struct zforce_point {
+       int coord_x;
+       int coord_y;
+       int state;
+       int id;
+       int area_major;
+       int area_minor;
+       int orientation;
+       int pressure;
+       int prblty;
+};
+
+/*
+ * @client             the i2c_client
+ * @input              the input device
+ * @suspending         in the process of going to suspend (don't emit wakeup
+ *                     events for commands executed to suspend the device)
+ * @suspended          device suspended
+ * @access_mutex       serialize i2c-access, to keep multipart reads together
+ * @command_done       completion to wait for the command result
+ * @command_mutex      serialize commands sent to the ic
+ * @command_waiting    the id of the command that is currently waiting
+ *                     for a result
+ * @command_result     returned result of the command
+ */
+struct zforce_ts {
+       struct i2c_client       *client;
+       struct input_dev        *input;
+       const struct zforce_ts_platdata *pdata;
+       char                    phys[32];
+
+       struct regulator        *reg_vdd;
+
+       bool                    suspending;
+       bool                    suspended;
+       bool                    boot_complete;
+
+       /* Firmware version information */
+       u16                     version_major;
+       u16                     version_minor;
+       u16                     version_build;
+       u16                     version_rev;
+
+       struct mutex            access_mutex;
+
+       struct completion       command_done;
+       struct mutex            command_mutex;
+       int                     command_waiting;
+       int                     command_result;
+};
+
+static int zforce_command(struct zforce_ts *ts, u8 cmd)
+{
+       struct i2c_client *client = ts->client;
+       char buf[3];
+       int ret;
+
+       dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
+
+       buf[0] = FRAME_START;
+       buf[1] = 1; /* data size, command only */
+       buf[2] = cmd;
+
+       mutex_lock(&ts->access_mutex);
+       ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf));
+       mutex_unlock(&ts->access_mutex);
+       if (ret < 0) {
+               dev_err(&client->dev, "i2c send data request error: %d\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len)
+{
+       struct i2c_client *client = ts->client;
+       int ret;
+
+       ret = mutex_trylock(&ts->command_mutex);
+       if (!ret) {
+               dev_err(&client->dev, "already waiting for a command\n");
+               return -EBUSY;
+       }
+
+       dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n",
+               buf[1], buf[2]);
+
+       ts->command_waiting = buf[2];
+
+       mutex_lock(&ts->access_mutex);
+       ret = i2c_master_send(client, buf, len);
+       mutex_unlock(&ts->access_mutex);
+       if (ret < 0) {
+               dev_err(&client->dev, "i2c send data request error: %d\n", ret);
+               goto unlock;
+       }
+
+       dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]);
+
+       if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) {
+               ret = -ETIME;
+               goto unlock;
+       }
+
+       ret = ts->command_result;
+
+unlock:
+       mutex_unlock(&ts->command_mutex);
+       return ret;
+}
+
+static int zforce_command_wait(struct zforce_ts *ts, u8 cmd)
+{
+       struct i2c_client *client = ts->client;
+       char buf[3];
+       int ret;
+
+       dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd);
+
+       buf[0] = FRAME_START;
+       buf[1] = 1; /* data size, command only */
+       buf[2] = cmd;
+
+       ret = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
+       if (ret < 0) {
+               dev_err(&client->dev, "i2c send data request error: %d\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y)
+{
+       struct i2c_client *client = ts->client;
+       char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION,
+                       (x & 0xff), ((x >> 8) & 0xff),
+                       (y & 0xff), ((y >> 8) & 0xff) };
+
+       dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y);
+
+       return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
+}
+
+static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger,
+                                u16 stylus)
+{
+       struct i2c_client *client = ts->client;
+       char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ,
+                       (idle & 0xff), ((idle >> 8) & 0xff),
+                       (finger & 0xff), ((finger >> 8) & 0xff),
+                       (stylus & 0xff), ((stylus >> 8) & 0xff) };
+
+       dev_dbg(&client->dev,
+               "set scan frequency to (idle: %d, finger: %d, stylus: %d)\n",
+               idle, finger, stylus);
+
+       return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
+}
+
+static int zforce_setconfig(struct zforce_ts *ts, char b1)
+{
+       struct i2c_client *client = ts->client;
+       char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG,
+                       b1, 0, 0, 0 };
+
+       dev_dbg(&client->dev, "set config to (%d)\n", b1);
+
+       return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf));
+}
+
+static int zforce_start(struct zforce_ts *ts)
+{
+       struct i2c_client *client = ts->client;
+       const struct zforce_ts_platdata *pdata = ts->pdata;
+       int ret;
+
+       dev_dbg(&client->dev, "starting device\n");
+
+       ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
+       if (ret) {
+               dev_err(&client->dev, "Unable to initialize, %d\n", ret);
+               return ret;
+       }
+
+       ret = zforce_resolution(ts, pdata->x_max, pdata->y_max);
+       if (ret) {
+               dev_err(&client->dev, "Unable to set resolution, %d\n", ret);
+               goto error;
+       }
+
+       ret = zforce_scan_frequency(ts, 10, 50, 50);
+       if (ret) {
+               dev_err(&client->dev, "Unable to set scan frequency, %d\n",
+                       ret);
+               goto error;
+       }
+
+       ret = zforce_setconfig(ts, SETCONFIG_DUALTOUCH);
+       if (ret) {
+               dev_err(&client->dev, "Unable to set config\n");
+               goto error;
+       }
+
+       /* start sending touch events */
+       ret = zforce_command(ts, COMMAND_DATAREQUEST);
+       if (ret) {
+               dev_err(&client->dev, "Unable to request data\n");
+               goto error;
+       }
+
+       /*
+        * Per NN, initial cal. take max. of 200msec.
+        * Allow time to complete this calibration
+        */
+       msleep(200);
+
+       return 0;
+
+error:
+       zforce_command_wait(ts, COMMAND_DEACTIVATE);
+       return ret;
+}
+
+static int zforce_stop(struct zforce_ts *ts)
+{
+       struct i2c_client *client = ts->client;
+       int ret;
+
+       dev_dbg(&client->dev, "stopping device\n");
+
+       /* Deactivates touch sensing and puts the device into sleep. */
+       ret = zforce_command_wait(ts, COMMAND_DEACTIVATE);
+       if (ret != 0) {
+               dev_err(&client->dev, "could not deactivate device, %d\n",
+                       ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
+{
+       struct i2c_client *client = ts->client;
+       const struct zforce_ts_platdata *pdata = ts->pdata;
+       struct zforce_point point;
+       int count, i, num = 0;
+
+       count = payload[0];
+       if (count > ZFORCE_REPORT_POINTS) {
+               dev_warn(&client->dev,
+                        "too many coordinates %d, expected max %d\n",
+                        count, ZFORCE_REPORT_POINTS);
+               count = ZFORCE_REPORT_POINTS;
+       }
+
+       for (i = 0; i < count; i++) {
+               point.coord_x =
+                       payload[9 * i + 2] << 8 | payload[9 * i + 1];
+               point.coord_y =
+                       payload[9 * i + 4] << 8 | payload[9 * i + 3];
+
+               if (point.coord_x > pdata->x_max ||
+                   point.coord_y > pdata->y_max) {
+                       dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
+                               point.coord_x, point.coord_y);
+                       point.coord_x = point.coord_y = 0;
+               }
+
+               point.state = payload[9 * i + 5] & 0x03;
+               point.id = (payload[9 * i + 5] & 0xfc) >> 2;
+
+               /* determine touch major, minor and orientation */
+               point.area_major = max(payload[9 * i + 6],
+                                         payload[9 * i + 7]);
+               point.area_minor = min(payload[9 * i + 6],
+                                         payload[9 * i + 7]);
+               point.orientation = payload[9 * i + 6] > payload[9 * i + 7];
+
+               point.pressure = payload[9 * i + 8];
+               point.prblty = payload[9 * i + 9];
+
+               dev_dbg(&client->dev,
+                       "point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
+                       i, count, point.state, point.id,
+                       point.pressure, point.prblty,
+                       point.coord_x, point.coord_y,
+                       point.area_major, point.area_minor,
+                       point.orientation);
+
+               /* the zforce id starts with "1", so needs to be decreased */
+               input_mt_slot(ts->input, point.id - 1);
+
+               input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
+                                               point.state != STATE_UP);
+
+               if (point.state != STATE_UP) {
+                       input_report_abs(ts->input, ABS_MT_POSITION_X,
+                                        point.coord_x);
+                       input_report_abs(ts->input, ABS_MT_POSITION_Y,
+                                        point.coord_y);
+                       input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
+                                        point.area_major);
+                       input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
+                                        point.area_minor);
+                       input_report_abs(ts->input, ABS_MT_ORIENTATION,
+                                        point.orientation);
+                       num++;
+               }
+       }
+
+       input_mt_sync_frame(ts->input);
+
+       input_mt_report_finger_count(ts->input, num);
+
+       input_sync(ts->input);
+
+       return 0;
+}
+
+static int zforce_read_packet(struct zforce_ts *ts, u8 *buf)
+{
+       struct i2c_client *client = ts->client;
+       int ret;
+
+       mutex_lock(&ts->access_mutex);
+
+       /* read 2 byte message header */
+       ret = i2c_master_recv(client, buf, 2);
+       if (ret < 0) {
+               dev_err(&client->dev, "error reading header: %d\n", ret);
+               goto unlock;
+       }
+
+       if (buf[PAYLOAD_HEADER] != FRAME_START) {
+               dev_err(&client->dev, "invalid frame start: %d\n", buf[0]);
+               ret = -EIO;
+               goto unlock;
+       }
+
+       if (buf[PAYLOAD_LENGTH] == 0) {
+               dev_err(&client->dev, "invalid payload length: %d\n",
+                       buf[PAYLOAD_LENGTH]);
+               ret = -EIO;
+               goto unlock;
+       }
+
+       /* read the message */
+       ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]);
+       if (ret < 0) {
+               dev_err(&client->dev, "error reading payload: %d\n", ret);
+               goto unlock;
+       }
+
+       dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n",
+               buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]);
+
+unlock:
+       mutex_unlock(&ts->access_mutex);
+       return ret;
+}
+
+static void zforce_complete(struct zforce_ts *ts, int cmd, int result)
+{
+       struct i2c_client *client = ts->client;
+
+       if (ts->command_waiting == cmd) {
+               dev_dbg(&client->dev, "completing command 0x%x\n", cmd);
+               ts->command_result = result;
+               complete(&ts->command_done);
+       } else {
+               dev_dbg(&client->dev, "command %d not for us\n", cmd);
+       }
+}
+
+static irqreturn_t zforce_irq(int irq, void *dev_id)
+{
+       struct zforce_ts *ts = dev_id;
+       struct i2c_client *client = ts->client;
+
+       if (ts->suspended && device_may_wakeup(&client->dev))
+               pm_wakeup_event(&client->dev, 500);
+
+       return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t zforce_irq_thread(int irq, void *dev_id)
+{
+       struct zforce_ts *ts = dev_id;
+       struct i2c_client *client = ts->client;
+       const struct zforce_ts_platdata *pdata = ts->pdata;
+       int ret;
+       u8 payload_buffer[FRAME_MAXSIZE];
+       u8 *payload;
+
+       /*
+        * When still suspended, return.
+        * Due to the level-interrupt we will get re-triggered later.
+        */
+       if (ts->suspended) {
+               msleep(20);
+               return IRQ_HANDLED;
+       }
+
+       dev_dbg(&client->dev, "handling interrupt\n");
+
+       /* Don't emit wakeup events from commands run by zforce_suspend */
+       if (!ts->suspending && device_may_wakeup(&client->dev))
+               pm_stay_awake(&client->dev);
+
+       while (!gpio_get_value(pdata->gpio_int)) {
+               ret = zforce_read_packet(ts, payload_buffer);
+               if (ret < 0) {
+                       dev_err(&client->dev,
+                               "could not read packet, ret: %d\n", ret);
+                       break;
+               }
+
+               payload =  &payload_buffer[PAYLOAD_BODY];
+
+               switch (payload[RESPONSE_ID]) {
+               case NOTIFICATION_TOUCH:
+                       /*
+                        * Always report touch-events received while
+                        * suspending, when being a wakeup source
+                        */
+                       if (ts->suspending && device_may_wakeup(&client->dev))
+                               pm_wakeup_event(&client->dev, 500);
+                       zforce_touch_event(ts, &payload[RESPONSE_DATA]);
+                       break;
+
+               case NOTIFICATION_BOOTCOMPLETE:
+                       ts->boot_complete = payload[RESPONSE_DATA];
+                       zforce_complete(ts, payload[RESPONSE_ID], 0);
+                       break;
+
+               case RESPONSE_INITIALIZE:
+               case RESPONSE_DEACTIVATE:
+               case RESPONSE_SETCONFIG:
+               case RESPONSE_RESOLUTION:
+               case RESPONSE_SCANFREQ:
+                       zforce_complete(ts, payload[RESPONSE_ID],
+                                       payload[RESPONSE_DATA]);
+                       break;
+
+               case RESPONSE_STATUS:
+                       /*
+                        * Version Payload Results
+                        * [2:major] [2:minor] [2:build] [2:rev]
+                        */
+                       ts->version_major = (payload[RESPONSE_DATA + 1] << 8) |
+                                               payload[RESPONSE_DATA];
+                       ts->version_minor = (payload[RESPONSE_DATA + 3] << 8) |
+                                               payload[RESPONSE_DATA + 2];
+                       ts->version_build = (payload[RESPONSE_DATA + 5] << 8) |
+                                               payload[RESPONSE_DATA + 4];
+                       ts->version_rev   = (payload[RESPONSE_DATA + 7] << 8) |
+                                               payload[RESPONSE_DATA + 6];
+                       dev_dbg(&ts->client->dev,
+                               "Firmware Version %04x:%04x %04x:%04x\n",
+                               ts->version_major, ts->version_minor,
+                               ts->version_build, ts->version_rev);
+
+                       zforce_complete(ts, payload[RESPONSE_ID], 0);
+                       break;
+
+               case NOTIFICATION_INVALID_COMMAND:
+                       dev_err(&ts->client->dev, "invalid command: 0x%x\n",
+                               payload[RESPONSE_DATA]);
+                       break;
+
+               default:
+                       dev_err(&ts->client->dev,
+                               "unrecognized response id: 0x%x\n",
+                               payload[RESPONSE_ID]);
+                       break;
+               }
+       }
+
+       if (!ts->suspending && device_may_wakeup(&client->dev))
+               pm_relax(&client->dev);
+
+       dev_dbg(&client->dev, "finished interrupt\n");
+
+       return IRQ_HANDLED;
+}
+
+static int zforce_input_open(struct input_dev *dev)
+{
+       struct zforce_ts *ts = input_get_drvdata(dev);
+       int ret;
+
+       ret = zforce_start(ts);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
+static void zforce_input_close(struct input_dev *dev)
+{
+       struct zforce_ts *ts = input_get_drvdata(dev);
+       struct i2c_client *client = ts->client;
+       int ret;
+
+       ret = zforce_stop(ts);
+       if (ret)
+               dev_warn(&client->dev, "stopping zforce failed\n");
+
+       return;
+}
+
+static int __maybe_unused zforce_suspend(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct zforce_ts *ts = i2c_get_clientdata(client);
+       struct input_dev *input = ts->input;
+       int ret = 0;
+
+       mutex_lock(&input->mutex);
+       ts->suspending = true;
+
+       /*
+        * When configured as a wakeup source device should always wake
+        * the system, therefore start device if necessary.
+        */
+       if (device_may_wakeup(&client->dev)) {
+               dev_dbg(&client->dev, "suspend while being a wakeup source\n");
+
+               /* Need to start device, if not open, to be a wakeup source. */
+               if (!input->users) {
+                       ret = zforce_start(ts);
+                       if (ret)
+                               goto unlock;
+               }
+
+               enable_irq_wake(client->irq);
+       } else if (input->users) {
+               dev_dbg(&client->dev,
+                       "suspend without being a wakeup source\n");
+
+               ret = zforce_stop(ts);
+               if (ret)
+                       goto unlock;
+
+               disable_irq(client->irq);
+       }
+
+       ts->suspended = true;
+
+unlock:
+       ts->suspending = false;
+       mutex_unlock(&input->mutex);
+
+       return ret;
+}
+
+static int __maybe_unused zforce_resume(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct zforce_ts *ts = i2c_get_clientdata(client);
+       struct input_dev *input = ts->input;
+       int ret = 0;
+
+       mutex_lock(&input->mutex);
+
+       ts->suspended = false;
+
+       if (device_may_wakeup(&client->dev)) {
+               dev_dbg(&client->dev, "resume from being a wakeup source\n");
+
+               disable_irq_wake(client->irq);
+
+               /* need to stop device if it was not open on suspend */
+               if (!input->users) {
+                       ret = zforce_stop(ts);
+                       if (ret)
+                               goto unlock;
+               }
+       } else if (input->users) {
+               dev_dbg(&client->dev, "resume without being a wakeup source\n");
+
+               enable_irq(client->irq);
+
+               ret = zforce_start(ts);
+               if (ret < 0)
+                       goto unlock;
+       }
+
+unlock:
+       mutex_unlock(&input->mutex);
+
+       return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume);
+
+static void zforce_reset(void *data)
+{
+       struct zforce_ts *ts = data;
+
+       gpio_set_value(ts->pdata->gpio_rst, 0);
+
+       udelay(10);
+
+       if (!IS_ERR(ts->reg_vdd))
+               regulator_disable(ts->reg_vdd);
+}
+
+static struct zforce_ts_platdata *zforce_parse_dt(struct device *dev)
+{
+       struct zforce_ts_platdata *pdata;
+       struct device_node *np = dev->of_node;
+
+       if (!np)
+               return ERR_PTR(-ENOENT);
+
+       pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+       if (!pdata) {
+               dev_err(dev, "failed to allocate platform data\n");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       pdata->gpio_int = of_get_gpio(np, 0);
+       if (!gpio_is_valid(pdata->gpio_int)) {
+               dev_err(dev, "failed to get interrupt gpio\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       pdata->gpio_rst = of_get_gpio(np, 1);
+       if (!gpio_is_valid(pdata->gpio_rst)) {
+               dev_err(dev, "failed to get reset gpio\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       if (of_property_read_u32(np, "x-size", &pdata->x_max)) {
+               dev_err(dev, "failed to get x-size property\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       if (of_property_read_u32(np, "y-size", &pdata->y_max)) {
+               dev_err(dev, "failed to get y-size property\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       return pdata;
+}
+
+static int zforce_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       const struct zforce_ts_platdata *pdata = dev_get_platdata(&client->dev);
+       struct zforce_ts *ts;
+       struct input_dev *input_dev;
+       int ret;
+
+       if (!pdata) {
+               pdata = zforce_parse_dt(&client->dev);
+               if (IS_ERR(pdata))
+                       return PTR_ERR(pdata);
+       }
+
+       ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
+       if (!ts)
+               return -ENOMEM;
+
+       ret = devm_gpio_request_one(&client->dev, pdata->gpio_int, GPIOF_IN,
+                                   "zforce_ts_int");
+       if (ret) {
+               dev_err(&client->dev, "request of gpio %d failed, %d\n",
+                       pdata->gpio_int, ret);
+               return ret;
+       }
+
+       ret = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
+                                   GPIOF_OUT_INIT_LOW, "zforce_ts_rst");
+       if (ret) {
+               dev_err(&client->dev, "request of gpio %d failed, %d\n",
+                       pdata->gpio_rst, ret);
+               return ret;
+       }
+
+       ts->reg_vdd = devm_regulator_get_optional(&client->dev, "vdd");
+       if (IS_ERR(ts->reg_vdd)) {
+               ret = PTR_ERR(ts->reg_vdd);
+               if (ret == -EPROBE_DEFER)
+                       return ret;
+       } else {
+               ret = regulator_enable(ts->reg_vdd);
+               if (ret)
+                       return ret;
+
+               /*
+                * according to datasheet add 100us grace time after regular
+                * regulator enable delay.
+                */
+               udelay(100);
+       }
+
+       ret = devm_add_action(&client->dev, zforce_reset, ts);
+       if (ret) {
+               dev_err(&client->dev, "failed to register reset action, %d\n",
+                       ret);
+
+               /* hereafter the regulator will be disabled by the action */
+               if (!IS_ERR(ts->reg_vdd))
+                       regulator_disable(ts->reg_vdd);
+
+               return ret;
+       }
+
+       snprintf(ts->phys, sizeof(ts->phys),
+                "%s/input0", dev_name(&client->dev));
+
+       input_dev = devm_input_allocate_device(&client->dev);
+       if (!input_dev) {
+               dev_err(&client->dev, "could not allocate input device\n");
+               return -ENOMEM;
+       }
+
+       mutex_init(&ts->access_mutex);
+       mutex_init(&ts->command_mutex);
+
+       ts->pdata = pdata;
+       ts->client = client;
+       ts->input = input_dev;
+
+       input_dev->name = "Neonode zForce touchscreen";
+       input_dev->phys = ts->phys;
+       input_dev->id.bustype = BUS_I2C;
+
+       input_dev->open = zforce_input_open;
+       input_dev->close = zforce_input_close;
+
+       __set_bit(EV_KEY, input_dev->evbit);
+       __set_bit(EV_SYN, input_dev->evbit);
+       __set_bit(EV_ABS, input_dev->evbit);
+
+       /* For multi touch */
+       input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
+                            pdata->x_max, 0, 0);
+       input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
+                            pdata->y_max, 0, 0);
+
+       input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
+                            ZFORCE_MAX_AREA, 0, 0);
+       input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
+                            ZFORCE_MAX_AREA, 0, 0);
+       input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
+       input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT);
+
+       input_set_drvdata(ts->input, ts);
+
+       init_completion(&ts->command_done);
+
+       /*
+        * The zforce pulls the interrupt low when it has data ready.
+        * After it is triggered the isr thread runs until all the available
+        * packets have been read and the interrupt is high again.
+        * Therefore we can trigger the interrupt anytime it is low and do
+        * not need to limit it to the interrupt edge.
+        */
+       ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                       zforce_irq, zforce_irq_thread,
+                                       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                       input_dev->name, ts);
+       if (ret) {
+               dev_err(&client->dev, "irq %d request failed\n", client->irq);
+               return ret;
+       }
+
+       i2c_set_clientdata(client, ts);
+
+       /* let the controller boot */
+       gpio_set_value(pdata->gpio_rst, 1);
+
+       ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
+       if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
+               dev_warn(&client->dev, "bootcomplete timed out\n");
+
+       /* need to start device to get version information */
+       ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
+       if (ret) {
+               dev_err(&client->dev, "unable to initialize, %d\n", ret);
+               return ret;
+       }
+
+       /* this gets the firmware version among other information */
+       ret = zforce_command_wait(ts, COMMAND_STATUS);
+       if (ret < 0) {
+               dev_err(&client->dev, "couldn't get status, %d\n", ret);
+               zforce_stop(ts);
+               return ret;
+       }
+
+       /* stop device and put it into sleep until it is opened */
+       ret = zforce_stop(ts);
+       if (ret < 0)
+               return ret;
+
+       device_set_wakeup_capable(&client->dev, true);
+
+       ret = input_register_device(input_dev);
+       if (ret) {
+               dev_err(&client->dev, "could not register input device, %d\n",
+                       ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static struct i2c_device_id zforce_idtable[] = {
+       { "zforce-ts", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, zforce_idtable);
+
+#ifdef CONFIG_OF
+static const struct of_device_id zforce_dt_idtable[] = {
+       { .compatible = "neonode,zforce" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, zforce_dt_idtable);
+#endif
+
+static struct i2c_driver zforce_driver = {
+       .driver = {
+               .owner  = THIS_MODULE,
+               .name   = "zforce-ts",
+               .pm     = &zforce_pm_ops,
+               .of_match_table = of_match_ptr(zforce_dt_idtable),
+       },
+       .probe          = zforce_probe,
+       .id_table       = zforce_idtable,
+};
+
+module_i2c_driver(zforce_driver);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_DESCRIPTION("zForce TouchScreen Driver");
+MODULE_LICENSE("GPL");