337 lines
8.1 KiB
C
337 lines
8.1 KiB
C
/*
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* Driver for ELAN eKTF2127 i2c touchscreen controller
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*
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* For this driver the layout of the Chipone icn8318 i2c
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* touchscreencontroller is used.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* Author:
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* Michel Verlaan <michel.verl@gmail.com>
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* Siebren Vroegindeweij <siebren.vroegindeweij@hotmail.com>
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*
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* Original chipone_icn8318 driver:
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* Hans de Goede <hdegoede@redhat.com>
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*/
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#include <linux/gpio/consumer.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/input.h>
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#include <linux/input/mt.h>
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#include <linux/input/touchscreen.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/delay.h>
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/* Packet header defines (first byte of data send / received) */
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#define EKTF2127_NOISE 0x40
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#define EKTF2127_RESPONSE 0x52
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#define EKTF2127_REQUEST 0x53
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#define EKTF2127_HELLO 0x55
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#define EKTF2127_REPORT 0x5d
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#define EKTF2127_CALIB_DONE 0x66
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/* Register defines (second byte of data send / received) */
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#define EKTF2127_ENV_NOISY 0x41
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#define EKTF2127_HEIGHT 0x60
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#define EKTF2127_WIDTH 0x63
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/* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */
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#define EKTF2127_TOUCH_REPORT_SIZE 21
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#define EKTF2127_MAX_TOUCHES 5
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struct ektf2127_ts {
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struct i2c_client *client;
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struct input_dev *input;
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struct gpio_desc *power_gpios;
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struct touchscreen_properties prop;
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};
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static void ektf2127_parse_coordinates(const u8* buf, unsigned int touch_count,
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struct input_mt_pos *touches)
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{
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int index = 0;
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int i;
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for (i = 0; i < touch_count; i++) {
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index = 2 + i * 3;
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touches[i].x = (buf[index] & 0x0f);
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touches[i].x <<= 8;
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touches[i].x |= buf[index + 2];
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touches[i].y = (buf[index] & 0xf0);
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touches[i].y <<= 4;
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touches[i].y |= buf[index + 1];
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}
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}
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static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf)
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{
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struct input_mt_pos touches[EKTF2127_MAX_TOUCHES];
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int slots[EKTF2127_MAX_TOUCHES];
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unsigned int touch_count, i;
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touch_count = buf[1] & 0x07;
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if (touch_count > EKTF2127_MAX_TOUCHES) {
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dev_err(&ts->client->dev,
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"Too many touches %d > %d\n",
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touch_count, EKTF2127_MAX_TOUCHES);
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touch_count = EKTF2127_MAX_TOUCHES;
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}
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ektf2127_parse_coordinates(buf, touch_count, touches);
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input_mt_assign_slots(ts->input, slots, touches,
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touch_count, 0);
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for (i = 0; i < touch_count; i++) {
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input_mt_slot(ts->input, slots[i]);
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input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
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touchscreen_report_pos(ts->input, &ts->prop,
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touches[i].x, touches[i].y, true);
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}
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input_mt_sync_frame(ts->input);
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input_sync(ts->input);
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}
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static irqreturn_t ektf2127_irq(int irq, void *dev_id)
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{
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struct ektf2127_ts *ts = dev_id;
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struct device *dev = &ts->client->dev;
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char buf[EKTF2127_TOUCH_REPORT_SIZE];
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int ret;
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ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE);
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if (ret != EKTF2127_TOUCH_REPORT_SIZE) {
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dev_err(dev, "Error reading touch data: %d\n", ret);
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goto out;
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}
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switch (buf[0]) {
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case EKTF2127_REPORT:
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ektf2127_report_event(ts, buf);
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break;
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case EKTF2127_NOISE:
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if (buf[1] == EKTF2127_ENV_NOISY)
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dev_dbg(dev, "Environment is electrically noisy\n");
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break;
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case EKTF2127_HELLO:
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case EKTF2127_CALIB_DONE:
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break;
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default:
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dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]);
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break;
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}
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out:
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return IRQ_HANDLED;
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}
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static int ektf2127_start(struct input_dev *dev)
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{
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struct ektf2127_ts *ts = input_get_drvdata(dev);
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enable_irq(ts->client->irq);
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gpiod_set_value_cansleep(ts->power_gpios, 1);
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return 0;
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}
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static void ektf2127_stop(struct input_dev *dev)
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{
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struct ektf2127_ts *ts = input_get_drvdata(dev);
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disable_irq(ts->client->irq);
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gpiod_set_value_cansleep(ts->power_gpios, 0);
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}
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static int __maybe_unused ektf2127_suspend(struct device *dev)
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{
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struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
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mutex_lock(&ts->input->mutex);
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if (ts->input->users)
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ektf2127_stop(ts->input);
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mutex_unlock(&ts->input->mutex);
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return 0;
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}
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static int __maybe_unused ektf2127_resume(struct device *dev)
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{
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struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
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mutex_lock(&ts->input->mutex);
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if (ts->input->users)
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ektf2127_start(ts->input);
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mutex_unlock(&ts->input->mutex);
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend,
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ektf2127_resume);
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static int ektf2127_query_dimension(struct i2c_client *client, bool width)
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{
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struct device *dev = &client->dev;
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const char *what = width ? "width" : "height";
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u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
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u8 buf[4];
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int ret;
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int error;
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/* Request dimension */
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buf[0] = EKTF2127_REQUEST;
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buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
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buf[2] = 0x00;
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buf[3] = 0x00;
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ret = i2c_master_send(client, buf, sizeof(buf));
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if (ret != sizeof(buf)) {
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error = ret < 0 ? ret : -EIO;
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dev_err(dev, "Failed to request %s: %d\n", what, error);
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return error;
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}
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msleep(20);
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/* Read response */
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ret = i2c_master_recv(client, buf, sizeof(buf));
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if (ret != sizeof(buf)) {
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error = ret < 0 ? ret : -EIO;
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dev_err(dev, "Failed to receive %s data: %d\n", what, error);
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return error;
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}
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if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) {
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dev_err(dev, "Unexpected %s data: %#02x %#02x\n",
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what, buf[0], buf[1]);
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return -EIO;
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}
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return (((buf[3] & 0xf0) << 4) | buf[2]) - 1;
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}
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static int ektf2127_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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struct ektf2127_ts *ts;
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struct input_dev *input;
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u8 buf[4];
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int max_x, max_y;
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int error;
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if (!client->irq) {
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dev_err(dev, "Error no irq specified\n");
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return -EINVAL;
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}
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ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
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if (!ts)
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return -ENOMEM;
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/* This requests the gpio *and* turns on the touchscreen controller */
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ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH);
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if (IS_ERR(ts->power_gpios)) {
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error = PTR_ERR(ts->power_gpios);
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if (error != -EPROBE_DEFER)
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dev_err(dev, "Error getting power gpio: %d\n", error);
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return error;
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}
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input = devm_input_allocate_device(dev);
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if (!input)
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return -ENOMEM;
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input->name = client->name;
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input->id.bustype = BUS_I2C;
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input->open = ektf2127_start;
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input->close = ektf2127_stop;
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ts->client = client;
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/* Read hello (ignore result, depends on initial power state) */
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msleep(20);
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i2c_master_recv(ts->client, buf, sizeof(buf));
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/* Read resolution from chip */
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max_x = ektf2127_query_dimension(client, true);
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if (max_x < 0)
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return max_x;
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max_y = ektf2127_query_dimension(client, false);
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if (max_y < 0)
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return max_y;
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input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
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input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
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touchscreen_parse_properties(input, true, &ts->prop);
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error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES,
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INPUT_MT_DIRECT |
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INPUT_MT_DROP_UNUSED |
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INPUT_MT_TRACK);
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if (error)
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return error;
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ts->input = input;
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input_set_drvdata(input, ts);
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error = devm_request_threaded_irq(dev, client->irq,
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NULL, ektf2127_irq,
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IRQF_ONESHOT, client->name, ts);
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if (error) {
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dev_err(dev, "Error requesting irq: %d\n", error);
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return error;
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}
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/* Stop device till opened */
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ektf2127_stop(ts->input);
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error = input_register_device(input);
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if (error)
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return error;
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i2c_set_clientdata(client, ts);
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id ektf2127_of_match[] = {
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{ .compatible = "elan,ektf2127" },
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{}
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};
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MODULE_DEVICE_TABLE(of, ektf2127_of_match);
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#endif
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static const struct i2c_device_id ektf2127_i2c_id[] = {
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{ "ektf2127", 0 },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id);
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static struct i2c_driver ektf2127_driver = {
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.driver = {
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.name = "elan_ektf2127",
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.pm = &ektf2127_pm_ops,
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.of_match_table = of_match_ptr(ektf2127_of_match),
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},
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.probe = ektf2127_probe,
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.id_table = ektf2127_i2c_id,
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};
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module_i2c_driver(ektf2127_driver);
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MODULE_DESCRIPTION("ELAN eKTF2127 I2C Touchscreen Driver");
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MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij");
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MODULE_LICENSE("GPL");
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