276 lines
6.6 KiB
C
276 lines
6.6 KiB
C
/*
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* Touch Screen driver for EETI's I2C connected touch screen panels
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* Copyright (c) 2009,2018 Daniel Mack <daniel@zonque.org>
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*
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* See EETI's software guide for the protocol specification:
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* http://home.eeti.com.tw/documentation.html
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*
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* Based on migor_ts.c
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* Copyright (c) 2008 Magnus Damm
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* Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
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*
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* This file is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This file is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/input.h>
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#include <linux/input/touchscreen.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/timer.h>
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#include <linux/gpio/consumer.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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#include <asm/unaligned.h>
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struct eeti_ts {
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struct i2c_client *client;
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struct input_dev *input;
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struct gpio_desc *attn_gpio;
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struct touchscreen_properties props;
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bool running;
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};
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#define EETI_TS_BITDEPTH (11)
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#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
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#define REPORT_BIT_PRESSED BIT(0)
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#define REPORT_BIT_AD0 BIT(1)
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#define REPORT_BIT_AD1 BIT(2)
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#define REPORT_BIT_HAS_PRESSURE BIT(6)
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#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
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static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf)
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{
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unsigned int res;
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u16 x, y;
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res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
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x = get_unaligned_be16(&buf[1]);
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y = get_unaligned_be16(&buf[3]);
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/* fix the range to 11 bits */
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x >>= res - EETI_TS_BITDEPTH;
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y >>= res - EETI_TS_BITDEPTH;
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if (buf[0] & REPORT_BIT_HAS_PRESSURE)
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input_report_abs(eeti->input, ABS_PRESSURE, buf[5]);
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touchscreen_report_pos(eeti->input, &eeti->props, x, y, false);
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input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED);
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input_sync(eeti->input);
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}
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static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
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{
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struct eeti_ts *eeti = dev_id;
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int len;
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int error;
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char buf[6];
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do {
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len = i2c_master_recv(eeti->client, buf, sizeof(buf));
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if (len != sizeof(buf)) {
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error = len < 0 ? len : -EIO;
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dev_err(&eeti->client->dev,
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"failed to read touchscreen data: %d\n",
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error);
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break;
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}
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if (buf[0] & 0x80) {
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/* Motion packet */
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eeti_ts_report_event(eeti, buf);
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}
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} while (eeti->running &&
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eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio));
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return IRQ_HANDLED;
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}
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static void eeti_ts_start(struct eeti_ts *eeti)
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{
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eeti->running = true;
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wmb();
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enable_irq(eeti->client->irq);
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}
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static void eeti_ts_stop(struct eeti_ts *eeti)
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{
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eeti->running = false;
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wmb();
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disable_irq(eeti->client->irq);
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}
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static int eeti_ts_open(struct input_dev *dev)
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{
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struct eeti_ts *eeti = input_get_drvdata(dev);
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eeti_ts_start(eeti);
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return 0;
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}
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static void eeti_ts_close(struct input_dev *dev)
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{
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struct eeti_ts *eeti = input_get_drvdata(dev);
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eeti_ts_stop(eeti);
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}
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static int eeti_ts_probe(struct i2c_client *client,
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const struct i2c_device_id *idp)
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{
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struct device *dev = &client->dev;
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struct eeti_ts *eeti;
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struct input_dev *input;
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int error;
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/*
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* In contrast to what's described in the datasheet, there seems
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* to be no way of probing the presence of that device using I2C
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* commands. So we need to blindly believe it is there, and wait
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* for interrupts to occur.
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*/
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eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL);
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if (!eeti) {
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dev_err(dev, "failed to allocate driver data\n");
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return -ENOMEM;
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}
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input = devm_input_allocate_device(dev);
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if (!input) {
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dev_err(dev, "Failed to allocate input device.\n");
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return -ENOMEM;
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}
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input_set_capability(input, EV_KEY, BTN_TOUCH);
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input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
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input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
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input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
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touchscreen_parse_properties(input, false, &eeti->props);
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input->name = client->name;
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input->id.bustype = BUS_I2C;
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input->open = eeti_ts_open;
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input->close = eeti_ts_close;
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eeti->client = client;
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eeti->input = input;
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eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN);
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if (IS_ERR(eeti->attn_gpio))
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return PTR_ERR(eeti->attn_gpio);
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i2c_set_clientdata(client, eeti);
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input_set_drvdata(input, eeti);
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error = devm_request_threaded_irq(dev, client->irq,
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NULL, eeti_ts_isr,
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IRQF_ONESHOT,
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client->name, eeti);
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if (error) {
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dev_err(dev, "Unable to request touchscreen IRQ: %d\n",
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error);
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return error;
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}
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/*
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* Disable the device for now. It will be enabled once the
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* input device is opened.
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*/
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eeti_ts_stop(eeti);
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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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return 0;
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}
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static int __maybe_unused eeti_ts_suspend(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct eeti_ts *eeti = i2c_get_clientdata(client);
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struct input_dev *input_dev = eeti->input;
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mutex_lock(&input_dev->mutex);
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if (input_dev->users)
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eeti_ts_stop(eeti);
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mutex_unlock(&input_dev->mutex);
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if (device_may_wakeup(&client->dev))
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enable_irq_wake(client->irq);
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return 0;
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}
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static int __maybe_unused eeti_ts_resume(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct eeti_ts *eeti = i2c_get_clientdata(client);
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struct input_dev *input_dev = eeti->input;
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if (device_may_wakeup(&client->dev))
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disable_irq_wake(client->irq);
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mutex_lock(&input_dev->mutex);
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if (input_dev->users)
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eeti_ts_start(eeti);
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mutex_unlock(&input_dev->mutex);
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
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static const struct i2c_device_id eeti_ts_id[] = {
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{ "eeti_ts", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
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#ifdef CONFIG_OF
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static const struct of_device_id of_eeti_ts_match[] = {
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{ .compatible = "eeti,exc3000-i2c", },
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{ }
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};
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#endif
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static struct i2c_driver eeti_ts_driver = {
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.driver = {
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.name = "eeti_ts",
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.pm = &eeti_ts_pm,
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.of_match_table = of_match_ptr(of_eeti_ts_match),
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},
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.probe = eeti_ts_probe,
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.id_table = eeti_ts_id,
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};
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module_i2c_driver(eeti_ts_driver);
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MODULE_DESCRIPTION("EETI Touchscreen driver");
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MODULE_AUTHOR("Daniel Mack <daniel@zonque.org>");
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MODULE_LICENSE("GPL");
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