333 lines
7.9 KiB
C
333 lines
7.9 KiB
C
/*
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* Touch Screen driver for EETI's I2C connected touch screen panels
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* Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
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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/web20/eg/guide.htm
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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/moduleparam.h>
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#include <linux/kernel.h>
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#include <linux/input.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.h>
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#include <linux/input/eeti_ts.h>
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#include <linux/slab.h>
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static bool flip_x;
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module_param(flip_x, bool, 0644);
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MODULE_PARM_DESC(flip_x, "flip x coordinate");
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static bool flip_y;
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module_param(flip_y, bool, 0644);
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MODULE_PARM_DESC(flip_y, "flip y coordinate");
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struct eeti_ts_priv {
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struct i2c_client *client;
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struct input_dev *input;
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struct work_struct work;
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struct mutex mutex;
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int irq_gpio, irq, irq_active_high;
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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 (1 << 0)
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#define REPORT_BIT_AD0 (1 << 1)
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#define REPORT_BIT_AD1 (1 << 2)
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#define REPORT_BIT_HAS_PRESSURE (1 << 6)
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#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
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static inline int eeti_ts_irq_active(struct eeti_ts_priv *priv)
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{
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return gpio_get_value(priv->irq_gpio) == priv->irq_active_high;
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}
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static void eeti_ts_read(struct work_struct *work)
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{
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char buf[6];
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unsigned int x, y, res, pressed, to = 100;
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struct eeti_ts_priv *priv =
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container_of(work, struct eeti_ts_priv, work);
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mutex_lock(&priv->mutex);
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while (eeti_ts_irq_active(priv) && --to)
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i2c_master_recv(priv->client, buf, sizeof(buf));
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if (!to) {
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dev_err(&priv->client->dev,
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"unable to clear IRQ - line stuck?\n");
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goto out;
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}
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/* drop non-report packets */
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if (!(buf[0] & 0x80))
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goto out;
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pressed = buf[0] & REPORT_BIT_PRESSED;
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res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
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x = buf[2] | (buf[1] << 8);
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y = buf[4] | (buf[3] << 8);
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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 (flip_x)
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x = EETI_MAXVAL - x;
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if (flip_y)
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y = EETI_MAXVAL - y;
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if (buf[0] & REPORT_BIT_HAS_PRESSURE)
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input_report_abs(priv->input, ABS_PRESSURE, buf[5]);
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input_report_abs(priv->input, ABS_X, x);
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input_report_abs(priv->input, ABS_Y, y);
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input_report_key(priv->input, BTN_TOUCH, !!pressed);
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input_sync(priv->input);
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out:
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mutex_unlock(&priv->mutex);
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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_priv *priv = dev_id;
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/* postpone I2C transactions as we are atomic */
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schedule_work(&priv->work);
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return IRQ_HANDLED;
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}
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static void eeti_ts_start(struct eeti_ts_priv *priv)
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{
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enable_irq(priv->irq);
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/* Read the events once to arm the IRQ */
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eeti_ts_read(&priv->work);
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}
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static void eeti_ts_stop(struct eeti_ts_priv *priv)
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{
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disable_irq(priv->irq);
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cancel_work_sync(&priv->work);
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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_priv *priv = input_get_drvdata(dev);
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eeti_ts_start(priv);
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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_priv *priv = input_get_drvdata(dev);
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eeti_ts_stop(priv);
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}
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static int __devinit 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 eeti_ts_platform_data *pdata = client->dev.platform_data;
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struct eeti_ts_priv *priv;
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struct input_dev *input;
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unsigned int irq_flags;
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int err = -ENOMEM;
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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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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv) {
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dev_err(&client->dev, "failed to allocate driver data\n");
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goto err0;
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}
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mutex_init(&priv->mutex);
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input = input_allocate_device();
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if (!input) {
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dev_err(&client->dev, "Failed to allocate input device.\n");
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goto err1;
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}
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input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
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input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(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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input->name = client->name;
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input->id.bustype = BUS_I2C;
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input->dev.parent = &client->dev;
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input->open = eeti_ts_open;
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input->close = eeti_ts_close;
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priv->client = client;
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priv->input = input;
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priv->irq_gpio = pdata->irq_gpio;
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priv->irq = gpio_to_irq(pdata->irq_gpio);
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err = gpio_request_one(pdata->irq_gpio, GPIOF_IN, client->name);
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if (err < 0)
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goto err1;
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if (pdata)
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priv->irq_active_high = pdata->irq_active_high;
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irq_flags = priv->irq_active_high ?
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IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
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INIT_WORK(&priv->work, eeti_ts_read);
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i2c_set_clientdata(client, priv);
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input_set_drvdata(input, priv);
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err = input_register_device(input);
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if (err)
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goto err2;
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err = request_irq(priv->irq, eeti_ts_isr, irq_flags,
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client->name, priv);
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if (err) {
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dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
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goto err3;
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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(priv);
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device_init_wakeup(&client->dev, 0);
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return 0;
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err3:
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input_unregister_device(input);
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input = NULL; /* so we dont try to free it below */
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err2:
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gpio_free(pdata->irq_gpio);
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err1:
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input_free_device(input);
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kfree(priv);
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err0:
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return err;
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}
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static int __devexit eeti_ts_remove(struct i2c_client *client)
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{
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struct eeti_ts_priv *priv = i2c_get_clientdata(client);
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free_irq(priv->irq, priv);
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/*
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* eeti_ts_stop() leaves IRQ disabled. We need to re-enable it
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* so that device still works if we reload the driver.
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*/
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enable_irq(priv->irq);
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input_unregister_device(priv->input);
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kfree(priv);
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return 0;
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}
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#ifdef CONFIG_PM
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static int 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_priv *priv = i2c_get_clientdata(client);
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struct input_dev *input_dev = priv->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(priv);
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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(priv->irq);
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return 0;
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}
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static int 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_priv *priv = i2c_get_clientdata(client);
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struct input_dev *input_dev = priv->input;
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if (device_may_wakeup(&client->dev))
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disable_irq_wake(priv->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(priv);
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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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#endif
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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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static struct i2c_driver eeti_ts_driver = {
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.driver = {
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.name = "eeti_ts",
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#ifdef CONFIG_PM
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.pm = &eeti_ts_pm,
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#endif
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},
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.probe = eeti_ts_probe,
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.remove = __devexit_p(eeti_ts_remove),
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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@caiaq.de>");
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MODULE_LICENSE("GPL");
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