2010-05-04 06:47:12 +00:00
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/*
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* Driver for keys on TCA6416 I2C IO expander
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*
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* Copyright (C) 2010 Texas Instruments
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*
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* Author : Sriramakrishnan.A.G. <srk@ti.com>
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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 version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/workqueue.h>
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#include <linux/gpio.h>
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#include <linux/i2c.h>
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#include <linux/input.h>
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#include <linux/tca6416_keypad.h>
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#define TCA6416_INPUT 0
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#define TCA6416_OUTPUT 1
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#define TCA6416_INVERT 2
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#define TCA6416_DIRECTION 3
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static const struct i2c_device_id tca6416_id[] = {
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{ "tca6416-keys", 16, },
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2010-12-07 10:54:00 +00:00
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{ "tca6408-keys", 8, },
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2010-05-04 06:47:12 +00:00
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, tca6416_id);
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struct tca6416_drv_data {
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struct input_dev *input;
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struct tca6416_button data[0];
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};
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struct tca6416_keypad_chip {
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uint16_t reg_output;
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uint16_t reg_direction;
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uint16_t reg_input;
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struct i2c_client *client;
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struct input_dev *input;
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struct delayed_work dwork;
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2010-12-07 10:54:00 +00:00
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int io_size;
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2010-05-04 06:47:12 +00:00
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int irqnum;
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2010-12-07 10:54:00 +00:00
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u16 pinmask;
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2010-05-04 06:47:12 +00:00
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bool use_polling;
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struct tca6416_button buttons[0];
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};
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static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val)
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{
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int error;
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2010-12-07 10:54:00 +00:00
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error = chip->io_size > 8 ?
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i2c_smbus_write_word_data(chip->client, reg << 1, val) :
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i2c_smbus_write_byte_data(chip->client, reg, val);
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2010-05-04 06:47:12 +00:00
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if (error < 0) {
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dev_err(&chip->client->dev,
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"%s failed, reg: %d, val: %d, error: %d\n",
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__func__, reg, val, error);
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return error;
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}
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return 0;
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}
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static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val)
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{
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int retval;
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2010-12-07 10:54:00 +00:00
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retval = chip->io_size > 8 ?
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i2c_smbus_read_word_data(chip->client, reg << 1) :
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i2c_smbus_read_byte_data(chip->client, reg);
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2010-05-04 06:47:12 +00:00
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if (retval < 0) {
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dev_err(&chip->client->dev, "%s failed, reg: %d, error: %d\n",
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__func__, reg, retval);
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return retval;
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}
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*val = (u16)retval;
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return 0;
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}
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static void tca6416_keys_scan(struct tca6416_keypad_chip *chip)
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{
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struct input_dev *input = chip->input;
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u16 reg_val, val;
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int error, i, pin_index;
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error = tca6416_read_reg(chip, TCA6416_INPUT, ®_val);
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if (error)
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return;
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reg_val &= chip->pinmask;
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/* Figure out which lines have changed */
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val = reg_val ^ chip->reg_input;
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chip->reg_input = reg_val;
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for (i = 0, pin_index = 0; i < 16; i++) {
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if (val & (1 << i)) {
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struct tca6416_button *button = &chip->buttons[pin_index];
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unsigned int type = button->type ?: EV_KEY;
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int state = ((reg_val & (1 << i)) ? 1 : 0)
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^ button->active_low;
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input_event(input, type, button->code, !!state);
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input_sync(input);
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}
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if (chip->pinmask & (1 << i))
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pin_index++;
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}
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}
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/*
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* This is threaded IRQ handler and this can (and will) sleep.
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*/
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static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
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{
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struct tca6416_keypad_chip *chip = dev_id;
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tca6416_keys_scan(chip);
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return IRQ_HANDLED;
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}
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static void tca6416_keys_work_func(struct work_struct *work)
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{
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struct tca6416_keypad_chip *chip =
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container_of(work, struct tca6416_keypad_chip, dwork.work);
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tca6416_keys_scan(chip);
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schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
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}
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static int tca6416_keys_open(struct input_dev *dev)
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{
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struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
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/* Get initial device state in case it has switches */
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tca6416_keys_scan(chip);
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if (chip->use_polling)
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schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
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else
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enable_irq(chip->irqnum);
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return 0;
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}
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static void tca6416_keys_close(struct input_dev *dev)
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{
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struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
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if (chip->use_polling)
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cancel_delayed_work_sync(&chip->dwork);
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else
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disable_irq(chip->irqnum);
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}
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static int __devinit tca6416_setup_registers(struct tca6416_keypad_chip *chip)
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{
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int error;
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error = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
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if (error)
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return error;
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error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
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if (error)
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return error;
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/* ensure that keypad pins are set to input */
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error = tca6416_write_reg(chip, TCA6416_DIRECTION,
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chip->reg_direction | chip->pinmask);
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if (error)
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return error;
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error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
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if (error)
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return error;
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error = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
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if (error)
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return error;
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chip->reg_input &= chip->pinmask;
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return 0;
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}
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static int __devinit tca6416_keypad_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct tca6416_keys_platform_data *pdata;
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struct tca6416_keypad_chip *chip;
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struct input_dev *input;
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int error;
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int i;
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/* Check functionality */
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
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dev_err(&client->dev, "%s adapter not supported\n",
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dev_driver_string(&client->adapter->dev));
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return -ENODEV;
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}
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pdata = client->dev.platform_data;
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if (!pdata) {
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dev_dbg(&client->dev, "no platform data\n");
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return -EINVAL;
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}
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chip = kzalloc(sizeof(struct tca6416_keypad_chip) +
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pdata->nbuttons * sizeof(struct tca6416_button),
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GFP_KERNEL);
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input = input_allocate_device();
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if (!chip || !input) {
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error = -ENOMEM;
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goto fail1;
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}
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chip->client = client;
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chip->input = input;
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2010-12-07 10:54:00 +00:00
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chip->io_size = id->driver_data;
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2010-05-04 06:47:12 +00:00
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chip->pinmask = pdata->pinmask;
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chip->use_polling = pdata->use_polling;
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INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
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input->phys = "tca6416-keys/input0";
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input->name = client->name;
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input->dev.parent = &client->dev;
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input->open = tca6416_keys_open;
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input->close = tca6416_keys_close;
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input->id.bustype = BUS_HOST;
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input->id.vendor = 0x0001;
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input->id.product = 0x0001;
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input->id.version = 0x0100;
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/* Enable auto repeat feature of Linux input subsystem */
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if (pdata->rep)
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__set_bit(EV_REP, input->evbit);
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for (i = 0; i < pdata->nbuttons; i++) {
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unsigned int type;
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chip->buttons[i] = pdata->buttons[i];
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type = (pdata->buttons[i].type) ?: EV_KEY;
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input_set_capability(input, type, pdata->buttons[i].code);
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}
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input_set_drvdata(input, chip);
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/*
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* Initialize cached registers from their original values.
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* we can't share this chip with another i2c master.
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*/
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error = tca6416_setup_registers(chip);
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if (error)
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goto fail1;
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if (!chip->use_polling) {
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if (pdata->irq_is_gpio)
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chip->irqnum = gpio_to_irq(client->irq);
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else
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chip->irqnum = client->irq;
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error = request_threaded_irq(chip->irqnum, NULL,
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tca6416_keys_isr,
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IRQF_TRIGGER_FALLING,
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"tca6416-keypad", chip);
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if (error) {
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dev_dbg(&client->dev,
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"Unable to claim irq %d; error %d\n",
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chip->irqnum, error);
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goto fail1;
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}
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disable_irq(chip->irqnum);
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}
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error = input_register_device(input);
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if (error) {
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dev_dbg(&client->dev,
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"Unable to register input device, error: %d\n", error);
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goto fail2;
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}
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i2c_set_clientdata(client, chip);
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return 0;
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fail2:
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if (!chip->use_polling) {
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free_irq(chip->irqnum, chip);
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enable_irq(chip->irqnum);
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}
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fail1:
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input_free_device(input);
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kfree(chip);
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return error;
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}
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static int __devexit tca6416_keypad_remove(struct i2c_client *client)
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{
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struct tca6416_keypad_chip *chip = i2c_get_clientdata(client);
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if (!chip->use_polling) {
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free_irq(chip->irqnum, chip);
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enable_irq(chip->irqnum);
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}
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input_unregister_device(chip->input);
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kfree(chip);
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return 0;
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}
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static struct i2c_driver tca6416_keypad_driver = {
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.driver = {
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.name = "tca6416-keypad",
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},
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.probe = tca6416_keypad_probe,
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.remove = __devexit_p(tca6416_keypad_remove),
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.id_table = tca6416_id,
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};
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static int __init tca6416_keypad_init(void)
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{
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return i2c_add_driver(&tca6416_keypad_driver);
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}
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subsys_initcall(tca6416_keypad_init);
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static void __exit tca6416_keypad_exit(void)
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{
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i2c_del_driver(&tca6416_keypad_driver);
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}
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module_exit(tca6416_keypad_exit);
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MODULE_AUTHOR("Sriramakrishnan <srk@ti.com>");
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MODULE_DESCRIPTION("Keypad driver over tca6146 IO expander");
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MODULE_LICENSE("GPL");
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