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