| /* |
| * 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 3 |
| |
| static 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)); |
| else |
| enable_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); |
| else |
| disable_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); |
| else |
| chip->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"); |