|  | /* | 
|  | * 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, }, | 
|  | { "tca6408-keys", 8, }, | 
|  | { } | 
|  | }; | 
|  | 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; | 
|  | int io_size; | 
|  | int irqnum; | 
|  | u16 pinmask; | 
|  | 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 = chip->io_size > 8 ? | 
|  | i2c_smbus_write_word_data(chip->client, reg << 1, val) : | 
|  | i2c_smbus_write_byte_data(chip->client, reg, 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 = chip->io_size > 8 ? | 
|  | i2c_smbus_read_word_data(chip->client, reg << 1) : | 
|  | i2c_smbus_read_byte_data(chip->client, reg); | 
|  | 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->io_size = id->driver_data; | 
|  | 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); | 
|  | device_init_wakeup(&client->dev, 1); | 
|  |  | 
|  | 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; | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_PM_SLEEP | 
|  | static int tca6416_keypad_suspend(struct device *dev) | 
|  | { | 
|  | struct i2c_client *client = to_i2c_client(dev); | 
|  | struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); | 
|  |  | 
|  | if (device_may_wakeup(dev)) | 
|  | enable_irq_wake(chip->irqnum); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int tca6416_keypad_resume(struct device *dev) | 
|  | { | 
|  | struct i2c_client *client = to_i2c_client(dev); | 
|  | struct tca6416_keypad_chip *chip = i2c_get_clientdata(client); | 
|  |  | 
|  | if (device_may_wakeup(dev)) | 
|  | disable_irq_wake(chip->irqnum); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  | #endif | 
|  |  | 
|  | static SIMPLE_DEV_PM_OPS(tca6416_keypad_dev_pm_ops, | 
|  | tca6416_keypad_suspend, tca6416_keypad_resume); | 
|  |  | 
|  | static struct i2c_driver tca6416_keypad_driver = { | 
|  | .driver = { | 
|  | .name	= "tca6416-keypad", | 
|  | .pm	= &tca6416_keypad_dev_pm_ops, | 
|  | }, | 
|  | .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"); |