From 30ba3ead05763b172acaa65ae1be71af2a878940 Mon Sep 17 00:00:00 2001 From: Sriramakrishnan Govindarajan Date: Mon, 3 May 2010 23:47:12 -0700 Subject: [PATCH] Input: add keypad driver for keys interfaced to TCA6416 This patch implements a simple Keypad driver that functions as an I2C client. It handles key press events for keys connected to TCA6416 I2C based IO expander. Signed-off-by: Sriramakrishnan Signed-off-by: Dmitry Torokhov --- drivers/input/keyboard/Kconfig | 16 ++ drivers/input/keyboard/Makefile | 1 + drivers/input/keyboard/tca6416-keypad.c | 349 ++++++++++++++++++++++++++++++++ include/linux/tca6416_keypad.h | 34 ++++ 4 files changed, 400 insertions(+) create mode 100644 drivers/input/keyboard/tca6416-keypad.c create mode 100644 include/linux/tca6416_keypad.h diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig index a829338..3525f53 100644 --- a/drivers/input/keyboard/Kconfig +++ b/drivers/input/keyboard/Kconfig @@ -179,6 +179,22 @@ config KEYBOARD_GPIO To compile this driver as a module, choose M here: the module will be called gpio_keys. +config KEYBOARD_TCA6416 + tristate "TCA6416 Keypad Support" + depends on I2C + help + This driver implements basic keypad functionality + for keys connected through TCA6416 IO expander + + Say Y here if your device has keys connected to + TCA6416 IO expander. Your board-specific setup logic + must also provide pin-mask details(of which TCA6416 pins + are used for keypad). + + If enabled the complete TCA6416 device will be managed through + this driver. + + config KEYBOARD_MATRIX tristate "GPIO driven matrix keypad support" depends on GENERIC_GPIO diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile index 9a74127..4596d0c 100644 --- a/drivers/input/keyboard/Makefile +++ b/drivers/input/keyboard/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_KEYBOARD_BFIN) += bf54x-keys.o obj-$(CONFIG_KEYBOARD_DAVINCI) += davinci_keyscan.o obj-$(CONFIG_KEYBOARD_EP93XX) += ep93xx_keypad.o obj-$(CONFIG_KEYBOARD_GPIO) += gpio_keys.o +obj-$(CONFIG_KEYBOARD_TCA6416) += tca6416-keypad.o obj-$(CONFIG_KEYBOARD_HIL) += hil_kbd.o obj-$(CONFIG_KEYBOARD_HIL_OLD) += hilkbd.o obj-$(CONFIG_KEYBOARD_IMX) += imx_keypad.o diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c new file mode 100644 index 0000000..493c93f --- /dev/null +++ b/drivers/input/keyboard/tca6416-keypad.c @@ -0,0 +1,349 @@ +/* + * Driver for keys on TCA6416 I2C IO expander + * + * Copyright (C) 2010 Texas Instruments + * + * Author : Sriramakrishnan.A.G. + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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); + + i2c_set_clientdata(client, NULL); + + 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 "); +MODULE_DESCRIPTION("Keypad driver over tca6146 IO expander"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/tca6416_keypad.h b/include/linux/tca6416_keypad.h new file mode 100644 index 0000000..7bd266f --- /dev/null +++ b/include/linux/tca6416_keypad.h @@ -0,0 +1,34 @@ +/* + * tca6416 keypad platform support + * + * Copyright (C) 2010 Texas Instruments + * + * Author: Sriramakrishnan + * + * 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. + */ + +#ifndef _TCA6416_KEYS_H +#define _TCA6416_KEYS_H + +#include + +struct tca6416_button { + /* Configuration parameters */ + int code; /* input event code (KEY_*, SW_*) */ + int active_low; + int type; /* input event type (EV_KEY, EV_SW) */ +}; + +struct tca6416_keys_platform_data { + struct tca6416_button *buttons; + int nbuttons; + unsigned int rep:1; /* enable input subsystem auto repeat */ + uint16_t pinmask; + uint16_t invert; + int irq_is_gpio; + int use_polling; /* use polling if Interrupt is not connected*/ +}; +#endif -- 2.7.4