diff options
Diffstat (limited to 'drivers/input/keyboard/tca8418_keypad.c')
| -rw-r--r-- | drivers/input/keyboard/tca8418_keypad.c | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/drivers/input/keyboard/tca8418_keypad.c b/drivers/input/keyboard/tca8418_keypad.c new file mode 100644 index 000000000..4e491c176 --- /dev/null +++ b/drivers/input/keyboard/tca8418_keypad.c @@ -0,0 +1,428 @@ +/* + * Driver for TCA8418 I2C keyboard + * + * Copyright (C) 2011 Fuel7, Inc. All rights reserved. + * + * Author: Kyle Manna <kyle.manna@fuel7.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * If you can't comply with GPLv2, alternative licensing terms may be + * arranged. Please contact Fuel7, Inc. (http://fuel7.com/) for proprietary + * alternative licensing inquiries. + */ + +#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/input/tca8418_keypad.h> +#include <linux/of.h> + +/* TCA8418 hardware limits */ +#define TCA8418_MAX_ROWS 8 +#define TCA8418_MAX_COLS 10 + +/* TCA8418 register offsets */ +#define REG_CFG 0x01 +#define REG_INT_STAT 0x02 +#define REG_KEY_LCK_EC 0x03 +#define REG_KEY_EVENT_A 0x04 +#define REG_KEY_EVENT_B 0x05 +#define REG_KEY_EVENT_C 0x06 +#define REG_KEY_EVENT_D 0x07 +#define REG_KEY_EVENT_E 0x08 +#define REG_KEY_EVENT_F 0x09 +#define REG_KEY_EVENT_G 0x0A +#define REG_KEY_EVENT_H 0x0B +#define REG_KEY_EVENT_I 0x0C +#define REG_KEY_EVENT_J 0x0D +#define REG_KP_LCK_TIMER 0x0E +#define REG_UNLOCK1 0x0F +#define REG_UNLOCK2 0x10 +#define REG_GPIO_INT_STAT1 0x11 +#define REG_GPIO_INT_STAT2 0x12 +#define REG_GPIO_INT_STAT3 0x13 +#define REG_GPIO_DAT_STAT1 0x14 +#define REG_GPIO_DAT_STAT2 0x15 +#define REG_GPIO_DAT_STAT3 0x16 +#define REG_GPIO_DAT_OUT1 0x17 +#define REG_GPIO_DAT_OUT2 0x18 +#define REG_GPIO_DAT_OUT3 0x19 +#define REG_GPIO_INT_EN1 0x1A +#define REG_GPIO_INT_EN2 0x1B +#define REG_GPIO_INT_EN3 0x1C +#define REG_KP_GPIO1 0x1D +#define REG_KP_GPIO2 0x1E +#define REG_KP_GPIO3 0x1F +#define REG_GPI_EM1 0x20 +#define REG_GPI_EM2 0x21 +#define REG_GPI_EM3 0x22 +#define REG_GPIO_DIR1 0x23 +#define REG_GPIO_DIR2 0x24 +#define REG_GPIO_DIR3 0x25 +#define REG_GPIO_INT_LVL1 0x26 +#define REG_GPIO_INT_LVL2 0x27 +#define REG_GPIO_INT_LVL3 0x28 +#define REG_DEBOUNCE_DIS1 0x29 +#define REG_DEBOUNCE_DIS2 0x2A +#define REG_DEBOUNCE_DIS3 0x2B +#define REG_GPIO_PULL1 0x2C +#define REG_GPIO_PULL2 0x2D +#define REG_GPIO_PULL3 0x2E + +/* TCA8418 bit definitions */ +#define CFG_AI BIT(7) +#define CFG_GPI_E_CFG BIT(6) +#define CFG_OVR_FLOW_M BIT(5) +#define CFG_INT_CFG BIT(4) +#define CFG_OVR_FLOW_IEN BIT(3) +#define CFG_K_LCK_IEN BIT(2) +#define CFG_GPI_IEN BIT(1) +#define CFG_KE_IEN BIT(0) + +#define INT_STAT_CAD_INT BIT(4) +#define INT_STAT_OVR_FLOW_INT BIT(3) +#define INT_STAT_K_LCK_INT BIT(2) +#define INT_STAT_GPI_INT BIT(1) +#define INT_STAT_K_INT BIT(0) + +/* TCA8418 register masks */ +#define KEY_LCK_EC_KEC 0x7 +#define KEY_EVENT_CODE 0x7f +#define KEY_EVENT_VALUE 0x80 + +struct tca8418_keypad { + struct i2c_client *client; + struct input_dev *input; + + unsigned int row_shift; +}; + +/* + * Write a byte to the TCA8418 + */ +static int tca8418_write_byte(struct tca8418_keypad *keypad_data, + int reg, u8 val) +{ + int error; + + error = i2c_smbus_write_byte_data(keypad_data->client, reg, val); + if (error < 0) { + dev_err(&keypad_data->client->dev, + "%s failed, reg: %d, val: %d, error: %d\n", + __func__, reg, val, error); + return error; + } + + return 0; +} + +/* + * Read a byte from the TCA8418 + */ +static int tca8418_read_byte(struct tca8418_keypad *keypad_data, + int reg, u8 *val) +{ + int error; + + error = i2c_smbus_read_byte_data(keypad_data->client, reg); + if (error < 0) { + dev_err(&keypad_data->client->dev, + "%s failed, reg: %d, error: %d\n", + __func__, reg, error); + return error; + } + + *val = (u8)error; + + return 0; +} + +static void tca8418_read_keypad(struct tca8418_keypad *keypad_data) +{ + struct input_dev *input = keypad_data->input; + unsigned short *keymap = input->keycode; + int error, col, row; + u8 reg, state, code; + + /* Initial read of the key event FIFO */ + error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®); + + /* Assume that key code 0 signifies empty FIFO */ + while (error >= 0 && reg > 0) { + state = reg & KEY_EVENT_VALUE; + code = reg & KEY_EVENT_CODE; + + row = code / TCA8418_MAX_COLS; + col = code % TCA8418_MAX_COLS; + + row = (col) ? row : row - 1; + col = (col) ? col - 1 : TCA8418_MAX_COLS - 1; + + code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift); + input_event(input, EV_MSC, MSC_SCAN, code); + input_report_key(input, keymap[code], state); + + /* Read for next loop */ + error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®); + } + + if (error < 0) + dev_err(&keypad_data->client->dev, + "unable to read REG_KEY_EVENT_A\n"); + + input_sync(input); +} + +/* + * Threaded IRQ handler and this can (and will) sleep. + */ +static irqreturn_t tca8418_irq_handler(int irq, void *dev_id) +{ + struct tca8418_keypad *keypad_data = dev_id; + u8 reg; + int error; + + error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®); + if (error) { + dev_err(&keypad_data->client->dev, + "unable to read REG_INT_STAT\n"); + return IRQ_NONE; + } + + if (!reg) + return IRQ_NONE; + + if (reg & INT_STAT_OVR_FLOW_INT) + dev_warn(&keypad_data->client->dev, "overflow occurred\n"); + + if (reg & INT_STAT_K_INT) + tca8418_read_keypad(keypad_data); + + /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */ + reg = 0xff; + error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg); + if (error) + dev_err(&keypad_data->client->dev, + "unable to clear REG_INT_STAT\n"); + + return IRQ_HANDLED; +} + +/* + * Configure the TCA8418 for keypad operation + */ +static int tca8418_configure(struct tca8418_keypad *keypad_data, + u32 rows, u32 cols) +{ + int reg, error; + + /* Write config register, if this fails assume device not present */ + error = tca8418_write_byte(keypad_data, REG_CFG, + CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN); + if (error < 0) + return -ENODEV; + + + /* Assemble a mask for row and column registers */ + reg = ~(~0 << rows); + reg += (~(~0 << cols)) << 8; + + /* Set registers to keypad mode */ + error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg); + error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8); + error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16); + + /* Enable column debouncing */ + error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg); + error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8); + error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16); + + return error; +} + +static int tca8418_keypad_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + const struct tca8418_keypad_platform_data *pdata = + dev_get_platdata(dev); + struct tca8418_keypad *keypad_data; + struct input_dev *input; + const struct matrix_keymap_data *keymap_data = NULL; + u32 rows = 0, cols = 0; + bool rep = false; + bool irq_is_gpio = false; + int irq; + int error, row_shift, max_keys; + + /* Copy the platform data */ + if (pdata) { + if (!pdata->keymap_data) { + dev_err(dev, "no keymap data defined\n"); + return -EINVAL; + } + keymap_data = pdata->keymap_data; + rows = pdata->rows; + cols = pdata->cols; + rep = pdata->rep; + irq_is_gpio = pdata->irq_is_gpio; + } else { + struct device_node *np = dev->of_node; + int err; + + err = matrix_keypad_parse_of_params(dev, &rows, &cols); + if (err) + return err; + rep = of_property_read_bool(np, "keypad,autorepeat"); + } + + if (!rows || rows > TCA8418_MAX_ROWS) { + dev_err(dev, "invalid rows\n"); + return -EINVAL; + } + + if (!cols || cols > TCA8418_MAX_COLS) { + dev_err(dev, "invalid columns\n"); + return -EINVAL; + } + + /* Check i2c driver capabilities */ + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) { + dev_err(dev, "%s adapter not supported\n", + dev_driver_string(&client->adapter->dev)); + return -ENODEV; + } + + row_shift = get_count_order(cols); + max_keys = rows << row_shift; + + /* Allocate memory for keypad_data and input device */ + keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL); + if (!keypad_data) + return -ENOMEM; + + keypad_data->client = client; + keypad_data->row_shift = row_shift; + + /* Initialize the chip or fail if chip isn't present */ + error = tca8418_configure(keypad_data, rows, cols); + if (error < 0) + return error; + + /* Configure input device */ + input = devm_input_allocate_device(dev); + if (!input) + return -ENOMEM; + + keypad_data->input = input; + + input->name = client->name; + input->id.bustype = BUS_I2C; + input->id.vendor = 0x0001; + input->id.product = 0x001; + input->id.version = 0x0001; + + error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols, + NULL, input); + if (error) { + dev_err(dev, "Failed to build keymap\n"); + return error; + } + + if (rep) + __set_bit(EV_REP, input->evbit); + input_set_capability(input, EV_MSC, MSC_SCAN); + + input_set_drvdata(input, keypad_data); + + irq = client->irq; + if (irq_is_gpio) + irq = gpio_to_irq(irq); + + error = devm_request_threaded_irq(dev, irq, NULL, tca8418_irq_handler, + IRQF_TRIGGER_FALLING | + IRQF_SHARED | + IRQF_ONESHOT, + client->name, keypad_data); + if (error) { + dev_err(dev, "Unable to claim irq %d; error %d\n", + client->irq, error); + return error; + } + + error = input_register_device(input); + if (error) { + dev_err(dev, "Unable to register input device, error: %d\n", + error); + return error; + } + + return 0; +} + +static const struct i2c_device_id tca8418_id[] = { + { TCA8418_NAME, 8418, }, + { } +}; +MODULE_DEVICE_TABLE(i2c, tca8418_id); + +#ifdef CONFIG_OF +static const struct of_device_id tca8418_dt_ids[] = { + { .compatible = "ti,tca8418", }, + { } +}; +MODULE_DEVICE_TABLE(of, tca8418_dt_ids); + +/* + * The device tree based i2c loader looks for + * "i2c:" + second_component_of(property("compatible")) + * and therefore we need an alias to be found. + */ +MODULE_ALIAS("i2c:tca8418"); +#endif + +static struct i2c_driver tca8418_keypad_driver = { + .driver = { + .name = TCA8418_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(tca8418_dt_ids), + }, + .probe = tca8418_keypad_probe, + .id_table = tca8418_id, +}; + +static int __init tca8418_keypad_init(void) +{ + return i2c_add_driver(&tca8418_keypad_driver); +} +subsys_initcall(tca8418_keypad_init); + +static void __exit tca8418_keypad_exit(void) +{ + i2c_del_driver(&tca8418_keypad_driver); +} +module_exit(tca8418_keypad_exit); + +MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>"); +MODULE_DESCRIPTION("Keypad driver for TCA8418"); +MODULE_LICENSE("GPL"); |