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linux/drivers/input/keyboard/tca8418_keypad.c
Arnd Bergmann ea4348c846 Input: tca8418_keypad - hide gcc-4.9 -Wmaybe-uninitialized warning 
Older versions of gcc warn about the tca8418_irq_handler function
as they can't keep track of the variable assignment inside of the
loop when using the -Wmaybe-unintialized flag:

drivers/input/keyboard/tca8418_keypad.c: In function ‘tca8418_irq_handler’:
drivers/input/keyboard/tca8418_keypad.c:172:9: error: ‘reg’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/input/keyboard/tca8418_keypad.c:165:5: note: ‘reg’ was declared here

This is fixed in gcc-6, but it's possible to rearrange the code
in a way that avoids the warning on older compilers as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2016-10-26 16:01:18 -07:00

431 lines
11 KiB
C
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/*
* 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;
do {
error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
if (error < 0) {
dev_err(&keypad_data->client->dev,
"unable to read REG_KEY_EVENT_A\n");
break;
}
/* Assume that key code 0 signifies empty FIFO */
if (reg <= 0)
break;
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, &reg);
} while (1);
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, &reg);
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,
.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");
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