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// SPDX-License-Identifier: GPL-2.0-only
/*
* LM8333 keypad driver
* Copyright (C) 2012 Wolfram Sang, Pengutronix <kernel@pengutronix.de>
*/
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/matrix_keypad.h>
#include <linux/input/lm8333.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/slab.h>
#define LM8333_FIFO_READ 0x20
#define LM8333_DEBOUNCE 0x22
#define LM8333_READ_INT 0xD0
#define LM8333_ACTIVE 0xE4
#define LM8333_READ_ERROR 0xF0
#define LM8333_KEYPAD_IRQ (1 << 0)
#define LM8333_ERROR_IRQ (1 << 3)
#define LM8333_ERROR_KEYOVR 0x04
#define LM8333_ERROR_FIFOOVR 0x40
#define LM8333_FIFO_TRANSFER_SIZE 16
#define LM8333_NUM_ROWS 8
#define LM8333_NUM_COLS 16
#define LM8333_ROW_SHIFT 4
struct lm8333 {
struct i2c_client *client;
struct input_dev *input;
unsigned short keycodes[LM8333_NUM_ROWS << LM8333_ROW_SHIFT];
};
/* The accessors try twice because the first access may be needed for wakeup */
#define LM8333_READ_RETRIES 2
int lm8333_read8(struct lm8333 *lm8333, u8 cmd)
{
int retries = 0, ret;
do {
ret = i2c_smbus_read_byte_data(lm8333->client, cmd);
} while (ret < 0 && retries++ < LM8333_READ_RETRIES);
return ret;
}
int lm8333_write8(struct lm8333 *lm8333, u8 cmd, u8 val)
{
int retries = 0, ret;
do {
ret = i2c_smbus_write_byte_data(lm8333->client, cmd, val);
} while (ret < 0 && retries++ < LM8333_READ_RETRIES);
return ret;
}
int lm8333_read_block(struct lm8333 *lm8333, u8 cmd, u8 len, u8 *buf)
{
int retries = 0, ret;
do {
ret = i2c_smbus_read_i2c_block_data(lm8333->client,
cmd, len, buf);
} while (ret < 0 && retries++ < LM8333_READ_RETRIES);
return ret;
}
static void lm8333_key_handler(struct lm8333 *lm8333)
{
struct input_dev *input = lm8333->input;
u8 keys[LM8333_FIFO_TRANSFER_SIZE];
u8 code, pressed;
int i, ret;
ret = lm8333_read_block(lm8333, LM8333_FIFO_READ,
LM8333_FIFO_TRANSFER_SIZE, keys);
if (ret != LM8333_FIFO_TRANSFER_SIZE) {
dev_err(&lm8333->client->dev,
"Error %d while reading FIFO\n", ret);
return;
}
for (i = 0; i < LM8333_FIFO_TRANSFER_SIZE && keys[i]; i++) {
pressed = keys[i] & 0x80;
code = keys[i] & 0x7f;
input_event(input, EV_MSC, MSC_SCAN, code);
input_report_key(input, lm8333->keycodes[code], pressed);
}
input_sync(input);
}
static irqreturn_t lm8333_irq_thread(int irq, void *data)
{
struct lm8333 *lm8333 = data;
u8 status = lm8333_read8(lm8333, LM8333_READ_INT);
if (!status)
return IRQ_NONE;
if (status & LM8333_ERROR_IRQ) {
u8 err = lm8333_read8(lm8333, LM8333_READ_ERROR);
if (err & (LM8333_ERROR_KEYOVR | LM8333_ERROR_FIFOOVR)) {
u8 dummy[LM8333_FIFO_TRANSFER_SIZE];
lm8333_read_block(lm8333, LM8333_FIFO_READ,
LM8333_FIFO_TRANSFER_SIZE, dummy);
}
dev_err(&lm8333->client->dev, "Got error %02x\n", err);
}
if (status & LM8333_KEYPAD_IRQ)
lm8333_key_handler(lm8333);
return IRQ_HANDLED;
}
static int lm8333_probe(struct i2c_client *client)
{
const struct lm8333_platform_data *pdata =
dev_get_platdata(&client->dev);
struct lm8333 *lm8333;
struct input_dev *input;
int err, active_time;
if (!pdata)
return -EINVAL;
active_time = pdata->active_time ?: 500;
if (active_time / 3 <= pdata->debounce_time / 3) {
dev_err(&client->dev, "Active time not big enough!\n");
return -EINVAL;
}
lm8333 = devm_kzalloc(&client->dev, sizeof(*lm8333), GFP_KERNEL);
if (!lm8333)
return -ENOMEM;
input = devm_input_allocate_device(&client->dev);
if (!input)
return -ENOMEM;
lm8333->client = client;
lm8333->input = input;
input->name = client->name;
input->id.bustype = BUS_I2C;
input_set_capability(input, EV_MSC, MSC_SCAN);
err = matrix_keypad_build_keymap(pdata->matrix_data, NULL,
LM8333_NUM_ROWS, LM8333_NUM_COLS,
lm8333->keycodes, input);
if (err)
return err;
if (pdata->debounce_time) {
err = lm8333_write8(lm8333, LM8333_DEBOUNCE,
pdata->debounce_time / 3);
if (err)
dev_warn(&client->dev, "Unable to set debounce time\n");
}
if (pdata->active_time) {
err = lm8333_write8(lm8333, LM8333_ACTIVE,
pdata->active_time / 3);
if (err)
dev_warn(&client->dev, "Unable to set active time\n");
}
err = devm_request_threaded_irq(&client->dev, client->irq,
NULL, lm8333_irq_thread,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
"lm8333", lm8333);
if (err)
return err;
err = input_register_device(input);
if (err)
return err;
i2c_set_clientdata(client, lm8333);
return 0;
}
static const struct i2c_device_id lm8333_id[] = {
{ "lm8333", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, lm8333_id);
static struct i2c_driver lm8333_driver = {
.driver = {
.name = "lm8333",
},
.probe = lm8333_probe,
.id_table = lm8333_id,
};
module_i2c_driver(lm8333_driver);
MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
MODULE_DESCRIPTION("LM8333 keyboard driver");
MODULE_LICENSE("GPL v2");
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