diff options
Diffstat (limited to 'drivers/input/keyboard/lm8333.c')
| -rw-r--r-- | drivers/input/keyboard/lm8333.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/input/keyboard/lm8333.c b/drivers/input/keyboard/lm8333.c new file mode 100644 index 000000000..3052cd6de --- /dev/null +++ b/drivers/input/keyboard/lm8333.c @@ -0,0 +1,230 @@ +// 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 i2c_device_id *id) +{ + 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 = kzalloc(sizeof(*lm8333), GFP_KERNEL); + input = input_allocate_device(); + if (!lm8333 || !input) { + err = -ENOMEM; + goto free_mem; + } + + lm8333->client = client; + lm8333->input = input; + + input->name = client->name; + input->dev.parent = &client->dev; + 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) + goto free_mem; + + 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 = request_threaded_irq(client->irq, NULL, lm8333_irq_thread, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + "lm8333", lm8333); + if (err) + goto free_mem; + + err = input_register_device(input); + if (err) + goto free_irq; + + i2c_set_clientdata(client, lm8333); + return 0; + + free_irq: + free_irq(client->irq, lm8333); + free_mem: + input_free_device(input); + kfree(lm8333); + return err; +} + +static void lm8333_remove(struct i2c_client *client) +{ + struct lm8333 *lm8333 = i2c_get_clientdata(client); + + free_irq(client->irq, lm8333); + input_unregister_device(lm8333->input); + kfree(lm8333); +} + +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, + .remove = lm8333_remove, + .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"); |