// SPDX-License-Identifier: GPL-2.0-only
/*
* D-Link DIR-685 router I2C-based Touchkeys input driver
* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
*
* This is a one-off touchkey controller based on the Cypress Semiconductor
* CY8C214 MCU with some firmware in its internal 8KB flash. The circuit
* board inside the router is named E119921
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/bitops.h>
struct dir685_touchkeys {
struct device *dev;
struct i2c_client *client;
struct input_dev *input;
unsigned long cur_key;
u16 codes[7];
};
static irqreturn_t dir685_tk_irq_thread(int irq, void *data)
{
struct dir685_touchkeys *tk = data;
const int num_bits = min_t(int, ARRAY_SIZE(tk->codes), 16);
unsigned long changed;
u8 buf[6];
unsigned long key;
int i;
int err;
memset(buf, 0, sizeof(buf));
err = i2c_master_recv(tk->client, buf, sizeof(buf));
if (err != sizeof(buf)) {
dev_err(tk->dev, "short read %d\n", err);
return IRQ_HANDLED;
}
dev_dbg(tk->dev, "IN: %*ph\n", (int)sizeof(buf), buf);
key = be16_to_cpup((__be16 *) &buf[4]);
/* Figure out if any bits went high or low since last message */
changed = tk->cur_key ^ key;
for_each_set_bit(i, &changed, num_bits) {
dev_dbg(tk->dev, "key %d is %s\n", i,
test_bit(i, &key) ? "down" : "up");
input_report_key(tk->input, tk->codes[i], test_bit(i, &key));
}
/* Store currently down keys */
tk->cur_key = key;
input_sync(tk->input);
return IRQ_HANDLED;
}
static int dir685_tk_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct dir685_touchkeys *tk;
struct device *dev = &client->dev;
u8 bl_data[] = { 0xa7, 0x40 };
int err;
int i;
tk = devm_kzalloc(&client->dev, sizeof(*tk), GFP_KERNEL);
if (!tk)
return -ENOMEM;
tk->input = devm_input_allocate_device(dev);
if (!tk->input)
return -ENOMEM;
tk->client = client;
tk->dev = dev;
tk->input->keycodesize = sizeof(u16);
tk->input->keycodemax = ARRAY_SIZE(tk->codes);
tk->input->keycode = tk->codes;
tk->codes[0] = KEY_UP;
tk->codes[1] = KEY_DOWN;
tk->codes[2] = KEY_LEFT;
tk->codes[3] = KEY_RIGHT;
tk->codes[4] = KEY_ENTER;
tk->codes[5] = KEY_WPS_BUTTON;
/*
* This key appears in the vendor driver, but I have
* not been able to activate it.
*/
tk->codes[6] = KEY_RESERVED;
__set_bit(EV_KEY, tk->input->evbit);
for (i = 0; i < ARRAY_SIZE(tk->codes); i++)
__set_bit(tk->codes[i], tk->input->keybit);
__clear_bit(KEY_RESERVED, tk->input->keybit);
tk->input->name = "D-Link DIR-685 touchkeys";
tk->input->id.bustype = BUS_I2C;
err = input_register_device(tk->input);
if (err)
return err;
/* Set the brightness to max level */
err = i2c_master_send(client, bl_data, sizeof(bl_data));
if (err != sizeof(bl_data))
dev_warn(tk->dev, "error setting brightness level\n");
if (!client->irq) {
dev_err(dev, "no IRQ on the I2C device\n");
return -ENODEV;
}
err = devm_request_threaded_irq(dev, client->irq,
NULL, dir685_tk_irq_thread,
IRQF_ONESHOT,
"dir685-tk", tk);
if (err) {
dev_err(dev, "can't request IRQ\n");
return err;
}
return 0;
}
static const struct i2c_device_id dir685_tk_id[] = {
{ "dir685tk", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, dir685_tk_id);
#ifdef CONFIG_OF
static const struct of_device_id dir685_tk_of_match[] = {
{ .compatible = "dlink,dir685-touchkeys" },
{},
};
MODULE_DEVICE_TABLE(of, dir685_tk_of_match);
#endif
static struct i2c_driver dir685_tk_i2c_driver = {
.driver = {
.name = "dlin-dir685-touchkeys",
.of_match_table = of_match_ptr(dir685_tk_of_match),
},
.probe = dir685_tk_probe,
.id_table = dir685_tk_id,
};
module_i2c_driver(dir685_tk_i2c_driver);
MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("D-Link DIR-685 touchkeys driver");
MODULE_LICENSE("GPL");
