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