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![Krzysztof Kozlowski](/assets/img/avatar_default.png)
i2c_driver does not need to set an owner because i2c_register_driver() will set it. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
224 lines
4.5 KiB
C
224 lines
4.5 KiB
C
/*
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* Driver for a keypad w/16 buttons connected to a PCF8574 I2C I/O expander
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*
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* Copyright 2005-2008 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/slab.h>
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#include <linux/workqueue.h>
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#define DRV_NAME "pcf8574_keypad"
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static const unsigned char pcf8574_kp_btncode[] = {
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[0] = KEY_RESERVED,
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[1] = KEY_ENTER,
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[2] = KEY_BACKSLASH,
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[3] = KEY_0,
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[4] = KEY_RIGHTBRACE,
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[5] = KEY_C,
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[6] = KEY_9,
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[7] = KEY_8,
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[8] = KEY_7,
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[9] = KEY_B,
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[10] = KEY_6,
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[11] = KEY_5,
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[12] = KEY_4,
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[13] = KEY_A,
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[14] = KEY_3,
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[15] = KEY_2,
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[16] = KEY_1
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};
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struct kp_data {
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unsigned short btncode[ARRAY_SIZE(pcf8574_kp_btncode)];
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struct input_dev *idev;
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struct i2c_client *client;
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char name[64];
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char phys[32];
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unsigned char laststate;
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};
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static short read_state(struct kp_data *lp)
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{
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unsigned char x, y, a, b;
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i2c_smbus_write_byte(lp->client, 240);
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x = 0xF & (~(i2c_smbus_read_byte(lp->client) >> 4));
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i2c_smbus_write_byte(lp->client, 15);
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y = 0xF & (~i2c_smbus_read_byte(lp->client));
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for (a = 0; x > 0; a++)
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x = x >> 1;
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for (b = 0; y > 0; b++)
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y = y >> 1;
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return ((a - 1) * 4) + b;
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}
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static irqreturn_t pcf8574_kp_irq_handler(int irq, void *dev_id)
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{
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struct kp_data *lp = dev_id;
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unsigned char nextstate = read_state(lp);
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if (lp->laststate != nextstate) {
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int key_down = nextstate < ARRAY_SIZE(lp->btncode);
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unsigned short keycode = key_down ?
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lp->btncode[nextstate] : lp->btncode[lp->laststate];
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input_report_key(lp->idev, keycode, key_down);
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input_sync(lp->idev);
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lp->laststate = nextstate;
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}
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return IRQ_HANDLED;
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}
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static int pcf8574_kp_probe(struct i2c_client *client, const struct i2c_device_id *id)
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{
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int i, ret;
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struct input_dev *idev;
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struct kp_data *lp;
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if (i2c_smbus_write_byte(client, 240) < 0) {
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dev_err(&client->dev, "probe: write fail\n");
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return -ENODEV;
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}
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lp = kzalloc(sizeof(*lp), GFP_KERNEL);
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if (!lp)
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return -ENOMEM;
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idev = input_allocate_device();
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if (!idev) {
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dev_err(&client->dev, "Can't allocate input device\n");
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ret = -ENOMEM;
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goto fail_allocate;
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}
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lp->idev = idev;
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lp->client = client;
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idev->evbit[0] = BIT_MASK(EV_KEY);
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idev->keycode = lp->btncode;
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idev->keycodesize = sizeof(lp->btncode[0]);
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idev->keycodemax = ARRAY_SIZE(lp->btncode);
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for (i = 0; i < ARRAY_SIZE(pcf8574_kp_btncode); i++) {
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if (lp->btncode[i] <= KEY_MAX) {
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lp->btncode[i] = pcf8574_kp_btncode[i];
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__set_bit(lp->btncode[i], idev->keybit);
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}
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}
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__clear_bit(KEY_RESERVED, idev->keybit);
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sprintf(lp->name, DRV_NAME);
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sprintf(lp->phys, "kp_data/input0");
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idev->name = lp->name;
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idev->phys = lp->phys;
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idev->id.bustype = BUS_I2C;
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idev->id.vendor = 0x0001;
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idev->id.product = 0x0001;
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idev->id.version = 0x0100;
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lp->laststate = read_state(lp);
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ret = request_threaded_irq(client->irq, NULL, pcf8574_kp_irq_handler,
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IRQF_TRIGGER_LOW | IRQF_ONESHOT,
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DRV_NAME, lp);
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if (ret) {
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dev_err(&client->dev, "IRQ %d is not free\n", client->irq);
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goto fail_free_device;
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}
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ret = input_register_device(idev);
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if (ret) {
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dev_err(&client->dev, "input_register_device() failed\n");
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goto fail_free_irq;
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}
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i2c_set_clientdata(client, lp);
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return 0;
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fail_free_irq:
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free_irq(client->irq, lp);
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fail_free_device:
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input_free_device(idev);
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fail_allocate:
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kfree(lp);
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return ret;
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}
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static int pcf8574_kp_remove(struct i2c_client *client)
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{
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struct kp_data *lp = i2c_get_clientdata(client);
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free_irq(client->irq, lp);
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input_unregister_device(lp->idev);
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kfree(lp);
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return 0;
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}
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#ifdef CONFIG_PM
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static int pcf8574_kp_resume(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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enable_irq(client->irq);
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return 0;
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}
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static int pcf8574_kp_suspend(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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disable_irq(client->irq);
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return 0;
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}
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static const struct dev_pm_ops pcf8574_kp_pm_ops = {
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.suspend = pcf8574_kp_suspend,
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.resume = pcf8574_kp_resume,
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};
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#else
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# define pcf8574_kp_resume NULL
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# define pcf8574_kp_suspend NULL
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#endif
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static const struct i2c_device_id pcf8574_kp_id[] = {
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{ DRV_NAME, 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, pcf8574_kp_id);
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static struct i2c_driver pcf8574_kp_driver = {
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.driver = {
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.name = DRV_NAME,
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#ifdef CONFIG_PM
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.pm = &pcf8574_kp_pm_ops,
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#endif
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},
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.probe = pcf8574_kp_probe,
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.remove = pcf8574_kp_remove,
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.id_table = pcf8574_kp_id,
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};
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module_i2c_driver(pcf8574_kp_driver);
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MODULE_AUTHOR("Michael Hennerich");
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MODULE_DESCRIPTION("Keypad input driver for 16 keys connected to PCF8574");
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MODULE_LICENSE("GPL");
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