Input: add PCF8574 I2C keypad input device driver
Signed-off-by: Bryan Wu <cooloney@kernel.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Bryan Wu
Dmitry Torokhov
parent
2adaabd471
commit
b91c4be730
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@ -277,6 +277,16 @@ config INPUT_PCF50633_PMU
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Say Y to include support for delivering PMU events via input
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layer on NXP PCF50633.
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config INPUT_PCF8574
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tristate "PCF8574 Keypad input device"
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depends on I2C && EXPERIMENTAL
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help
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Say Y here if you want to support a keypad connetced via I2C
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with a PCF8574.
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To compile this driver as a module, choose M here: the
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module will be called pcf8574_keypad.
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config INPUT_GPIO_ROTARY_ENCODER
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tristate "Rotary encoders connected to GPIO pins"
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depends on GPIOLIB && GENERIC_GPIO
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@ -19,6 +19,7 @@ obj-$(CONFIG_INPUT_KEYSPAN_REMOTE) += keyspan_remote.o
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obj-$(CONFIG_INPUT_M68K_BEEP) += m68kspkr.o
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obj-$(CONFIG_INPUT_PCAP) += pcap_keys.o
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obj-$(CONFIG_INPUT_PCF50633_PMU) += pcf50633-input.o
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obj-$(CONFIG_INPUT_PCF8574) += pcf8574_keypad.o
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obj-$(CONFIG_INPUT_PCSPKR) += pcspkr.o
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obj-$(CONFIG_INPUT_POWERMATE) += powermate.o
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obj-$(CONFIG_INPUT_RB532_BUTTON) += rb532_button.o
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@ -0,0 +1,227 @@
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/*
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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/init.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 __devinit 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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lp->btncode[i] = pcf8574_kp_btncode[i];
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__set_bit(lp->btncode[i] & KEY_MAX, idev->keybit);
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}
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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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input_set_drvdata(idev, lp);
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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_register;
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}
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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_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_irq:
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input_unregister_device(idev);
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fail_register:
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input_set_drvdata(idev, NULL);
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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 __devexit 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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i2c_set_clientdata(client, NULL);
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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 i2c_client *client)
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{
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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 i2c_client *client, pm_message_t mesg)
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{
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disable_irq(client->irq);
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return 0;
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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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.owner = THIS_MODULE,
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},
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.probe = pcf8574_kp_probe,
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.remove = __devexit_p(pcf8574_kp_remove),
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.suspend = pcf8574_kp_suspend,
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.resume = pcf8574_kp_resume,
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.id_table = pcf8574_kp_id,
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};
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static int __init pcf8574_kp_init(void)
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{
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return i2c_add_driver(&pcf8574_kp_driver);
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}
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module_init(pcf8574_kp_init);
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static void __exit pcf8574_kp_exit(void)
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{
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i2c_del_driver(&pcf8574_kp_driver);
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}
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module_exit(pcf8574_kp_exit);
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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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