1 files changed, 225 insertions, 0 deletions

diff --git a/kernel/drivers/input/misc/pcf8574_keypad.c b/kernel/drivers/input/misc/pcf8574_keypad.c
new file mode 100644
index 000000000..97f711a7b
--- /dev/null
+++ b/kernel/drivers/input/misc/pcf8574_keypad.c
@@ -0,0 +1,225 @@
+/*
+ * Driver for a keypad w/16 buttons connected to a PCF8574 I2C I/O expander
+ *
+ * Copyright 2005-2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define DRV_NAME "pcf8574_keypad"
+
+static const unsigned char pcf8574_kp_btncode[] = {
+	[0] = KEY_RESERVED,
+	[1] = KEY_ENTER,
+	[2] = KEY_BACKSLASH,
+	[3] = KEY_0,
+	[4] = KEY_RIGHTBRACE,
+	[5] = KEY_C,
+	[6] = KEY_9,
+	[7] = KEY_8,
+	[8] = KEY_7,
+	[9] = KEY_B,
+	[10] = KEY_6,
+	[11] = KEY_5,
+	[12] = KEY_4,
+	[13] = KEY_A,
+	[14] = KEY_3,
+	[15] = KEY_2,
+	[16] = KEY_1
+};
+
+struct kp_data {
+	unsigned short btncode[ARRAY_SIZE(pcf8574_kp_btncode)];
+	struct input_dev *idev;
+	struct i2c_client *client;
+	char name[64];
+	char phys[32];
+	unsigned char laststate;
+};
+
+static short read_state(struct kp_data *lp)
+{
+	unsigned char x, y, a, b;
+
+	i2c_smbus_write_byte(lp->client, 240);
+	x = 0xF & (~(i2c_smbus_read_byte(lp->client) >> 4));
+
+	i2c_smbus_write_byte(lp->client, 15);
+	y = 0xF & (~i2c_smbus_read_byte(lp->client));
+
+	for (a = 0; x > 0; a++)
+		x = x >> 1;
+	for (b = 0; y > 0; b++)
+		y = y >> 1;
+
+	return ((a - 1) * 4) + b;
+}
+
+static irqreturn_t pcf8574_kp_irq_handler(int irq, void *dev_id)
+{
+	struct kp_data *lp = dev_id;
+	unsigned char nextstate = read_state(lp);
+
+	if (lp->laststate != nextstate) {
+		int key_down = nextstate < ARRAY_SIZE(lp->btncode);
+		unsigned short keycode = key_down ?
+			lp->btncode[nextstate] : lp->btncode[lp->laststate];
+
+		input_report_key(lp->idev, keycode, key_down);
+		input_sync(lp->idev);
+
+		lp->laststate = nextstate;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int pcf8574_kp_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+	int i, ret;
+	struct input_dev *idev;
+	struct kp_data *lp;
+
+	if (i2c_smbus_write_byte(client, 240) < 0) {
+		dev_err(&client->dev, "probe: write fail\n");
+		return -ENODEV;
+	}
+
+	lp = kzalloc(sizeof(*lp), GFP_KERNEL);
+	if (!lp)
+		return -ENOMEM;
+
+	idev = input_allocate_device();
+	if (!idev) {
+		dev_err(&client->dev, "Can't allocate input device\n");
+		ret = -ENOMEM;
+		goto fail_allocate;
+	}
+
+	lp->idev = idev;
+	lp->client = client;
+
+	idev->evbit[0] = BIT_MASK(EV_KEY);
+	idev->keycode = lp->btncode;
+	idev->keycodesize = sizeof(lp->btncode[0]);
+	idev->keycodemax = ARRAY_SIZE(lp->btncode);
+
+	for (i = 0; i < ARRAY_SIZE(pcf8574_kp_btncode); i++) {
+		if (lp->btncode[i] <= KEY_MAX) {
+			lp->btncode[i] = pcf8574_kp_btncode[i];
+			__set_bit(lp->btncode[i], idev->keybit);
+		}
+	}
+	__clear_bit(KEY_RESERVED, idev->keybit);
+
+	sprintf(lp->name, DRV_NAME);
+	sprintf(lp->phys, "kp_data/input0");
+
+	idev->name = lp->name;
+	idev->phys = lp->phys;
+	idev->id.bustype = BUS_I2C;
+	idev->id.vendor = 0x0001;
+	idev->id.product = 0x0001;
+	idev->id.version = 0x0100;
+
+	lp->laststate = read_state(lp);
+
+	ret = request_threaded_irq(client->irq, NULL, pcf8574_kp_irq_handler,
+				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				   DRV_NAME, lp);
+	if (ret) {
+		dev_err(&client->dev, "IRQ %d is not free\n", client->irq);
+		goto fail_free_device;
+	}
+
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(&client->dev, "input_register_device() failed\n");
+		goto fail_free_irq;
+	}
+
+	i2c_set_clientdata(client, lp);
+	return 0;
+
+ fail_free_irq:
+	free_irq(client->irq, lp);
+ fail_free_device:
+	input_free_device(idev);
+ fail_allocate:
+	kfree(lp);
+
+	return ret;
+}
+
+static int pcf8574_kp_remove(struct i2c_client *client)
+{
+	struct kp_data *lp = i2c_get_clientdata(client);
+
+	free_irq(client->irq, lp);
+
+	input_unregister_device(lp->idev);
+	kfree(lp);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int pcf8574_kp_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	enable_irq(client->irq);
+
+	return 0;
+}
+
+static int pcf8574_kp_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	disable_irq(client->irq);
+
+	return 0;
+}
+
+static const struct dev_pm_ops pcf8574_kp_pm_ops = {
+	.suspend	= pcf8574_kp_suspend,
+	.resume		= pcf8574_kp_resume,
+};
+
+#else
+# define pcf8574_kp_resume  NULL
+# define pcf8574_kp_suspend NULL
+#endif
+
+static const struct i2c_device_id pcf8574_kp_id[] = {
+	{ DRV_NAME, 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pcf8574_kp_id);
+
+static struct i2c_driver pcf8574_kp_driver = {
+	.driver = {
+		.name  = DRV_NAME,
+		.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm = &pcf8574_kp_pm_ops,
+#endif
+	},
+	.probe    = pcf8574_kp_probe,
+	.remove   = pcf8574_kp_remove,
+	.id_table = pcf8574_kp_id,
+};
+
+module_i2c_driver(pcf8574_kp_driver);
+
+MODULE_AUTHOR("Michael Hennerich");
+MODULE_DESCRIPTION("Keypad input driver for 16 keys connected to PCF8574");
+MODULE_LICENSE("GPL");