@@ -354,4 +354,14 @@ config INPUT_PCAP
To compile this driver as a module, choose M here: the
module will be called pcap_keys.
+config INPUT_PCF8574
+ tristate "PCF8574 Keypad input device"
+ depends on I2C && EXPERIMENTAL
+ help
+ Say Y here if you want to support a keypad connetced via I2C
+ with a PCF8574.
+
+ To compile this driver as a module, choose M here: the
+ module will be called pcf8574_keypad.
+
endif
@@ -6,6 +6,7 @@
obj-$(CONFIG_INPUT_88PM860X_ONKEY) += 88pm860x_onkey.o
obj-$(CONFIG_INPUT_APANEL) += apanel.o
+obj-$(CONFIG_INPUT_PCF8574) += pcf8574_keypad.o
obj-$(CONFIG_INPUT_ATI_REMOTE) += ati_remote.o
obj-$(CONFIG_INPUT_ATI_REMOTE2) += ati_remote2.o
obj-$(CONFIG_INPUT_ATLAS_BTNS) += atlas_btns.o
new file mode 100644
@@ -0,0 +1,227 @@
+/*
+ * 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/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.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 __devinit 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(pcf8574_kp_btncode);
+ idev->keycodemax = ARRAY_SIZE(pcf8574_kp_btncode);
+
+ for (i = 0; i < ARRAY_SIZE(pcf8574_kp_btncode); i++) {
+ lp->btncode[i] = pcf8574_kp_btncode[i];
+ __set_bit(lp->btncode[i] & KEY_MAX, 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;
+
+ input_set_drvdata(idev, lp);
+
+ ret = input_register_device(idev);
+ if (ret) {
+ dev_err(&client->dev, "input_register_device() failed\n");
+ goto fail_register;
+ }
+
+ 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_irq;
+ }
+
+ i2c_set_clientdata(client, lp);
+ return 0;
+
+ fail_irq:
+ input_unregister_device(idev);
+ fail_register:
+ input_set_drvdata(idev, NULL);
+ input_free_device(idev);
+ fail_allocate:
+ kfree(lp);
+
+ return ret;
+}
+
+static int __devexit 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);
+
+ i2c_set_clientdata(client, NULL);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int pcf8574_kp_resume(struct i2c_client *client)
+{
+ enable_irq(client->irq);
+
+ return 0;
+}
+
+static int pcf8574_kp_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+ disable_irq(client->irq);
+
+ return 0;
+}
+#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,
+ },
+ .probe = pcf8574_kp_probe,
+ .remove = __devexit_p(pcf8574_kp_remove),
+ .suspend = pcf8574_kp_suspend,
+ .resume = pcf8574_kp_resume,
+ .id_table = pcf8574_kp_id,
+};
+
+static int __init pcf8574_kp_init(void)
+{
+ return i2c_add_driver(&pcf8574_kp_driver);
+}
+module_init(pcf8574_kp_init);
+
+static void __exit pcf8574_kp_exit(void)
+{
+ i2c_del_driver(&pcf8574_kp_driver);
+}
+module_exit(pcf8574_kp_exit);
+
+MODULE_AUTHOR("Michael Hennerich");
+MODULE_DESCRIPTION("Keypad input driver for 16 keys connected to PCF8574");
+MODULE_LICENSE("GPL");