Input: add driver for Maxim MAX7359 key switch controller

The Maxim MAX7359 is a I2C interfaced key switch controller which
provides microprocessors with management of up to 64 key switches.
This patch adds support for the MAX7359 key switch controller.

Signed-off-by: Kim Kyuwon <q1.kim@samsung.com>
Reviewed-by: Trilok Soni <soni.trilok@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/Kconfig

@@ -261,6 +261,17 @@ config KEYBOARD_MAPLE
 	  To compile this driver as a module, choose M here: the
 	  module will be called maple_keyb.
 
+config KEYBOARD_MAX7359
+	tristate "Maxim MAX7359 Key Switch Controller"
+	depends on I2C
+	help
+	  If you say yes here you get support for the Maxim MAX7359 Key
+	  Switch Controller chip. This providers microprocessors with
+	  management of up to 64 key switches
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called max7359_keypad.
+
 config KEYBOARD_NEWTON
 	tristate "Newton keyboard"
 	select SERIO

drivers/input/keyboard/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_KEYBOARD_LM8323)		+= lm8323.o
 obj-$(CONFIG_KEYBOARD_LOCOMO)		+= locomokbd.o
 obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o
 obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
+obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
 obj-$(CONFIG_KEYBOARD_NEWTON)		+= newtonkbd.o
 obj-$(CONFIG_KEYBOARD_OMAP)		+= omap-keypad.o
 obj-$(CONFIG_KEYBOARD_OPENCORES)	+= opencores-kbd.o

drivers/input/keyboard/max7359_keypad.c

@@ -0,0 +1,352 @@
+/*
+ * max7359_keypad.c - MAX7359 Key Switch Controller Driver
+ *
+ * Copyright (C) 2009 Samsung Electronics
+ * Kim Kyuwon <q1.kim@samsung.com>
+ *
+ * Based on pxa27x_keypad.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Datasheet: http://www.maxim-ic.com/quick_view2.cfm/qv_pk/5456
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/input/matrix_keypad.h>
+
+#define MAX7359_MAX_KEY_ROWS	8
+#define MAX7359_MAX_KEY_COLS	8
+#define MAX7359_MAX_KEY_NUM	(MAX7359_MAX_KEY_ROWS * MAX7359_MAX_KEY_COLS)
+#define MAX7359_ROW_SHIFT	3
+
+/*
+ * MAX7359 registers
+ */
+#define MAX7359_REG_KEYFIFO	0x00
+#define MAX7359_REG_CONFIG	0x01
+#define MAX7359_REG_DEBOUNCE	0x02
+#define MAX7359_REG_INTERRUPT	0x03
+#define MAX7359_REG_PORTS	0x04
+#define MAX7359_REG_KEYREP	0x05
+#define MAX7359_REG_SLEEP	0x06
+
+/*
+ * Configuration register bits
+ */
+#define MAX7359_CFG_SLEEP	(1 << 7)
+#define MAX7359_CFG_INTERRUPT	(1 << 5)
+#define MAX7359_CFG_KEY_RELEASE	(1 << 3)
+#define MAX7359_CFG_WAKEUP	(1 << 1)
+#define MAX7359_CFG_TIMEOUT	(1 << 0)
+
+/*
+ * Autosleep register values (ms)
+ */
+#define MAX7359_AUTOSLEEP_8192	0x01
+#define MAX7359_AUTOSLEEP_4096	0x02
+#define MAX7359_AUTOSLEEP_2048	0x03
+#define MAX7359_AUTOSLEEP_1024	0x04
+#define MAX7359_AUTOSLEEP_512	0x05
+#define MAX7359_AUTOSLEEP_256	0x06
+
+struct max7359_keypad {
+	/* matrix key code map */
+	unsigned short keycodes[MAX7359_MAX_KEY_NUM];
+
+	struct work_struct work;
+
+	struct input_dev *input_dev;
+	struct i2c_client *client;
+
+	u32 irq;
+};
+
+static int max7359_write_reg(struct i2c_client *client, u8 reg, u8 val)
+{
+	int ret = i2c_smbus_write_byte_data(client, reg, val);
+
+	if (ret < 0)
+		dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
+			__func__, reg, val, ret);
+	return ret;
+}
+
+static int max7359_read_reg(struct i2c_client *client, int reg)
+{
+	int ret = i2c_smbus_read_byte_data(client, reg);
+
+	if (ret < 0)
+		dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
+			__func__, reg, ret);
+	return ret;
+}
+
+static void max7359_build_keycode(struct max7359_keypad *keypad,
+				const struct matrix_keymap_data *keymap_data)
+{
+	struct input_dev *input_dev = keypad->input_dev;
+	int i;
+
+	for (i = 0; i < keymap_data->keymap_size; i++) {
+		unsigned int key = keymap_data->keymap[i];
+		unsigned int row = KEY_ROW(key);
+		unsigned int col = KEY_COL(key);
+		unsigned int scancode = MATRIX_SCAN_CODE(row, col,
+						MAX7359_ROW_SHIFT);
+		unsigned short keycode = KEY_VAL(key);
+
+		keypad->keycodes[scancode] = keycode;
+		__set_bit(keycode, input_dev->keybit);
+	}
+	__clear_bit(KEY_RESERVED, input_dev->keybit);
+}
+
+static void max7359_worker(struct work_struct *work)
+{
+	struct max7359_keypad *keypad =
+			container_of(work, struct max7359_keypad, work);
+	struct input_dev *input_dev = keypad->input_dev;
+	int val, row, col, release, code;
+
+	val = max7359_read_reg(keypad->client, MAX7359_REG_KEYFIFO);
+	row = val & 0x7;
+	col = (val >> 3) & 0x7;
+	release = val & 0x40;
+
+	code = MATRIX_SCAN_CODE(row, col, MAX7359_ROW_SHIFT);
+
+	input_event(input_dev, EV_MSC, MSC_SCAN, code);
+	input_report_key(input_dev, keypad->keycodes[code], !release);
+	input_sync(input_dev);
+
+	enable_irq(keypad->irq);
+
+	dev_dbg(&keypad->client->dev, "key[%d:%d] %s\n", row, col,
+					(release ? "release" : "press"));
+}
+
+static irqreturn_t max7359_interrupt(int irq, void *dev_id)
+{
+	struct max7359_keypad *keypad = dev_id;
+
+	if (!work_pending(&keypad->work)) {
+		disable_irq_nosync(keypad->irq);
+		schedule_work(&keypad->work);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Let MAX7359 fall into a deep sleep:
+ * If no keys are pressed, enter sleep mode for 8192 ms. And if any
+ * key is pressed, the MAX7359 returns to normal operating mode.
+ */
+static inline void max7359_fall_deepsleep(struct i2c_client *client)
+{
+	max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_8192);
+}
+
+/*
+ * Let MAX7359 take a catnap:
+ * Autosleep just for 256 ms.
+ */
+static inline void max7359_take_catnap(struct i2c_client *client)
+{
+	max7359_write_reg(client, MAX7359_REG_SLEEP, MAX7359_AUTOSLEEP_256);
+}
+
+static int max7359_open(struct input_dev *dev)
+{
+	struct max7359_keypad *keypad = input_get_drvdata(dev);
+
+	max7359_take_catnap(keypad->client);
+
+	return 0;
+}
+
+static void max7359_close(struct input_dev *dev)
+{
+	struct max7359_keypad *keypad = input_get_drvdata(dev);
+
+	max7359_fall_deepsleep(keypad->client);
+}
+
+static void max7359_initialize(struct i2c_client *client)
+{
+	max7359_write_reg(client, MAX7359_REG_CONFIG,
+		MAX7359_CFG_INTERRUPT | /* Irq clears after host read */
+		MAX7359_CFG_KEY_RELEASE | /* Key release enable */
+		MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
+
+	/* Full key-scan functionality */
+	max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
+
+	/* nINT asserts every debounce cycles */
+	max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
+
+	max7359_fall_deepsleep(client);
+}
+
+static int __devinit max7359_probe(struct i2c_client *client,
+					const struct i2c_device_id *id)
+{
+	const struct matrix_keymap_data *keymap_data = client->dev.platform_data;
+	struct max7359_keypad *keypad;
+	struct input_dev *input_dev;
+	int ret;
+	int error;
+
+	if (!client->irq) {
+		dev_err(&client->dev, "The irq number should not be zero\n");
+		return -EINVAL;
+	}
+
+	/* Detect MAX7359: The initial Keys FIFO value is '0x3F' */
+	ret = max7359_read_reg(client, MAX7359_REG_KEYFIFO);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to detect device\n");
+		return -ENODEV;
+	}
+
+	dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
+
+	keypad = kzalloc(sizeof(struct max7359_keypad), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!keypad || !input_dev) {
+		dev_err(&client->dev, "failed to allocate memory\n");
+		error = -ENOMEM;
+		goto failed_free_mem;
+	}
+
+	keypad->client = client;
+	keypad->input_dev = input_dev;
+	keypad->irq = client->irq;
+	INIT_WORK(&keypad->work, max7359_worker);
+
+	input_dev->name = client->name;
+	input_dev->id.bustype = BUS_I2C;
+	input_dev->open = max7359_open;
+	input_dev->close = max7359_close;
+	input_dev->dev.parent = &client->dev;
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
+	input_dev->keycodesize = sizeof(keypad->keycodes[0]);
+	input_dev->keycodemax = ARRAY_SIZE(keypad->keycodes);
+	input_dev->keycode = keypad->keycodes;
+
+	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+	input_set_drvdata(input_dev, keypad);
+
+	max7359_build_keycode(keypad, keymap_data);
+
+	error = request_irq(keypad->irq, max7359_interrupt,
+			    IRQF_TRIGGER_LOW, client->name, keypad);
+	if (error) {
+		dev_err(&client->dev, "failed to register interrupt\n");
+		goto failed_free_mem;
+	}
+
+	/* Register the input device */
+	error = input_register_device(input_dev);
+	if (error) {
+		dev_err(&client->dev, "failed to register input device\n");
+		goto failed_free_irq;
+	}
+
+	/* Initialize MAX7359 */
+	max7359_initialize(client);
+
+	i2c_set_clientdata(client, keypad);
+	device_init_wakeup(&client->dev, 1);
+
+	return 0;
+
+failed_free_irq:
+	free_irq(keypad->irq, keypad);
+failed_free_mem:
+	input_free_device(input_dev);
+	kfree(keypad);
+	return error;
+}
+
+static int __devexit max7359_remove(struct i2c_client *client)
+{
+	struct max7359_keypad *keypad = i2c_get_clientdata(client);
+
+	cancel_work_sync(&keypad->work);
+	input_unregister_device(keypad->input_dev);
+	free_irq(keypad->irq, keypad);
+	i2c_set_clientdata(client, NULL);
+	kfree(keypad);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int max7359_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	struct max7359_keypad *keypad = i2c_get_clientdata(client);
+
+	max7359_fall_deepsleep(client);
+
+	if (device_may_wakeup(&client->dev))
+		enable_irq_wake(keypad->irq);
+
+	return 0;
+}
+
+static int max7359_resume(struct i2c_client *client)
+{
+	struct max7359_keypad *keypad = i2c_get_clientdata(client);
+
+	if (device_may_wakeup(&client->dev))
+		disable_irq_wake(keypad->irq);
+
+	/* Restore the default setting */
+	max7359_take_catnap(client);
+
+	return 0;
+}
+#else
+#define max7359_suspend	NULL
+#define max7359_resume	NULL
+#endif
+
+static const struct i2c_device_id max7359_ids[] = {
+	{ "max7359", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max7359_ids);
+
+static struct i2c_driver max7359_i2c_driver = {
+	.driver = {
+		.name = "max7359",
+	},
+	.probe		= max7359_probe,
+	.remove		= __devexit_p(max7359_remove),
+	.suspend	= max7359_suspend,
+	.resume		= max7359_resume,
+	.id_table	= max7359_ids,
+};
+
+static int __init max7359_init(void)
+{
+	return i2c_add_driver(&max7359_i2c_driver);
+}
+module_init(max7359_init);
+
+static void __exit max7359_exit(void)
+{
+	i2c_del_driver(&max7359_i2c_driver);
+}
+module_exit(max7359_exit);
+
+MODULE_AUTHOR("Kim Kyuwon <q1.kim@samsung.com>");
+MODULE_DESCRIPTION("MAX7359 Key Switch Controller Driver");
+MODULE_LICENSE("GPL v2");