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>

3 files changed, 364 insertions, 0 deletions

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index d615c09a83c6..57055bcbd7a6 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/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
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index a5c08cdf8083..85ab894f613a 100644
--- a/drivers/input/keyboard/Makefile
+++ b/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
diff --git a/drivers/input/keyboard/max7359_keypad.c b/drivers/input/keyboard/max7359_keypad.c
new file mode 100644
index 000000000000..8b3ee142a6c6
--- /dev/null
+++ b/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");