Input: mcs - Add MCS touchkey driver

This adds support for MELPAS MCS5000/MSC5080 touch key controllers.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

6 files changed, 289 insertions, 27 deletions

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index d8fa5d724c57..c7480934ceeb 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -297,6 +297,18 @@ config KEYBOARD_MAX7359
           To compile this driver as a module, choose M here: the
           module will be called max7359_keypad.
 
+config KEYBOARD_MCS
+        tristate "MELFAS MCS Touchkey"
+        depends on I2C
+        help
+          Say Y here if you have the MELFAS MCS5000/5080 touchkey controller
+          chip in your system.
+
+          If unsure, say N.
+
+          To compile this driver as a module, choose M here: the
+          module will be called mcs_touchkey.
+
 config KEYBOARD_IMX
         tristate "IMX keypad support"
         depends on ARCH_MXC
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 4596d0c6f922..0a16674ed3d2 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -26,6 +26,7 @@ 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-$(CONFIG_KEYBOARD_MCS)              += mcs_touchkey.o
 obj-$(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/mcs_touchkey.c b/drivers/input/keyboard/mcs_touchkey.c
new file mode 100644
index 000000000000..63b849d7e90b
--- /dev/null
+++ b/drivers/input/keyboard/mcs_touchkey.c
@@ -0,0 +1,239 @@
+/*
+ * mcs_touchkey.c - Touchkey driver for MELFAS MCS5000/5080 controller
+ *
+ * Copyright (C) 2010 Samsung Electronics Co.Ltd
+ * Author: HeungJun Kim <riverful.kim@samsung.com>
+ * Author: Joonyoung Shim <jy0922.shim@samsung.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/i2c/mcs.h>
+#include <linux/interrupt.h>
+#include <linux/input.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+
+/* MCS5000 Touchkey */
+#define MCS5000_TOUCHKEY_STATUS         0x04
+#define MCS5000_TOUCHKEY_STATUS_PRESS   7
+#define MCS5000_TOUCHKEY_FW             0x0a
+#define MCS5000_TOUCHKEY_BASE_VAL       0x61
+
+/* MCS5080 Touchkey */
+#define MCS5080_TOUCHKEY_STATUS         0x00
+#define MCS5080_TOUCHKEY_STATUS_PRESS   3
+#define MCS5080_TOUCHKEY_FW             0x01
+#define MCS5080_TOUCHKEY_BASE_VAL       0x1
+
+enum mcs_touchkey_type {
+        MCS5000_TOUCHKEY,
+        MCS5080_TOUCHKEY,
+};
+
+struct mcs_touchkey_chip {
+        unsigned int status_reg;
+        unsigned int pressbit;
+        unsigned int press_invert;
+        unsigned int baseval;
+};
+
+struct mcs_touchkey_data {
+        struct i2c_client *client;
+        struct input_dev *input_dev;
+        struct mcs_touchkey_chip chip;
+        unsigned int key_code;
+        unsigned int key_val;
+        unsigned short keycodes[];
+};
+
+static irqreturn_t mcs_touchkey_interrupt(int irq, void *dev_id)
+{
+        struct mcs_touchkey_data *data = dev_id;
+        struct mcs_touchkey_chip *chip = &data->chip;
+        struct i2c_client *client = data->client;
+        struct input_dev *input = data->input_dev;
+        unsigned int key_val;
+        unsigned int pressed;
+        int val;
+
+        val = i2c_smbus_read_byte_data(client, chip->status_reg);
+        if (val < 0) {
+                dev_err(&client->dev, "i2c read error [%d]\n", val);
+                goto out;
+        }
+
+        pressed = (val & (1 << chip->pressbit)) >> chip->pressbit;
+        if (chip->press_invert)
+                pressed ^= chip->press_invert;
+
+        /* key_val is 0 when released, so we should use key_val of press. */
+        if (pressed) {
+                key_val = val & (0xff >> (8 - chip->pressbit));
+                if (!key_val)
+                        goto out;
+                key_val -= chip->baseval;
+                data->key_code = data->keycodes[key_val];
+                data->key_val = key_val;
+        }
+
+        input_event(input, EV_MSC, MSC_SCAN, data->key_val);
+        input_report_key(input, data->key_code, pressed);
+        input_sync(input);
+
+        dev_dbg(&client->dev, "key %d %d %s\n", data->key_val, data->key_code,
+                pressed ? "pressed" : "released");
+
+ out:
+        return IRQ_HANDLED;
+}
+
+static int __devinit mcs_touchkey_probe(struct i2c_client *client,
+                const struct i2c_device_id *id)
+{
+        const struct mcs_platform_data *pdata;
+        struct mcs_touchkey_data *data;
+        struct input_dev *input_dev;
+        unsigned int fw_reg;
+        int fw_ver;
+        int error;
+        int i;
+
+        pdata = client->dev.platform_data;
+        if (!pdata) {
+                dev_err(&client->dev, "no platform data defined\n");
+                return -EINVAL;
+        }
+
+        data = kzalloc(sizeof(struct mcs_touchkey_data) +
+                        sizeof(data->keycodes[0]) * (pdata->key_maxval + 1),
+                        GFP_KERNEL);
+        input_dev = input_allocate_device();
+        if (!data || !input_dev) {
+                dev_err(&client->dev, "Failed to allocate memory\n");
+                error = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        data->client = client;
+        data->input_dev = input_dev;
+
+        if (id->driver_data == MCS5000_TOUCHKEY) {
+                data->chip.status_reg = MCS5000_TOUCHKEY_STATUS;
+                data->chip.pressbit = MCS5000_TOUCHKEY_STATUS_PRESS;
+                data->chip.baseval = MCS5000_TOUCHKEY_BASE_VAL;
+                fw_reg = MCS5000_TOUCHKEY_FW;
+        } else {
+                data->chip.status_reg = MCS5080_TOUCHKEY_STATUS;
+                data->chip.pressbit = MCS5080_TOUCHKEY_STATUS_PRESS;
+                data->chip.press_invert = 1;
+                data->chip.baseval = MCS5080_TOUCHKEY_BASE_VAL;
+                fw_reg = MCS5080_TOUCHKEY_FW;
+        }
+
+        fw_ver = i2c_smbus_read_byte_data(client, fw_reg);
+        if (fw_ver < 0) {
+                error = fw_ver;
+                dev_err(&client->dev, "i2c read error[%d]\n", error);