drivers/input/keyboard/mpr121_touchkey.c - maze/linux - Git at Google

 /*
  * Touchkey driver for Freescale MPR121 Controllor
  *
  * Copyright (C) 2011 Freescale Semiconductor, Inc.
  * Author: Zhang Jiejing <jiejing.zhang@freescale.com>
  *
  * Based on mcs_touchkey.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.
  *
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/input.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/bitops.h>
 #include <linux/interrupt.h>
 #include <linux/i2c/mpr121_touchkey.h>

 /* Register definitions */
 #define ELE_TOUCH_STATUS_0_ADDR	0x0
 #define ELE_TOUCH_STATUS_1_ADDR	0X1
 #define MHD_RISING_ADDR		0x2b
 #define NHD_RISING_ADDR		0x2c
 #define NCL_RISING_ADDR		0x2d
 #define FDL_RISING_ADDR		0x2e
 #define MHD_FALLING_ADDR	0x2f
 #define NHD_FALLING_ADDR	0x30
 #define NCL_FALLING_ADDR	0x31
 #define FDL_FALLING_ADDR	0x32
 #define ELE0_TOUCH_THRESHOLD_ADDR	0x41
 #define ELE0_RELEASE_THRESHOLD_ADDR	0x42
 #define AFE_CONF_ADDR			0x5c
 #define FILTER_CONF_ADDR		0x5d

 /*
  * ELECTRODE_CONF_ADDR: This register configures the number of
  * enabled capacitance sensing inputs and its run/suspend mode.
  */
 #define ELECTRODE_CONF_ADDR		0x5e
 #define ELECTRODE_CONF_QUICK_CHARGE	0x80
 #define AUTO_CONFIG_CTRL_ADDR		0x7b
 #define AUTO_CONFIG_USL_ADDR		0x7d
 #define AUTO_CONFIG_LSL_ADDR		0x7e
 #define AUTO_CONFIG_TL_ADDR		0x7f

 /* Threshold of touch/release trigger */
 #define TOUCH_THRESHOLD			0x08
 #define RELEASE_THRESHOLD		0x05
 /* Masks for touch and release triggers */
 #define TOUCH_STATUS_MASK		0xfff
 /* MPR121 has 12 keys */
 #define MPR121_MAX_KEY_COUNT		12

 struct mpr121_touchkey {
 	struct i2c_client	*client;
 	struct input_dev	*input_dev;
 	unsigned int		key_val;
 	unsigned int		statusbits;
 	unsigned int		keycount;
 	u16			keycodes[MPR121_MAX_KEY_COUNT];
 };

 struct mpr121_init_register {
 	int addr;
 	u8 val;
 };

 static const struct mpr121_init_register init_reg_table[] = {
 	{ MHD_RISING_ADDR,	0x1 },
 	{ NHD_RISING_ADDR,	0x1 },
 	{ MHD_FALLING_ADDR,	0x1 },
 	{ NHD_FALLING_ADDR,	0x1 },
 	{ NCL_FALLING_ADDR,	0xff },
 	{ FDL_FALLING_ADDR,	0x02 },
 	{ FILTER_CONF_ADDR,	0x04 },
 	{ AFE_CONF_ADDR,	0x0b },
 	{ AUTO_CONFIG_CTRL_ADDR, 0x0b },
 };

 static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
 {
 	struct mpr121_touchkey *mpr121 = dev_id;
 	struct i2c_client *client = mpr121->client;
 	struct input_dev *input = mpr121->input_dev;
 	unsigned int key_num, key_val, pressed;
 	int reg;

 	reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR);
 	if (reg < 0) {
 		dev_err(&client->dev, "i2c read error [%d]\n", reg);
 		goto out;
 	}

 	reg <<= 8;
 	reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR);
 	if (reg < 0) {
 		dev_err(&client->dev, "i2c read error [%d]\n", reg);
 		goto out;
 	}

 	reg &= TOUCH_STATUS_MASK;
 	/* use old press bit to figure out which bit changed */
 	key_num = ffs(reg ^ mpr121->statusbits) - 1;
 	pressed = reg & (1 << key_num);
 	mpr121->statusbits = reg;

 	key_val = mpr121->keycodes[key_num];

 	input_event(input, EV_MSC, MSC_SCAN, key_num);
 	input_report_key(input, key_val, pressed);
 	input_sync(input);

 	dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val,
 		pressed ? "pressed" : "released");

 out:
 	return IRQ_HANDLED;
 }

 static int mpr121_phys_init(const struct mpr121_platform_data *pdata,
 				      struct mpr121_touchkey *mpr121,
 				      struct i2c_client *client)
 {
 	const struct mpr121_init_register *reg;
 	unsigned char usl, lsl, tl, eleconf;
 	int i, t, vdd, ret;

 	/* Set up touch/release threshold for ele0-ele11 */
 	for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) {
 		t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2);
 		ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD);
 		if (ret < 0)
 			goto err_i2c_write;
 		ret = i2c_smbus_write_byte_data(client, t + 1,
 						RELEASE_THRESHOLD);
 		if (ret < 0)
 			goto err_i2c_write;
 	}

 	/* Set up init register */
 	for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) {
 		reg = &init_reg_table[i];
 		ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val);
 		if (ret < 0)
 			goto err_i2c_write;
 	}


 	/*
 	 * Capacitance on sensing input varies and needs to be compensated.
 	 * The internal MPR121-auto-configuration can do this if it's
 	 * registers are set properly (based on pdata->vdd_uv).
 	 */
 	vdd = pdata->vdd_uv / 1000;
 	usl = ((vdd - 700) * 256) / vdd;
 	lsl = (usl * 65) / 100;
 	tl = (usl * 90) / 100;
 	ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl);
 	ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl);
 	ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl);

 	/*
 	 * Quick charge bit will let the capacitive charge to ready
 	 * state quickly, or the buttons may not function after system
 	 * boot.
 	 */
 	eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE;
 	ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
 					 eleconf);
 	if (ret != 0)
 		goto err_i2c_write;

 	dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount);

 	return 0;

 err_i2c_write:
 	dev_err(&client->dev, "i2c write error: %d\n", ret);
 	return ret;
 }

 static int mpr_touchkey_probe(struct i2c_client *client,
 			      const struct i2c_device_id *id)
 {
 	const struct mpr121_platform_data *pdata = client->dev.platform_data;
 	struct mpr121_touchkey *mpr121;
 	struct input_dev *input_dev;
 	int error;
 	int i;

 	if (!pdata) {
 		dev_err(&client->dev, "no platform data defined\n");
 		return -EINVAL;
 	}

 	if (!pdata->keymap || !pdata->keymap_size) {
 		dev_err(&client->dev, "missing keymap data\n");
 		return -EINVAL;
 	}

 	if (pdata->keymap_size > MPR121_MAX_KEY_COUNT) {
 		dev_err(&client->dev, "too many keys defined\n");
 		return -EINVAL;
 	}

 	if (!client->irq) {
 		dev_err(&client->dev, "irq number should not be zero\n");
 		return -EINVAL;
 	}

 	mpr121 = kzalloc(sizeof(struct mpr121_touchkey), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!mpr121 || !input_dev) {
 		dev_err(&client->dev, "Failed to allocate memory\n");
 		error = -ENOMEM;
 		goto err_free_mem;
 	}

 	mpr121->client = client;
 	mpr121->input_dev = input_dev;
 	mpr121->keycount = pdata->keymap_size;

 	input_dev->name = "Freescale MPR121 Touchkey";
 	input_dev->id.bustype = BUS_I2C;
 	input_dev->dev.parent = &client->dev;
 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);

 	input_dev->keycode = mpr121->keycodes;
 	input_dev->keycodesize = sizeof(mpr121->keycodes[0]);
 	input_dev->keycodemax = mpr121->keycount;

 	for (i = 0; i < pdata->keymap_size; i++) {
 		input_set_capability(input_dev, EV_KEY, pdata->keymap[i]);
 		mpr121->keycodes[i] = pdata->keymap[i];
 	}

 	error = mpr121_phys_init(pdata, mpr121, client);
 	if (error) {
 		dev_err(&client->dev, "Failed to init register\n");
 		goto err_free_mem;
 	}

 	error = request_threaded_irq(client->irq, NULL,
 				     mpr_touchkey_interrupt,
 				     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 				     client->dev.driver->name, mpr121);
 	if (error) {
 		dev_err(&client->dev, "Failed to register interrupt\n");
 		goto err_free_mem;
 	}

 	error = input_register_device(input_dev);
 	if (error)
 		goto err_free_irq;

 	i2c_set_clientdata(client, mpr121);
 	device_init_wakeup(&client->dev, pdata->wakeup);

 	return 0;

 err_free_irq:
 	free_irq(client->irq, mpr121);
 err_free_mem:
 	input_free_device(input_dev);
 	kfree(mpr121);
 	return error;
 }

 static int mpr_touchkey_remove(struct i2c_client *client)
 {
 	struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);

 	free_irq(client->irq, mpr121);
 	input_unregister_device(mpr121->input_dev);
 	kfree(mpr121);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int mpr_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);

 	if (device_may_wakeup(&client->dev))
 		enable_irq_wake(client->irq);

 	i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00);

 	return 0;
 }

 static int mpr_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);

 	if (device_may_wakeup(&client->dev))
 		disable_irq_wake(client->irq);

 	i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
 				  mpr121->keycount);

 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume);

 static const struct i2c_device_id mpr121_id[] = {
 	{ "mpr121_touchkey", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, mpr121_id);

 static struct i2c_driver mpr_touchkey_driver = {
 	.driver = {
 		.name	= "mpr121",
 		.owner	= THIS_MODULE,
 		.pm	= &mpr121_touchkey_pm_ops,
 	},
 	.id_table	= mpr121_id,
 	.probe		= mpr_touchkey_probe,
 	.remove		= mpr_touchkey_remove,
 };

 module_i2c_driver(mpr_touchkey_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
 MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip");
	/*
	* Touchkey driver for Freescale MPR121 Controllor
	*
	* Copyright (C) 2011 Freescale Semiconductor, Inc.
	* Author: Zhang Jiejing <jiejing.zhang@freescale.com>
	*
	* Based on mcs_touchkey.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.
	*
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/input.h>
	#include <linux/i2c.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include <linux/bitops.h>
	#include <linux/interrupt.h>
	#include <linux/i2c/mpr121_touchkey.h>

	/* Register definitions */
	#define ELE_TOUCH_STATUS_0_ADDR 0x0
	#define ELE_TOUCH_STATUS_1_ADDR 0X1
	#define MHD_RISING_ADDR 0x2b
	#define NHD_RISING_ADDR 0x2c
	#define NCL_RISING_ADDR 0x2d
	#define FDL_RISING_ADDR 0x2e
	#define MHD_FALLING_ADDR 0x2f
	#define NHD_FALLING_ADDR 0x30
	#define NCL_FALLING_ADDR 0x31
	#define FDL_FALLING_ADDR 0x32
	#define ELE0_TOUCH_THRESHOLD_ADDR 0x41
	#define ELE0_RELEASE_THRESHOLD_ADDR 0x42
	#define AFE_CONF_ADDR 0x5c
	#define FILTER_CONF_ADDR 0x5d

	/*
	* ELECTRODE_CONF_ADDR: This register configures the number of
	* enabled capacitance sensing inputs and its run/suspend mode.
	*/
	#define ELECTRODE_CONF_ADDR 0x5e
	#define ELECTRODE_CONF_QUICK_CHARGE 0x80
	#define AUTO_CONFIG_CTRL_ADDR 0x7b
	#define AUTO_CONFIG_USL_ADDR 0x7d
	#define AUTO_CONFIG_LSL_ADDR 0x7e
	#define AUTO_CONFIG_TL_ADDR 0x7f

	/* Threshold of touch/release trigger */
	#define TOUCH_THRESHOLD 0x08
	#define RELEASE_THRESHOLD 0x05
	/* Masks for touch and release triggers */
	#define TOUCH_STATUS_MASK 0xfff
	/* MPR121 has 12 keys */
	#define MPR121_MAX_KEY_COUNT 12

	struct mpr121_touchkey {
	struct i2c_client *client;
	struct input_dev *input_dev;
	unsigned int key_val;
	unsigned int statusbits;
	unsigned int keycount;
	u16 keycodes[MPR121_MAX_KEY_COUNT];
	};

	struct mpr121_init_register {
	int addr;
	u8 val;
	};

	static const struct mpr121_init_register init_reg_table[] = {
	{ MHD_RISING_ADDR, 0x1 },
	{ NHD_RISING_ADDR, 0x1 },
	{ MHD_FALLING_ADDR, 0x1 },
	{ NHD_FALLING_ADDR, 0x1 },
	{ NCL_FALLING_ADDR, 0xff },
	{ FDL_FALLING_ADDR, 0x02 },
	{ FILTER_CONF_ADDR, 0x04 },
	{ AFE_CONF_ADDR, 0x0b },
	{ AUTO_CONFIG_CTRL_ADDR, 0x0b },
	};

	static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
	{
	struct mpr121_touchkey *mpr121 = dev_id;
	struct i2c_client *client = mpr121->client;
	struct input_dev *input = mpr121->input_dev;
	unsigned int key_num, key_val, pressed;
	int reg;

	reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR);
	if (reg < 0) {
	dev_err(&client->dev, "i2c read error [%d]\n", reg);
	goto out;
	}

	reg <<= 8;
	reg \|= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR);
	if (reg < 0) {
	dev_err(&client->dev, "i2c read error [%d]\n", reg);
	goto out;
	}

	reg &= TOUCH_STATUS_MASK;
	/* use old press bit to figure out which bit changed */
	key_num = ffs(reg ^ mpr121->statusbits) - 1;
	pressed = reg & (1 << key_num);
	mpr121->statusbits = reg;

	key_val = mpr121->keycodes[key_num];

	input_event(input, EV_MSC, MSC_SCAN, key_num);
	input_report_key(input, key_val, pressed);
	input_sync(input);

	dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val,
	pressed ? "pressed" : "released");

	out:
	return IRQ_HANDLED;
	}

	static int mpr121_phys_init(const struct mpr121_platform_data *pdata,
	struct mpr121_touchkey *mpr121,
	struct i2c_client *client)
	{
	const struct mpr121_init_register *reg;
	unsigned char usl, lsl, tl, eleconf;
	int i, t, vdd, ret;

	/* Set up touch/release threshold for ele0-ele11 */
	for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) {
	t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2);
	ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD);
	if (ret < 0)
	goto err_i2c_write;
	ret = i2c_smbus_write_byte_data(client, t + 1,
	RELEASE_THRESHOLD);
	if (ret < 0)
	goto err_i2c_write;
	}

	/* Set up init register */
	for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) {
	reg = &init_reg_table[i];
	ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val);
	if (ret < 0)
	goto err_i2c_write;
	}


	/*
	* Capacitance on sensing input varies and needs to be compensated.
	* The internal MPR121-auto-configuration can do this if it's
	* registers are set properly (based on pdata->vdd_uv).
	*/
	vdd = pdata->vdd_uv / 1000;
	usl = ((vdd - 700) * 256) / vdd;
	lsl = (usl * 65) / 100;
	tl = (usl * 90) / 100;
	ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl);
	ret \|= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl);
	ret \|= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl);

	/*
	* Quick charge bit will let the capacitive charge to ready
	* state quickly, or the buttons may not function after system
	* boot.
	*/
	eleconf = mpr121->keycount \| ELECTRODE_CONF_QUICK_CHARGE;
	ret \|= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
	eleconf);
	if (ret != 0)
	goto err_i2c_write;

	dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount);

	return 0;

	err_i2c_write:
	dev_err(&client->dev, "i2c write error: %d\n", ret);
	return ret;
	}

	static int mpr_touchkey_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	const struct mpr121_platform_data *pdata = client->dev.platform_data;
	struct mpr121_touchkey *mpr121;
	struct input_dev *input_dev;
	int error;
	int i;

	if (!pdata) {
	dev_err(&client->dev, "no platform data defined\n");
	return -EINVAL;
	}

	if (!pdata->keymap \|\| !pdata->keymap_size) {
	dev_err(&client->dev, "missing keymap data\n");
	return -EINVAL;
	}

	if (pdata->keymap_size > MPR121_MAX_KEY_COUNT) {
	dev_err(&client->dev, "too many keys defined\n");
	return -EINVAL;
	}

	if (!client->irq) {
	dev_err(&client->dev, "irq number should not be zero\n");
	return -EINVAL;
	}

	mpr121 = kzalloc(sizeof(struct mpr121_touchkey), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!mpr121 \|\| !input_dev) {
	dev_err(&client->dev, "Failed to allocate memory\n");
	error = -ENOMEM;
	goto err_free_mem;
	}

	mpr121->client = client;
	mpr121->input_dev = input_dev;
	mpr121->keycount = pdata->keymap_size;

	input_dev->name = "Freescale MPR121 Touchkey";
	input_dev->id.bustype = BUS_I2C;
	input_dev->dev.parent = &client->dev;
	input_dev->evbit[0] = BIT_MASK(EV_KEY) \| BIT_MASK(EV_REP);

	input_dev->keycode = mpr121->keycodes;
	input_dev->keycodesize = sizeof(mpr121->keycodes[0]);
	input_dev->keycodemax = mpr121->keycount;

	for (i = 0; i < pdata->keymap_size; i++) {
	input_set_capability(input_dev, EV_KEY, pdata->keymap[i]);
	mpr121->keycodes[i] = pdata->keymap[i];
	}

	error = mpr121_phys_init(pdata, mpr121, client);
	if (error) {
	dev_err(&client->dev, "Failed to init register\n");
	goto err_free_mem;
	}

	error = request_threaded_irq(client->irq, NULL,
	mpr_touchkey_interrupt,
	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	client->dev.driver->name, mpr121);
	if (error) {
	dev_err(&client->dev, "Failed to register interrupt\n");
	goto err_free_mem;
	}

	error = input_register_device(input_dev);
	if (error)
	goto err_free_irq;

	i2c_set_clientdata(client, mpr121);
	device_init_wakeup(&client->dev, pdata->wakeup);

	return 0;

	err_free_irq:
	free_irq(client->irq, mpr121);
	err_free_mem:
	input_free_device(input_dev);
	kfree(mpr121);
	return error;
	}

	static int mpr_touchkey_remove(struct i2c_client *client)
	{
	struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);

	free_irq(client->irq, mpr121);
	input_unregister_device(mpr121->input_dev);
	kfree(mpr121);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int mpr_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);

	if (device_may_wakeup(&client->dev))
	enable_irq_wake(client->irq);

	i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00);

	return 0;
	}

	static int mpr_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);

	if (device_may_wakeup(&client->dev))
	disable_irq_wake(client->irq);

	i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
	mpr121->keycount);

	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume);

	static const struct i2c_device_id mpr121_id[] = {
	{ "mpr121_touchkey", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, mpr121_id);

	static struct i2c_driver mpr_touchkey_driver = {
	.driver = {
	.name = "mpr121",
	.owner = THIS_MODULE,
	.pm = &mpr121_touchkey_pm_ops,
	},
	.id_table = mpr121_id,
	.probe = mpr_touchkey_probe,
	.remove = mpr_touchkey_remove,
	};

	module_i2c_driver(mpr_touchkey_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
	MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip");