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kernel-fxtec-pro1x/drivers/input/keyboard/mpr121_touchkey.c
Jiejing Zhang c7b4a5d58b Input: mpr121 - improve sensibility of touch key 
The Quick Charge bit in Electrode conf register should be set in init
function. This bit was missed in chip's document, which may cause touch
controller charge too slow to generate an interrupt.

Also, adjust the default vlaue of touch and release threshold
to make touch key more sensitive, this fix touch may not sensitive
after setup with plastic case.

Signed-off-by: Jiejing Zhang <jiejing.zhang@freescale.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2011-06-29 01:32:49 -07:00

347 lines
8.8 KiB
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/*
* 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[] __devinitconst = {
{ 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 __devinit 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 __devinit 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,
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 __devexit 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 = __devexit_p(mpr_touchkey_remove),
};
static int __init mpr_touchkey_init(void)
{
return i2c_add_driver(&mpr_touchkey_driver);
}
module_init(mpr_touchkey_init);
static void __exit mpr_touchkey_exit(void)
{
i2c_del_driver(&mpr_touchkey_driver);
}
module_exit(mpr_touchkey_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip");
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