337 lines
8.6 KiB
C
337 lines
8.6 KiB
C
/*
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* Touchkey driver for Freescale MPR121 Controllor
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*
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* Copyright (C) 2011 Freescale Semiconductor, Inc.
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* Author: Zhang Jiejing <jiejing.zhang@freescale.com>
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*
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* Based on mcs_touchkey.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/i2c.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/bitops.h>
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#include <linux/interrupt.h>
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#include <linux/i2c/mpr121_touchkey.h>
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/* Register definitions */
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#define ELE_TOUCH_STATUS_0_ADDR 0x0
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#define ELE_TOUCH_STATUS_1_ADDR 0X1
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#define MHD_RISING_ADDR 0x2b
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#define NHD_RISING_ADDR 0x2c
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#define NCL_RISING_ADDR 0x2d
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#define FDL_RISING_ADDR 0x2e
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#define MHD_FALLING_ADDR 0x2f
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#define NHD_FALLING_ADDR 0x30
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#define NCL_FALLING_ADDR 0x31
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#define FDL_FALLING_ADDR 0x32
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#define ELE0_TOUCH_THRESHOLD_ADDR 0x41
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#define ELE0_RELEASE_THRESHOLD_ADDR 0x42
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#define AFE_CONF_ADDR 0x5c
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#define FILTER_CONF_ADDR 0x5d
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/*
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* ELECTRODE_CONF_ADDR: This register configures the number of
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* enabled capacitance sensing inputs and its run/suspend mode.
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*/
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#define ELECTRODE_CONF_ADDR 0x5e
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#define ELECTRODE_CONF_QUICK_CHARGE 0x80
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#define AUTO_CONFIG_CTRL_ADDR 0x7b
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#define AUTO_CONFIG_USL_ADDR 0x7d
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#define AUTO_CONFIG_LSL_ADDR 0x7e
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#define AUTO_CONFIG_TL_ADDR 0x7f
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/* Threshold of touch/release trigger */
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#define TOUCH_THRESHOLD 0x08
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#define RELEASE_THRESHOLD 0x05
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/* Masks for touch and release triggers */
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#define TOUCH_STATUS_MASK 0xfff
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/* MPR121 has 12 keys */
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#define MPR121_MAX_KEY_COUNT 12
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struct mpr121_touchkey {
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struct i2c_client *client;
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struct input_dev *input_dev;
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unsigned int key_val;
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unsigned int statusbits;
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unsigned int keycount;
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u16 keycodes[MPR121_MAX_KEY_COUNT];
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};
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struct mpr121_init_register {
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int addr;
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u8 val;
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};
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static const struct mpr121_init_register init_reg_table[] = {
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{ MHD_RISING_ADDR, 0x1 },
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{ NHD_RISING_ADDR, 0x1 },
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{ MHD_FALLING_ADDR, 0x1 },
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{ NHD_FALLING_ADDR, 0x1 },
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{ NCL_FALLING_ADDR, 0xff },
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{ FDL_FALLING_ADDR, 0x02 },
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{ FILTER_CONF_ADDR, 0x04 },
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{ AFE_CONF_ADDR, 0x0b },
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{ AUTO_CONFIG_CTRL_ADDR, 0x0b },
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};
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static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
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{
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struct mpr121_touchkey *mpr121 = dev_id;
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struct i2c_client *client = mpr121->client;
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struct input_dev *input = mpr121->input_dev;
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unsigned int key_num, key_val, pressed;
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int reg;
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reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR);
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if (reg < 0) {
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dev_err(&client->dev, "i2c read error [%d]\n", reg);
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goto out;
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}
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reg <<= 8;
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reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR);
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if (reg < 0) {
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dev_err(&client->dev, "i2c read error [%d]\n", reg);
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goto out;
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}
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reg &= TOUCH_STATUS_MASK;
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/* use old press bit to figure out which bit changed */
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key_num = ffs(reg ^ mpr121->statusbits) - 1;
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pressed = reg & (1 << key_num);
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mpr121->statusbits = reg;
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key_val = mpr121->keycodes[key_num];
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input_event(input, EV_MSC, MSC_SCAN, key_num);
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input_report_key(input, key_val, pressed);
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input_sync(input);
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dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val,
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pressed ? "pressed" : "released");
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out:
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return IRQ_HANDLED;
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}
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static int mpr121_phys_init(const struct mpr121_platform_data *pdata,
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struct mpr121_touchkey *mpr121,
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struct i2c_client *client)
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{
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const struct mpr121_init_register *reg;
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unsigned char usl, lsl, tl, eleconf;
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int i, t, vdd, ret;
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/* Set up touch/release threshold for ele0-ele11 */
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for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) {
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t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2);
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ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD);
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if (ret < 0)
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goto err_i2c_write;
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ret = i2c_smbus_write_byte_data(client, t + 1,
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RELEASE_THRESHOLD);
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if (ret < 0)
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goto err_i2c_write;
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}
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/* Set up init register */
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for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) {
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reg = &init_reg_table[i];
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ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val);
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if (ret < 0)
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goto err_i2c_write;
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}
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/*
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* Capacitance on sensing input varies and needs to be compensated.
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* The internal MPR121-auto-configuration can do this if it's
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* registers are set properly (based on pdata->vdd_uv).
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*/
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vdd = pdata->vdd_uv / 1000;
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usl = ((vdd - 700) * 256) / vdd;
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lsl = (usl * 65) / 100;
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tl = (usl * 90) / 100;
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ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl);
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ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl);
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ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl);
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/*
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* Quick charge bit will let the capacitive charge to ready
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* state quickly, or the buttons may not function after system
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* boot.
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*/
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eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE;
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ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
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eleconf);
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if (ret != 0)
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goto err_i2c_write;
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dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount);
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return 0;
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err_i2c_write:
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dev_err(&client->dev, "i2c write error: %d\n", ret);
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return ret;
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}
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static int mpr_touchkey_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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const struct mpr121_platform_data *pdata =
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dev_get_platdata(&client->dev);
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struct mpr121_touchkey *mpr121;
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struct input_dev *input_dev;
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int error;
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int i;
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if (!pdata) {
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dev_err(&client->dev, "no platform data defined\n");
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return -EINVAL;
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}
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if (!pdata->keymap || !pdata->keymap_size) {
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dev_err(&client->dev, "missing keymap data\n");
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return -EINVAL;
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}
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if (pdata->keymap_size > MPR121_MAX_KEY_COUNT) {
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dev_err(&client->dev, "too many keys defined\n");
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return -EINVAL;
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}
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if (!client->irq) {
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dev_err(&client->dev, "irq number should not be zero\n");
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return -EINVAL;
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}
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mpr121 = kzalloc(sizeof(struct mpr121_touchkey), GFP_KERNEL);
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input_dev = input_allocate_device();
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if (!mpr121 || !input_dev) {
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dev_err(&client->dev, "Failed to allocate memory\n");
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error = -ENOMEM;
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goto err_free_mem;
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}
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mpr121->client = client;
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mpr121->input_dev = input_dev;
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mpr121->keycount = pdata->keymap_size;
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input_dev->name = "Freescale MPR121 Touchkey";
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input_dev->id.bustype = BUS_I2C;
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input_dev->dev.parent = &client->dev;
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input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
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input_dev->keycode = mpr121->keycodes;
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input_dev->keycodesize = sizeof(mpr121->keycodes[0]);
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input_dev->keycodemax = mpr121->keycount;
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for (i = 0; i < pdata->keymap_size; i++) {
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input_set_capability(input_dev, EV_KEY, pdata->keymap[i]);
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mpr121->keycodes[i] = pdata->keymap[i];
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}
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error = mpr121_phys_init(pdata, mpr121, client);
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if (error) {
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dev_err(&client->dev, "Failed to init register\n");
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goto err_free_mem;
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}
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error = request_threaded_irq(client->irq, NULL,
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mpr_touchkey_interrupt,
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IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
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client->dev.driver->name, mpr121);
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if (error) {
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dev_err(&client->dev, "Failed to register interrupt\n");
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goto err_free_mem;
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}
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error = input_register_device(input_dev);
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if (error)
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goto err_free_irq;
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i2c_set_clientdata(client, mpr121);
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device_init_wakeup(&client->dev, pdata->wakeup);
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return 0;
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err_free_irq:
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free_irq(client->irq, mpr121);
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err_free_mem:
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input_free_device(input_dev);
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kfree(mpr121);
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return error;
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}
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static int mpr_touchkey_remove(struct i2c_client *client)
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{
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struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);
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free_irq(client->irq, mpr121);
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input_unregister_device(mpr121->input_dev);
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kfree(mpr121);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int mpr_suspend(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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if (device_may_wakeup(&client->dev))
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enable_irq_wake(client->irq);
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i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00);
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return 0;
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}
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static int mpr_resume(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);
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if (device_may_wakeup(&client->dev))
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disable_irq_wake(client->irq);
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i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
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mpr121->keycount);
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return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume);
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static const struct i2c_device_id mpr121_id[] = {
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{ "mpr121_touchkey", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, mpr121_id);
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static struct i2c_driver mpr_touchkey_driver = {
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.driver = {
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.name = "mpr121",
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.owner = THIS_MODULE,
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.pm = &mpr121_touchkey_pm_ops,
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},
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.id_table = mpr121_id,
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.probe = mpr_touchkey_probe,
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.remove = mpr_touchkey_remove,
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};
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module_i2c_driver(mpr_touchkey_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
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MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip");
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