428 lines
11 KiB
C
428 lines
11 KiB
C
/*
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* Driver for TCA8418 I2C keyboard
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*
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* Copyright (C) 2011 Fuel7, Inc. All rights reserved.
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*
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* Author: Kyle Manna <kyle.manna@fuel7.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*
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* If you can't comply with GPLv2, alternative licensing terms may be
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* arranged. Please contact Fuel7, Inc. (http://fuel7.com/) for proprietary
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* alternative licensing inquiries.
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*/
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/workqueue.h>
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#include <linux/gpio.h>
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#include <linux/i2c.h>
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#include <linux/input.h>
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#include <linux/input/tca8418_keypad.h>
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#include <linux/of.h>
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/* TCA8418 hardware limits */
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#define TCA8418_MAX_ROWS 8
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#define TCA8418_MAX_COLS 10
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/* TCA8418 register offsets */
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#define REG_CFG 0x01
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#define REG_INT_STAT 0x02
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#define REG_KEY_LCK_EC 0x03
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#define REG_KEY_EVENT_A 0x04
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#define REG_KEY_EVENT_B 0x05
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#define REG_KEY_EVENT_C 0x06
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#define REG_KEY_EVENT_D 0x07
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#define REG_KEY_EVENT_E 0x08
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#define REG_KEY_EVENT_F 0x09
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#define REG_KEY_EVENT_G 0x0A
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#define REG_KEY_EVENT_H 0x0B
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#define REG_KEY_EVENT_I 0x0C
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#define REG_KEY_EVENT_J 0x0D
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#define REG_KP_LCK_TIMER 0x0E
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#define REG_UNLOCK1 0x0F
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#define REG_UNLOCK2 0x10
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#define REG_GPIO_INT_STAT1 0x11
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#define REG_GPIO_INT_STAT2 0x12
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#define REG_GPIO_INT_STAT3 0x13
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#define REG_GPIO_DAT_STAT1 0x14
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#define REG_GPIO_DAT_STAT2 0x15
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#define REG_GPIO_DAT_STAT3 0x16
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#define REG_GPIO_DAT_OUT1 0x17
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#define REG_GPIO_DAT_OUT2 0x18
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#define REG_GPIO_DAT_OUT3 0x19
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#define REG_GPIO_INT_EN1 0x1A
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#define REG_GPIO_INT_EN2 0x1B
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#define REG_GPIO_INT_EN3 0x1C
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#define REG_KP_GPIO1 0x1D
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#define REG_KP_GPIO2 0x1E
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#define REG_KP_GPIO3 0x1F
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#define REG_GPI_EM1 0x20
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#define REG_GPI_EM2 0x21
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#define REG_GPI_EM3 0x22
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#define REG_GPIO_DIR1 0x23
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#define REG_GPIO_DIR2 0x24
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#define REG_GPIO_DIR3 0x25
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#define REG_GPIO_INT_LVL1 0x26
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#define REG_GPIO_INT_LVL2 0x27
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#define REG_GPIO_INT_LVL3 0x28
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#define REG_DEBOUNCE_DIS1 0x29
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#define REG_DEBOUNCE_DIS2 0x2A
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#define REG_DEBOUNCE_DIS3 0x2B
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#define REG_GPIO_PULL1 0x2C
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#define REG_GPIO_PULL2 0x2D
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#define REG_GPIO_PULL3 0x2E
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/* TCA8418 bit definitions */
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#define CFG_AI BIT(7)
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#define CFG_GPI_E_CFG BIT(6)
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#define CFG_OVR_FLOW_M BIT(5)
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#define CFG_INT_CFG BIT(4)
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#define CFG_OVR_FLOW_IEN BIT(3)
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#define CFG_K_LCK_IEN BIT(2)
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#define CFG_GPI_IEN BIT(1)
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#define CFG_KE_IEN BIT(0)
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#define INT_STAT_CAD_INT BIT(4)
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#define INT_STAT_OVR_FLOW_INT BIT(3)
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#define INT_STAT_K_LCK_INT BIT(2)
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#define INT_STAT_GPI_INT BIT(1)
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#define INT_STAT_K_INT BIT(0)
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/* TCA8418 register masks */
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#define KEY_LCK_EC_KEC 0x7
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#define KEY_EVENT_CODE 0x7f
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#define KEY_EVENT_VALUE 0x80
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struct tca8418_keypad {
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struct i2c_client *client;
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struct input_dev *input;
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unsigned int row_shift;
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};
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/*
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* Write a byte to the TCA8418
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*/
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static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
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int reg, u8 val)
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{
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int error;
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error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
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if (error < 0) {
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dev_err(&keypad_data->client->dev,
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"%s failed, reg: %d, val: %d, error: %d\n",
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__func__, reg, val, error);
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return error;
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}
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return 0;
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}
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/*
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* Read a byte from the TCA8418
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*/
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static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
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int reg, u8 *val)
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{
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int error;
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error = i2c_smbus_read_byte_data(keypad_data->client, reg);
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if (error < 0) {
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dev_err(&keypad_data->client->dev,
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"%s failed, reg: %d, error: %d\n",
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__func__, reg, error);
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return error;
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}
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*val = (u8)error;
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return 0;
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}
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static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
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{
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struct input_dev *input = keypad_data->input;
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unsigned short *keymap = input->keycode;
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int error, col, row;
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u8 reg, state, code;
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/* Initial read of the key event FIFO */
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error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
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/* Assume that key code 0 signifies empty FIFO */
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while (error >= 0 && reg > 0) {
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state = reg & KEY_EVENT_VALUE;
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code = reg & KEY_EVENT_CODE;
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row = code / TCA8418_MAX_COLS;
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col = code % TCA8418_MAX_COLS;
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row = (col) ? row : row - 1;
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col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
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code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
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input_event(input, EV_MSC, MSC_SCAN, code);
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input_report_key(input, keymap[code], state);
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/* Read for next loop */
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error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, ®);
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}
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if (error < 0)
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dev_err(&keypad_data->client->dev,
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"unable to read REG_KEY_EVENT_A\n");
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input_sync(input);
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}
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/*
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* Threaded IRQ handler and this can (and will) sleep.
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*/
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static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
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{
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struct tca8418_keypad *keypad_data = dev_id;
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u8 reg;
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int error;
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error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®);
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if (error) {
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dev_err(&keypad_data->client->dev,
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"unable to read REG_INT_STAT\n");
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return IRQ_NONE;
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}
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if (!reg)
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return IRQ_NONE;
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if (reg & INT_STAT_OVR_FLOW_INT)
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dev_warn(&keypad_data->client->dev, "overflow occurred\n");
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if (reg & INT_STAT_K_INT)
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tca8418_read_keypad(keypad_data);
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/* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
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reg = 0xff;
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error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
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if (error)
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dev_err(&keypad_data->client->dev,
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"unable to clear REG_INT_STAT\n");
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return IRQ_HANDLED;
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}
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/*
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* Configure the TCA8418 for keypad operation
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*/
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static int tca8418_configure(struct tca8418_keypad *keypad_data,
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u32 rows, u32 cols)
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{
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int reg, error;
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/* Write config register, if this fails assume device not present */
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error = tca8418_write_byte(keypad_data, REG_CFG,
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CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
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if (error < 0)
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return -ENODEV;
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/* Assemble a mask for row and column registers */
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reg = ~(~0 << rows);
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reg += (~(~0 << cols)) << 8;
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/* Set registers to keypad mode */
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error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
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error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
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error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
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/* Enable column debouncing */
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error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
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error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
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error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
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return error;
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}
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static int tca8418_keypad_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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const struct tca8418_keypad_platform_data *pdata =
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dev_get_platdata(dev);
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struct tca8418_keypad *keypad_data;
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struct input_dev *input;
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const struct matrix_keymap_data *keymap_data = NULL;
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u32 rows = 0, cols = 0;
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bool rep = false;
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bool irq_is_gpio = false;
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int irq;
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int error, row_shift, max_keys;
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/* Copy the platform data */
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if (pdata) {
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if (!pdata->keymap_data) {
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dev_err(dev, "no keymap data defined\n");
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return -EINVAL;
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}
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keymap_data = pdata->keymap_data;
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rows = pdata->rows;
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cols = pdata->cols;
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rep = pdata->rep;
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irq_is_gpio = pdata->irq_is_gpio;
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} else {
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struct device_node *np = dev->of_node;
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int err;
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err = matrix_keypad_parse_of_params(dev, &rows, &cols);
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if (err)
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return err;
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rep = of_property_read_bool(np, "keypad,autorepeat");
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}
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if (!rows || rows > TCA8418_MAX_ROWS) {
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dev_err(dev, "invalid rows\n");
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return -EINVAL;
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}
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if (!cols || cols > TCA8418_MAX_COLS) {
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dev_err(dev, "invalid columns\n");
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return -EINVAL;
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}
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/* Check i2c driver capabilities */
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
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dev_err(dev, "%s adapter not supported\n",
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dev_driver_string(&client->adapter->dev));
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return -ENODEV;
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}
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row_shift = get_count_order(cols);
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max_keys = rows << row_shift;
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/* Allocate memory for keypad_data and input device */
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keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL);
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if (!keypad_data)
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return -ENOMEM;
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keypad_data->client = client;
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keypad_data->row_shift = row_shift;
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/* Initialize the chip or fail if chip isn't present */
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error = tca8418_configure(keypad_data, rows, cols);
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if (error < 0)
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return error;
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/* Configure input device */
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input = devm_input_allocate_device(dev);
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if (!input)
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return -ENOMEM;
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keypad_data->input = input;
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input->name = client->name;
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input->id.bustype = BUS_I2C;
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input->id.vendor = 0x0001;
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input->id.product = 0x001;
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input->id.version = 0x0001;
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error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols,
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NULL, input);
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if (error) {
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dev_err(dev, "Failed to build keymap\n");
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return error;
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}
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if (rep)
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__set_bit(EV_REP, input->evbit);
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input_set_capability(input, EV_MSC, MSC_SCAN);
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input_set_drvdata(input, keypad_data);
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irq = client->irq;
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if (irq_is_gpio)
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irq = gpio_to_irq(irq);
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error = devm_request_threaded_irq(dev, irq, NULL, tca8418_irq_handler,
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IRQF_TRIGGER_FALLING |
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IRQF_SHARED |
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IRQF_ONESHOT,
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client->name, keypad_data);
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if (error) {
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dev_err(dev, "Unable to claim irq %d; error %d\n",
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client->irq, error);
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return error;
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}
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error = input_register_device(input);
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if (error) {
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dev_err(dev, "Unable to register input device, error: %d\n",
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error);
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return error;
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}
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return 0;
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}
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static const struct i2c_device_id tca8418_id[] = {
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{ TCA8418_NAME, 8418, },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, tca8418_id);
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#ifdef CONFIG_OF
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static const struct of_device_id tca8418_dt_ids[] = {
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{ .compatible = "ti,tca8418", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, tca8418_dt_ids);
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/*
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* The device tree based i2c loader looks for
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* "i2c:" + second_component_of(property("compatible"))
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* and therefore we need an alias to be found.
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*/
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MODULE_ALIAS("i2c:tca8418");
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#endif
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static struct i2c_driver tca8418_keypad_driver = {
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.driver = {
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.name = TCA8418_NAME,
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(tca8418_dt_ids),
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},
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.probe = tca8418_keypad_probe,
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.id_table = tca8418_id,
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};
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static int __init tca8418_keypad_init(void)
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{
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return i2c_add_driver(&tca8418_keypad_driver);
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}
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subsys_initcall(tca8418_keypad_init);
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static void __exit tca8418_keypad_exit(void)
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{
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i2c_del_driver(&tca8418_keypad_driver);
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}
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module_exit(tca8418_keypad_exit);
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MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
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MODULE_DESCRIPTION("Keypad driver for TCA8418");
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MODULE_LICENSE("GPL");
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