Zhang Jiejing | 4203306 | 2011-04-11 23:48:23 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Driver for MAXI MAX11801 - A Resistive touch screen controller with |
| 3 | * i2c interface |
| 4 | * |
| 5 | * Copyright (C) 2011 Freescale Semiconductor, Inc. |
| 6 | * Author: Zhang Jiejing <jiejing.zhang@freescale.com> |
| 7 | * |
| 8 | * Based on mcs5000_ts.c |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
Jiejing Zhang | d70d43d | 2011-08-20 14:38:01 -0700 | [diff] [blame] | 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
Zhang Jiejing | 4203306 | 2011-04-11 23:48:23 -0700 | [diff] [blame] | 14 | */ |
| 15 | |
| 16 | /* |
| 17 | * This driver aims to support the series of MAXI touch chips max11801 |
| 18 | * through max11803. The main difference between these 4 chips can be |
| 19 | * found in the table below: |
| 20 | * ----------------------------------------------------- |
| 21 | * | CHIP | AUTO MODE SUPPORT(FIFO) | INTERFACE | |
| 22 | * |----------------------------------------------------| |
| 23 | * | max11800 | YES | SPI | |
| 24 | * | max11801 | YES | I2C | |
| 25 | * | max11802 | NO | SPI | |
| 26 | * | max11803 | NO | I2C | |
| 27 | * ------------------------------------------------------ |
| 28 | * |
| 29 | * Currently, this driver only supports max11801. |
| 30 | * |
| 31 | * Data Sheet: |
| 32 | * http://www.maxim-ic.com/datasheet/index.mvp/id/5943 |
| 33 | */ |
| 34 | |
| 35 | #include <linux/module.h> |
| 36 | #include <linux/init.h> |
| 37 | #include <linux/i2c.h> |
| 38 | #include <linux/interrupt.h> |
| 39 | #include <linux/input.h> |
| 40 | #include <linux/slab.h> |
| 41 | #include <linux/bitops.h> |
| 42 | |
| 43 | /* Register Address define */ |
| 44 | #define GENERNAL_STATUS_REG 0x00 |
| 45 | #define GENERNAL_CONF_REG 0x01 |
| 46 | #define MESURE_RES_CONF_REG 0x02 |
| 47 | #define MESURE_AVER_CONF_REG 0x03 |
| 48 | #define ADC_SAMPLE_TIME_CONF_REG 0x04 |
| 49 | #define PANEL_SETUPTIME_CONF_REG 0x05 |
| 50 | #define DELAY_CONVERSION_CONF_REG 0x06 |
| 51 | #define TOUCH_DETECT_PULLUP_CONF_REG 0x07 |
| 52 | #define AUTO_MODE_TIME_CONF_REG 0x08 /* only for max11800/max11801 */ |
| 53 | #define APERTURE_CONF_REG 0x09 /* only for max11800/max11801 */ |
| 54 | #define AUX_MESURE_CONF_REG 0x0a |
| 55 | #define OP_MODE_CONF_REG 0x0b |
| 56 | |
| 57 | /* FIFO is found only in max11800 and max11801 */ |
| 58 | #define FIFO_RD_CMD (0x50 << 1) |
| 59 | #define MAX11801_FIFO_INT (1 << 2) |
| 60 | #define MAX11801_FIFO_OVERFLOW (1 << 3) |
| 61 | |
| 62 | #define XY_BUFSIZE 4 |
| 63 | #define XY_BUF_OFFSET 4 |
| 64 | |
| 65 | #define MAX11801_MAX_X 0xfff |
| 66 | #define MAX11801_MAX_Y 0xfff |
| 67 | |
| 68 | #define MEASURE_TAG_OFFSET 2 |
| 69 | #define MEASURE_TAG_MASK (3 << MEASURE_TAG_OFFSET) |
| 70 | #define EVENT_TAG_OFFSET 0 |
| 71 | #define EVENT_TAG_MASK (3 << EVENT_TAG_OFFSET) |
| 72 | #define MEASURE_X_TAG (0 << MEASURE_TAG_OFFSET) |
| 73 | #define MEASURE_Y_TAG (1 << MEASURE_TAG_OFFSET) |
| 74 | |
| 75 | /* These are the state of touch event state machine */ |
| 76 | enum { |
| 77 | EVENT_INIT, |
| 78 | EVENT_MIDDLE, |
| 79 | EVENT_RELEASE, |
| 80 | EVENT_FIFO_END |
| 81 | }; |
| 82 | |
| 83 | struct max11801_data { |
| 84 | struct i2c_client *client; |
| 85 | struct input_dev *input_dev; |
| 86 | }; |
| 87 | |
| 88 | static u8 read_register(struct i2c_client *client, int addr) |
| 89 | { |
| 90 | /* XXX: The chip ignores LSB of register address */ |
| 91 | return i2c_smbus_read_byte_data(client, addr << 1); |
| 92 | } |
| 93 | |
| 94 | static int max11801_write_reg(struct i2c_client *client, int addr, int data) |
| 95 | { |
| 96 | /* XXX: The chip ignores LSB of register address */ |
| 97 | return i2c_smbus_write_byte_data(client, addr << 1, data); |
| 98 | } |
| 99 | |
| 100 | static irqreturn_t max11801_ts_interrupt(int irq, void *dev_id) |
| 101 | { |
| 102 | struct max11801_data *data = dev_id; |
| 103 | struct i2c_client *client = data->client; |
| 104 | int status, i, ret; |
| 105 | u8 buf[XY_BUFSIZE]; |
| 106 | int x = -1; |
| 107 | int y = -1; |
| 108 | |
| 109 | status = read_register(data->client, GENERNAL_STATUS_REG); |
| 110 | |
| 111 | if (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) { |
| 112 | status = read_register(data->client, GENERNAL_STATUS_REG); |
| 113 | |
| 114 | ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD, |
| 115 | XY_BUFSIZE, buf); |
| 116 | |
| 117 | /* |
| 118 | * We should get 4 bytes buffer that contains X,Y |
| 119 | * and event tag |
| 120 | */ |
| 121 | if (ret < XY_BUFSIZE) |
| 122 | goto out; |
| 123 | |
| 124 | for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) { |
| 125 | if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_X_TAG) |
| 126 | x = (buf[i] << XY_BUF_OFFSET) + |
| 127 | (buf[i + 1] >> XY_BUF_OFFSET); |
| 128 | else if ((buf[i + 1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG) |
| 129 | y = (buf[i] << XY_BUF_OFFSET) + |
| 130 | (buf[i + 1] >> XY_BUF_OFFSET); |
| 131 | } |
| 132 | |
| 133 | if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK)) |
| 134 | goto out; |
| 135 | |
| 136 | switch (buf[1] & EVENT_TAG_MASK) { |
| 137 | case EVENT_INIT: |
| 138 | /* fall through */ |
| 139 | case EVENT_MIDDLE: |
| 140 | input_report_abs(data->input_dev, ABS_X, x); |
| 141 | input_report_abs(data->input_dev, ABS_Y, y); |
| 142 | input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1); |
| 143 | input_sync(data->input_dev); |
| 144 | break; |
| 145 | |
| 146 | case EVENT_RELEASE: |
| 147 | input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0); |
| 148 | input_sync(data->input_dev); |
| 149 | break; |
| 150 | |
| 151 | case EVENT_FIFO_END: |
| 152 | break; |
| 153 | } |
| 154 | } |
| 155 | out: |
| 156 | return IRQ_HANDLED; |
| 157 | } |
| 158 | |
| 159 | static void __devinit max11801_ts_phy_init(struct max11801_data *data) |
| 160 | { |
| 161 | struct i2c_client *client = data->client; |
| 162 | |
| 163 | /* Average X,Y, take 16 samples, average eight media sample */ |
| 164 | max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff); |
| 165 | /* X,Y panel setup time set to 20us */ |
| 166 | max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11); |
| 167 | /* Rough pullup time (2uS), Fine pullup time (10us) */ |
| 168 | max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10); |
| 169 | /* Auto mode init period = 5ms , scan period = 5ms*/ |
| 170 | max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa); |
| 171 | /* Aperture X,Y set to +- 4LSB */ |
| 172 | max11801_write_reg(client, APERTURE_CONF_REG, 0x33); |
| 173 | /* Enable Power, enable Automode, enable Aperture, enable Average X,Y */ |
| 174 | max11801_write_reg(client, OP_MODE_CONF_REG, 0x36); |
| 175 | } |
| 176 | |
| 177 | static int __devinit max11801_ts_probe(struct i2c_client *client, |
| 178 | const struct i2c_device_id *id) |
| 179 | { |
| 180 | struct max11801_data *data; |
| 181 | struct input_dev *input_dev; |
| 182 | int error; |
| 183 | |
| 184 | data = kzalloc(sizeof(struct max11801_data), GFP_KERNEL); |
| 185 | input_dev = input_allocate_device(); |
| 186 | if (!data || !input_dev) { |
| 187 | dev_err(&client->dev, "Failed to allocate memory\n"); |
| 188 | error = -ENOMEM; |
| 189 | goto err_free_mem; |
| 190 | } |
| 191 | |
| 192 | data->client = client; |
| 193 | data->input_dev = input_dev; |
| 194 | |
| 195 | input_dev->name = "max11801_ts"; |
| 196 | input_dev->id.bustype = BUS_I2C; |
| 197 | input_dev->dev.parent = &client->dev; |
| 198 | |
| 199 | __set_bit(EV_ABS, input_dev->evbit); |
| 200 | __set_bit(EV_KEY, input_dev->evbit); |
| 201 | __set_bit(BTN_TOUCH, input_dev->keybit); |
| 202 | input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0); |
| 203 | input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0); |
| 204 | input_set_drvdata(input_dev, data); |
| 205 | |
| 206 | max11801_ts_phy_init(data); |
| 207 | |
| 208 | error = request_threaded_irq(client->irq, NULL, max11801_ts_interrupt, |
| 209 | IRQF_TRIGGER_LOW | IRQF_ONESHOT, |
| 210 | "max11801_ts", data); |
| 211 | if (error) { |
| 212 | dev_err(&client->dev, "Failed to register interrupt\n"); |
| 213 | goto err_free_mem; |
| 214 | } |
| 215 | |
| 216 | error = input_register_device(data->input_dev); |
| 217 | if (error) |
| 218 | goto err_free_irq; |
| 219 | |
| 220 | i2c_set_clientdata(client, data); |
| 221 | return 0; |
| 222 | |
| 223 | err_free_irq: |
| 224 | free_irq(client->irq, data); |
| 225 | err_free_mem: |
| 226 | input_free_device(input_dev); |
| 227 | kfree(data); |
| 228 | return error; |
| 229 | } |
| 230 | |
| 231 | static __devexit int max11801_ts_remove(struct i2c_client *client) |
| 232 | { |
| 233 | struct max11801_data *data = i2c_get_clientdata(client); |
| 234 | |
| 235 | free_irq(client->irq, data); |
| 236 | input_unregister_device(data->input_dev); |
| 237 | kfree(data); |
| 238 | |
| 239 | return 0; |
| 240 | } |
| 241 | |
| 242 | static const struct i2c_device_id max11801_ts_id[] = { |
| 243 | {"max11801", 0}, |
| 244 | { } |
| 245 | }; |
| 246 | MODULE_DEVICE_TABLE(i2c, max11801_ts_id); |
| 247 | |
| 248 | static struct i2c_driver max11801_ts_driver = { |
| 249 | .driver = { |
| 250 | .name = "max11801_ts", |
| 251 | .owner = THIS_MODULE, |
| 252 | }, |
| 253 | .id_table = max11801_ts_id, |
| 254 | .probe = max11801_ts_probe, |
| 255 | .remove = __devexit_p(max11801_ts_remove), |
| 256 | }; |
| 257 | |
Axel Lin | 1b92c1c | 2012-03-16 23:05:41 -0700 | [diff] [blame] | 258 | module_i2c_driver(max11801_ts_driver); |
Zhang Jiejing | 4203306 | 2011-04-11 23:48:23 -0700 | [diff] [blame] | 259 | |
| 260 | MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>"); |
| 261 | MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller"); |
| 262 | MODULE_LICENSE("GPL"); |