1 /* 2 * Driver for EETI eGalax Multiple Touch Controller 3 * 4 * Copyright (C) 2011 Freescale Semiconductor, Inc. 5 * 6 * based on max11801_ts.c 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 /* EETI eGalax serial touch screen controller is a I2C based multiple 14 * touch screen controller, it supports 5 point multiple touch. */ 15 16 /* TODO: 17 - auto idle mode support 18 */ 19 20 #include <linux/module.h> 21 #include <linux/init.h> 22 #include <linux/i2c.h> 23 #include <linux/interrupt.h> 24 #include <linux/input.h> 25 #include <linux/irq.h> 26 #include <linux/gpio.h> 27 #include <linux/delay.h> 28 #include <linux/slab.h> 29 #include <linux/bitops.h> 30 #include <linux/input/mt.h> 31 #include <linux/of_gpio.h> 32 33 /* 34 * Mouse Mode: some panel may configure the controller to mouse mode, 35 * which can only report one point at a given time. 36 * This driver will ignore events in this mode. 37 */ 38 #define REPORT_MODE_MOUSE 0x1 39 /* 40 * Vendor Mode: this mode is used to transfer some vendor specific 41 * messages. 42 * This driver will ignore events in this mode. 43 */ 44 #define REPORT_MODE_VENDOR 0x3 45 /* Multiple Touch Mode */ 46 #define REPORT_MODE_MTTOUCH 0x4 47 48 #define MAX_SUPPORT_POINTS 5 49 50 #define EVENT_VALID_OFFSET 7 51 #define EVENT_VALID_MASK (0x1 << EVENT_VALID_OFFSET) 52 #define EVENT_ID_OFFSET 2 53 #define EVENT_ID_MASK (0xf << EVENT_ID_OFFSET) 54 #define EVENT_IN_RANGE (0x1 << 1) 55 #define EVENT_DOWN_UP (0X1 << 0) 56 57 #define MAX_I2C_DATA_LEN 10 58 59 #define EGALAX_MAX_X 32760 60 #define EGALAX_MAX_Y 32760 61 #define EGALAX_MAX_TRIES 100 62 63 struct egalax_ts { 64 struct i2c_client *client; 65 struct input_dev *input_dev; 66 }; 67 68 static irqreturn_t egalax_ts_interrupt(int irq, void *dev_id) 69 { 70 struct egalax_ts *ts = dev_id; 71 struct input_dev *input_dev = ts->input_dev; 72 struct i2c_client *client = ts->client; 73 u8 buf[MAX_I2C_DATA_LEN]; 74 int id, ret, x, y, z; 75 int tries = 0; 76 bool down, valid; 77 u8 state; 78 79 do { 80 ret = i2c_master_recv(client, buf, MAX_I2C_DATA_LEN); 81 } while (ret == -EAGAIN && tries++ < EGALAX_MAX_TRIES); 82 83 if (ret < 0) 84 return IRQ_HANDLED; 85 86 if (buf[0] != REPORT_MODE_MTTOUCH) { 87 /* ignore mouse events and vendor events */ 88 return IRQ_HANDLED; 89 } 90 91 state = buf[1]; 92 x = (buf[3] << 8) | buf[2]; 93 y = (buf[5] << 8) | buf[4]; 94 z = (buf[7] << 8) | buf[6]; 95 96 valid = state & EVENT_VALID_MASK; 97 id = (state & EVENT_ID_MASK) >> EVENT_ID_OFFSET; 98 down = state & EVENT_DOWN_UP; 99 100 if (!valid || id > MAX_SUPPORT_POINTS) { 101 dev_dbg(&client->dev, "point invalid\n"); 102 return IRQ_HANDLED; 103 } 104 105 input_mt_slot(input_dev, id); 106 input_mt_report_slot_state(input_dev, MT_TOOL_FINGER, down); 107 108 dev_dbg(&client->dev, "%s id:%d x:%d y:%d z:%d", 109 down ? "down" : "up", id, x, y, z); 110 111 if (down) { 112 input_report_abs(input_dev, ABS_MT_POSITION_X, x); 113 input_report_abs(input_dev, ABS_MT_POSITION_Y, y); 114 input_report_abs(input_dev, ABS_MT_PRESSURE, z); 115 } 116 117 input_mt_report_pointer_emulation(input_dev, true); 118 input_sync(input_dev); 119 120 return IRQ_HANDLED; 121 } 122 123 /* wake up controller by an falling edge of interrupt gpio. */ 124 static int egalax_wake_up_device(struct i2c_client *client) 125 { 126 struct device_node *np = client->dev.of_node; 127 int gpio; 128 int ret; 129 130 if (!np) 131 return -ENODEV; 132 133 gpio = of_get_named_gpio(np, "wakeup-gpios", 0); 134 if (!gpio_is_valid(gpio)) 135 return -ENODEV; 136 137 ret = gpio_request(gpio, "egalax_irq"); 138 if (ret < 0) { 139 dev_err(&client->dev, 140 "request gpio failed, cannot wake up controller: %d\n", 141 ret); 142 return ret; 143 } 144 145 /* wake up controller via an falling edge on IRQ gpio. */ 146 gpio_direction_output(gpio, 0); 147 gpio_set_value(gpio, 1); 148 149 /* controller should be waken up, return irq. */ 150 gpio_direction_input(gpio); 151 gpio_free(gpio); 152 153 return 0; 154 } 155 156 static int egalax_firmware_version(struct i2c_client *client) 157 { 158 static const u8 cmd[MAX_I2C_DATA_LEN] = { 0x03, 0x03, 0xa, 0x01, 0x41 }; 159 int ret; 160 161 ret = i2c_master_send(client, cmd, MAX_I2C_DATA_LEN); 162 if (ret < 0) 163 return ret; 164 165 return 0; 166 } 167 168 static int egalax_ts_probe(struct i2c_client *client, 169 const struct i2c_device_id *id) 170 { 171 struct egalax_ts *ts; 172 struct input_dev *input_dev; 173 int error; 174 175 ts = devm_kzalloc(&client->dev, sizeof(struct egalax_ts), GFP_KERNEL); 176 if (!ts) { 177 dev_err(&client->dev, "Failed to allocate memory\n"); 178 return -ENOMEM; 179 } 180 181 input_dev = devm_input_allocate_device(&client->dev); 182 if (!input_dev) { 183 dev_err(&client->dev, "Failed to allocate memory\n"); 184 return -ENOMEM; 185 } 186 187 ts->client = client; 188 ts->input_dev = input_dev; 189 190 /* controller may be in sleep, wake it up. */ 191 error = egalax_wake_up_device(client); 192 if (error) { 193 dev_err(&client->dev, "Failed to wake up the controller\n"); 194 return error; 195 } 196 197 error = egalax_firmware_version(client); 198 if (error < 0) { 199 dev_err(&client->dev, "Failed to read firmware version\n"); 200 return error; 201 } 202 203 input_dev->name = "EETI eGalax Touch Screen"; 204 input_dev->id.bustype = BUS_I2C; 205 206 __set_bit(EV_ABS, input_dev->evbit); 207 __set_bit(EV_KEY, input_dev->evbit); 208 __set_bit(BTN_TOUCH, input_dev->keybit); 209 210 input_set_abs_params(input_dev, ABS_X, 0, EGALAX_MAX_X, 0, 0); 211 input_set_abs_params(input_dev, ABS_Y, 0, EGALAX_MAX_Y, 0, 0); 212 input_set_abs_params(input_dev, 213 ABS_MT_POSITION_X, 0, EGALAX_MAX_X, 0, 0); 214 input_set_abs_params(input_dev, 215 ABS_MT_POSITION_Y, 0, EGALAX_MAX_Y, 0, 0); 216 input_mt_init_slots(input_dev, MAX_SUPPORT_POINTS, 0); 217 218 input_set_drvdata(input_dev, ts); 219 220 error = devm_request_threaded_irq(&client->dev, client->irq, NULL, 221 egalax_ts_interrupt, 222 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 223 "egalax_ts", ts); 224 if (error < 0) { 225 dev_err(&client->dev, "Failed to register interrupt\n"); 226 return error; 227 } 228 229 error = input_register_device(ts->input_dev); 230 if (error) 231 return error; 232 233 i2c_set_clientdata(client, ts); 234 return 0; 235 } 236 237 static const struct i2c_device_id egalax_ts_id[] = { 238 { "egalax_ts", 0 }, 239 { } 240 }; 241 MODULE_DEVICE_TABLE(i2c, egalax_ts_id); 242 243 #ifdef CONFIG_PM_SLEEP 244 static int egalax_ts_suspend(struct device *dev) 245 { 246 static const u8 suspend_cmd[MAX_I2C_DATA_LEN] = { 247 0x3, 0x6, 0xa, 0x3, 0x36, 0x3f, 0x2, 0, 0, 0 248 }; 249 struct i2c_client *client = to_i2c_client(dev); 250 int ret; 251 252 ret = i2c_master_send(client, suspend_cmd, MAX_I2C_DATA_LEN); 253 return ret > 0 ? 0 : ret; 254 } 255 256 static int egalax_ts_resume(struct device *dev) 257 { 258 struct i2c_client *client = to_i2c_client(dev); 259 260 return egalax_wake_up_device(client); 261 } 262 #endif 263 264 static SIMPLE_DEV_PM_OPS(egalax_ts_pm_ops, egalax_ts_suspend, egalax_ts_resume); 265 266 static struct of_device_id egalax_ts_dt_ids[] = { 267 { .compatible = "eeti,egalax_ts" }, 268 { /* sentinel */ } 269 }; 270 271 static struct i2c_driver egalax_ts_driver = { 272 .driver = { 273 .name = "egalax_ts", 274 .owner = THIS_MODULE, 275 .pm = &egalax_ts_pm_ops, 276 .of_match_table = egalax_ts_dt_ids, 277 }, 278 .id_table = egalax_ts_id, 279 .probe = egalax_ts_probe, 280 }; 281 282 module_i2c_driver(egalax_ts_driver); 283 284 MODULE_AUTHOR("Freescale Semiconductor, Inc."); 285 MODULE_DESCRIPTION("Touchscreen driver for EETI eGalax touch controller"); 286 MODULE_LICENSE("GPL"); 287