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