1 /* 2 * Driver for ChipOne icn8318 i2c touchscreen controller 3 * 4 * Copyright (c) 2015 Red Hat Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * Red Hat authors: 12 * Hans de Goede <hdegoede@redhat.com> 13 */ 14 15 #include <linux/gpio/consumer.h> 16 #include <linux/interrupt.h> 17 #include <linux/i2c.h> 18 #include <linux/input.h> 19 #include <linux/input/mt.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 23 #define ICN8318_REG_POWER 4 24 #define ICN8318_REG_TOUCHDATA 16 25 26 #define ICN8318_POWER_ACTIVE 0 27 #define ICN8318_POWER_MONITOR 1 28 #define ICN8318_POWER_HIBERNATE 2 29 30 #define ICN8318_MAX_TOUCHES 5 31 32 struct icn8318_touch { 33 __u8 slot; 34 __be16 x; 35 __be16 y; 36 __u8 pressure; /* Seems more like finger width then pressure really */ 37 __u8 event; 38 /* The difference between 2 and 3 is unclear */ 39 #define ICN8318_EVENT_NO_DATA 1 /* No finger seen yet since wakeup */ 40 #define ICN8318_EVENT_UPDATE1 2 /* New or updated coordinates */ 41 #define ICN8318_EVENT_UPDATE2 3 /* New or updated coordinates */ 42 #define ICN8318_EVENT_END 4 /* Finger lifted */ 43 } __packed; 44 45 struct icn8318_touch_data { 46 __u8 softbutton; 47 __u8 touch_count; 48 struct icn8318_touch touches[ICN8318_MAX_TOUCHES]; 49 } __packed; 50 51 struct icn8318_data { 52 struct i2c_client *client; 53 struct input_dev *input; 54 struct gpio_desc *wake_gpio; 55 u32 max_x; 56 u32 max_y; 57 bool invert_x; 58 bool invert_y; 59 bool swap_x_y; 60 }; 61 62 static int icn8318_read_touch_data(struct i2c_client *client, 63 struct icn8318_touch_data *touch_data) 64 { 65 u8 reg = ICN8318_REG_TOUCHDATA; 66 struct i2c_msg msg[2] = { 67 { 68 .addr = client->addr, 69 .len = 1, 70 .buf = ® 71 }, 72 { 73 .addr = client->addr, 74 .flags = I2C_M_RD, 75 .len = sizeof(struct icn8318_touch_data), 76 .buf = (u8 *)touch_data 77 } 78 }; 79 80 return i2c_transfer(client->adapter, msg, 2); 81 } 82 83 static inline bool icn8318_touch_active(u8 event) 84 { 85 return (event == ICN8318_EVENT_UPDATE1) || 86 (event == ICN8318_EVENT_UPDATE2); 87 } 88 89 static irqreturn_t icn8318_irq(int irq, void *dev_id) 90 { 91 struct icn8318_data *data = dev_id; 92 struct device *dev = &data->client->dev; 93 struct icn8318_touch_data touch_data; 94 int i, ret, x, y; 95 96 ret = icn8318_read_touch_data(data->client, &touch_data); 97 if (ret < 0) { 98 dev_err(dev, "Error reading touch data: %d\n", ret); 99 return IRQ_HANDLED; 100 } 101 102 if (touch_data.softbutton) { 103 /* 104 * Other data is invalid when a softbutton is pressed. 105 * This needs some extra devicetree bindings to map the icn8318 106 * softbutton codes to evdev codes. Currently no known devices 107 * use this. 108 */ 109 return IRQ_HANDLED; 110 } 111 112 if (touch_data.touch_count > ICN8318_MAX_TOUCHES) { 113 dev_warn(dev, "Too much touches %d > %d\n", 114 touch_data.touch_count, ICN8318_MAX_TOUCHES); 115 touch_data.touch_count = ICN8318_MAX_TOUCHES; 116 } 117 118 for (i = 0; i < touch_data.touch_count; i++) { 119 struct icn8318_touch *touch = &touch_data.touches[i]; 120 bool act = icn8318_touch_active(touch->event); 121 122 input_mt_slot(data->input, touch->slot); 123 input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act); 124 if (!act) 125 continue; 126 127 x = be16_to_cpu(touch->x); 128 y = be16_to_cpu(touch->y); 129 130 if (data->invert_x) 131 x = data->max_x - x; 132 133 if (data->invert_y) 134 y = data->max_y - y; 135 136 if (!data->swap_x_y) { 137 input_event(data->input, EV_ABS, ABS_MT_POSITION_X, x); 138 input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, y); 139 } else { 140 input_event(data->input, EV_ABS, ABS_MT_POSITION_X, y); 141 input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, x); 142 } 143 } 144 145 input_mt_sync_frame(data->input); 146 input_sync(data->input); 147 148 return IRQ_HANDLED; 149 } 150 151 static int icn8318_start(struct input_dev *dev) 152 { 153 struct icn8318_data *data = input_get_drvdata(dev); 154 155 enable_irq(data->client->irq); 156 gpiod_set_value_cansleep(data->wake_gpio, 1); 157 158 return 0; 159 } 160 161 static void icn8318_stop(struct input_dev *dev) 162 { 163 struct icn8318_data *data = input_get_drvdata(dev); 164 165 disable_irq(data->client->irq); 166 i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER, 167 ICN8318_POWER_HIBERNATE); 168 gpiod_set_value_cansleep(data->wake_gpio, 0); 169 } 170 171 #ifdef CONFIG_PM_SLEEP 172 static int icn8318_suspend(struct device *dev) 173 { 174 struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev)); 175 176 mutex_lock(&data->input->mutex); 177 if (data->input->users) 178 icn8318_stop(data->input); 179 mutex_unlock(&data->input->mutex); 180 181 return 0; 182 } 183 184 static int icn8318_resume(struct device *dev) 185 { 186 struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev)); 187 188 mutex_lock(&data->input->mutex); 189 if (data->input->users) 190 icn8318_start(data->input); 191 mutex_unlock(&data->input->mutex); 192 193 return 0; 194 } 195 #endif 196 197 static SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume); 198 199 static int icn8318_probe(struct i2c_client *client, 200 const struct i2c_device_id *id) 201 { 202 struct device *dev = &client->dev; 203 struct device_node *np = dev->of_node; 204 struct icn8318_data *data; 205 struct input_dev *input; 206 u32 fuzz_x = 0, fuzz_y = 0; 207 int error; 208 209 if (!client->irq) { 210 dev_err(dev, "Error no irq specified\n"); 211 return -EINVAL; 212 } 213 214 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 215 if (!data) 216 return -ENOMEM; 217 218 data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW); 219 if (IS_ERR(data->wake_gpio)) { 220 error = PTR_ERR(data->wake_gpio); 221 if (error != -EPROBE_DEFER) 222 dev_err(dev, "Error getting wake gpio: %d\n", error); 223 return error; 224 } 225 226 if (of_property_read_u32(np, "touchscreen-size-x", &data->max_x) || 227 of_property_read_u32(np, "touchscreen-size-y", &data->max_y)) { 228 dev_err(dev, "Error touchscreen-size-x and/or -y missing\n"); 229 return -EINVAL; 230 } 231 232 /* Optional */ 233 of_property_read_u32(np, "touchscreen-fuzz-x", &fuzz_x); 234 of_property_read_u32(np, "touchscreen-fuzz-y", &fuzz_y); 235 data->invert_x = of_property_read_bool(np, "touchscreen-inverted-x"); 236 data->invert_y = of_property_read_bool(np, "touchscreen-inverted-y"); 237 data->swap_x_y = of_property_read_bool(np, "touchscreen-swapped-x-y"); 238 239 input = devm_input_allocate_device(dev); 240 if (!input) 241 return -ENOMEM; 242 243 input->name = client->name; 244 input->id.bustype = BUS_I2C; 245 input->open = icn8318_start; 246 input->close = icn8318_stop; 247 input->dev.parent = dev; 248 249 if (!data->swap_x_y) { 250 input_set_abs_params(input, ABS_MT_POSITION_X, 0, 251 data->max_x, fuzz_x, 0); 252 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 253 data->max_y, fuzz_y, 0); 254 } else { 255 input_set_abs_params(input, ABS_MT_POSITION_X, 0, 256 data->max_y, fuzz_y, 0); 257 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 258 data->max_x, fuzz_x, 0); 259 } 260 261 error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES, 262 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); 263 if (error) 264 return error; 265 266 data->client = client; 267 data->input = input; 268 input_set_drvdata(input, data); 269 270 error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq, 271 IRQF_ONESHOT, client->name, data); 272 if (error) { 273 dev_err(dev, "Error requesting irq: %d\n", error); 274 return error; 275 } 276 277 /* Stop device till opened */ 278 icn8318_stop(data->input); 279 280 error = input_register_device(input); 281 if (error) 282 return error; 283 284 i2c_set_clientdata(client, data); 285 286 return 0; 287 } 288 289 static const struct of_device_id icn8318_of_match[] = { 290 { .compatible = "chipone,icn8318" }, 291 { } 292 }; 293 MODULE_DEVICE_TABLE(of, icn8318_of_match); 294 295 /* This is useless for OF-enabled devices, but it is needed by I2C subsystem */ 296 static const struct i2c_device_id icn8318_i2c_id[] = { 297 { }, 298 }; 299 MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id); 300 301 static struct i2c_driver icn8318_driver = { 302 .driver = { 303 .name = "chipone_icn8318", 304 .pm = &icn8318_pm_ops, 305 .of_match_table = icn8318_of_match, 306 }, 307 .probe = icn8318_probe, 308 .id_table = icn8318_i2c_id, 309 }; 310 311 module_i2c_driver(icn8318_driver); 312 313 MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver"); 314 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 315 MODULE_LICENSE("GPL"); 316