rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * Driver for ELAN eKTF2127 i2c touchscreen controller |
| 3 | * |
| 4 | * For this driver the layout of the Chipone icn8318 i2c |
| 5 | * touchscreencontroller is used. |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * Author: |
| 13 | * Michel Verlaan <michel.verl@gmail.com> |
| 14 | * Siebren Vroegindeweij <siebren.vroegindeweij@hotmail.com> |
| 15 | * |
| 16 | * Original chipone_icn8318 driver: |
| 17 | * Hans de Goede <hdegoede@redhat.com> |
| 18 | */ |
| 19 | |
| 20 | #include <linux/gpio/consumer.h> |
| 21 | #include <linux/interrupt.h> |
| 22 | #include <linux/i2c.h> |
| 23 | #include <linux/input.h> |
| 24 | #include <linux/input/mt.h> |
| 25 | #include <linux/input/touchscreen.h> |
| 26 | #include <linux/module.h> |
| 27 | #include <linux/of.h> |
| 28 | #include <linux/delay.h> |
| 29 | |
| 30 | /* Packet header defines (first byte of data send / received) */ |
| 31 | #define EKTF2127_NOISE 0x40 |
| 32 | #define EKTF2127_RESPONSE 0x52 |
| 33 | #define EKTF2127_REQUEST 0x53 |
| 34 | #define EKTF2127_HELLO 0x55 |
| 35 | #define EKTF2127_REPORT 0x5d |
| 36 | #define EKTF2127_CALIB_DONE 0x66 |
| 37 | |
| 38 | /* Register defines (second byte of data send / received) */ |
| 39 | #define EKTF2127_ENV_NOISY 0x41 |
| 40 | #define EKTF2127_HEIGHT 0x60 |
| 41 | #define EKTF2127_WIDTH 0x63 |
| 42 | |
| 43 | /* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */ |
| 44 | #define EKTF2127_TOUCH_REPORT_SIZE 21 |
| 45 | #define EKTF2127_MAX_TOUCHES 5 |
| 46 | |
| 47 | struct ektf2127_ts { |
| 48 | struct i2c_client *client; |
| 49 | struct input_dev *input; |
| 50 | struct gpio_desc *power_gpios; |
| 51 | struct touchscreen_properties prop; |
| 52 | }; |
| 53 | |
| 54 | static void ektf2127_parse_coordinates(const u8* buf, unsigned int touch_count, |
| 55 | struct input_mt_pos *touches) |
| 56 | { |
| 57 | int index = 0; |
| 58 | int i; |
| 59 | |
| 60 | for (i = 0; i < touch_count; i++) { |
| 61 | index = 2 + i * 3; |
| 62 | |
| 63 | touches[i].x = (buf[index] & 0x0f); |
| 64 | touches[i].x <<= 8; |
| 65 | touches[i].x |= buf[index + 2]; |
| 66 | |
| 67 | touches[i].y = (buf[index] & 0xf0); |
| 68 | touches[i].y <<= 4; |
| 69 | touches[i].y |= buf[index + 1]; |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf) |
| 74 | { |
| 75 | struct input_mt_pos touches[EKTF2127_MAX_TOUCHES]; |
| 76 | int slots[EKTF2127_MAX_TOUCHES]; |
| 77 | unsigned int touch_count, i; |
| 78 | |
| 79 | touch_count = buf[1] & 0x07; |
| 80 | if (touch_count > EKTF2127_MAX_TOUCHES) { |
| 81 | dev_err(&ts->client->dev, |
| 82 | "Too many touches %d > %d\n", |
| 83 | touch_count, EKTF2127_MAX_TOUCHES); |
| 84 | touch_count = EKTF2127_MAX_TOUCHES; |
| 85 | } |
| 86 | |
| 87 | ektf2127_parse_coordinates(buf, touch_count, touches); |
| 88 | input_mt_assign_slots(ts->input, slots, touches, |
| 89 | touch_count, 0); |
| 90 | |
| 91 | for (i = 0; i < touch_count; i++) { |
| 92 | input_mt_slot(ts->input, slots[i]); |
| 93 | input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true); |
| 94 | touchscreen_report_pos(ts->input, &ts->prop, |
| 95 | touches[i].x, touches[i].y, true); |
| 96 | } |
| 97 | |
| 98 | input_mt_sync_frame(ts->input); |
| 99 | input_sync(ts->input); |
| 100 | } |
| 101 | |
| 102 | static irqreturn_t ektf2127_irq(int irq, void *dev_id) |
| 103 | { |
| 104 | struct ektf2127_ts *ts = dev_id; |
| 105 | struct device *dev = &ts->client->dev; |
| 106 | char buf[EKTF2127_TOUCH_REPORT_SIZE]; |
| 107 | int ret; |
| 108 | |
| 109 | ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE); |
| 110 | if (ret != EKTF2127_TOUCH_REPORT_SIZE) { |
| 111 | dev_err(dev, "Error reading touch data: %d\n", ret); |
| 112 | goto out; |
| 113 | } |
| 114 | |
| 115 | switch (buf[0]) { |
| 116 | case EKTF2127_REPORT: |
| 117 | ektf2127_report_event(ts, buf); |
| 118 | break; |
| 119 | |
| 120 | case EKTF2127_NOISE: |
| 121 | if (buf[1] == EKTF2127_ENV_NOISY) |
| 122 | dev_dbg(dev, "Environment is electrically noisy\n"); |
| 123 | break; |
| 124 | |
| 125 | case EKTF2127_HELLO: |
| 126 | case EKTF2127_CALIB_DONE: |
| 127 | break; |
| 128 | |
| 129 | default: |
| 130 | dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]); |
| 131 | break; |
| 132 | } |
| 133 | |
| 134 | out: |
| 135 | return IRQ_HANDLED; |
| 136 | } |
| 137 | |
| 138 | static int ektf2127_start(struct input_dev *dev) |
| 139 | { |
| 140 | struct ektf2127_ts *ts = input_get_drvdata(dev); |
| 141 | |
| 142 | enable_irq(ts->client->irq); |
| 143 | gpiod_set_value_cansleep(ts->power_gpios, 1); |
| 144 | |
| 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | static void ektf2127_stop(struct input_dev *dev) |
| 149 | { |
| 150 | struct ektf2127_ts *ts = input_get_drvdata(dev); |
| 151 | |
| 152 | disable_irq(ts->client->irq); |
| 153 | gpiod_set_value_cansleep(ts->power_gpios, 0); |
| 154 | } |
| 155 | |
| 156 | static int __maybe_unused ektf2127_suspend(struct device *dev) |
| 157 | { |
| 158 | struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); |
| 159 | |
| 160 | mutex_lock(&ts->input->mutex); |
| 161 | if (ts->input->users) |
| 162 | ektf2127_stop(ts->input); |
| 163 | mutex_unlock(&ts->input->mutex); |
| 164 | |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | static int __maybe_unused ektf2127_resume(struct device *dev) |
| 169 | { |
| 170 | struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); |
| 171 | |
| 172 | mutex_lock(&ts->input->mutex); |
| 173 | if (ts->input->users) |
| 174 | ektf2127_start(ts->input); |
| 175 | mutex_unlock(&ts->input->mutex); |
| 176 | |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | static SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend, |
| 181 | ektf2127_resume); |
| 182 | |
| 183 | static int ektf2127_query_dimension(struct i2c_client *client, bool width) |
| 184 | { |
| 185 | struct device *dev = &client->dev; |
| 186 | const char *what = width ? "width" : "height"; |
| 187 | u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; |
| 188 | u8 buf[4]; |
| 189 | int ret; |
| 190 | int error; |
| 191 | |
| 192 | /* Request dimension */ |
| 193 | buf[0] = EKTF2127_REQUEST; |
| 194 | buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; |
| 195 | buf[2] = 0x00; |
| 196 | buf[3] = 0x00; |
| 197 | ret = i2c_master_send(client, buf, sizeof(buf)); |
| 198 | if (ret != sizeof(buf)) { |
| 199 | error = ret < 0 ? ret : -EIO; |
| 200 | dev_err(dev, "Failed to request %s: %d\n", what, error); |
| 201 | return error; |
| 202 | } |
| 203 | |
| 204 | msleep(20); |
| 205 | |
| 206 | /* Read response */ |
| 207 | ret = i2c_master_recv(client, buf, sizeof(buf)); |
| 208 | if (ret != sizeof(buf)) { |
| 209 | error = ret < 0 ? ret : -EIO; |
| 210 | dev_err(dev, "Failed to receive %s data: %d\n", what, error); |
| 211 | return error; |
| 212 | } |
| 213 | |
| 214 | if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) { |
| 215 | dev_err(dev, "Unexpected %s data: %#02x %#02x\n", |
| 216 | what, buf[0], buf[1]); |
| 217 | return -EIO; |
| 218 | } |
| 219 | |
| 220 | return (((buf[3] & 0xf0) << 4) | buf[2]) - 1; |
| 221 | } |
| 222 | |
| 223 | static int ektf2127_probe(struct i2c_client *client, |
| 224 | const struct i2c_device_id *id) |
| 225 | { |
| 226 | struct device *dev = &client->dev; |
| 227 | struct ektf2127_ts *ts; |
| 228 | struct input_dev *input; |
| 229 | u8 buf[4]; |
| 230 | int max_x, max_y; |
| 231 | int error; |
| 232 | |
| 233 | if (!client->irq) { |
| 234 | dev_err(dev, "Error no irq specified\n"); |
| 235 | return -EINVAL; |
| 236 | } |
| 237 | |
| 238 | ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); |
| 239 | if (!ts) |
| 240 | return -ENOMEM; |
| 241 | |
| 242 | /* This requests the gpio *and* turns on the touchscreen controller */ |
| 243 | ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH); |
| 244 | if (IS_ERR(ts->power_gpios)) { |
| 245 | error = PTR_ERR(ts->power_gpios); |
| 246 | if (error != -EPROBE_DEFER) |
| 247 | dev_err(dev, "Error getting power gpio: %d\n", error); |
| 248 | return error; |
| 249 | } |
| 250 | |
| 251 | input = devm_input_allocate_device(dev); |
| 252 | if (!input) |
| 253 | return -ENOMEM; |
| 254 | |
| 255 | input->name = client->name; |
| 256 | input->id.bustype = BUS_I2C; |
| 257 | input->open = ektf2127_start; |
| 258 | input->close = ektf2127_stop; |
| 259 | |
| 260 | ts->client = client; |
| 261 | |
| 262 | /* Read hello (ignore result, depends on initial power state) */ |
| 263 | msleep(20); |
| 264 | i2c_master_recv(ts->client, buf, sizeof(buf)); |
| 265 | |
| 266 | /* Read resolution from chip */ |
| 267 | max_x = ektf2127_query_dimension(client, true); |
| 268 | if (max_x < 0) |
| 269 | return max_x; |
| 270 | |
| 271 | max_y = ektf2127_query_dimension(client, false); |
| 272 | if (max_y < 0) |
| 273 | return max_y; |
| 274 | |
| 275 | input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0); |
| 276 | input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0); |
| 277 | touchscreen_parse_properties(input, true, &ts->prop); |
| 278 | |
| 279 | error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES, |
| 280 | INPUT_MT_DIRECT | |
| 281 | INPUT_MT_DROP_UNUSED | |
| 282 | INPUT_MT_TRACK); |
| 283 | if (error) |
| 284 | return error; |
| 285 | |
| 286 | ts->input = input; |
| 287 | input_set_drvdata(input, ts); |
| 288 | |
| 289 | error = devm_request_threaded_irq(dev, client->irq, |
| 290 | NULL, ektf2127_irq, |
| 291 | IRQF_ONESHOT, client->name, ts); |
| 292 | if (error) { |
| 293 | dev_err(dev, "Error requesting irq: %d\n", error); |
| 294 | return error; |
| 295 | } |
| 296 | |
| 297 | /* Stop device till opened */ |
| 298 | ektf2127_stop(ts->input); |
| 299 | |
| 300 | error = input_register_device(input); |
| 301 | if (error) |
| 302 | return error; |
| 303 | |
| 304 | i2c_set_clientdata(client, ts); |
| 305 | |
| 306 | return 0; |
| 307 | } |
| 308 | |
| 309 | #ifdef CONFIG_OF |
| 310 | static const struct of_device_id ektf2127_of_match[] = { |
| 311 | { .compatible = "elan,ektf2127" }, |
| 312 | {} |
| 313 | }; |
| 314 | MODULE_DEVICE_TABLE(of, ektf2127_of_match); |
| 315 | #endif |
| 316 | |
| 317 | static const struct i2c_device_id ektf2127_i2c_id[] = { |
| 318 | { "ektf2127", 0 }, |
| 319 | {} |
| 320 | }; |
| 321 | MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id); |
| 322 | |
| 323 | static struct i2c_driver ektf2127_driver = { |
| 324 | .driver = { |
| 325 | .name = "elan_ektf2127", |
| 326 | .pm = &ektf2127_pm_ops, |
| 327 | .of_match_table = of_match_ptr(ektf2127_of_match), |
| 328 | }, |
| 329 | .probe = ektf2127_probe, |
| 330 | .id_table = ektf2127_i2c_id, |
| 331 | }; |
| 332 | module_i2c_driver(ektf2127_driver); |
| 333 | |
| 334 | MODULE_DESCRIPTION("ELAN eKTF2127 I2C Touchscreen Driver"); |
| 335 | MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij"); |
| 336 | MODULE_LICENSE("GPL"); |