1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ST1232 Touchscreen Controller Driver 4 * 5 * Copyright (C) 2010 Renesas Solutions Corp. 6 * Tony SIM <chinyeow.sim.xt@renesas.com> 7 * 8 * Using code from: 9 * - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c 10 * Copyright (C) 2007 Google, Inc. 11 */ 12 13 #include <linux/delay.h> 14 #include <linux/gpio/consumer.h> 15 #include <linux/i2c.h> 16 #include <linux/input.h> 17 #include <linux/input/mt.h> 18 #include <linux/input/touchscreen.h> 19 #include <linux/interrupt.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/pm_qos.h> 23 #include <linux/slab.h> 24 #include <linux/types.h> 25 #include <linux/input/touch-overlay.h> 26 27 #define ST1232_TS_NAME "st1232-ts" 28 #define ST1633_TS_NAME "st1633-ts" 29 30 #define REG_STATUS 0x01 /* Device Status | Error Code */ 31 32 #define STATUS_NORMAL 0x00 33 #define STATUS_INIT 0x01 34 #define STATUS_ERROR 0x02 35 #define STATUS_AUTO_TUNING 0x03 36 #define STATUS_IDLE 0x04 37 #define STATUS_POWER_DOWN 0x05 38 39 #define ERROR_NONE 0x00 40 #define ERROR_INVALID_ADDRESS 0x10 41 #define ERROR_INVALID_VALUE 0x20 42 #define ERROR_INVALID_PLATFORM 0x30 43 44 #define REG_XY_RESOLUTION 0x04 45 #define REG_XY_COORDINATES 0x12 46 #define ST_TS_MAX_FINGERS 10 47 48 struct st_chip_info { 49 bool have_z; 50 u16 max_area; 51 u16 max_fingers; 52 }; 53 54 struct st1232_ts_data { 55 struct i2c_client *client; 56 struct input_dev *input_dev; 57 struct touchscreen_properties prop; 58 struct dev_pm_qos_request low_latency_req; 59 struct gpio_desc *reset_gpio; 60 const struct st_chip_info *chip_info; 61 struct list_head touch_overlay_list; 62 int read_buf_len; 63 u8 *read_buf; 64 }; 65 66 static int st1232_ts_read_data(struct st1232_ts_data *ts, u8 reg, 67 unsigned int n) 68 { 69 struct i2c_client *client = ts->client; 70 struct i2c_msg msg[] = { 71 { 72 .addr = client->addr, 73 .len = sizeof(reg), 74 .buf = ®, 75 }, 76 { 77 .addr = client->addr, 78 .flags = I2C_M_RD | I2C_M_DMA_SAFE, 79 .len = n, 80 .buf = ts->read_buf, 81 } 82 }; 83 int ret; 84 85 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg)); 86 if (ret != ARRAY_SIZE(msg)) 87 return ret < 0 ? ret : -EIO; 88 89 return 0; 90 } 91 92 static int st1232_ts_wait_ready(struct st1232_ts_data *ts) 93 { 94 unsigned int retries; 95 int error; 96 97 for (retries = 100; retries; retries--) { 98 error = st1232_ts_read_data(ts, REG_STATUS, 1); 99 if (!error) { 100 switch (ts->read_buf[0]) { 101 case STATUS_NORMAL | ERROR_NONE: 102 case STATUS_IDLE | ERROR_NONE: 103 return 0; 104 } 105 } 106 107 usleep_range(1000, 2000); 108 } 109 110 return -ENXIO; 111 } 112 113 static int st1232_ts_read_resolution(struct st1232_ts_data *ts, u16 *max_x, 114 u16 *max_y) 115 { 116 u8 *buf; 117 int error; 118 119 /* select resolution register */ 120 error = st1232_ts_read_data(ts, REG_XY_RESOLUTION, 3); 121 if (error) 122 return error; 123 124 buf = ts->read_buf; 125 126 *max_x = (((buf[0] & 0x0070) << 4) | buf[1]) - 1; 127 *max_y = (((buf[0] & 0x0007) << 8) | buf[2]) - 1; 128 129 return 0; 130 } 131 132 static int st1232_ts_parse_and_report(struct st1232_ts_data *ts) 133 { 134 struct input_dev *input = ts->input_dev; 135 struct input_mt_pos pos[ST_TS_MAX_FINGERS]; 136 u8 z[ST_TS_MAX_FINGERS]; 137 int slots[ST_TS_MAX_FINGERS]; 138 int n_contacts = 0; 139 int i; 140 141 for (i = 0; i < ts->chip_info->max_fingers; i++) { 142 u8 *buf = &ts->read_buf[i * 4]; 143 144 if (buf[0] & BIT(7)) { 145 unsigned int x = ((buf[0] & 0x70) << 4) | buf[1]; 146 unsigned int y = ((buf[0] & 0x07) << 8) | buf[2]; 147 148 touchscreen_set_mt_pos(&pos[n_contacts], 149 &ts->prop, x, y); 150 151 /* st1232 includes a z-axis / touch strength */ 152 if (ts->chip_info->have_z) 153 z[n_contacts] = ts->read_buf[i + 6]; 154 155 n_contacts++; 156 } 157 } 158 159 input_mt_assign_slots(input, slots, pos, n_contacts, 0); 160 for (i = 0; i < n_contacts; i++) { 161 if (touch_overlay_process_contact(&ts->touch_overlay_list, 162 input, &pos[i], slots[i])) 163 continue; 164 165 input_mt_slot(input, slots[i]); 166 input_mt_report_slot_state(input, MT_TOOL_FINGER, true); 167 input_report_abs(input, ABS_MT_POSITION_X, pos[i].x); 168 input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y); 169 if (ts->chip_info->have_z) 170 input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]); 171 } 172 173 touch_overlay_sync_frame(&ts->touch_overlay_list, input); 174 input_mt_sync_frame(input); 175 input_sync(input); 176 177 return n_contacts; 178 } 179 180 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id) 181 { 182 struct st1232_ts_data *ts = dev_id; 183 int count; 184 int error; 185 186 error = st1232_ts_read_data(ts, REG_XY_COORDINATES, ts->read_buf_len); 187 if (error) 188 goto out; 189 190 count = st1232_ts_parse_and_report(ts); 191 if (!count) { 192 if (ts->low_latency_req.dev) { 193 dev_pm_qos_remove_request(&ts->low_latency_req); 194 ts->low_latency_req.dev = NULL; 195 } 196 } else if (!ts->low_latency_req.dev) { 197 /* First contact, request 100 us latency. */ 198 dev_pm_qos_add_ancestor_request(&ts->client->dev, 199 &ts->low_latency_req, 200 DEV_PM_QOS_RESUME_LATENCY, 100); 201 } 202 203 out: 204 return IRQ_HANDLED; 205 } 206 207 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron) 208 { 209 if (ts->reset_gpio) 210 gpiod_set_value_cansleep(ts->reset_gpio, !poweron); 211 } 212 213 static void st1232_ts_power_off(void *data) 214 { 215 st1232_ts_power(data, false); 216 } 217 218 static const struct st_chip_info st1232_chip_info = { 219 .have_z = true, 220 .max_area = 0xff, 221 .max_fingers = 2, 222 }; 223 224 static const struct st_chip_info st1633_chip_info = { 225 .have_z = false, 226 .max_area = 0x00, 227 .max_fingers = 5, 228 }; 229 230 static int st1232_ts_probe(struct i2c_client *client) 231 { 232 const struct i2c_device_id *id = i2c_client_get_device_id(client); 233 const struct st_chip_info *match; 234 struct st1232_ts_data *ts; 235 struct input_dev *input_dev; 236 u16 max_x, max_y; 237 int error; 238 239 match = device_get_match_data(&client->dev); 240 if (!match && id) 241 match = (const void *)id->driver_data; 242 if (!match) { 243 dev_err(&client->dev, "unknown device model\n"); 244 return -ENODEV; 245 } 246 247 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 248 dev_err(&client->dev, "need I2C_FUNC_I2C\n"); 249 return -EIO; 250 } 251 252 if (!client->irq) { 253 dev_err(&client->dev, "no IRQ?\n"); 254 return -EINVAL; 255 } 256 257 ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL); 258 if (!ts) 259 return -ENOMEM; 260 261 ts->chip_info = match; 262 263 /* allocate a buffer according to the number of registers to read */ 264 ts->read_buf_len = ts->chip_info->max_fingers * 4; 265 ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL); 266 if (!ts->read_buf) 267 return -ENOMEM; 268 269 input_dev = devm_input_allocate_device(&client->dev); 270 if (!input_dev) 271 return -ENOMEM; 272 273 ts->client = client; 274 ts->input_dev = input_dev; 275 276 ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL, 277 GPIOD_OUT_HIGH); 278 if (IS_ERR(ts->reset_gpio)) { 279 error = PTR_ERR(ts->reset_gpio); 280 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n", 281 error); 282 return error; 283 } 284 285 st1232_ts_power(ts, true); 286 287 error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts); 288 if (error) { 289 dev_err(&client->dev, 290 "Failed to install power off action: %d\n", error); 291 return error; 292 } 293 294 input_dev->name = "st1232-touchscreen"; 295 input_dev->id.bustype = BUS_I2C; 296 297 /* Wait until device is ready */ 298 error = st1232_ts_wait_ready(ts); 299 if (error) 300 return error; 301 302 if (ts->chip_info->have_z) 303 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 304 ts->chip_info->max_area, 0, 0); 305 306 /* map overlay objects if defined in the device tree */ 307 INIT_LIST_HEAD(&ts->touch_overlay_list); 308 error = touch_overlay_map(&ts->touch_overlay_list, input_dev); 309 if (error) 310 return error; 311 312 if (touch_overlay_mapped_touchscreen(&ts->touch_overlay_list)) { 313 /* Read resolution from the overlay touchscreen if defined */ 314 touch_overlay_get_touchscreen_abs(&ts->touch_overlay_list, 315 &max_x, &max_y); 316 } else { 317 /* Read resolution from the chip */ 318 error = st1232_ts_read_resolution(ts, &max_x, &max_y); 319 if (error) { 320 dev_err(&client->dev, 321 "Failed to read resolution: %d\n", error); 322 return error; 323 } 324 } 325 326 input_set_abs_params(input_dev, ABS_MT_POSITION_X, 327 0, max_x, 0, 0); 328 input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 329 0, max_y, 0, 0); 330 331 touchscreen_parse_properties(input_dev, true, &ts->prop); 332 333 error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers, 334 INPUT_MT_DIRECT | INPUT_MT_TRACK | 335 INPUT_MT_DROP_UNUSED); 336 if (error) { 337 dev_err(&client->dev, "failed to initialize MT slots\n"); 338 return error; 339 } 340 341 error = devm_request_threaded_irq(&client->dev, client->irq, 342 NULL, st1232_ts_irq_handler, 343 IRQF_ONESHOT, 344 client->name, ts); 345 if (error) { 346 dev_err(&client->dev, "Failed to register interrupt\n"); 347 return error; 348 } 349 350 error = input_register_device(ts->input_dev); 351 if (error) { 352 dev_err(&client->dev, "Unable to register %s input device\n", 353 input_dev->name); 354 return error; 355 } 356 357 i2c_set_clientdata(client, ts); 358 359 return 0; 360 } 361 362 static int st1232_ts_suspend(struct device *dev) 363 { 364 struct i2c_client *client = to_i2c_client(dev); 365 struct st1232_ts_data *ts = i2c_get_clientdata(client); 366 367 disable_irq(client->irq); 368 369 if (!device_may_wakeup(&client->dev)) 370 st1232_ts_power(ts, false); 371 372 return 0; 373 } 374 375 static int st1232_ts_resume(struct device *dev) 376 { 377 struct i2c_client *client = to_i2c_client(dev); 378 struct st1232_ts_data *ts = i2c_get_clientdata(client); 379 380 if (!device_may_wakeup(&client->dev)) 381 st1232_ts_power(ts, true); 382 383 enable_irq(client->irq); 384 385 return 0; 386 } 387 388 static DEFINE_SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops, 389 st1232_ts_suspend, st1232_ts_resume); 390 391 static const struct i2c_device_id st1232_ts_id[] = { 392 { ST1232_TS_NAME, (unsigned long)&st1232_chip_info }, 393 { ST1633_TS_NAME, (unsigned long)&st1633_chip_info }, 394 { } 395 }; 396 MODULE_DEVICE_TABLE(i2c, st1232_ts_id); 397 398 static const struct of_device_id st1232_ts_dt_ids[] = { 399 { .compatible = "sitronix,st1232", .data = &st1232_chip_info }, 400 { .compatible = "sitronix,st1633", .data = &st1633_chip_info }, 401 { } 402 }; 403 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids); 404 405 static struct i2c_driver st1232_ts_driver = { 406 .probe = st1232_ts_probe, 407 .id_table = st1232_ts_id, 408 .driver = { 409 .name = ST1232_TS_NAME, 410 .of_match_table = st1232_ts_dt_ids, 411 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 412 .pm = pm_sleep_ptr(&st1232_ts_pm_ops), 413 }, 414 }; 415 416 module_i2c_driver(st1232_ts_driver); 417 418 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>"); 419 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>"); 420 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver"); 421 MODULE_LICENSE("GPL v2"); 422