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