drivers/input/touchscreen/st1232.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ST1232 Touchscreen Controller Driver
   4  *
   5  * Copyright (C) 2010 Renesas Solutions Corp.
   6  *      Tony SIM <[email protected]>
   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    = &reg,
  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                            const struct i2c_device_id *id)
 225 {
 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 __maybe_unused 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 __maybe_unused 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 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     = &st1232_ts_pm_ops,
 394         },
 395 };
 396
 397 module_i2c_driver(st1232_ts_driver);
 398
 399 MODULE_AUTHOR("Tony SIM <[email protected]>");
 400 MODULE_AUTHOR("Martin Kepplinger <[email protected]>");
 401 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 402 MODULE_LICENSE("GPL v2");