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/interrupt.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/pm_qos.h>
  21 #include <linux/slab.h>
  22 #include <linux/types.h>
  23 #include <linux/input/touchscreen.h>
  24
  25 #define ST1232_TS_NAME  "st1232-ts"
  26 #define ST1633_TS_NAME  "st1633-ts"
  27
  28 struct st1232_ts_finger {
  29         u16 x;
  30         u16 y;
  31         u8 t;
  32         bool is_valid;
  33 };
  34
  35 struct st_chip_info {
  36         bool    have_z;
  37         u16     max_x;
  38         u16     max_y;
  39         u16     max_area;
  40         u16     max_fingers;
  41         u8      start_reg;
  42 };
  43
  44 struct st1232_ts_data {
  45         struct i2c_client *client;
  46         struct input_dev *input_dev;
  47         struct touchscreen_properties prop;
  48         struct dev_pm_qos_request low_latency_req;
  49         struct gpio_desc *reset_gpio;
  50         const struct st_chip_info *chip_info;
  51         int read_buf_len;
  52         u8 *read_buf;
  53         struct st1232_ts_finger *finger;
  54 };
  55
  56 static int st1232_ts_read_data(struct st1232_ts_data *ts)
  57 {
  58         struct st1232_ts_finger *finger = ts->finger;
  59         struct i2c_client *client = ts->client;
  60         struct i2c_msg msg[2];
  61         int error;
  62         int i, y;
  63         u8 start_reg = ts->chip_info->start_reg;
  64         u8 *buf = ts->read_buf;
  65
  66         /* read touchscreen data */
  67         msg[0].addr = client->addr;
  68         msg[0].flags = 0;
  69         msg[0].len = 1;
  70         msg[0].buf = &start_reg;
  71
  72         msg[1].addr = ts->client->addr;
  73         msg[1].flags = I2C_M_RD;
  74         msg[1].len = ts->read_buf_len;
  75         msg[1].buf = buf;
  76
  77         error = i2c_transfer(client->adapter, msg, 2);
  78         if (error < 0)
  79                 return error;
  80
  81         for (i = 0, y = 0; i < ts->chip_info->max_fingers; i++, y += 3) {
  82                 finger[i].is_valid = buf[i + y] >> 7;
  83                 if (finger[i].is_valid) {
  84                         finger[i].x = ((buf[i + y] & 0x0070) << 4) | buf[i + 1];
  85                         finger[i].y = ((buf[i + y] & 0x0007) << 8) | buf[i + 2];
  86
  87                         /* st1232 includes a z-axis / touch strength */
  88                         if (ts->chip_info->have_z)
  89                                 finger[i].t = buf[i + 6];
  90                 }
  91         }
  92
  93         return 0;
  94 }
  95
  96 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
  97 {
  98         struct st1232_ts_data *ts = dev_id;
  99         struct st1232_ts_finger *finger = ts->finger;
 100         struct input_dev *input_dev = ts->input_dev;
 101         int count = 0;
 102         int i, ret;
 103
 104         ret = st1232_ts_read_data(ts);
 105         if (ret < 0)
 106                 goto end;
 107
 108         /* multi touch protocol */
 109         for (i = 0; i < ts->chip_info->max_fingers; i++) {
 110                 if (!finger[i].is_valid)
 111                         continue;
 112
 113                 if (ts->chip_info->have_z)
 114                         input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
 115                                          finger[i].t);
 116
 117                 touchscreen_report_pos(input_dev, &ts->prop,
 118                                         finger[i].x, finger[i].y, true);
 119                 input_mt_sync(input_dev);
 120                 count++;
 121         }
 122
 123         /* SYN_MT_REPORT only if no contact */
 124         if (!count) {
 125                 input_mt_sync(input_dev);
 126                 if (ts->low_latency_req.dev) {
 127                         dev_pm_qos_remove_request(&ts->low_latency_req);
 128                         ts->low_latency_req.dev = NULL;
 129                 }
 130         } else if (!ts->low_latency_req.dev) {
 131                 /* First contact, request 100 us latency. */
 132                 dev_pm_qos_add_ancestor_request(&ts->client->dev,
 133                                                 &ts->low_latency_req,
 134                                                 DEV_PM_QOS_RESUME_LATENCY, 100);
 135         }
 136
 137         /* SYN_REPORT */
 138         input_sync(input_dev);
 139
 140 end:
 141         return IRQ_HANDLED;
 142 }
 143
 144 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
 145 {
 146         if (ts->reset_gpio)
 147                 gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
 148 }
 149
 150 static const struct st_chip_info st1232_chip_info = {
 151         .have_z         = true,
 152         .max_x          = 0x31f, /* 800 - 1 */
 153         .max_y          = 0x1df, /* 480 -1 */
 154         .max_area       = 0xff,
 155         .max_fingers    = 2,
 156         .start_reg      = 0x12,
 157 };
 158
 159 static const struct st_chip_info st1633_chip_info = {
 160         .have_z         = false,
 161         .max_x          = 0x13f, /* 320 - 1 */
 162         .max_y          = 0x1df, /* 480 -1 */
 163         .max_area       = 0x00,
 164         .max_fingers    = 5,
 165         .start_reg      = 0x12,
 166 };
 167
 168 static int st1232_ts_probe(struct i2c_client *client,
 169                            const struct i2c_device_id *id)
 170 {
 171         const struct st_chip_info *match;
 172         struct st1232_ts_data *ts;
 173         struct st1232_ts_finger *finger;
 174         struct input_dev *input_dev;
 175         int error;
 176
 177         match = device_get_match_data(&client->dev);
 178         if (!match && id)
 179                 match = (const void *)id->driver_data;
 180         if (!match) {
 181                 dev_err(&client->dev, "unknown device model\n");
 182                 return -ENODEV;
 183         }
 184
 185         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 186                 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
 187                 return -EIO;
 188         }
 189
 190         if (!client->irq) {
 191                 dev_err(&client->dev, "no IRQ?\n");
 192                 return -EINVAL;
 193         }
 194
 195         ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
 196         if (!ts)
 197                 return -ENOMEM;
 198
 199         ts->chip_info = match;
 200         ts->finger = devm_kcalloc(&client->dev,
 201                                   ts->chip_info->max_fingers, sizeof(*finger),
 202                                   GFP_KERNEL);
 203         if (!ts->finger)
 204                 return -ENOMEM;
 205
 206         /* allocate a buffer according to the number of registers to read */
 207         ts->read_buf_len = ts->chip_info->max_fingers * 4;
 208         ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
 209         if (!ts->read_buf)
 210                 return -ENOMEM;
 211
 212         input_dev = devm_input_allocate_device(&client->dev);
 213         if (!input_dev)
 214                 return -ENOMEM;
 215
 216         ts->client = client;
 217         ts->input_dev = input_dev;
 218
 219         ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
 220                                                  GPIOD_OUT_HIGH);
 221         if (IS_ERR(ts->reset_gpio)) {
 222                 error = PTR_ERR(ts->reset_gpio);
 223                 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
 224                         error);
 225                 return error;
 226         }
 227
 228         st1232_ts_power(ts, true);
 229
 230         input_dev->name = "st1232-touchscreen";
 231         input_dev->id.bustype = BUS_I2C;
 232         input_dev->dev.parent = &client->dev;
 233
 234         __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
 235         __set_bit(EV_SYN, input_dev->evbit);
 236         __set_bit(EV_KEY, input_dev->evbit);
 237         __set_bit(EV_ABS, input_dev->evbit);
 238
 239         if (ts->chip_info->have_z)
 240                 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 241                                      ts->chip_info->max_area, 0, 0);
 242
 243         input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 244                              0, ts->chip_info->max_x, 0, 0);
 245         input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 246                              0, ts->chip_info->max_y, 0, 0);
 247
 248         touchscreen_parse_properties(input_dev, true, &ts->prop);
 249
 250         error = devm_request_threaded_irq(&client->dev, client->irq,
 251                                           NULL, st1232_ts_irq_handler,
 252                                           IRQF_ONESHOT,
 253                                           client->name, ts);
 254         if (error) {
 255                 dev_err(&client->dev, "Failed to register interrupt\n");
 256                 return error;
 257         }
 258
 259         error = input_register_device(ts->input_dev);
 260         if (error) {
 261                 dev_err(&client->dev, "Unable to register %s input device\n",
 262                         input_dev->name);
 263                 return error;
 264         }
 265
 266         i2c_set_clientdata(client, ts);
 267         device_init_wakeup(&client->dev, 1);
 268
 269         return 0;
 270 }
 271
 272 static int st1232_ts_remove(struct i2c_client *client)
 273 {
 274         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 275
 276         st1232_ts_power(ts, false);
 277
 278         return 0;
 279 }
 280
 281 static int __maybe_unused st1232_ts_suspend(struct device *dev)
 282 {
 283         struct i2c_client *client = to_i2c_client(dev);
 284         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 285
 286         if (device_may_wakeup(&client->dev)) {
 287                 enable_irq_wake(client->irq);
 288         } else {
 289                 disable_irq(client->irq);
 290                 st1232_ts_power(ts, false);
 291         }
 292
 293         return 0;
 294 }
 295
 296 static int __maybe_unused st1232_ts_resume(struct device *dev)
 297 {
 298         struct i2c_client *client = to_i2c_client(dev);
 299         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 300
 301         if (device_may_wakeup(&client->dev)) {
 302                 disable_irq_wake(client->irq);
 303         } else {
 304                 st1232_ts_power(ts, true);
 305                 enable_irq(client->irq);
 306         }
 307
 308         return 0;
 309 }
 310
 311 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
 312                          st1232_ts_suspend, st1232_ts_resume);
 313
 314 static const struct i2c_device_id st1232_ts_id[] = {
 315         { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
 316         { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
 317         { }
 318 };
 319 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 320
 321 static const struct of_device_id st1232_ts_dt_ids[] = {
 322         { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
 323         { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
 324         { }
 325 };
 326 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
 327
 328 static struct i2c_driver st1232_ts_driver = {
 329         .probe          = st1232_ts_probe,
 330         .remove         = st1232_ts_remove,
 331         .id_table       = st1232_ts_id,
 332         .driver = {
 333                 .name   = ST1232_TS_NAME,
 334                 .of_match_table = st1232_ts_dt_ids,
 335                 .pm     = &st1232_ts_pm_ops,
 336         },
 337 };
 338
 339 module_i2c_driver(st1232_ts_driver);
 340
 341 MODULE_AUTHOR("Tony SIM <[email protected]>");
 342 MODULE_AUTHOR("Martin Kepplinger <[email protected]>");
 343 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 344 MODULE_LICENSE("GPL v2");