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 <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/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) |
  85                                         buf[i + y + 1];
  86                         finger[i].y = ((buf[i + y] & 0x0007) << 8) |
  87                                         buf[i + y + 2];
  88
  89                         /* st1232 includes a z-axis / touch strength */
  90                         if (ts->chip_info->have_z)
  91                                 finger[i].t = buf[i + 6];
  92                 }
  93         }
  94
  95         return 0;
  96 }
  97
  98 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
  99 {
 100         struct st1232_ts_data *ts = dev_id;
 101         struct st1232_ts_finger *finger = ts->finger;
 102         struct input_dev *input_dev = ts->input_dev;
 103         int count = 0;
 104         int i, ret;
 105
 106         ret = st1232_ts_read_data(ts);
 107         if (ret < 0)
 108                 goto end;
 109
 110         /* multi touch protocol */
 111         for (i = 0; i < ts->chip_info->max_fingers; i++) {
 112                 if (!finger[i].is_valid)
 113                         continue;
 114
 115                 if (ts->chip_info->have_z)
 116                         input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
 117                                          finger[i].t);
 118
 119                 touchscreen_report_pos(input_dev, &ts->prop,
 120                                         finger[i].x, finger[i].y, true);
 121                 input_mt_sync(input_dev);
 122                 count++;
 123         }
 124
 125         /* SYN_MT_REPORT only if no contact */
 126         if (!count) {
 127                 input_mt_sync(input_dev);
 128                 if (ts->low_latency_req.dev) {
 129                         dev_pm_qos_remove_request(&ts->low_latency_req);
 130                         ts->low_latency_req.dev = NULL;
 131                 }
 132         } else if (!ts->low_latency_req.dev) {
 133                 /* First contact, request 100 us latency. */
 134                 dev_pm_qos_add_ancestor_request(&ts->client->dev,
 135                                                 &ts->low_latency_req,
 136                                                 DEV_PM_QOS_RESUME_LATENCY, 100);
 137         }
 138
 139         /* SYN_REPORT */
 140         input_sync(input_dev);
 141
 142 end:
 143         return IRQ_HANDLED;
 144 }
 145
 146 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
 147 {
 148         if (ts->reset_gpio)
 149                 gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
 150 }
 151
 152 static void st1232_ts_power_off(void *data)
 153 {
 154         st1232_ts_power(data, false);
 155 }
 156
 157 static const struct st_chip_info st1232_chip_info = {
 158         .have_z         = true,
 159         .max_x          = 0x31f, /* 800 - 1 */
 160         .max_y          = 0x1df, /* 480 -1 */
 161         .max_area       = 0xff,
 162         .max_fingers    = 2,
 163         .start_reg      = 0x12,
 164 };
 165
 166 static const struct st_chip_info st1633_chip_info = {
 167         .have_z         = false,
 168         .max_x          = 0x13f, /* 320 - 1 */
 169         .max_y          = 0x1df, /* 480 -1 */
 170         .max_area       = 0x00,
 171         .max_fingers    = 5,
 172         .start_reg      = 0x12,
 173 };
 174
 175 static int st1232_ts_probe(struct i2c_client *client,
 176                            const struct i2c_device_id *id)
 177 {
 178         const struct st_chip_info *match;
 179         struct st1232_ts_data *ts;
 180         struct st1232_ts_finger *finger;
 181         struct input_dev *input_dev;
 182         int error;
 183
 184         match = device_get_match_data(&client->dev);
 185         if (!match && id)
 186                 match = (const void *)id->driver_data;
 187         if (!match) {
 188                 dev_err(&client->dev, "unknown device model\n");
 189                 return -ENODEV;
 190         }
 191
 192         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 193                 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
 194                 return -EIO;
 195         }
 196
 197         if (!client->irq) {
 198                 dev_err(&client->dev, "no IRQ?\n");
 199                 return -EINVAL;
 200         }
 201
 202         ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
 203         if (!ts)
 204                 return -ENOMEM;
 205
 206         ts->chip_info = match;
 207         ts->finger = devm_kcalloc(&client->dev,
 208                                   ts->chip_info->max_fingers, sizeof(*finger),
 209                                   GFP_KERNEL);
 210         if (!ts->finger)
 211                 return -ENOMEM;
 212
 213         /* allocate a buffer according to the number of registers to read */
 214         ts->read_buf_len = ts->chip_info->max_fingers * 4;
 215         ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
 216         if (!ts->read_buf)
 217                 return -ENOMEM;
 218
 219         input_dev = devm_input_allocate_device(&client->dev);
 220         if (!input_dev)
 221                 return -ENOMEM;
 222
 223         ts->client = client;
 224         ts->input_dev = input_dev;
 225
 226         ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
 227                                                  GPIOD_OUT_HIGH);
 228         if (IS_ERR(ts->reset_gpio)) {
 229                 error = PTR_ERR(ts->reset_gpio);
 230                 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
 231                         error);
 232                 return error;
 233         }
 234
 235         st1232_ts_power(ts, true);
 236
 237         error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
 238         if (error) {
 239                 dev_err(&client->dev,
 240                         "Failed to install power off action: %d\n", error);
 241                 return error;
 242         }
 243
 244         input_dev->name = "st1232-touchscreen";
 245         input_dev->id.bustype = BUS_I2C;
 246         input_dev->dev.parent = &client->dev;
 247
 248         __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
 249         __set_bit(EV_SYN, input_dev->evbit);
 250         __set_bit(EV_KEY, input_dev->evbit);
 251         __set_bit(EV_ABS, input_dev->evbit);
 252
 253         if (ts->chip_info->have_z)
 254                 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 255                                      ts->chip_info->max_area, 0, 0);
 256
 257         input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 258                              0, ts->chip_info->max_x, 0, 0);
 259         input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 260                              0, ts->chip_info->max_y, 0, 0);
 261
 262         touchscreen_parse_properties(input_dev, true, &ts->prop);
 263
 264         error = devm_request_threaded_irq(&client->dev, client->irq,
 265                                           NULL, st1232_ts_irq_handler,
 266                                           IRQF_ONESHOT,
 267                                           client->name, ts);
 268         if (error) {
 269                 dev_err(&client->dev, "Failed to register interrupt\n");
 270                 return error;
 271         }
 272
 273         error = input_register_device(ts->input_dev);
 274         if (error) {
 275                 dev_err(&client->dev, "Unable to register %s input device\n",
 276                         input_dev->name);
 277                 return error;
 278         }
 279
 280         i2c_set_clientdata(client, ts);
 281         device_init_wakeup(&client->dev, 1);
 282
 283         return 0;
 284 }
 285
 286 static int __maybe_unused st1232_ts_suspend(struct device *dev)
 287 {
 288         struct i2c_client *client = to_i2c_client(dev);
 289         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 290
 291         if (device_may_wakeup(&client->dev)) {
 292                 enable_irq_wake(client->irq);
 293         } else {
 294                 disable_irq(client->irq);
 295                 st1232_ts_power(ts, false);
 296         }
 297
 298         return 0;
 299 }
 300
 301 static int __maybe_unused st1232_ts_resume(struct device *dev)
 302 {
 303         struct i2c_client *client = to_i2c_client(dev);
 304         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 305
 306         if (device_may_wakeup(&client->dev)) {
 307                 disable_irq_wake(client->irq);
 308         } else {
 309                 st1232_ts_power(ts, true);
 310                 enable_irq(client->irq);
 311         }
 312
 313         return 0;
 314 }
 315
 316 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
 317                          st1232_ts_suspend, st1232_ts_resume);
 318
 319 static const struct i2c_device_id st1232_ts_id[] = {
 320         { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
 321         { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
 322         { }
 323 };
 324 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 325
 326 static const struct of_device_id st1232_ts_dt_ids[] = {
 327         { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
 328         { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
 329         { }
 330 };
 331 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
 332
 333 static struct i2c_driver st1232_ts_driver = {
 334         .probe          = st1232_ts_probe,
 335         .id_table       = st1232_ts_id,
 336         .driver = {
 337                 .name   = ST1232_TS_NAME,
 338                 .of_match_table = st1232_ts_dt_ids,
 339                 .pm     = &st1232_ts_pm_ops,
 340         },
 341 };
 342
 343 module_i2c_driver(st1232_ts_driver);
 344
 345 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
 346 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
 347 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 348 MODULE_LICENSE("GPL v2");