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 fingers[];
  54 };
  55
  56 static int st1232_ts_read_data(struct st1232_ts_data *ts)
  57 {
  58         struct st1232_ts_finger *finger = ts->fingers;
  59         struct i2c_client *client = ts->client;
  60         u8 start_reg = ts->chip_info->start_reg;
  61         struct i2c_msg msg[] = {
  62                 {
  63                         .addr   = client->addr,
  64                         .len    = sizeof(start_reg),
  65                         .buf    = &start_reg,
  66                 },
  67                 {
  68                         .addr   = client->addr,
  69                         .flags  = I2C_M_RD | I2C_M_DMA_SAFE,
  70                         .len    = ts->read_buf_len,
  71                         .buf    = ts->read_buf,
  72                 }
  73         };
  74         int ret;
  75         int i;
  76         u8 *buf;
  77
  78         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  79         if (ret != ARRAY_SIZE(msg))
  80                 return ret < 0 ? ret : -EIO;
  81
  82         for (i = 0; i < ts->chip_info->max_fingers; i++) {
  83                 buf = &ts->read_buf[i * 4];
  84                 finger[i].is_valid = buf[0] >> 7;
  85                 if (finger[i].is_valid) {
  86                         finger[i].x = ((buf[0] & 0x70) << 4) | buf[1];
  87                         finger[i].y = ((buf[0] & 0x07) << 8) | buf[2];
  88
  89                         /* st1232 includes a z-axis / touch strength */
  90                         if (ts->chip_info->have_z)
  91                                 finger[i].t = ts->read_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->fingers;
 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 input_dev *input_dev;
 181         int error;
 182
 183         match = device_get_match_data(&client->dev);
 184         if (!match && id)
 185                 match = (const void *)id->driver_data;
 186         if (!match) {
 187                 dev_err(&client->dev, "unknown device model\n");
 188                 return -ENODEV;
 189         }
 190
 191         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 192                 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
 193                 return -EIO;
 194         }
 195
 196         if (!client->irq) {
 197                 dev_err(&client->dev, "no IRQ?\n");
 198                 return -EINVAL;
 199         }
 200
 201         ts = devm_kzalloc(&client->dev,
 202                           struct_size(ts, fingers, match->max_fingers),
 203                           GFP_KERNEL);
 204         if (!ts)
 205                 return -ENOMEM;
 206
 207         ts->chip_info = match;
 208
 209         /* allocate a buffer according to the number of registers to read */
 210         ts->read_buf_len = ts->chip_info->max_fingers * 4;
 211         ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
 212         if (!ts->read_buf)
 213                 return -ENOMEM;
 214
 215         input_dev = devm_input_allocate_device(&client->dev);
 216         if (!input_dev)
 217                 return -ENOMEM;
 218
 219         ts->client = client;
 220         ts->input_dev = input_dev;
 221
 222         ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
 223                                                  GPIOD_OUT_HIGH);
 224         if (IS_ERR(ts->reset_gpio)) {
 225                 error = PTR_ERR(ts->reset_gpio);
 226                 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
 227                         error);
 228                 return error;
 229         }
 230
 231         st1232_ts_power(ts, true);
 232
 233         error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
 234         if (error) {
 235                 dev_err(&client->dev,
 236                         "Failed to install power off action: %d\n", error);
 237                 return error;
 238         }
 239
 240         input_dev->name = "st1232-touchscreen";
 241         input_dev->id.bustype = BUS_I2C;
 242
 243         __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
 244         __set_bit(EV_SYN, input_dev->evbit);
 245         __set_bit(EV_KEY, input_dev->evbit);
 246         __set_bit(EV_ABS, input_dev->evbit);
 247
 248         if (ts->chip_info->have_z)
 249                 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 250                                      ts->chip_info->max_area, 0, 0);
 251
 252         input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 253                              0, ts->chip_info->max_x, 0, 0);
 254         input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 255                              0, ts->chip_info->max_y, 0, 0);
 256
 257         touchscreen_parse_properties(input_dev, true, &ts->prop);
 258
 259         error = devm_request_threaded_irq(&client->dev, client->irq,
 260                                           NULL, st1232_ts_irq_handler,
 261                                           IRQF_ONESHOT,
 262                                           client->name, ts);
 263         if (error) {
 264                 dev_err(&client->dev, "Failed to register interrupt\n");
 265                 return error;
 266         }
 267
 268         error = input_register_device(ts->input_dev);
 269         if (error) {
 270                 dev_err(&client->dev, "Unable to register %s input device\n",
 271                         input_dev->name);
 272                 return error;
 273         }
 274
 275         i2c_set_clientdata(client, ts);
 276
 277         return 0;
 278 }
 279
 280 static int __maybe_unused st1232_ts_suspend(struct device *dev)
 281 {
 282         struct i2c_client *client = to_i2c_client(dev);
 283         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 284
 285         disable_irq(client->irq);
 286
 287         if (!device_may_wakeup(&client->dev))
 288                 st1232_ts_power(ts, false);
 289
 290         return 0;
 291 }
 292
 293 static int __maybe_unused st1232_ts_resume(struct device *dev)
 294 {
 295         struct i2c_client *client = to_i2c_client(dev);
 296         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 297
 298         if (!device_may_wakeup(&client->dev))
 299                 st1232_ts_power(ts, true);
 300
 301         enable_irq(client->irq);
 302
 303         return 0;
 304 }
 305
 306 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
 307                          st1232_ts_suspend, st1232_ts_resume);
 308
 309 static const struct i2c_device_id st1232_ts_id[] = {
 310         { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
 311         { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
 312         { }
 313 };
 314 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 315
 316 static const struct of_device_id st1232_ts_dt_ids[] = {
 317         { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
 318         { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
 319         { }
 320 };
 321 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
 322
 323 static struct i2c_driver st1232_ts_driver = {
 324         .probe          = st1232_ts_probe,
 325         .id_table       = st1232_ts_id,
 326         .driver = {
 327                 .name   = ST1232_TS_NAME,
 328                 .of_match_table = st1232_ts_dt_ids,
 329                 .pm     = &st1232_ts_pm_ops,
 330         },
 331 };
 332
 333 module_i2c_driver(st1232_ts_driver);
 334
 335 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
 336 MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
 337 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 338 MODULE_LICENSE("GPL v2");