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