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 ST_TS_MAX_FINGERS       10
  30
  31 struct st_chip_info {
  32         bool    have_z;
  33         u16     max_x;
  34         u16     max_y;
  35         u16     max_area;
  36         u16     max_fingers;
  37         u8      start_reg;
  38 };
  39
  40 struct st1232_ts_data {
  41         struct i2c_client *client;
  42         struct input_dev *input_dev;
  43         struct touchscreen_properties prop;
  44         struct dev_pm_qos_request low_latency_req;
  45         struct gpio_desc *reset_gpio;
  46         const struct st_chip_info *chip_info;
  47         int read_buf_len;
  48         u8 *read_buf;
  49 };
  50
  51 static int st1232_ts_read_data(struct st1232_ts_data *ts)
  52 {
  53         struct i2c_client *client = ts->client;
  54         u8 start_reg = ts->chip_info->start_reg;
  55         struct i2c_msg msg[] = {
  56                 {
  57                         .addr   = client->addr,
  58                         .len    = sizeof(start_reg),
  59                         .buf    = &start_reg,
  60                 },
  61                 {
  62                         .addr   = client->addr,
  63                         .flags  = I2C_M_RD | I2C_M_DMA_SAFE,
  64                         .len    = ts->read_buf_len,
  65                         .buf    = ts->read_buf,
  66                 }
  67         };
  68         int ret;
  69
  70         ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  71         if (ret != ARRAY_SIZE(msg))
  72                 return ret < 0 ? ret : -EIO;
  73
  74         return 0;
  75 }
  76
  77 static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
  78 {
  79         struct input_dev *input = ts->input_dev;
  80         struct input_mt_pos pos[ST_TS_MAX_FINGERS];
  81         u8 z[ST_TS_MAX_FINGERS];
  82         int slots[ST_TS_MAX_FINGERS];
  83         int n_contacts = 0;
  84         int i;
  85
  86         for (i = 0; i < ts->chip_info->max_fingers; i++) {
  87                 u8 *buf = &ts->read_buf[i * 4];
  88
  89                 if (buf[0] & BIT(7)) {
  90                         unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
  91                         unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
  92
  93                         touchscreen_set_mt_pos(&pos[n_contacts],
  94                                                &ts->prop, x, y);
  95
  96                         /* st1232 includes a z-axis / touch strength */
  97                         if (ts->chip_info->have_z)
  98                                 z[n_contacts] = ts->read_buf[i + 6];
  99
 100                         n_contacts++;
 101                 }
 102         }
 103
 104         input_mt_assign_slots(input, slots, pos, n_contacts, 0);
 105         for (i = 0; i < n_contacts; i++) {
 106                 input_mt_slot(input, slots[i]);
 107                 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 108                 input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
 109                 input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
 110                 if (ts->chip_info->have_z)
 111                         input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
 112         }
 113
 114         input_mt_sync_frame(input);
 115         input_sync(input);
 116
 117         return n_contacts;
 118 }
 119
 120 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
 121 {
 122         struct st1232_ts_data *ts = dev_id;
 123         int count;
 124         int error;
 125
 126         error = st1232_ts_read_data(ts);
 127         if (error)
 128                 goto out;
 129
 130         count = st1232_ts_parse_and_report(ts);
 131         if (!count) {
 132                 if (ts->low_latency_req.dev) {
 133                         dev_pm_qos_remove_request(&ts->low_latency_req);
 134                         ts->low_latency_req.dev = NULL;
 135                 }
 136         } else if (!ts->low_latency_req.dev) {
 137                 /* First contact, request 100 us latency. */
 138                 dev_pm_qos_add_ancestor_request(&ts->client->dev,
 139                                                 &ts->low_latency_req,
 140                                                 DEV_PM_QOS_RESUME_LATENCY, 100);
 141         }
 142
 143 out:
 144         return IRQ_HANDLED;
 145 }
 146
 147 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
 148 {
 149         if (ts->reset_gpio)
 150                 gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
 151 }
 152
 153 static void st1232_ts_power_off(void *data)
 154 {
 155         st1232_ts_power(data, false);
 156 }
 157
 158 static const struct st_chip_info st1232_chip_info = {
 159         .have_z         = true,
 160         .max_x          = 0x31f, /* 800 - 1 */
 161         .max_y          = 0x1df, /* 480 -1 */
 162         .max_area       = 0xff,
 163         .max_fingers    = 2,
 164         .start_reg      = 0x12,
 165 };
 166
 167 static const struct st_chip_info st1633_chip_info = {
 168         .have_z         = false,
 169         .max_x          = 0x13f, /* 320 - 1 */
 170         .max_y          = 0x1df, /* 480 -1 */
 171         .max_area       = 0x00,
 172         .max_fingers    = 5,
 173         .start_reg      = 0x12,
 174 };
 175
 176 static int st1232_ts_probe(struct i2c_client *client,
 177                            const struct i2c_device_id *id)
 178 {
 179         const struct st_chip_info *match;
 180         struct st1232_ts_data *ts;
 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
 208         /* allocate a buffer according to the number of registers to read */
 209         ts->read_buf_len = ts->chip_info->max_fingers * 4;
 210         ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
 211         if (!ts->read_buf)
 212                 return -ENOMEM;
 213
 214         input_dev = devm_input_allocate_device(&client->dev);
 215         if (!input_dev)
 216                 return -ENOMEM;
 217
 218         ts->client = client;
 219         ts->input_dev = input_dev;
 220
 221         ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
 222                                                  GPIOD_OUT_HIGH);
 223         if (IS_ERR(ts->reset_gpio)) {
 224                 error = PTR_ERR(ts->reset_gpio);
 225                 dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
 226                         error);
 227                 return error;
 228         }
 229
 230         st1232_ts_power(ts, true);
 231
 232         error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
 233         if (error) {
 234                 dev_err(&client->dev,
 235                         "Failed to install power off action: %d\n", error);
 236                 return error;
 237         }
 238
 239         input_dev->name = "st1232-touchscreen";
 240         input_dev->id.bustype = BUS_I2C;
 241
 242         if (ts->chip_info->have_z)
 243                 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 244                                      ts->chip_info->max_area, 0, 0);
 245
 246         input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 247                              0, ts->chip_info->max_x, 0, 0);
 248         input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 249                              0, ts->chip_info->max_y, 0, 0);
 250
 251         touchscreen_parse_properties(input_dev, true, &ts->prop);
 252
 253         error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers,
 254                                     INPUT_MT_DIRECT | INPUT_MT_TRACK |
 255                                         INPUT_MT_DROP_UNUSED);
 256         if (error) {
 257                 dev_err(&client->dev, "failed to initialize MT slots\n");
 258                 return error;
 259         }
 260
 261         error = devm_request_threaded_irq(&client->dev, client->irq,
 262                                           NULL, st1232_ts_irq_handler,
 263                                           IRQF_ONESHOT,
 264                                           client->name, ts);
 265         if (error) {
 266                 dev_err(&client->dev, "Failed to register interrupt\n");
 267                 return error;
 268         }
 269
 270         error = input_register_device(ts->input_dev);
 271         if (error) {
 272                 dev_err(&client->dev, "Unable to register %s input device\n",
 273                         input_dev->name);
 274                 return error;
 275         }
 276
 277         i2c_set_clientdata(client, ts);
 278
 279         return 0;
 280 }
 281
 282 static int __maybe_unused st1232_ts_suspend(struct device *dev)
 283 {
 284         struct i2c_client *client = to_i2c_client(dev);
 285         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 286
 287         disable_irq(client->irq);
 288
 289         if (!device_may_wakeup(&client->dev))
 290                 st1232_ts_power(ts, false);
 291
 292         return 0;
 293 }
 294
 295 static int __maybe_unused st1232_ts_resume(struct device *dev)
 296 {
 297         struct i2c_client *client = to_i2c_client(dev);
 298         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 299
 300         if (!device_may_wakeup(&client->dev))
 301                 st1232_ts_power(ts, true);
 302
 303         enable_irq(client->irq);
 304
 305         return 0;
 306 }
 307
 308 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
 309                          st1232_ts_suspend, st1232_ts_resume);
 310
 311 static const struct i2c_device_id st1232_ts_id[] = {
 312         { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
 313         { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
 314         { }
 315 };
 316 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 317
 318 static const struct of_device_id st1232_ts_dt_ids[] = {
 319         { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
 320         { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
 321         { }
 322 };
 323 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
 324
 325 static struct i2c_driver st1232_ts_driver = {
 326         .probe          = st1232_ts_probe,
 327         .id_table       = st1232_ts_id,
 328         .driver = {
 329                 .name   = ST1232_TS_NAME,
 330                 .of_match_table = st1232_ts_dt_ids,
 331                 .pm     = &st1232_ts_pm_ops,
 332         },
 333 };
 334
 335 module_i2c_driver(st1232_ts_driver);
 336
 337 MODULE_AUTHOR("Tony SIM <[email protected]>");
 338 MODULE_AUTHOR("Martin Kepplinger <[email protected]>");
 339 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 340 MODULE_LICENSE("GPL v2");