linux/drivers/input/touchscreen/st1232.c
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   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_STATUS              0x01    /* Device Status | Error Code */
  30
  31#define STATUS_NORMAL           0x00
  32#define STATUS_INIT             0x01
  33#define STATUS_ERROR            0x02
  34#define STATUS_AUTO_TUNING      0x03
  35#define STATUS_IDLE             0x04
  36#define STATUS_POWER_DOWN       0x05
  37
  38#define ERROR_NONE              0x00
  39#define ERROR_INVALID_ADDRESS   0x10
  40#define ERROR_INVALID_VALUE     0x20
  41#define ERROR_INVALID_PLATFORM  0x30
  42
  43#define REG_XY_RESOLUTION       0x04
  44#define REG_XY_COORDINATES      0x12
  45#define ST_TS_MAX_FINGERS       10
  46
  47struct st_chip_info {
  48        bool    have_z;
  49        u16     max_area;
  50        u16     max_fingers;
  51};
  52
  53struct st1232_ts_data {
  54        struct i2c_client *client;
  55        struct input_dev *input_dev;
  56        struct touchscreen_properties prop;
  57        struct dev_pm_qos_request low_latency_req;
  58        struct gpio_desc *reset_gpio;
  59        const struct st_chip_info *chip_info;
  60        int read_buf_len;
  61        u8 *read_buf;
  62};
  63
  64static int st1232_ts_read_data(struct st1232_ts_data *ts, u8 reg,
  65                               unsigned int n)
  66{
  67        struct i2c_client *client = ts->client;
  68        struct i2c_msg msg[] = {
  69                {
  70                        .addr   = client->addr,
  71                        .len    = sizeof(reg),
  72                        .buf    = &reg,
  73                },
  74                {
  75                        .addr   = client->addr,
  76                        .flags  = I2C_M_RD | I2C_M_DMA_SAFE,
  77                        .len    = n,
  78                        .buf    = ts->read_buf,
  79                }
  80        };
  81        int ret;
  82
  83        ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  84        if (ret != ARRAY_SIZE(msg))
  85                return ret < 0 ? ret : -EIO;
  86
  87        return 0;
  88}
  89
  90static int st1232_ts_wait_ready(struct st1232_ts_data *ts)
  91{
  92        unsigned int retries;
  93        int error;
  94
  95        for (retries = 100; retries; retries--) {
  96                error = st1232_ts_read_data(ts, REG_STATUS, 1);
  97                if (!error) {
  98                        switch (ts->read_buf[0]) {
  99                        case STATUS_NORMAL | ERROR_NONE:
 100                        case STATUS_IDLE | ERROR_NONE:
 101                                return 0;
 102                        }
 103                }
 104
 105                usleep_range(1000, 2000);
 106        }
 107
 108        return -ENXIO;
 109}
 110
 111static int st1232_ts_read_resolution(struct st1232_ts_data *ts, u16 *max_x,
 112                                     u16 *max_y)
 113{
 114        u8 *buf;
 115        int error;
 116
 117        /* select resolution register */
 118        error = st1232_ts_read_data(ts, REG_XY_RESOLUTION, 3);
 119        if (error)
 120                return error;
 121
 122        buf = ts->read_buf;
 123
 124        *max_x = (((buf[0] & 0x0070) << 4) | buf[1]) - 1;
 125        *max_y = (((buf[0] & 0x0007) << 8) | buf[2]) - 1;
 126
 127        return 0;
 128}
 129
 130static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
 131{
 132        struct input_dev *input = ts->input_dev;
 133        struct input_mt_pos pos[ST_TS_MAX_FINGERS];
 134        u8 z[ST_TS_MAX_FINGERS];
 135        int slots[ST_TS_MAX_FINGERS];
 136        int n_contacts = 0;
 137        int i;
 138
 139        for (i = 0; i < ts->chip_info->max_fingers; i++) {
 140                u8 *buf = &ts->read_buf[i * 4];
 141
 142                if (buf[0] & BIT(7)) {
 143                        unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
 144                        unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
 145
 146                        touchscreen_set_mt_pos(&pos[n_contacts],
 147                                               &ts->prop, x, y);
 148
 149                        /* st1232 includes a z-axis / touch strength */
 150                        if (ts->chip_info->have_z)
 151                                z[n_contacts] = ts->read_buf[i + 6];
 152
 153                        n_contacts++;
 154                }
 155        }
 156
 157        input_mt_assign_slots(input, slots, pos, n_contacts, 0);
 158        for (i = 0; i < n_contacts; i++) {
 159                input_mt_slot(input, slots[i]);
 160                input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 161                input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
 162                input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
 163                if (ts->chip_info->have_z)
 164                        input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
 165        }
 166
 167        input_mt_sync_frame(input);
 168        input_sync(input);
 169
 170        return n_contacts;
 171}
 172
 173static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
 174{
 175        struct st1232_ts_data *ts = dev_id;
 176        int count;
 177        int error;
 178
 179        error = st1232_ts_read_data(ts, REG_XY_COORDINATES, ts->read_buf_len);
 180        if (error)
 181                goto out;
 182
 183        count = st1232_ts_parse_and_report(ts);
 184        if (!count) {
 185                if (ts->low_latency_req.dev) {
 186                        dev_pm_qos_remove_request(&ts->low_latency_req);
 187                        ts->low_latency_req.dev = NULL;
 188                }
 189        } else if (!ts->low_latency_req.dev) {
 190                /* First contact, request 100 us latency. */
 191                dev_pm_qos_add_ancestor_request(&ts->client->dev,
 192                                                &ts->low_latency_req,
 193                                                DEV_PM_QOS_RESUME_LATENCY, 100);
 194        }
 195
 196out:
 197        return IRQ_HANDLED;
 198}
 199
 200static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
 201{
 202        if (ts->reset_gpio)
 203                gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
 204}
 205
 206static void st1232_ts_power_off(void *data)
 207{
 208        st1232_ts_power(data, false);
 209}
 210
 211static const struct st_chip_info st1232_chip_info = {
 212        .have_z         = true,
 213        .max_area       = 0xff,
 214        .max_fingers    = 2,
 215};
 216
 217static const struct st_chip_info st1633_chip_info = {
 218        .have_z         = false,
 219        .max_area       = 0x00,
 220        .max_fingers    = 5,
 221};
 222
 223static int st1232_ts_probe(struct i2c_client *client,
 224                           const struct i2c_device_id *id)
 225{
 226        const struct st_chip_info *match;
 227        struct st1232_ts_data *ts;
 228        struct input_dev *input_dev;
 229        u16 max_x, max_y;
 230        int error;
 231
 232        match = device_get_match_data(&client->dev);
 233        if (!match && id)
 234                match = (const void *)id->driver_data;
 235        if (!match) {
 236                dev_err(&client->dev, "unknown device model\n");
 237                return -ENODEV;
 238        }
 239
 240        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 241                dev_err(&client->dev, "need I2C_FUNC_I2C\n");
 242                return -EIO;
 243        }
 244
 245        if (!client->irq) {
 246                dev_err(&client->dev, "no IRQ?\n");
 247                return -EINVAL;
 248        }
 249
 250        ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
 251        if (!ts)
 252                return -ENOMEM;
 253
 254        ts->chip_info = match;
 255
 256        /* allocate a buffer according to the number of registers to read */
 257        ts->read_buf_len = ts->chip_info->max_fingers * 4;
 258        ts->read_buf = devm_kzalloc(&client->dev, ts->read_buf_len, GFP_KERNEL);
 259        if (!ts->read_buf)
 260                return -ENOMEM;
 261
 262        input_dev = devm_input_allocate_device(&client->dev);
 263        if (!input_dev)
 264                return -ENOMEM;
 265
 266        ts->client = client;
 267        ts->input_dev = input_dev;
 268
 269        ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
 270                                                 GPIOD_OUT_HIGH);
 271        if (IS_ERR(ts->reset_gpio)) {
 272                error = PTR_ERR(ts->reset_gpio);
 273                dev_err(&client->dev, "Unable to request GPIO pin: %d.\n",
 274                        error);
 275                return error;
 276        }
 277
 278        st1232_ts_power(ts, true);
 279
 280        error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
 281        if (error) {
 282                dev_err(&client->dev,
 283                        "Failed to install power off action: %d\n", error);
 284                return error;
 285        }
 286
 287        input_dev->name = "st1232-touchscreen";
 288        input_dev->id.bustype = BUS_I2C;
 289
 290        /* Wait until device is ready */
 291        error = st1232_ts_wait_ready(ts);
 292        if (error)
 293                return error;
 294
 295        /* Read resolution from the chip */
 296        error = st1232_ts_read_resolution(ts, &max_x, &max_y);
 297        if (error) {
 298                dev_err(&client->dev,
 299                        "Failed to read resolution: %d\n", error);
 300                return error;
 301        }
 302
 303        if (ts->chip_info->have_z)
 304                input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
 305                                     ts->chip_info->max_area, 0, 0);
 306
 307        input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 308                             0, max_x, 0, 0);
 309        input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 310                             0, max_y, 0, 0);
 311
 312        touchscreen_parse_properties(input_dev, true, &ts->prop);
 313
 314        error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers,
 315                                    INPUT_MT_DIRECT | INPUT_MT_TRACK |
 316                                        INPUT_MT_DROP_UNUSED);
 317        if (error) {
 318                dev_err(&client->dev, "failed to initialize MT slots\n");
 319                return error;
 320        }
 321
 322        error = devm_request_threaded_irq(&client->dev, client->irq,
 323                                          NULL, st1232_ts_irq_handler,
 324                                          IRQF_ONESHOT,
 325                                          client->name, ts);
 326        if (error) {
 327                dev_err(&client->dev, "Failed to register interrupt\n");
 328                return error;
 329        }
 330
 331        error = input_register_device(ts->input_dev);
 332        if (error) {
 333                dev_err(&client->dev, "Unable to register %s input device\n",
 334                        input_dev->name);
 335                return error;
 336        }
 337
 338        i2c_set_clientdata(client, ts);
 339
 340        return 0;
 341}
 342
 343static int __maybe_unused st1232_ts_suspend(struct device *dev)
 344{
 345        struct i2c_client *client = to_i2c_client(dev);
 346        struct st1232_ts_data *ts = i2c_get_clientdata(client);
 347
 348        disable_irq(client->irq);
 349
 350        if (!device_may_wakeup(&client->dev))
 351                st1232_ts_power(ts, false);
 352
 353        return 0;
 354}
 355
 356static int __maybe_unused st1232_ts_resume(struct device *dev)
 357{
 358        struct i2c_client *client = to_i2c_client(dev);
 359        struct st1232_ts_data *ts = i2c_get_clientdata(client);
 360
 361        if (!device_may_wakeup(&client->dev))
 362                st1232_ts_power(ts, true);
 363
 364        enable_irq(client->irq);
 365
 366        return 0;
 367}
 368
 369static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
 370                         st1232_ts_suspend, st1232_ts_resume);
 371
 372static const struct i2c_device_id st1232_ts_id[] = {
 373        { ST1232_TS_NAME, (unsigned long)&st1232_chip_info },
 374        { ST1633_TS_NAME, (unsigned long)&st1633_chip_info },
 375        { }
 376};
 377MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 378
 379static const struct of_device_id st1232_ts_dt_ids[] = {
 380        { .compatible = "sitronix,st1232", .data = &st1232_chip_info },
 381        { .compatible = "sitronix,st1633", .data = &st1633_chip_info },
 382        { }
 383};
 384MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
 385
 386static struct i2c_driver st1232_ts_driver = {
 387        .probe          = st1232_ts_probe,
 388        .id_table       = st1232_ts_id,
 389        .driver = {
 390                .name   = ST1232_TS_NAME,
 391                .of_match_table = st1232_ts_dt_ids,
 392                .probe_type     = PROBE_PREFER_ASYNCHRONOUS,
 393                .pm     = &st1232_ts_pm_ops,
 394        },
 395};
 396
 397module_i2c_driver(st1232_ts_driver);
 398
 399MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
 400MODULE_AUTHOR("Martin Kepplinger <martin.kepplinger@ginzinger.com>");
 401MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 402MODULE_LICENSE("GPL v2");
 403