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.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/of_gpio.h>
  21 #include <linux/pm_qos.h>
  22 #include <linux/slab.h>
  23 #include <linux/types.h>
  24
  25 #define ST1232_TS_NAME  "st1232-ts"
  26
  27 #define MIN_X           0x00
  28 #define MIN_Y           0x00
  29 #define MAX_X           0x31f   /* (800 - 1) */
  30 #define MAX_Y           0x1df   /* (480 - 1) */
  31 #define MAX_AREA        0xff
  32 #define MAX_FINGERS     2
  33
  34 struct st1232_ts_finger {
  35         u16 x;
  36         u16 y;
  37         u8 t;
  38         bool is_valid;
  39 };
  40
  41 struct st1232_ts_data {
  42         struct i2c_client *client;
  43         struct input_dev *input_dev;
  44         struct st1232_ts_finger finger[MAX_FINGERS];
  45         struct dev_pm_qos_request low_latency_req;
  46         int reset_gpio;
  47 };
  48
  49 static int st1232_ts_read_data(struct st1232_ts_data *ts)
  50 {
  51         struct st1232_ts_finger *finger = ts->finger;
  52         struct i2c_client *client = ts->client;
  53         struct i2c_msg msg[2];
  54         int error;
  55         u8 start_reg;
  56         u8 buf[10];
  57
  58         /* read touchscreen data from ST1232 */
  59         msg[0].addr = client->addr;
  60         msg[0].flags = 0;
  61         msg[0].len = 1;
  62         msg[0].buf = &start_reg;
  63         start_reg = 0x10;
  64
  65         msg[1].addr = ts->client->addr;
  66         msg[1].flags = I2C_M_RD;
  67         msg[1].len = sizeof(buf);
  68         msg[1].buf = buf;
  69
  70         error = i2c_transfer(client->adapter, msg, 2);
  71         if (error < 0)
  72                 return error;
  73
  74         /* get "valid" bits */
  75         finger[0].is_valid = buf[2] >> 7;
  76         finger[1].is_valid = buf[5] >> 7;
  77
  78         /* get xy coordinate */
  79         if (finger[0].is_valid) {
  80                 finger[0].x = ((buf[2] & 0x0070) << 4) | buf[3];
  81                 finger[0].y = ((buf[2] & 0x0007) << 8) | buf[4];
  82                 finger[0].t = buf[8];
  83         }
  84
  85         if (finger[1].is_valid) {
  86                 finger[1].x = ((buf[5] & 0x0070) << 4) | buf[6];
  87                 finger[1].y = ((buf[5] & 0x0007) << 8) | buf[7];
  88                 finger[1].t = buf[9];
  89         }
  90
  91         return 0;
  92 }
  93
  94 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
  95 {
  96         struct st1232_ts_data *ts = dev_id;
  97         struct st1232_ts_finger *finger = ts->finger;
  98         struct input_dev *input_dev = ts->input_dev;
  99         int count = 0;
 100         int i, ret;
 101
 102         ret = st1232_ts_read_data(ts);
 103         if (ret < 0)
 104                 goto end;
 105
 106         /* multi touch protocol */
 107         for (i = 0; i < MAX_FINGERS; i++) {
 108                 if (!finger[i].is_valid)
 109                         continue;
 110
 111                 input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, finger[i].t);
 112                 input_report_abs(input_dev, ABS_MT_POSITION_X, finger[i].x);
 113                 input_report_abs(input_dev, ABS_MT_POSITION_Y, finger[i].y);
 114                 input_mt_sync(input_dev);
 115                 count++;
 116         }
 117
 118         /* SYN_MT_REPORT only if no contact */
 119         if (!count) {
 120                 input_mt_sync(input_dev);
 121                 if (ts->low_latency_req.dev) {
 122                         dev_pm_qos_remove_request(&ts->low_latency_req);
 123                         ts->low_latency_req.dev = NULL;
 124                 }
 125         } else if (!ts->low_latency_req.dev) {
 126                 /* First contact, request 100 us latency. */
 127                 dev_pm_qos_add_ancestor_request(&ts->client->dev,
 128                                                 &ts->low_latency_req,
 129                                                 DEV_PM_QOS_RESUME_LATENCY, 100);
 130         }
 131
 132         /* SYN_REPORT */
 133         input_sync(input_dev);
 134
 135 end:
 136         return IRQ_HANDLED;
 137 }
 138
 139 static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
 140 {
 141         if (gpio_is_valid(ts->reset_gpio))
 142                 gpio_direction_output(ts->reset_gpio, poweron);
 143 }
 144
 145 static int st1232_ts_probe(struct i2c_client *client,
 146                            const struct i2c_device_id *id)
 147 {
 148         struct st1232_ts_data *ts;
 149         struct input_dev *input_dev;
 150         int error;
 151
 152         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 153                 dev_err(&client->dev, "need I2C_FUNC_I2C\n");
 154                 return -EIO;
 155         }
 156
 157         if (!client->irq) {
 158                 dev_err(&client->dev, "no IRQ?\n");
 159                 return -EINVAL;
 160         }
 161
 162         ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
 163         if (!ts)
 164                 return -ENOMEM;
 165
 166         input_dev = devm_input_allocate_device(&client->dev);
 167         if (!input_dev)
 168                 return -ENOMEM;
 169
 170         ts->client = client;
 171         ts->input_dev = input_dev;
 172
 173         ts->reset_gpio = of_get_gpio(client->dev.of_node, 0);
 174         if (gpio_is_valid(ts->reset_gpio)) {
 175                 error = devm_gpio_request(&client->dev, ts->reset_gpio, NULL);
 176                 if (error) {
 177                         dev_err(&client->dev,
 178                                 "Unable to request GPIO pin %d.\n",
 179                                 ts->reset_gpio);
 180                                 return error;
 181                 }
 182         }
 183
 184         st1232_ts_power(ts, true);
 185
 186         input_dev->name = "st1232-touchscreen";
 187         input_dev->id.bustype = BUS_I2C;
 188         input_dev->dev.parent = &client->dev;
 189
 190         __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
 191         __set_bit(EV_SYN, input_dev->evbit);
 192         __set_bit(EV_KEY, input_dev->evbit);
 193         __set_bit(EV_ABS, input_dev->evbit);
 194
 195         input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
 196         input_set_abs_params(input_dev, ABS_MT_POSITION_X, MIN_X, MAX_X, 0, 0);
 197         input_set_abs_params(input_dev, ABS_MT_POSITION_Y, MIN_Y, MAX_Y, 0, 0);
 198
 199         error = devm_request_threaded_irq(&client->dev, client->irq,
 200                                           NULL, st1232_ts_irq_handler,
 201                                           IRQF_ONESHOT,
 202                                           client->name, ts);
 203         if (error) {
 204                 dev_err(&client->dev, "Failed to register interrupt\n");
 205                 return error;
 206         }
 207
 208         error = input_register_device(ts->input_dev);
 209         if (error) {
 210                 dev_err(&client->dev, "Unable to register %s input device\n",
 211                         input_dev->name);
 212                 return error;
 213         }
 214
 215         i2c_set_clientdata(client, ts);
 216         device_init_wakeup(&client->dev, 1);
 217
 218         return 0;
 219 }
 220
 221 static int st1232_ts_remove(struct i2c_client *client)
 222 {
 223         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 224
 225         st1232_ts_power(ts, false);
 226
 227         return 0;
 228 }
 229
 230 static int __maybe_unused st1232_ts_suspend(struct device *dev)
 231 {
 232         struct i2c_client *client = to_i2c_client(dev);
 233         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 234
 235         if (device_may_wakeup(&client->dev)) {
 236                 enable_irq_wake(client->irq);
 237         } else {
 238                 disable_irq(client->irq);
 239                 st1232_ts_power(ts, false);
 240         }
 241
 242         return 0;
 243 }
 244
 245 static int __maybe_unused st1232_ts_resume(struct device *dev)
 246 {
 247         struct i2c_client *client = to_i2c_client(dev);
 248         struct st1232_ts_data *ts = i2c_get_clientdata(client);
 249
 250         if (device_may_wakeup(&client->dev)) {
 251                 disable_irq_wake(client->irq);
 252         } else {
 253                 st1232_ts_power(ts, true);
 254                 enable_irq(client->irq);
 255         }
 256
 257         return 0;
 258 }
 259
 260 static SIMPLE_DEV_PM_OPS(st1232_ts_pm_ops,
 261                          st1232_ts_suspend, st1232_ts_resume);
 262
 263 static const struct i2c_device_id st1232_ts_id[] = {
 264         { ST1232_TS_NAME, 0 },
 265         { }
 266 };
 267 MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
 268
 269 static const struct of_device_id st1232_ts_dt_ids[] = {
 270         { .compatible = "sitronix,st1232", },
 271         { }
 272 };
 273 MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);
 274
 275 static struct i2c_driver st1232_ts_driver = {
 276         .probe          = st1232_ts_probe,
 277         .remove         = st1232_ts_remove,
 278         .id_table       = st1232_ts_id,
 279         .driver = {
 280                 .name   = ST1232_TS_NAME,
 281                 .of_match_table = st1232_ts_dt_ids,
 282                 .pm     = &st1232_ts_pm_ops,
 283         },
 284 };
 285
 286 module_i2c_driver(st1232_ts_driver);
 287
 288 MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
 289 MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
 290 MODULE_LICENSE("GPL v2");