drivers/input/touchscreen/zet6223.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2016, Jelle van der Waa <jelle@vdwaa.nl>
   4  */
   5
   6 #include <linux/delay.h>
   7 #include <linux/i2c.h>
   8 #include <linux/input.h>
   9 #include <linux/input/mt.h>
  10 #include <linux/input/touchscreen.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/module.h>
  13 #include <linux/regulator/consumer.h>
  14 #include <linux/unaligned.h>
  15
  16 #define ZET6223_MAX_FINGERS             16
  17 #define ZET6223_MAX_PKT_SIZE            (3 + 4 * ZET6223_MAX_FINGERS)
  18
  19 #define ZET6223_CMD_INFO                0xB2
  20 #define ZET6223_CMD_INFO_LENGTH         17
  21 #define ZET6223_VALID_PACKET            0x3c
  22
  23 #define ZET6223_POWER_ON_DELAY_MSEC     30
  24
  25 struct zet6223_ts {
  26         struct i2c_client *client;
  27         struct input_dev *input;
  28         struct touchscreen_properties prop;
  29         struct regulator_bulk_data supplies[2];
  30         u16 max_x;
  31         u16 max_y;
  32         u8 fingernum;
  33 };
  34
  35 static int zet6223_start(struct input_dev *dev)
  36 {
  37         struct zet6223_ts *ts = input_get_drvdata(dev);
  38
  39         enable_irq(ts->client->irq);
  40
  41         return 0;
  42 }
  43
  44 static void zet6223_stop(struct input_dev *dev)
  45 {
  46         struct zet6223_ts *ts = input_get_drvdata(dev);
  47
  48         disable_irq(ts->client->irq);
  49 }
  50
  51 static irqreturn_t zet6223_irq(int irq, void *dev_id)
  52 {
  53         struct zet6223_ts *ts = dev_id;
  54         u16 finger_bits;
  55
  56         /*
  57          * First 3 bytes are an identifier, two bytes of finger data.
  58          * X, Y data per finger is 4 bytes.
  59          */
  60         u8 bufsize = 3 + 4 * ts->fingernum;
  61         u8 buf[ZET6223_MAX_PKT_SIZE];
  62         int i;
  63         int ret;
  64         int error;
  65
  66         ret = i2c_master_recv(ts->client, buf, bufsize);
  67         if (ret != bufsize) {
  68                 error = ret < 0 ? ret : -EIO;
  69                 dev_err_ratelimited(&ts->client->dev,
  70                                     "Error reading input data: %d\n", error);
  71                 return IRQ_HANDLED;
  72         }
  73
  74         if (buf[0] != ZET6223_VALID_PACKET)
  75                 return IRQ_HANDLED;
  76
  77         finger_bits = get_unaligned_be16(buf + 1);
  78         for (i = 0; i < ts->fingernum; i++) {
  79                 if (!(finger_bits & BIT(15 - i)))
  80                         continue;
  81
  82                 input_mt_slot(ts->input, i);
  83                 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
  84                 input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
  85                                 ((buf[i + 3] >> 4) << 8) + buf[i + 4]);
  86                 input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
  87                                 ((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
  88         }
  89
  90         input_mt_sync_frame(ts->input);
  91         input_sync(ts->input);
  92
  93         return IRQ_HANDLED;
  94 }
  95
  96 static void zet6223_power_off(void *_ts)
  97 {
  98         struct zet6223_ts *ts = _ts;
  99
 100         regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
 101 }
 102
 103 static int zet6223_power_on(struct zet6223_ts *ts)
 104 {
 105         struct device *dev = &ts->client->dev;
 106         int error;
 107
 108         ts->supplies[0].supply = "vio";
 109         ts->supplies[1].supply = "vcc";
 110
 111         error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
 112                                         ts->supplies);
 113         if (error)
 114                 return error;
 115
 116         error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
 117         if (error)
 118                 return error;
 119
 120         msleep(ZET6223_POWER_ON_DELAY_MSEC);
 121
 122         error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
 123         if (error) {
 124                 dev_err(dev, "failed to install poweroff action: %d\n", error);
 125                 return error;
 126         }
 127
 128         return 0;
 129 }
 130
 131 static int zet6223_query_device(struct zet6223_ts *ts)
 132 {
 133         u8 buf[ZET6223_CMD_INFO_LENGTH];
 134         u8 cmd = ZET6223_CMD_INFO;
 135         int ret;
 136         int error;
 137
 138         ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
 139         if (ret != sizeof(cmd)) {
 140                 error = ret < 0 ? ret : -EIO;
 141                 dev_err(&ts->client->dev,
 142                         "touchpanel info cmd failed: %d\n", error);
 143                 return error;
 144         }
 145
 146         ret = i2c_master_recv(ts->client, buf, sizeof(buf));
 147         if (ret != sizeof(buf)) {
 148                 error = ret < 0 ? ret : -EIO;
 149                 dev_err(&ts->client->dev,
 150                         "failed to retrieve touchpanel info: %d\n", error);
 151                 return error;
 152         }
 153
 154         ts->fingernum = buf[15] & 0x7F;
 155         if (ts->fingernum > ZET6223_MAX_FINGERS) {
 156                 dev_warn(&ts->client->dev,
 157                          "touchpanel reports %d fingers, limiting to %d\n",
 158                          ts->fingernum, ZET6223_MAX_FINGERS);
 159                 ts->fingernum = ZET6223_MAX_FINGERS;
 160         }
 161
 162         ts->max_x = get_unaligned_le16(&buf[8]);
 163         ts->max_y = get_unaligned_le16(&buf[10]);
 164
 165         return 0;
 166 }
 167
 168 static int zet6223_probe(struct i2c_client *client)
 169 {
 170         struct device *dev = &client->dev;
 171         struct zet6223_ts *ts;
 172         struct input_dev *input;
 173         int error;
 174
 175         if (!client->irq) {
 176                 dev_err(dev, "no irq specified\n");
 177                 return -EINVAL;
 178         }
 179
 180         ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
 181         if (!ts)
 182                 return -ENOMEM;
 183
 184         ts->client = client;
 185
 186         error = zet6223_power_on(ts);
 187         if (error)
 188                 return error;
 189
 190         error = zet6223_query_device(ts);
 191         if (error)
 192                 return error;
 193
 194         ts->input = input = devm_input_allocate_device(dev);
 195         if (!input)
 196                 return -ENOMEM;
 197
 198         input_set_drvdata(input, ts);
 199
 200         input->name = client->name;
 201         input->id.bustype = BUS_I2C;
 202         input->open = zet6223_start;
 203         input->close = zet6223_stop;
 204
 205         input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
 206         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
 207
 208         touchscreen_parse_properties(input, true, &ts->prop);
 209
 210         error = input_mt_init_slots(input, ts->fingernum,
 211                                     INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
 212         if (error)
 213                 return error;
 214
 215         error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
 216                                           IRQF_ONESHOT, client->name, ts);
 217         if (error) {
 218                 dev_err(dev, "failed to request irq %d: %d\n",
 219                         client->irq, error);
 220                 return error;
 221         }
 222
 223         zet6223_stop(input);
 224
 225         error = input_register_device(input);
 226         if (error)
 227                 return error;
 228
 229         return 0;
 230 }
 231
 232 static const struct of_device_id zet6223_of_match[] = {
 233         { .compatible = "zeitec,zet6223" },
 234         { }
 235 };
 236 MODULE_DEVICE_TABLE(of, zet6223_of_match);
 237
 238 static const struct i2c_device_id zet6223_id[] = {
 239         { "zet6223" },
 240         { }
 241 };
 242 MODULE_DEVICE_TABLE(i2c, zet6223_id);
 243
 244 static struct i2c_driver zet6223_driver = {
 245         .driver = {
 246                 .name = "zet6223",
 247                 .of_match_table = zet6223_of_match,
 248         },
 249         .probe = zet6223_probe,
 250         .id_table = zet6223_id
 251 };
 252 module_i2c_driver(zet6223_driver);
 253
 254 MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
 255 MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
 256 MODULE_LICENSE("GPL");