drivers/hid/hid-elo.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * HID driver for ELO usb touchscreen 4000/4500
   4  *
   5  * Copyright (c) 2013 Jiri Slaby
   6  *
   7  * Data parsing taken from elousb driver by Vojtech Pavlik.
   8  */
   9
  10 #include <linux/hid.h>
  11 #include <linux/input.h>
  12 #include <linux/module.h>
  13 #include <linux/usb.h>
  14 #include <linux/workqueue.h>
  15
  16 #include "hid-ids.h"
  17
  18 #define ELO_PERIODIC_READ_INTERVAL      HZ
  19 #define ELO_SMARTSET_CMD_TIMEOUT        2000 /* msec */
  20
  21 /* Elo SmartSet commands */
  22 #define ELO_FLUSH_SMARTSET_RESPONSES    0x02 /* Flush all pending smartset responses */
  23 #define ELO_SEND_SMARTSET_COMMAND       0x05 /* Send a smartset command */
  24 #define ELO_GET_SMARTSET_RESPONSE       0x06 /* Get a smartset response */
  25 #define ELO_DIAG                        0x64 /* Diagnostics command */
  26 #define ELO_SMARTSET_PACKET_SIZE        8
  27
  28 struct elo_priv {
  29         struct usb_device *usbdev;
  30         struct delayed_work work;
  31         unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
  32 };
  33
  34 static struct workqueue_struct *wq;
  35 static bool use_fw_quirk = true;
  36 module_param(use_fw_quirk, bool, S_IRUGO);
  37 MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
  38
  39 static int elo_input_configured(struct hid_device *hdev,
  40                 struct hid_input *hidinput)
  41 {
  42         struct input_dev *input = hidinput->input;
  43
  44         /*
  45          * ELO devices have one Button usage in GenDesk field, which makes
  46          * hid-input map it to BTN_LEFT; that confuses userspace, which then
  47          * considers the device to be a mouse/touchpad instead of touchscreen.
  48          */
  49         clear_bit(BTN_LEFT, input->keybit);
  50         set_bit(BTN_TOUCH, input->keybit);
  51         set_bit(ABS_PRESSURE, input->absbit);
  52         input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
  53
  54         return 0;
  55 }
  56
  57 static void elo_process_data(struct input_dev *input, const u8 *data, int size)
  58 {
  59         int press;
  60
  61         input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
  62         input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
  63
  64         press = 0;
  65         if (data[1] & 0x80)
  66                 press = (data[7] << 8) | data[6];
  67         input_report_abs(input, ABS_PRESSURE, press);
  68
  69         if (data[1] & 0x03) {
  70                 input_report_key(input, BTN_TOUCH, 1);
  71                 input_sync(input);
  72         }
  73
  74         if (data[1] & 0x04)
  75                 input_report_key(input, BTN_TOUCH, 0);
  76
  77         input_sync(input);
  78 }
  79
  80 static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
  81          u8 *data, int size)
  82 {
  83         struct hid_input *hidinput;
  84
  85         if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
  86                 return 0;
  87
  88         hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
  89
  90         switch (report->id) {
  91         case 0:
  92                 if (data[0] == 'T') {   /* Mandatory ELO packet marker */
  93                         elo_process_data(hidinput->input, data, size);
  94                         return 1;
  95                 }
  96                 break;
  97         default:        /* unknown report */
  98                 /* Unknown report type; pass upstream */
  99                 hid_info(hdev, "unknown report type %d\n", report->id);
 100                 break;
 101         }
 102
 103         return 0;
 104 }
 105
 106 static int elo_smartset_send_get(struct usb_device *dev, u8 command,
 107                 void *data)
 108 {
 109         unsigned int pipe;
 110         u8 dir;
 111
 112         if (command == ELO_SEND_SMARTSET_COMMAND) {
 113                 pipe = usb_sndctrlpipe(dev, 0);
 114                 dir = USB_DIR_OUT;
 115         } else if (command == ELO_GET_SMARTSET_RESPONSE) {
 116                 pipe = usb_rcvctrlpipe(dev, 0);
 117                 dir = USB_DIR_IN;
 118         } else
 119                 return -EINVAL;
 120
 121         return usb_control_msg(dev, pipe, command,
 122                         dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 123                         0, 0, data, ELO_SMARTSET_PACKET_SIZE,
 124                         ELO_SMARTSET_CMD_TIMEOUT);
 125 }
 126
 127 static int elo_flush_smartset_responses(struct usb_device *dev)
 128 {
 129         return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
 130                         ELO_FLUSH_SMARTSET_RESPONSES,
 131                         USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 132                         0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 133 }
 134
 135 static void elo_work(struct work_struct *work)
 136 {
 137         struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
 138         struct usb_device *dev = priv->usbdev;
 139         unsigned char *buffer = priv->buffer;
 140         int ret;
 141
 142         ret = elo_flush_smartset_responses(dev);
 143         if (ret < 0) {
 144                 dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
 145                                 ret);
 146                 goto fail;
 147         }
 148
 149         /* send Diagnostics command */
 150         *buffer = ELO_DIAG;
 151         ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
 152         if (ret < 0) {
 153                 dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
 154                                 ret);
 155                 goto fail;
 156         }
 157
 158         /* get the result */
 159         ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
 160         if (ret < 0) {
 161                 dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
 162                                 ret);
 163                 goto fail;
 164         }
 165
 166         /* read the ack */
 167         if (*buffer != 'A') {
 168                 ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
 169                                 buffer);
 170                 if (ret < 0) {
 171                         dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
 172                                         ret);
 173                         goto fail;
 174                 }
 175         }
 176
 177 fail:
 178         ret = elo_flush_smartset_responses(dev);
 179         if (ret < 0)
 180                 dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
 181                                 ret);
 182         queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
 183 }
 184
 185 /*
 186  * Not all Elo devices need the periodic HID descriptor reads.
 187  * Only firmware version M needs this.
 188  */
 189 static bool elo_broken_firmware(struct usb_device *dev)
 190 {
 191         struct usb_device *hub = dev->parent;
 192         struct usb_device *child = NULL;
 193         u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
 194         u16 child_vid, child_pid;
 195         int i;
 196
 197         if (!use_fw_quirk)
 198                 return false;
 199         if (fw_lvl != 0x10d)
 200                 return false;
 201
 202         /* iterate sibling devices of the touch controller */
 203         usb_hub_for_each_child(hub, i, child) {
 204                 child_vid = le16_to_cpu(child->descriptor.idVendor);
 205                 child_pid = le16_to_cpu(child->descriptor.idProduct);
 206
 207                 /*
 208                  * If one of the devices below is present attached as a sibling of
 209                  * the touch controller then  this is a newer IBM 4820 monitor that
 210                  * does not need the IBM-requested workaround if fw level is
 211                  * 0x010d - aka 'M'.
 212                  * No other HW can have this combination.
 213                  */
 214                 if (child_vid==0x04b3) {
 215                         switch (child_pid) {
 216                         case 0x4676: /* 4820 21x Video */
 217                         case 0x4677: /* 4820 51x Video */
 218                         case 0x4678: /* 4820 2Lx Video */
 219                         case 0x4679: /* 4820 5Lx Video */
 220                                 return false;
 221                         }
 222                 }
 223         }
 224         return true;
 225 }
 226
 227 static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
 228 {
 229         struct elo_priv *priv;
 230         int ret;
 231
 232         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 233         if (!priv)
 234                 return -ENOMEM;
 235
 236         INIT_DELAYED_WORK(&priv->work, elo_work);
 237         priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
 238
 239         hid_set_drvdata(hdev, priv);
 240
 241         ret = hid_parse(hdev);
 242         if (ret) {
 243                 hid_err(hdev, "parse failed\n");
 244                 goto err_free;
 245         }
 246
 247         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 248         if (ret) {
 249                 hid_err(hdev, "hw start failed\n");
 250                 goto err_free;
 251         }
 252
 253         if (elo_broken_firmware(priv->usbdev)) {
 254                 hid_info(hdev, "broken firmware found, installing workaround\n");
 255                 queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
 256         }
 257
 258         return 0;
 259 err_free:
 260         kfree(priv);
 261         return ret;
 262 }
 263
 264 static void elo_remove(struct hid_device *hdev)
 265 {
 266         struct elo_priv *priv = hid_get_drvdata(hdev);
 267
 268         hid_hw_stop(hdev);
 269         cancel_delayed_work_sync(&priv->work);
 270         kfree(priv);
 271 }
 272
 273 static const struct hid_device_id elo_devices[] = {
 274         { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
 275         { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
 276         { }
 277 };
 278 MODULE_DEVICE_TABLE(hid, elo_devices);
 279
 280 static struct hid_driver elo_driver = {
 281         .name = "elo",
 282         .id_table = elo_devices,
 283         .probe = elo_probe,
 284         .remove = elo_remove,
 285         .raw_event = elo_raw_event,
 286         .input_configured = elo_input_configured,
 287 };
 288
 289 static int __init elo_driver_init(void)
 290 {
 291         int ret;
 292
 293         wq = create_singlethread_workqueue("elousb");
 294         if (!wq)
 295                 return -ENOMEM;
 296
 297         ret = hid_register_driver(&elo_driver);
 298         if (ret)
 299                 destroy_workqueue(wq);
 300
 301         return ret;
 302 }
 303 module_init(elo_driver_init);
 304
 305 static void __exit elo_driver_exit(void)
 306 {
 307         hid_unregister_driver(&elo_driver);
 308         destroy_workqueue(wq);
 309 }
 310 module_exit(elo_driver_exit);
 311
 312 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
 313 MODULE_LICENSE("GPL");