kernel/drivers/hid/hid-elo.c

   1 /*
   2  * HID driver for ELO usb touchscreen 4000/4500
   3  *
   4  * Copyright (c) 2013 Jiri Slaby
   5  *
   6  * Data parsing taken from elousb driver by Vojtech Pavlik.
   7  *
   8  * This driver is licensed under the terms of GPLv2.
   9  */
  10
  11 #include <linux/hid.h>
  12 #include <linux/input.h>
  13 #include <linux/module.h>
  14 #include <linux/usb.h>
  15 #include <linux/workqueue.h>
  16
  17 #include "hid-ids.h"
  18
  19 #define ELO_PERIODIC_READ_INTERVAL      HZ
  20 #define ELO_SMARTSET_CMD_TIMEOUT        2000 /* msec */
  21
  22 /* Elo SmartSet commands */
  23 #define ELO_FLUSH_SMARTSET_RESPONSES    0x02 /* Flush all pending smartset responses */
  24 #define ELO_SEND_SMARTSET_COMMAND       0x05 /* Send a smartset command */
  25 #define ELO_GET_SMARTSET_RESPONSE       0x06 /* Get a smartset response */
  26 #define ELO_DIAG                        0x64 /* Diagnostics command */
  27 #define ELO_SMARTSET_PACKET_SIZE        8
  28
  29 struct elo_priv {
  30         struct usb_device *usbdev;
  31         struct delayed_work work;
  32         unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
  33 };
  34
  35 static struct workqueue_struct *wq;
  36 static bool use_fw_quirk = true;
  37 module_param(use_fw_quirk, bool, S_IRUGO);
  38 MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
  39
  40 static int elo_input_configured(struct hid_device *hdev,
  41                 struct hid_input *hidinput)
  42 {
  43         struct input_dev *input = hidinput->input;
  44
  45         set_bit(BTN_TOUCH, input->keybit);
  46         set_bit(ABS_PRESSURE, input->absbit);
  47         input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
  48
  49         return 0;
  50 }
  51
  52 static void elo_process_data(struct input_dev *input, const u8 *data, int size)
  53 {
  54         int press;
  55
  56         input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
  57         input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
  58
  59         press = 0;
  60         if (data[1] & 0x80)
  61                 press = (data[7] << 8) | data[6];
  62         input_report_abs(input, ABS_PRESSURE, press);
  63
  64         if (data[1] & 0x03) {
  65                 input_report_key(input, BTN_TOUCH, 1);
  66                 input_sync(input);
  67         }
  68
  69         if (data[1] & 0x04)
  70                 input_report_key(input, BTN_TOUCH, 0);
  71
  72         input_sync(input);
  73 }
  74
  75 static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
  76          u8 *data, int size)
  77 {
  78         struct hid_input *hidinput;
  79
  80         if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
  81                 return 0;
  82
  83         hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
  84
  85         switch (report->id) {
  86         case 0:
  87                 if (data[0] == 'T') {   /* Mandatory ELO packet marker */
  88                         elo_process_data(hidinput->input, data, size);
  89                         return 1;
  90                 }
  91                 break;
  92         default:        /* unknown report */
  93                 /* Unknown report type; pass upstream */
  94                 hid_info(hdev, "unknown report type %d\n", report->id);
  95                 break;
  96         }
  97
  98         return 0;
  99 }
 100
 101 static int elo_smartset_send_get(struct usb_device *dev, u8 command,
 102                 void *data)
 103 {
 104         unsigned int pipe;
 105         u8 dir;
 106
 107         if (command == ELO_SEND_SMARTSET_COMMAND) {
 108                 pipe = usb_sndctrlpipe(dev, 0);
 109                 dir = USB_DIR_OUT;
 110         } else if (command == ELO_GET_SMARTSET_RESPONSE) {
 111                 pipe = usb_rcvctrlpipe(dev, 0);
 112                 dir = USB_DIR_IN;
 113         } else
 114                 return -EINVAL;
 115
 116         return usb_control_msg(dev, pipe, command,
 117                         dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 118                         0, 0, data, ELO_SMARTSET_PACKET_SIZE,
 119                         ELO_SMARTSET_CMD_TIMEOUT);
 120 }
 121
 122 static int elo_flush_smartset_responses(struct usb_device *dev)
 123 {
 124         return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
 125                         ELO_FLUSH_SMARTSET_RESPONSES,
 126                         USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 127                         0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 128 }
 129
 130 static void elo_work(struct work_struct *work)
 131 {
 132         struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
 133         struct usb_device *dev = priv->usbdev;
 134         unsigned char *buffer = priv->buffer;
 135         int ret;
 136
 137         ret = elo_flush_smartset_responses(dev);
 138         if (ret < 0) {
 139                 dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
 140                                 ret);
 141                 goto fail;
 142         }
 143
 144         /* send Diagnostics command */
 145         *buffer = ELO_DIAG;
 146         ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
 147         if (ret < 0) {
 148                 dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
 149                                 ret);
 150                 goto fail;
 151         }
 152
 153         /* get the result */
 154         ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
 155         if (ret < 0) {
 156                 dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
 157                                 ret);
 158                 goto fail;
 159         }
 160
 161         /* read the ack */
 162         if (*buffer != 'A') {
 163                 ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
 164                                 buffer);
 165                 if (ret < 0) {
 166                         dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
 167                                         ret);
 168                         goto fail;
 169                 }
 170         }
 171
 172 fail:
 173         ret = elo_flush_smartset_responses(dev);
 174         if (ret < 0)
 175                 dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
 176                                 ret);
 177         queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
 178 }
 179
 180 /*
 181  * Not all Elo devices need the periodic HID descriptor reads.
 182  * Only firmware version M needs this.
 183  */
 184 static bool elo_broken_firmware(struct usb_device *dev)
 185 {
 186         struct usb_device *hub = dev->parent;
 187         struct usb_device *child = NULL;
 188         u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
 189         u16 child_vid, child_pid;
 190         int i;
 191
 192         if (!use_fw_quirk)
 193                 return false;
 194         if (fw_lvl != 0x10d)
 195                 return false;
 196
 197         /* iterate sibling devices of the touch controller */
 198         usb_hub_for_each_child(hub, i, child) {
 199                 child_vid = le16_to_cpu(child->descriptor.idVendor);
 200                 child_pid = le16_to_cpu(child->descriptor.idProduct);
 201
 202                 /*
 203                  * If one of the devices below is present attached as a sibling of
 204                  * the touch controller then  this is a newer IBM 4820 monitor that
 205                  * does not need the IBM-requested workaround if fw level is
 206                  * 0x010d - aka 'M'.
 207                  * No other HW can have this combination.
 208                  */
 209                 if (child_vid==0x04b3) {
 210                         switch (child_pid) {
 211                         case 0x4676: /* 4820 21x Video */
 212                         case 0x4677: /* 4820 51x Video */
 213                         case 0x4678: /* 4820 2Lx Video */
 214                         case 0x4679: /* 4820 5Lx Video */
 215                                 return false;
 216                         }
 217                 }
 218         }
 219         return true;
 220 }
 221
 222 static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
 223 {
 224         struct elo_priv *priv;
 225         int ret;
 226
 227         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 228         if (!priv)
 229                 return -ENOMEM;
 230
 231         INIT_DELAYED_WORK(&priv->work, elo_work);
 232         priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
 233
 234         hid_set_drvdata(hdev, priv);
 235
 236         ret = hid_parse(hdev);
 237         if (ret) {
 238                 hid_err(hdev, "parse failed\n");
 239                 goto err_free;
 240         }
 241
 242         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 243         if (ret) {
 244                 hid_err(hdev, "hw start failed\n");
 245                 goto err_free;
 246         }
 247
 248         if (elo_broken_firmware(priv->usbdev)) {
 249                 hid_info(hdev, "broken firmware found, installing workaround\n");
 250                 queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
 251         }
 252
 253         return 0;
 254 err_free:
 255         kfree(priv);
 256         return ret;
 257 }
 258
 259 static void elo_remove(struct hid_device *hdev)
 260 {
 261         struct elo_priv *priv = hid_get_drvdata(hdev);
 262
 263         hid_hw_stop(hdev);
 264         cancel_delayed_work_sync(&priv->work);
 265         kfree(priv);
 266 }
 267
 268 static const struct hid_device_id elo_devices[] = {
 269         { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
 270         { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
 271         { }
 272 };
 273 MODULE_DEVICE_TABLE(hid, elo_devices);
 274
 275 static struct hid_driver elo_driver = {
 276         .name = "elo",
 277         .id_table = elo_devices,
 278         .probe = elo_probe,
 279         .remove = elo_remove,
 280         .raw_event = elo_raw_event,
 281         .input_configured = elo_input_configured,
 282 };
 283
 284 static int __init elo_driver_init(void)
 285 {
 286         int ret;
 287
 288         wq = create_singlethread_workqueue("elousb");
 289         if (!wq)
 290                 return -ENOMEM;
 291
 292         ret = hid_register_driver(&elo_driver);
 293         if (ret)
 294                 destroy_workqueue(wq);
 295
 296         return ret;
 297 }
 298 module_init(elo_driver_init);
 299
 300 static void __exit elo_driver_exit(void)
 301 {
 302         hid_unregister_driver(&elo_driver);
 303         destroy_workqueue(wq);
 304 }
 305 module_exit(elo_driver_exit);
 306
 307 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
 308 MODULE_LICENSE("GPL");