linux/drivers/hid/hid-elo.c
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   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
  29struct elo_priv {
  30        struct usb_device *usbdev;
  31        struct delayed_work work;
  32        unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
  33};
  34
  35static struct workqueue_struct *wq;
  36static bool use_fw_quirk = true;
  37module_param(use_fw_quirk, bool, S_IRUGO);
  38MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
  39
  40static int elo_input_configured(struct hid_device *hdev,
  41                struct hid_input *hidinput)
  42{
  43        struct input_dev *input = hidinput->input;
  44
  45        /*
  46         * ELO devices have one Button usage in GenDesk field, which makes
  47         * hid-input map it to BTN_LEFT; that confuses userspace, which then
  48         * considers the device to be a mouse/touchpad instead of touchscreen.
  49         */
  50        clear_bit(BTN_LEFT, input->keybit);
  51        set_bit(BTN_TOUCH, input->keybit);
  52        set_bit(ABS_PRESSURE, input->absbit);
  53        input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
  54
  55        return 0;
  56}
  57
  58static void elo_process_data(struct input_dev *input, const u8 *data, int size)
  59{
  60        int press;
  61
  62        input_report_abs(input, ABS_X, (data[3] << 8) | data[2]);
  63        input_report_abs(input, ABS_Y, (data[5] << 8) | data[4]);
  64
  65        press = 0;
  66        if (data[1] & 0x80)
  67                press = (data[7] << 8) | data[6];
  68        input_report_abs(input, ABS_PRESSURE, press);
  69
  70        if (data[1] & 0x03) {
  71                input_report_key(input, BTN_TOUCH, 1);
  72                input_sync(input);
  73        }
  74
  75        if (data[1] & 0x04)
  76                input_report_key(input, BTN_TOUCH, 0);
  77
  78        input_sync(input);
  79}
  80
  81static int elo_raw_event(struct hid_device *hdev, struct hid_report *report,
  82         u8 *data, int size)
  83{
  84        struct hid_input *hidinput;
  85
  86        if (!(hdev->claimed & HID_CLAIMED_INPUT) || list_empty(&hdev->inputs))
  87                return 0;
  88
  89        hidinput = list_first_entry(&hdev->inputs, struct hid_input, list);
  90
  91        switch (report->id) {
  92        case 0:
  93                if (data[0] == 'T') {   /* Mandatory ELO packet marker */
  94                        elo_process_data(hidinput->input, data, size);
  95                        return 1;
  96                }
  97                break;
  98        default:        /* unknown report */
  99                /* Unknown report type; pass upstream */
 100                hid_info(hdev, "unknown report type %d\n", report->id);
 101                break;
 102        }
 103
 104        return 0;
 105}
 106
 107static int elo_smartset_send_get(struct usb_device *dev, u8 command,
 108                void *data)
 109{
 110        unsigned int pipe;
 111        u8 dir;
 112
 113        if (command == ELO_SEND_SMARTSET_COMMAND) {
 114                pipe = usb_sndctrlpipe(dev, 0);
 115                dir = USB_DIR_OUT;
 116        } else if (command == ELO_GET_SMARTSET_RESPONSE) {
 117                pipe = usb_rcvctrlpipe(dev, 0);
 118                dir = USB_DIR_IN;
 119        } else
 120                return -EINVAL;
 121
 122        return usb_control_msg(dev, pipe, command,
 123                        dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 124                        0, 0, data, ELO_SMARTSET_PACKET_SIZE,
 125                        ELO_SMARTSET_CMD_TIMEOUT);
 126}
 127
 128static int elo_flush_smartset_responses(struct usb_device *dev)
 129{
 130        return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
 131                        ELO_FLUSH_SMARTSET_RESPONSES,
 132                        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 133                        0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
 134}
 135
 136static void elo_work(struct work_struct *work)
 137{
 138        struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
 139        struct usb_device *dev = priv->usbdev;
 140        unsigned char *buffer = priv->buffer;
 141        int ret;
 142
 143        ret = elo_flush_smartset_responses(dev);
 144        if (ret < 0) {
 145                dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
 146                                ret);
 147                goto fail;
 148        }
 149
 150        /* send Diagnostics command */
 151        *buffer = ELO_DIAG;
 152        ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
 153        if (ret < 0) {
 154                dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
 155                                ret);
 156                goto fail;
 157        }
 158
 159        /* get the result */
 160        ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
 161        if (ret < 0) {
 162                dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
 163                                ret);
 164                goto fail;
 165        }
 166
 167        /* read the ack */
 168        if (*buffer != 'A') {
 169                ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
 170                                buffer);
 171                if (ret < 0) {
 172                        dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
 173                                        ret);
 174                        goto fail;
 175                }
 176        }
 177
 178fail:
 179        ret = elo_flush_smartset_responses(dev);
 180        if (ret < 0)
 181                dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
 182                                ret);
 183        queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
 184}
 185
 186/*
 187 * Not all Elo devices need the periodic HID descriptor reads.
 188 * Only firmware version M needs this.
 189 */
 190static bool elo_broken_firmware(struct usb_device *dev)
 191{
 192        struct usb_device *hub = dev->parent;
 193        struct usb_device *child = NULL;
 194        u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice);
 195        u16 child_vid, child_pid;
 196        int i;
 197    
 198        if (!use_fw_quirk)
 199                return false;
 200        if (fw_lvl != 0x10d)
 201                return false;
 202
 203        /* iterate sibling devices of the touch controller */
 204        usb_hub_for_each_child(hub, i, child) {
 205                child_vid = le16_to_cpu(child->descriptor.idVendor);
 206                child_pid = le16_to_cpu(child->descriptor.idProduct);
 207
 208                /*
 209                 * If one of the devices below is present attached as a sibling of 
 210                 * the touch controller then  this is a newer IBM 4820 monitor that 
 211                 * does not need the IBM-requested workaround if fw level is
 212                 * 0x010d - aka 'M'.
 213                 * No other HW can have this combination.
 214                 */
 215                if (child_vid==0x04b3) {
 216                        switch (child_pid) {
 217                        case 0x4676: /* 4820 21x Video */
 218                        case 0x4677: /* 4820 51x Video */
 219                        case 0x4678: /* 4820 2Lx Video */
 220                        case 0x4679: /* 4820 5Lx Video */
 221                                return false;
 222                        }
 223                }
 224        }
 225        return true;
 226}
 227
 228static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
 229{
 230        struct elo_priv *priv;
 231        int ret;
 232
 233        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 234        if (!priv)
 235                return -ENOMEM;
 236
 237        INIT_DELAYED_WORK(&priv->work, elo_work);
 238        priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
 239
 240        hid_set_drvdata(hdev, priv);
 241
 242        ret = hid_parse(hdev);
 243        if (ret) {
 244                hid_err(hdev, "parse failed\n");
 245                goto err_free;
 246        }
 247
 248        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 249        if (ret) {
 250                hid_err(hdev, "hw start failed\n");
 251                goto err_free;
 252        }
 253
 254        if (elo_broken_firmware(priv->usbdev)) {
 255                hid_info(hdev, "broken firmware found, installing workaround\n");
 256                queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
 257        }
 258
 259        return 0;
 260err_free:
 261        kfree(priv);
 262        return ret;
 263}
 264
 265static void elo_remove(struct hid_device *hdev)
 266{
 267        struct elo_priv *priv = hid_get_drvdata(hdev);
 268
 269        hid_hw_stop(hdev);
 270        cancel_delayed_work_sync(&priv->work);
 271        kfree(priv);
 272}
 273
 274static const struct hid_device_id elo_devices[] = {
 275        { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), },
 276        { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), },
 277        { }
 278};
 279MODULE_DEVICE_TABLE(hid, elo_devices);
 280
 281static struct hid_driver elo_driver = {
 282        .name = "elo",
 283        .id_table = elo_devices,
 284        .probe = elo_probe,
 285        .remove = elo_remove,
 286        .raw_event = elo_raw_event,
 287        .input_configured = elo_input_configured,
 288};
 289
 290static int __init elo_driver_init(void)
 291{
 292        int ret;
 293
 294        wq = create_singlethread_workqueue("elousb");
 295        if (!wq)
 296                return -ENOMEM;
 297
 298        ret = hid_register_driver(&elo_driver);
 299        if (ret)
 300                destroy_workqueue(wq);
 301
 302        return ret;
 303}
 304module_init(elo_driver_init);
 305
 306static void __exit elo_driver_exit(void)
 307{
 308        hid_unregister_driver(&elo_driver);
 309        destroy_workqueue(wq);
 310}
 311module_exit(elo_driver_exit);
 312
 313MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>");
 314MODULE_LICENSE("GPL");
 315