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