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 struct usb_device *udev; 232 233 if (!hid_is_usb(hdev)) 234 return -EINVAL; 235 236 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 237 if (!priv) 238 return -ENOMEM; 239 240 INIT_DELAYED_WORK(&priv->work, elo_work); 241 udev = interface_to_usbdev(to_usb_interface(hdev->dev.parent)); 242 priv->usbdev = usb_get_dev(udev); 243 244 hid_set_drvdata(hdev, priv); 245 246 ret = hid_parse(hdev); 247 if (ret) { 248 hid_err(hdev, "parse failed\n"); 249 goto err_free; 250 } 251 252 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); 253 if (ret) { 254 hid_err(hdev, "hw start failed\n"); 255 goto err_free; 256 } 257 258 if (elo_broken_firmware(priv->usbdev)) { 259 hid_info(hdev, "broken firmware found, installing workaround\n"); 260 queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL); 261 } 262 263 return 0; 264 err_free: 265 kfree(priv); 266 return ret; 267 } 268 269 static void elo_remove(struct hid_device *hdev) 270 { 271 struct elo_priv *priv = hid_get_drvdata(hdev); 272 273 usb_put_dev(priv->usbdev); 274 275 hid_hw_stop(hdev); 276 cancel_delayed_work_sync(&priv->work); 277 kfree(priv); 278 } 279 280 static const struct hid_device_id elo_devices[] = { 281 { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), }, 282 { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), }, 283 { } 284 }; 285 MODULE_DEVICE_TABLE(hid, elo_devices); 286 287 static struct hid_driver elo_driver = { 288 .name = "elo", 289 .id_table = elo_devices, 290 .probe = elo_probe, 291 .remove = elo_remove, 292 .raw_event = elo_raw_event, 293 .input_configured = elo_input_configured, 294 }; 295 296 static int __init elo_driver_init(void) 297 { 298 int ret; 299 300 wq = create_singlethread_workqueue("elousb"); 301 if (!wq) 302 return -ENOMEM; 303 304 ret = hid_register_driver(&elo_driver); 305 if (ret) 306 destroy_workqueue(wq); 307 308 return ret; 309 } 310 module_init(elo_driver_init); 311 312 static void __exit elo_driver_exit(void) 313 { 314 hid_unregister_driver(&elo_driver); 315 destroy_workqueue(wq); 316 } 317 module_exit(elo_driver_exit); 318 319 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>"); 320 MODULE_LICENSE("GPL"); 321