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 if (size < ELO_SMARTSET_PACKET_SIZE) 89 return 0; 90 91 hidinput = list_first_entry(&hdev->inputs, struct hid_input, list); 92 93 switch (report->id) { 94 case 0: 95 if (data[0] == 'T') { /* Mandatory ELO packet marker */ 96 elo_process_data(hidinput->input, data, size); 97 return 1; 98 } 99 break; 100 default: /* unknown report */ 101 /* Unknown report type; pass upstream */ 102 hid_info(hdev, "unknown report type %d\n", report->id); 103 break; 104 } 105 106 return 0; 107 } 108 109 static int elo_smartset_send_get(struct usb_device *dev, u8 command, 110 void *data) 111 { 112 unsigned int pipe; 113 u8 dir; 114 115 if (command == ELO_SEND_SMARTSET_COMMAND) { 116 pipe = usb_sndctrlpipe(dev, 0); 117 dir = USB_DIR_OUT; 118 } else if (command == ELO_GET_SMARTSET_RESPONSE) { 119 pipe = usb_rcvctrlpipe(dev, 0); 120 dir = USB_DIR_IN; 121 } else 122 return -EINVAL; 123 124 return usb_control_msg(dev, pipe, command, 125 dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 126 0, 0, data, ELO_SMARTSET_PACKET_SIZE, 127 ELO_SMARTSET_CMD_TIMEOUT); 128 } 129 130 static int elo_flush_smartset_responses(struct usb_device *dev) 131 { 132 return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), 133 ELO_FLUSH_SMARTSET_RESPONSES, 134 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 135 0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT); 136 } 137 138 static void elo_work(struct work_struct *work) 139 { 140 struct elo_priv *priv = container_of(work, struct elo_priv, work.work); 141 struct usb_device *dev = priv->usbdev; 142 unsigned char *buffer = priv->buffer; 143 int ret; 144 145 ret = elo_flush_smartset_responses(dev); 146 if (ret < 0) { 147 dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n", 148 ret); 149 goto fail; 150 } 151 152 /* send Diagnostics command */ 153 *buffer = ELO_DIAG; 154 ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer); 155 if (ret < 0) { 156 dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n", 157 ret); 158 goto fail; 159 } 160 161 /* get the result */ 162 ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer); 163 if (ret < 0) { 164 dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n", 165 ret); 166 goto fail; 167 } 168 169 /* read the ack */ 170 if (*buffer != 'A') { 171 ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, 172 buffer); 173 if (ret < 0) { 174 dev_err(&dev->dev, "get acknowledge response failed, error %d\n", 175 ret); 176 goto fail; 177 } 178 } 179 180 fail: 181 ret = elo_flush_smartset_responses(dev); 182 if (ret < 0) 183 dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n", 184 ret); 185 queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL); 186 } 187 188 /* 189 * Not all Elo devices need the periodic HID descriptor reads. 190 * Only firmware version M needs this. 191 */ 192 static bool elo_broken_firmware(struct usb_device *dev) 193 { 194 struct usb_device *hub = dev->parent; 195 struct usb_device *child = NULL; 196 u16 fw_lvl = le16_to_cpu(dev->descriptor.bcdDevice); 197 u16 child_vid, child_pid; 198 int i; 199 200 if (!use_fw_quirk) 201 return false; 202 if (fw_lvl != 0x10d) 203 return false; 204 205 /* iterate sibling devices of the touch controller */ 206 usb_hub_for_each_child(hub, i, child) { 207 child_vid = le16_to_cpu(child->descriptor.idVendor); 208 child_pid = le16_to_cpu(child->descriptor.idProduct); 209 210 /* 211 * If one of the devices below is present attached as a sibling of 212 * the touch controller then this is a newer IBM 4820 monitor that 213 * does not need the IBM-requested workaround if fw level is 214 * 0x010d - aka 'M'. 215 * No other HW can have this combination. 216 */ 217 if (child_vid==0x04b3) { 218 switch (child_pid) { 219 case 0x4676: /* 4820 21x Video */ 220 case 0x4677: /* 4820 51x Video */ 221 case 0x4678: /* 4820 2Lx Video */ 222 case 0x4679: /* 4820 5Lx Video */ 223 return false; 224 } 225 } 226 } 227 return true; 228 } 229 230 static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id) 231 { 232 struct elo_priv *priv; 233 int ret; 234 235 if (!hid_is_usb(hdev)) 236 return -EINVAL; 237 238 priv = kzalloc_obj(*priv); 239 if (!priv) 240 return -ENOMEM; 241 242 INIT_DELAYED_WORK(&priv->work, elo_work); 243 priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent)); 244 245 hid_set_drvdata(hdev, priv); 246 247 ret = hid_parse(hdev); 248 if (ret) { 249 hid_err(hdev, "parse failed\n"); 250 goto err_free; 251 } 252 253 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT); 254 if (ret) { 255 hid_err(hdev, "hw start failed\n"); 256 goto err_free; 257 } 258 259 if (elo_broken_firmware(priv->usbdev)) { 260 hid_info(hdev, "broken firmware found, installing workaround\n"); 261 queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL); 262 } 263 264 return 0; 265 err_free: 266 kfree(priv); 267 return ret; 268 } 269 270 static void elo_remove(struct hid_device *hdev) 271 { 272 struct elo_priv *priv = hid_get_drvdata(hdev); 273 274 hid_hw_stop(hdev); 275 cancel_delayed_work_sync(&priv->work); 276 kfree(priv); 277 } 278 279 static const struct hid_device_id elo_devices[] = { 280 { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0009), }, 281 { HID_USB_DEVICE(USB_VENDOR_ID_ELO, 0x0030), }, 282 { } 283 }; 284 MODULE_DEVICE_TABLE(hid, elo_devices); 285 286 static struct hid_driver elo_driver = { 287 .name = "elo", 288 .id_table = elo_devices, 289 .probe = elo_probe, 290 .remove = elo_remove, 291 .raw_event = elo_raw_event, 292 .input_configured = elo_input_configured, 293 }; 294 295 static int __init elo_driver_init(void) 296 { 297 int ret; 298 299 wq = create_singlethread_workqueue("elousb"); 300 if (!wq) 301 return -ENOMEM; 302 303 ret = hid_register_driver(&elo_driver); 304 if (ret) 305 destroy_workqueue(wq); 306 307 return ret; 308 } 309 module_init(elo_driver_init); 310 311 static void __exit elo_driver_exit(void) 312 { 313 hid_unregister_driver(&elo_driver); 314 destroy_workqueue(wq); 315 } 316 module_exit(elo_driver_exit); 317 318 MODULE_AUTHOR("Jiri Slaby <jslaby@suse.cz>"); 319 MODULE_DESCRIPTION("HID driver for ELO usb touchscreen 4000/4500"); 320 MODULE_LICENSE("GPL"); 321