1 /* -*- linux-c -*- 2 * Cypress USB Thermometer driver 3 * 4 * Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com> 5 * 6 * This driver works with Elektor magazine USB Interface as published in 7 * issue #291. It should also work with the original starter kit/demo board 8 * from Cypress. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License as 12 * published by the Free Software Foundation, version 2. 13 * 14 */ 15 16 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/slab.h> 20 #include <linux/module.h> 21 #include <linux/usb.h> 22 23 #define DRIVER_VERSION "v1.0" 24 #define DRIVER_AUTHOR "Erik Rigtorp" 25 #define DRIVER_DESC "Cypress USB Thermometer driver" 26 27 #define USB_SKEL_VENDOR_ID 0x04b4 28 #define USB_SKEL_PRODUCT_ID 0x0002 29 30 static const struct usb_device_id id_table[] = { 31 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, 32 { } 33 }; 34 MODULE_DEVICE_TABLE (usb, id_table); 35 36 /* Structure to hold all of our device specific stuff */ 37 struct usb_cytherm { 38 struct usb_device *udev; /* save off the usb device pointer */ 39 struct usb_interface *interface; /* the interface for this device */ 40 int brightness; 41 }; 42 43 44 /* local function prototypes */ 45 static int cytherm_probe(struct usb_interface *interface, 46 const struct usb_device_id *id); 47 static void cytherm_disconnect(struct usb_interface *interface); 48 49 50 /* usb specific object needed to register this driver with the usb subsystem */ 51 static struct usb_driver cytherm_driver = { 52 .name = "cytherm", 53 .probe = cytherm_probe, 54 .disconnect = cytherm_disconnect, 55 .id_table = id_table, 56 }; 57 58 /* Vendor requests */ 59 /* They all operate on one byte at a time */ 60 #define PING 0x00 61 #define READ_ROM 0x01 /* Reads form ROM, value = address */ 62 #define READ_RAM 0x02 /* Reads form RAM, value = address */ 63 #define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */ 64 #define READ_PORT 0x04 /* Reads from port, value = address */ 65 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */ 66 67 68 /* Send a vendor command to device */ 69 static int vendor_command(struct usb_device *dev, unsigned char request, 70 unsigned char value, unsigned char index, 71 void *buf, int size) 72 { 73 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), 74 request, 75 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER, 76 value, 77 index, buf, size, 78 USB_CTRL_GET_TIMEOUT); 79 } 80 81 82 83 #define BRIGHTNESS 0x2c /* RAM location for brightness value */ 84 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */ 85 86 static ssize_t show_brightness(struct device *dev, struct device_attribute *attr, char *buf) 87 { 88 struct usb_interface *intf = to_usb_interface(dev); 89 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 90 91 return sprintf(buf, "%i", cytherm->brightness); 92 } 93 94 static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf, 95 size_t count) 96 { 97 struct usb_interface *intf = to_usb_interface(dev); 98 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 99 100 unsigned char *buffer; 101 int retval; 102 103 buffer = kmalloc(8, GFP_KERNEL); 104 if (!buffer) { 105 dev_err(&cytherm->udev->dev, "out of memory\n"); 106 return 0; 107 } 108 109 cytherm->brightness = simple_strtoul(buf, NULL, 10); 110 111 if (cytherm->brightness > 0xFF) 112 cytherm->brightness = 0xFF; 113 else if (cytherm->brightness < 0) 114 cytherm->brightness = 0; 115 116 /* Set brightness */ 117 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS, 118 cytherm->brightness, buffer, 8); 119 if (retval) 120 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 121 /* Inform µC that we have changed the brightness setting */ 122 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM, 123 0x01, buffer, 8); 124 if (retval) 125 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 126 127 kfree(buffer); 128 129 return count; 130 } 131 132 static DEVICE_ATTR(brightness, S_IRUGO | S_IWUSR | S_IWGRP, 133 show_brightness, set_brightness); 134 135 136 #define TEMP 0x33 /* RAM location for temperature */ 137 #define SIGN 0x34 /* RAM location for temperature sign */ 138 139 static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf) 140 { 141 142 struct usb_interface *intf = to_usb_interface(dev); 143 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 144 145 int retval; 146 unsigned char *buffer; 147 148 int temp, sign; 149 150 buffer = kmalloc(8, GFP_KERNEL); 151 if (!buffer) { 152 dev_err(&cytherm->udev->dev, "out of memory\n"); 153 return 0; 154 } 155 156 /* read temperature */ 157 retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8); 158 if (retval) 159 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 160 temp = buffer[1]; 161 162 /* read sign */ 163 retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8); 164 if (retval) 165 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 166 sign = buffer[1]; 167 168 kfree(buffer); 169 170 return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1, 171 5*(temp - ((temp >> 1) << 1))); 172 } 173 174 175 static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 176 { 177 return count; 178 } 179 180 static DEVICE_ATTR(temp, S_IRUGO, show_temp, set_temp); 181 182 183 #define BUTTON 0x7a 184 185 static ssize_t show_button(struct device *dev, struct device_attribute *attr, char *buf) 186 { 187 188 struct usb_interface *intf = to_usb_interface(dev); 189 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 190 191 int retval; 192 unsigned char *buffer; 193 194 buffer = kmalloc(8, GFP_KERNEL); 195 if (!buffer) { 196 dev_err(&cytherm->udev->dev, "out of memory\n"); 197 return 0; 198 } 199 200 /* check button */ 201 retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8); 202 if (retval) 203 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 204 205 retval = buffer[1]; 206 207 kfree(buffer); 208 209 if (retval) 210 return sprintf(buf, "1"); 211 else 212 return sprintf(buf, "0"); 213 } 214 215 216 static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 217 { 218 return count; 219 } 220 221 static DEVICE_ATTR(button, S_IRUGO, show_button, set_button); 222 223 224 static ssize_t show_port0(struct device *dev, struct device_attribute *attr, char *buf) 225 { 226 struct usb_interface *intf = to_usb_interface(dev); 227 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 228 229 int retval; 230 unsigned char *buffer; 231 232 buffer = kmalloc(8, GFP_KERNEL); 233 if (!buffer) { 234 dev_err(&cytherm->udev->dev, "out of memory\n"); 235 return 0; 236 } 237 238 retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8); 239 if (retval) 240 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 241 242 retval = buffer[1]; 243 244 kfree(buffer); 245 246 return sprintf(buf, "%d", retval); 247 } 248 249 250 static ssize_t set_port0(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 251 { 252 struct usb_interface *intf = to_usb_interface(dev); 253 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 254 255 unsigned char *buffer; 256 int retval; 257 int tmp; 258 259 buffer = kmalloc(8, GFP_KERNEL); 260 if (!buffer) { 261 dev_err(&cytherm->udev->dev, "out of memory\n"); 262 return 0; 263 } 264 265 tmp = simple_strtoul(buf, NULL, 10); 266 267 if (tmp > 0xFF) 268 tmp = 0xFF; 269 else if (tmp < 0) 270 tmp = 0; 271 272 retval = vendor_command(cytherm->udev, WRITE_PORT, 0, 273 tmp, buffer, 8); 274 if (retval) 275 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 276 277 kfree(buffer); 278 279 return count; 280 } 281 282 static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR | S_IWGRP, show_port0, set_port0); 283 284 static ssize_t show_port1(struct device *dev, struct device_attribute *attr, char *buf) 285 { 286 struct usb_interface *intf = to_usb_interface(dev); 287 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 288 289 int retval; 290 unsigned char *buffer; 291 292 buffer = kmalloc(8, GFP_KERNEL); 293 if (!buffer) { 294 dev_err(&cytherm->udev->dev, "out of memory\n"); 295 return 0; 296 } 297 298 retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8); 299 if (retval) 300 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 301 302 retval = buffer[1]; 303 304 kfree(buffer); 305 306 return sprintf(buf, "%d", retval); 307 } 308 309 310 static ssize_t set_port1(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 311 { 312 struct usb_interface *intf = to_usb_interface(dev); 313 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 314 315 unsigned char *buffer; 316 int retval; 317 int tmp; 318 319 buffer = kmalloc(8, GFP_KERNEL); 320 if (!buffer) { 321 dev_err(&cytherm->udev->dev, "out of memory\n"); 322 return 0; 323 } 324 325 tmp = simple_strtoul(buf, NULL, 10); 326 327 if (tmp > 0xFF) 328 tmp = 0xFF; 329 else if (tmp < 0) 330 tmp = 0; 331 332 retval = vendor_command(cytherm->udev, WRITE_PORT, 1, 333 tmp, buffer, 8); 334 if (retval) 335 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 336 337 kfree(buffer); 338 339 return count; 340 } 341 342 static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR | S_IWGRP, show_port1, set_port1); 343 344 345 346 static int cytherm_probe(struct usb_interface *interface, 347 const struct usb_device_id *id) 348 { 349 struct usb_device *udev = interface_to_usbdev(interface); 350 struct usb_cytherm *dev = NULL; 351 int retval = -ENOMEM; 352 353 dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL); 354 if (dev == NULL) { 355 dev_err (&interface->dev, "Out of memory\n"); 356 goto error_mem; 357 } 358 359 dev->udev = usb_get_dev(udev); 360 361 usb_set_intfdata (interface, dev); 362 363 dev->brightness = 0xFF; 364 365 retval = device_create_file(&interface->dev, &dev_attr_brightness); 366 if (retval) 367 goto error; 368 retval = device_create_file(&interface->dev, &dev_attr_temp); 369 if (retval) 370 goto error; 371 retval = device_create_file(&interface->dev, &dev_attr_button); 372 if (retval) 373 goto error; 374 retval = device_create_file(&interface->dev, &dev_attr_port0); 375 if (retval) 376 goto error; 377 retval = device_create_file(&interface->dev, &dev_attr_port1); 378 if (retval) 379 goto error; 380 381 dev_info (&interface->dev, 382 "Cypress thermometer device now attached\n"); 383 return 0; 384 error: 385 device_remove_file(&interface->dev, &dev_attr_brightness); 386 device_remove_file(&interface->dev, &dev_attr_temp); 387 device_remove_file(&interface->dev, &dev_attr_button); 388 device_remove_file(&interface->dev, &dev_attr_port0); 389 device_remove_file(&interface->dev, &dev_attr_port1); 390 usb_set_intfdata (interface, NULL); 391 usb_put_dev(dev->udev); 392 kfree(dev); 393 error_mem: 394 return retval; 395 } 396 397 static void cytherm_disconnect(struct usb_interface *interface) 398 { 399 struct usb_cytherm *dev; 400 401 dev = usb_get_intfdata (interface); 402 403 device_remove_file(&interface->dev, &dev_attr_brightness); 404 device_remove_file(&interface->dev, &dev_attr_temp); 405 device_remove_file(&interface->dev, &dev_attr_button); 406 device_remove_file(&interface->dev, &dev_attr_port0); 407 device_remove_file(&interface->dev, &dev_attr_port1); 408 409 /* first remove the files, then NULL the pointer */ 410 usb_set_intfdata (interface, NULL); 411 412 usb_put_dev(dev->udev); 413 414 kfree(dev); 415 416 dev_info(&interface->dev, "Cypress thermometer now disconnected\n"); 417 } 418 419 module_usb_driver(cytherm_driver); 420 421 MODULE_AUTHOR(DRIVER_AUTHOR); 422 MODULE_DESCRIPTION(DRIVER_DESC); 423 MODULE_LICENSE("GPL"); 424