cytherm.c revision 5a0e3ad6af8660be21ca98a971cd00f331318c05
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/init.h> 20#include <linux/slab.h> 21#include <linux/module.h> 22#include <linux/usb.h> 23 24#define DRIVER_VERSION "v1.0" 25#define DRIVER_AUTHOR "Erik Rigtorp" 26#define DRIVER_DESC "Cypress USB Thermometer driver" 27 28#define USB_SKEL_VENDOR_ID 0x04b4 29#define USB_SKEL_PRODUCT_ID 0x0002 30 31static const struct usb_device_id id_table[] = { 32 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, 33 { } 34}; 35MODULE_DEVICE_TABLE (usb, id_table); 36 37/* Structure to hold all of our device specific stuff */ 38struct usb_cytherm { 39 struct usb_device *udev; /* save off the usb device pointer */ 40 struct usb_interface *interface; /* the interface for this device */ 41 int brightness; 42}; 43 44 45/* local function prototypes */ 46static int cytherm_probe(struct usb_interface *interface, 47 const struct usb_device_id *id); 48static void cytherm_disconnect(struct usb_interface *interface); 49 50 51/* usb specific object needed to register this driver with the usb subsystem */ 52static struct usb_driver cytherm_driver = { 53 .name = "cytherm", 54 .probe = cytherm_probe, 55 .disconnect = cytherm_disconnect, 56 .id_table = id_table, 57}; 58 59/* Vendor requests */ 60/* They all operate on one byte at a time */ 61#define PING 0x00 62#define READ_ROM 0x01 /* Reads form ROM, value = address */ 63#define READ_RAM 0x02 /* Reads form RAM, value = address */ 64#define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */ 65#define READ_PORT 0x04 /* Reads from port, value = address */ 66#define WRITE_PORT 0x05 /* Write to port, value = address, index = data */ 67 68 69/* Send a vendor command to device */ 70static int vendor_command(struct usb_device *dev, unsigned char request, 71 unsigned char value, unsigned char index, 72 void *buf, int size) 73{ 74 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), 75 request, 76 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER, 77 value, 78 index, buf, size, 79 USB_CTRL_GET_TIMEOUT); 80} 81 82 83 84#define BRIGHTNESS 0x2c /* RAM location for brightness value */ 85#define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */ 86 87static ssize_t show_brightness(struct device *dev, struct device_attribute *attr, char *buf) 88{ 89 struct usb_interface *intf = to_usb_interface(dev); 90 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 91 92 return sprintf(buf, "%i", cytherm->brightness); 93} 94 95static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf, 96 size_t count) 97{ 98 struct usb_interface *intf = to_usb_interface(dev); 99 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 100 101 unsigned char *buffer; 102 int retval; 103 104 buffer = kmalloc(8, GFP_KERNEL); 105 if (!buffer) { 106 dev_err(&cytherm->udev->dev, "out of memory\n"); 107 return 0; 108 } 109 110 cytherm->brightness = simple_strtoul(buf, NULL, 10); 111 112 if (cytherm->brightness > 0xFF) 113 cytherm->brightness = 0xFF; 114 else if (cytherm->brightness < 0) 115 cytherm->brightness = 0; 116 117 /* Set brightness */ 118 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS, 119 cytherm->brightness, buffer, 8); 120 if (retval) 121 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 122 /* Inform µC that we have changed the brightness setting */ 123 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM, 124 0x01, buffer, 8); 125 if (retval) 126 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 127 128 kfree(buffer); 129 130 return count; 131} 132 133static DEVICE_ATTR(brightness, S_IRUGO | S_IWUSR | S_IWGRP, 134 show_brightness, set_brightness); 135 136 137#define TEMP 0x33 /* RAM location for temperature */ 138#define SIGN 0x34 /* RAM location for temperature sign */ 139 140static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf) 141{ 142 143 struct usb_interface *intf = to_usb_interface(dev); 144 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 145 146 int retval; 147 unsigned char *buffer; 148 149 int temp, sign; 150 151 buffer = kmalloc(8, GFP_KERNEL); 152 if (!buffer) { 153 dev_err(&cytherm->udev->dev, "out of memory\n"); 154 return 0; 155 } 156 157 /* read temperature */ 158 retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8); 159 if (retval) 160 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 161 temp = buffer[1]; 162 163 /* read sign */ 164 retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8); 165 if (retval) 166 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 167 sign = buffer[1]; 168 169 kfree(buffer); 170 171 return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1, 172 5*(temp - ((temp >> 1) << 1))); 173} 174 175 176static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 177{ 178 return count; 179} 180 181static DEVICE_ATTR(temp, S_IRUGO, show_temp, set_temp); 182 183 184#define BUTTON 0x7a 185 186static ssize_t show_button(struct device *dev, struct device_attribute *attr, char *buf) 187{ 188 189 struct usb_interface *intf = to_usb_interface(dev); 190 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 191 192 int retval; 193 unsigned char *buffer; 194 195 buffer = kmalloc(8, GFP_KERNEL); 196 if (!buffer) { 197 dev_err(&cytherm->udev->dev, "out of memory\n"); 198 return 0; 199 } 200 201 /* check button */ 202 retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8); 203 if (retval) 204 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 205 206 retval = buffer[1]; 207 208 kfree(buffer); 209 210 if (retval) 211 return sprintf(buf, "1"); 212 else 213 return sprintf(buf, "0"); 214} 215 216 217static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 218{ 219 return count; 220} 221 222static DEVICE_ATTR(button, S_IRUGO, show_button, set_button); 223 224 225static ssize_t show_port0(struct device *dev, struct device_attribute *attr, char *buf) 226{ 227 struct usb_interface *intf = to_usb_interface(dev); 228 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 229 230 int retval; 231 unsigned char *buffer; 232 233 buffer = kmalloc(8, GFP_KERNEL); 234 if (!buffer) { 235 dev_err(&cytherm->udev->dev, "out of memory\n"); 236 return 0; 237 } 238 239 retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8); 240 if (retval) 241 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 242 243 retval = buffer[1]; 244 245 kfree(buffer); 246 247 return sprintf(buf, "%d", retval); 248} 249 250 251static ssize_t set_port0(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 252{ 253 struct usb_interface *intf = to_usb_interface(dev); 254 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 255 256 unsigned char *buffer; 257 int retval; 258 int tmp; 259 260 buffer = kmalloc(8, GFP_KERNEL); 261 if (!buffer) { 262 dev_err(&cytherm->udev->dev, "out of memory\n"); 263 return 0; 264 } 265 266 tmp = simple_strtoul(buf, NULL, 10); 267 268 if (tmp > 0xFF) 269 tmp = 0xFF; 270 else if (tmp < 0) 271 tmp = 0; 272 273 retval = vendor_command(cytherm->udev, WRITE_PORT, 0, 274 tmp, buffer, 8); 275 if (retval) 276 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 277 278 kfree(buffer); 279 280 return count; 281} 282 283static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR | S_IWGRP, show_port0, set_port0); 284 285static ssize_t show_port1(struct device *dev, struct device_attribute *attr, char *buf) 286{ 287 struct usb_interface *intf = to_usb_interface(dev); 288 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 289 290 int retval; 291 unsigned char *buffer; 292 293 buffer = kmalloc(8, GFP_KERNEL); 294 if (!buffer) { 295 dev_err(&cytherm->udev->dev, "out of memory\n"); 296 return 0; 297 } 298 299 retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8); 300 if (retval) 301 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 302 303 retval = buffer[1]; 304 305 kfree(buffer); 306 307 return sprintf(buf, "%d", retval); 308} 309 310 311static ssize_t set_port1(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 312{ 313 struct usb_interface *intf = to_usb_interface(dev); 314 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 315 316 unsigned char *buffer; 317 int retval; 318 int tmp; 319 320 buffer = kmalloc(8, GFP_KERNEL); 321 if (!buffer) { 322 dev_err(&cytherm->udev->dev, "out of memory\n"); 323 return 0; 324 } 325 326 tmp = simple_strtoul(buf, NULL, 10); 327 328 if (tmp > 0xFF) 329 tmp = 0xFF; 330 else if (tmp < 0) 331 tmp = 0; 332 333 retval = vendor_command(cytherm->udev, WRITE_PORT, 1, 334 tmp, buffer, 8); 335 if (retval) 336 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 337 338 kfree(buffer); 339 340 return count; 341} 342 343static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR | S_IWGRP, show_port1, set_port1); 344 345 346 347static int cytherm_probe(struct usb_interface *interface, 348 const struct usb_device_id *id) 349{ 350 struct usb_device *udev = interface_to_usbdev(interface); 351 struct usb_cytherm *dev = NULL; 352 int retval = -ENOMEM; 353 354 dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL); 355 if (dev == NULL) { 356 dev_err (&interface->dev, "Out of memory\n"); 357 goto error_mem; 358 } 359 360 dev->udev = usb_get_dev(udev); 361 362 usb_set_intfdata (interface, dev); 363 364 dev->brightness = 0xFF; 365 366 retval = device_create_file(&interface->dev, &dev_attr_brightness); 367 if (retval) 368 goto error; 369 retval = device_create_file(&interface->dev, &dev_attr_temp); 370 if (retval) 371 goto error; 372 retval = device_create_file(&interface->dev, &dev_attr_button); 373 if (retval) 374 goto error; 375 retval = device_create_file(&interface->dev, &dev_attr_port0); 376 if (retval) 377 goto error; 378 retval = device_create_file(&interface->dev, &dev_attr_port1); 379 if (retval) 380 goto error; 381 382 dev_info (&interface->dev, 383 "Cypress thermometer device now attached\n"); 384 return 0; 385error: 386 device_remove_file(&interface->dev, &dev_attr_brightness); 387 device_remove_file(&interface->dev, &dev_attr_temp); 388 device_remove_file(&interface->dev, &dev_attr_button); 389 device_remove_file(&interface->dev, &dev_attr_port0); 390 device_remove_file(&interface->dev, &dev_attr_port1); 391 usb_set_intfdata (interface, NULL); 392 usb_put_dev(dev->udev); 393 kfree(dev); 394error_mem: 395 return retval; 396} 397 398static void cytherm_disconnect(struct usb_interface *interface) 399{ 400 struct usb_cytherm *dev; 401 402 dev = usb_get_intfdata (interface); 403 404 device_remove_file(&interface->dev, &dev_attr_brightness); 405 device_remove_file(&interface->dev, &dev_attr_temp); 406 device_remove_file(&interface->dev, &dev_attr_button); 407 device_remove_file(&interface->dev, &dev_attr_port0); 408 device_remove_file(&interface->dev, &dev_attr_port1); 409 410 /* first remove the files, then NULL the pointer */ 411 usb_set_intfdata (interface, NULL); 412 413 usb_put_dev(dev->udev); 414 415 kfree(dev); 416 417 dev_info(&interface->dev, "Cypress thermometer now disconnected\n"); 418} 419 420 421static int __init usb_cytherm_init(void) 422{ 423 int result; 424 425 result = usb_register(&cytherm_driver); 426 if (result) { 427 printk(KERN_ERR KBUILD_MODNAME ": usb_register failed! " 428 "Error number: %d\n", result); 429 return result; 430 } 431 432 printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":" 433 DRIVER_DESC "\n"); 434 return 0; 435} 436 437static void __exit usb_cytherm_exit(void) 438{ 439 usb_deregister(&cytherm_driver); 440} 441 442 443module_init (usb_cytherm_init); 444module_exit (usb_cytherm_exit); 445 446MODULE_AUTHOR(DRIVER_AUTHOR); 447MODULE_DESCRIPTION(DRIVER_DESC); 448MODULE_LICENSE("GPL"); 449