1 // SPDX-License-Identifier: GPL-2.0 2 /* -*- linux-c -*- 3 * Cypress USB Thermometer driver 4 * 5 * Copyright (c) 2004 Erik Rigtorp <erkki@linux.nu> <erik@rigtorp.com> 6 * 7 * This driver works with Elektor magazine USB Interface as published in 8 * issue #291. It should also work with the original starter kit/demo board 9 * from Cypress. 10 */ 11 12 13 #include <linux/kernel.h> 14 #include <linux/errno.h> 15 #include <linux/slab.h> 16 #include <linux/module.h> 17 #include <linux/usb.h> 18 19 #define DRIVER_AUTHOR "Erik Rigtorp" 20 #define DRIVER_DESC "Cypress USB Thermometer driver" 21 22 #define USB_SKEL_VENDOR_ID 0x04b4 23 #define USB_SKEL_PRODUCT_ID 0x0002 24 25 static const struct usb_device_id id_table[] = { 26 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, 27 { } 28 }; 29 MODULE_DEVICE_TABLE (usb, id_table); 30 31 /* Structure to hold all of our device specific stuff */ 32 struct usb_cytherm { 33 struct usb_device *udev; /* save off the usb device pointer */ 34 struct usb_interface *interface; /* the interface for this device */ 35 int brightness; 36 }; 37 38 39 /* Vendor requests */ 40 /* They all operate on one byte at a time */ 41 #define PING 0x00 42 #define READ_ROM 0x01 /* Reads form ROM, value = address */ 43 #define READ_RAM 0x02 /* Reads form RAM, value = address */ 44 #define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */ 45 #define READ_PORT 0x04 /* Reads from port, value = address */ 46 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */ 47 48 49 /* Send a vendor command to device */ 50 static int vendor_command(struct usb_device *dev, unsigned char request, 51 unsigned char value, unsigned char index, 52 void *buf, int size) 53 { 54 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), 55 request, 56 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER, 57 value, 58 index, buf, size, 59 USB_CTRL_GET_TIMEOUT); 60 } 61 62 63 64 #define BRIGHTNESS 0x2c /* RAM location for brightness value */ 65 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */ 66 67 static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf) 68 { 69 struct usb_interface *intf = to_usb_interface(dev); 70 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 71 72 return sprintf(buf, "%i", cytherm->brightness); 73 } 74 75 static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf, 76 size_t count) 77 { 78 struct usb_interface *intf = to_usb_interface(dev); 79 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 80 81 unsigned char *buffer; 82 int retval; 83 84 buffer = kmalloc(8, GFP_KERNEL); 85 if (!buffer) 86 return 0; 87 88 cytherm->brightness = simple_strtoul(buf, NULL, 10); 89 90 if (cytherm->brightness > 0xFF) 91 cytherm->brightness = 0xFF; 92 else if (cytherm->brightness < 0) 93 cytherm->brightness = 0; 94 95 /* Set brightness */ 96 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS, 97 cytherm->brightness, buffer, 8); 98 if (retval) 99 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 100 /* Inform µC that we have changed the brightness setting */ 101 retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM, 102 0x01, buffer, 8); 103 if (retval) 104 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 105 106 kfree(buffer); 107 108 return count; 109 } 110 static DEVICE_ATTR_RW(brightness); 111 112 113 #define TEMP 0x33 /* RAM location for temperature */ 114 #define SIGN 0x34 /* RAM location for temperature sign */ 115 116 static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf) 117 { 118 119 struct usb_interface *intf = to_usb_interface(dev); 120 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 121 122 int retval; 123 unsigned char *buffer; 124 125 int temp, sign; 126 127 buffer = kmalloc(8, GFP_KERNEL); 128 if (!buffer) 129 return 0; 130 131 /* read temperature */ 132 retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8); 133 if (retval) 134 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 135 temp = buffer[1]; 136 137 /* read sign */ 138 retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8); 139 if (retval) 140 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 141 sign = buffer[1]; 142 143 kfree(buffer); 144 145 return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1, 146 5*(temp - ((temp >> 1) << 1))); 147 } 148 static DEVICE_ATTR_RO(temp); 149 150 151 #define BUTTON 0x7a 152 153 static ssize_t button_show(struct device *dev, struct device_attribute *attr, char *buf) 154 { 155 156 struct usb_interface *intf = to_usb_interface(dev); 157 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 158 159 int retval; 160 unsigned char *buffer; 161 162 buffer = kmalloc(8, GFP_KERNEL); 163 if (!buffer) 164 return 0; 165 166 /* check button */ 167 retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8); 168 if (retval) 169 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 170 171 retval = buffer[1]; 172 173 kfree(buffer); 174 175 if (retval) 176 return sprintf(buf, "1"); 177 else 178 return sprintf(buf, "0"); 179 } 180 static DEVICE_ATTR_RO(button); 181 182 183 static ssize_t port0_show(struct device *dev, struct device_attribute *attr, char *buf) 184 { 185 struct usb_interface *intf = to_usb_interface(dev); 186 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 187 188 int retval; 189 unsigned char *buffer; 190 191 buffer = kmalloc(8, GFP_KERNEL); 192 if (!buffer) 193 return 0; 194 195 retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8); 196 if (retval) 197 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 198 199 retval = buffer[1]; 200 201 kfree(buffer); 202 203 return sprintf(buf, "%d", retval); 204 } 205 206 207 static ssize_t port0_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 208 { 209 struct usb_interface *intf = to_usb_interface(dev); 210 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 211 212 unsigned char *buffer; 213 int retval; 214 int tmp; 215 216 buffer = kmalloc(8, GFP_KERNEL); 217 if (!buffer) 218 return 0; 219 220 tmp = simple_strtoul(buf, NULL, 10); 221 222 if (tmp > 0xFF) 223 tmp = 0xFF; 224 else if (tmp < 0) 225 tmp = 0; 226 227 retval = vendor_command(cytherm->udev, WRITE_PORT, 0, 228 tmp, buffer, 8); 229 if (retval) 230 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 231 232 kfree(buffer); 233 234 return count; 235 } 236 static DEVICE_ATTR_RW(port0); 237 238 static ssize_t port1_show(struct device *dev, struct device_attribute *attr, char *buf) 239 { 240 struct usb_interface *intf = to_usb_interface(dev); 241 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 242 243 int retval; 244 unsigned char *buffer; 245 246 buffer = kmalloc(8, GFP_KERNEL); 247 if (!buffer) 248 return 0; 249 250 retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8); 251 if (retval) 252 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 253 254 retval = buffer[1]; 255 256 kfree(buffer); 257 258 return sprintf(buf, "%d", retval); 259 } 260 261 262 static ssize_t port1_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) 263 { 264 struct usb_interface *intf = to_usb_interface(dev); 265 struct usb_cytherm *cytherm = usb_get_intfdata(intf); 266 267 unsigned char *buffer; 268 int retval; 269 int tmp; 270 271 buffer = kmalloc(8, GFP_KERNEL); 272 if (!buffer) 273 return 0; 274 275 tmp = simple_strtoul(buf, NULL, 10); 276 277 if (tmp > 0xFF) 278 tmp = 0xFF; 279 else if (tmp < 0) 280 tmp = 0; 281 282 retval = vendor_command(cytherm->udev, WRITE_PORT, 1, 283 tmp, buffer, 8); 284 if (retval) 285 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval); 286 287 kfree(buffer); 288 289 return count; 290 } 291 static DEVICE_ATTR_RW(port1); 292 293 static struct attribute *cytherm_attrs[] = { 294 &dev_attr_brightness.attr, 295 &dev_attr_temp.attr, 296 &dev_attr_button.attr, 297 &dev_attr_port0.attr, 298 &dev_attr_port1.attr, 299 NULL, 300 }; 301 ATTRIBUTE_GROUPS(cytherm); 302 303 static int cytherm_probe(struct usb_interface *interface, 304 const struct usb_device_id *id) 305 { 306 struct usb_device *udev = interface_to_usbdev(interface); 307 struct usb_cytherm *dev; 308 int retval = -ENOMEM; 309 310 dev = kzalloc(sizeof(struct usb_cytherm), GFP_KERNEL); 311 if (!dev) 312 goto error_mem; 313 314 dev->udev = usb_get_dev(udev); 315 316 usb_set_intfdata(interface, dev); 317 318 dev->brightness = 0xFF; 319 320 dev_info(&interface->dev, 321 "Cypress thermometer device now attached\n"); 322 return 0; 323 324 error_mem: 325 return retval; 326 } 327 328 static void cytherm_disconnect(struct usb_interface *interface) 329 { 330 struct usb_cytherm *dev; 331 332 dev = usb_get_intfdata(interface); 333 334 /* first remove the files, then NULL the pointer */ 335 usb_set_intfdata(interface, NULL); 336 337 usb_put_dev(dev->udev); 338 339 kfree(dev); 340 341 dev_info(&interface->dev, "Cypress thermometer now disconnected\n"); 342 } 343 344 /* usb specific object needed to register this driver with the usb subsystem */ 345 static struct usb_driver cytherm_driver = { 346 .name = "cytherm", 347 .probe = cytherm_probe, 348 .disconnect = cytherm_disconnect, 349 .id_table = id_table, 350 .dev_groups = cytherm_groups, 351 }; 352 353 module_usb_driver(cytherm_driver); 354 355 MODULE_AUTHOR(DRIVER_AUTHOR); 356 MODULE_DESCRIPTION(DRIVER_DESC); 357 MODULE_LICENSE("GPL"); 358