drivers/usb/misc/cytherm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* -*- linux-c -*-
   3  * Cypress USB Thermometer driver
   4  *
   5  * Copyright (c) 2004 Erik Rigtorp <[email protected]> <[email protected]>
   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 /* local function prototypes */
  40 static int cytherm_probe(struct usb_interface *interface,
  41                          const struct usb_device_id *id);
  42 static void cytherm_disconnect(struct usb_interface *interface);
  43
  44
  45 /* usb specific object needed to register this driver with the usb subsystem */
  46 static struct usb_driver cytherm_driver = {
  47         .name =         "cytherm",
  48         .probe =        cytherm_probe,
  49         .disconnect =   cytherm_disconnect,
  50         .id_table =     id_table,
  51 };
  52
  53 /* Vendor requests */
  54 /* They all operate on one byte at a time */
  55 #define PING       0x00
  56 #define READ_ROM   0x01 /* Reads form ROM, value = address */
  57 #define READ_RAM   0x02 /* Reads form RAM, value = address */
  58 #define WRITE_RAM  0x03 /* Write to RAM, value = address, index = data */
  59 #define READ_PORT  0x04 /* Reads from port, value = address */
  60 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */
  61
  62
  63 /* Send a vendor command to device */
  64 static int vendor_command(struct usb_device *dev, unsigned char request,
  65                           unsigned char value, unsigned char index,
  66                           void *buf, int size)
  67 {
  68         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
  69                                request,
  70                                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
  71                                value,
  72                                index, buf, size,
  73                                USB_CTRL_GET_TIMEOUT);
  74 }
  75
  76
  77
  78 #define BRIGHTNESS 0x2c     /* RAM location for brightness value */
  79 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
  80
  81 static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf)
  82 {
  83         struct usb_interface *intf = to_usb_interface(dev);
  84         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
  85
  86         return sprintf(buf, "%i", cytherm->brightness);
  87 }
  88
  89 static ssize_t brightness_store(struct device *dev, struct device_attribute *attr, const char *buf,
  90                               size_t count)
  91 {
  92         struct usb_interface *intf = to_usb_interface(dev);
  93         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
  94
  95         unsigned char *buffer;
  96         int retval;
  97
  98         buffer = kmalloc(8, GFP_KERNEL);
  99         if (!buffer)
 100                 return 0;
 101
 102         cytherm->brightness = simple_strtoul(buf, NULL, 10);
 103
 104         if (cytherm->brightness > 0xFF)
 105                 cytherm->brightness = 0xFF;
 106         else if (cytherm->brightness < 0)
 107                 cytherm->brightness = 0;
 108
 109         /* Set brightness */
 110         retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS,
 111                                 cytherm->brightness, buffer, 8);
 112         if (retval)
 113                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 114         /* Inform µC that we have changed the brightness setting */
 115         retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
 116                                 0x01, buffer, 8);
 117         if (retval)
 118                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 119
 120         kfree(buffer);
 121
 122         return count;
 123 }
 124 static DEVICE_ATTR_RW(brightness);
 125
 126
 127 #define TEMP 0x33 /* RAM location for temperature */
 128 #define SIGN 0x34 /* RAM location for temperature sign */
 129
 130 static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf)
 131 {
 132
 133         struct usb_interface *intf = to_usb_interface(dev);
 134         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 135
 136         int retval;
 137         unsigned char *buffer;
 138
 139         int temp, sign;
 140
 141         buffer = kmalloc(8, GFP_KERNEL);
 142         if (!buffer)
 143                 return 0;
 144
 145         /* read temperature */
 146         retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
 147         if (retval)
 148                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 149         temp = buffer[1];
 150
 151         /* read sign */
 152         retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
 153         if (retval)
 154                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 155         sign = buffer[1];
 156
 157         kfree(buffer);
 158
 159         return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
 160                        5*(temp - ((temp >> 1) << 1)));
 161 }
 162 static DEVICE_ATTR_RO(temp);
 163
 164
 165 #define BUTTON 0x7a
 166
 167 static ssize_t button_show(struct device *dev, struct device_attribute *attr, char *buf)
 168 {
 169
 170         struct usb_interface *intf = to_usb_interface(dev);
 171         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 172
 173         int retval;
 174         unsigned char *buffer;
 175
 176         buffer = kmalloc(8, GFP_KERNEL);
 177         if (!buffer)
 178                 return 0;
 179
 180         /* check button */
 181         retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
 182         if (retval)
 183                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 184
 185         retval = buffer[1];
 186
 187         kfree(buffer);
 188
 189         if (retval)
 190                 return sprintf(buf, "1");
 191         else
 192                 return sprintf(buf, "0");
 193 }
 194 static DEVICE_ATTR_RO(button);
 195
 196
 197 static ssize_t port0_show(struct device *dev, struct device_attribute *attr, char *buf)
 198 {
 199         struct usb_interface *intf = to_usb_interface(dev);
 200         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 201
 202         int retval;
 203         unsigned char *buffer;
 204
 205         buffer = kmalloc(8, GFP_KERNEL);
 206         if (!buffer)
 207                 return 0;
 208
 209         retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
 210         if (retval)
 211                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 212
 213         retval = buffer[1];
 214
 215         kfree(buffer);
 216
 217         return sprintf(buf, "%d", retval);
 218 }
 219
 220
 221 static ssize_t port0_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 222 {
 223         struct usb_interface *intf = to_usb_interface(dev);
 224         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 225
 226         unsigned char *buffer;
 227         int retval;
 228         int tmp;
 229
 230         buffer = kmalloc(8, GFP_KERNEL);
 231         if (!buffer)
 232                 return 0;
 233
 234         tmp = simple_strtoul(buf, NULL, 10);
 235
 236         if (tmp > 0xFF)
 237                 tmp = 0xFF;
 238         else if (tmp < 0)
 239                 tmp = 0;
 240
 241         retval = vendor_command(cytherm->udev, WRITE_PORT, 0,
 242                                 tmp, buffer, 8);
 243         if (retval)
 244                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 245
 246         kfree(buffer);
 247
 248         return count;
 249 }
 250 static DEVICE_ATTR_RW(port0);
 251
 252 static ssize_t port1_show(struct device *dev, struct device_attribute *attr, char *buf)
 253 {
 254         struct usb_interface *intf = to_usb_interface(dev);
 255         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 256
 257         int retval;
 258         unsigned char *buffer;
 259
 260         buffer = kmalloc(8, GFP_KERNEL);
 261         if (!buffer)
 262                 return 0;
 263
 264         retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);
 265         if (retval)
 266                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 267
 268         retval = buffer[1];
 269
 270         kfree(buffer);
 271
 272         return sprintf(buf, "%d", retval);
 273 }
 274
 275
 276 static ssize_t port1_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 277 {
 278         struct usb_interface *intf = to_usb_interface(dev);
 279         struct usb_cytherm *cytherm = usb_get_intfdata(intf);
 280
 281         unsigned char *buffer;
 282         int retval;
 283         int tmp;
 284
 285         buffer = kmalloc(8, GFP_KERNEL);
 286         if (!buffer)
 287                 return 0;
 288
 289         tmp = simple_strtoul(buf, NULL, 10);
 290
 291         if (tmp > 0xFF)
 292                 tmp = 0xFF;
 293         else if (tmp < 0)
 294                 tmp = 0;
 295
 296         retval = vendor_command(cytherm->udev, WRITE_PORT, 1,
 297                                 tmp, buffer, 8);
 298         if (retval)
 299                 dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
 300
 301         kfree(buffer);
 302
 303         return count;
 304 }
 305 static DEVICE_ATTR_RW(port1);
 306
 307
 308 static int cytherm_probe(struct usb_interface *interface,
 309                          const struct usb_device_id *id)
 310 {
 311         struct usb_device *udev = interface_to_usbdev(interface);
 312         struct usb_cytherm *dev = NULL;
 313         int retval = -ENOMEM;
 314
 315         dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL);
 316         if (!dev)
 317                 goto error_mem;
 318
 319         dev->udev = usb_get_dev(udev);
 320
 321         usb_set_intfdata (interface, dev);
 322
 323         dev->brightness = 0xFF;
 324
 325         retval = device_create_file(&interface->dev, &dev_attr_brightness);
 326         if (retval)
 327                 goto error;
 328         retval = device_create_file(&interface->dev, &dev_attr_temp);
 329         if (retval)
 330                 goto error;
 331         retval = device_create_file(&interface->dev, &dev_attr_button);
 332         if (retval)
 333                 goto error;
 334         retval = device_create_file(&interface->dev, &dev_attr_port0);
 335         if (retval)
 336                 goto error;
 337         retval = device_create_file(&interface->dev, &dev_attr_port1);
 338         if (retval)
 339                 goto error;
 340
 341         dev_info (&interface->dev,
 342                   "Cypress thermometer device now attached\n");
 343         return 0;
 344 error:
 345         device_remove_file(&interface->dev, &dev_attr_brightness);
 346         device_remove_file(&interface->dev, &dev_attr_temp);
 347         device_remove_file(&interface->dev, &dev_attr_button);
 348         device_remove_file(&interface->dev, &dev_attr_port0);
 349         device_remove_file(&interface->dev, &dev_attr_port1);
 350         usb_set_intfdata (interface, NULL);
 351         usb_put_dev(dev->udev);
 352         kfree(dev);
 353 error_mem:
 354         return retval;
 355 }
 356
 357 static void cytherm_disconnect(struct usb_interface *interface)
 358 {
 359         struct usb_cytherm *dev;
 360
 361         dev = usb_get_intfdata (interface);
 362
 363         device_remove_file(&interface->dev, &dev_attr_brightness);
 364         device_remove_file(&interface->dev, &dev_attr_temp);
 365         device_remove_file(&interface->dev, &dev_attr_button);
 366         device_remove_file(&interface->dev, &dev_attr_port0);
 367         device_remove_file(&interface->dev, &dev_attr_port1);
 368
 369         /* first remove the files, then NULL the pointer */
 370         usb_set_intfdata (interface, NULL);
 371
 372         usb_put_dev(dev->udev);
 373
 374         kfree(dev);
 375
 376         dev_info(&interface->dev, "Cypress thermometer now disconnected\n");
 377 }
 378
 379 module_usb_driver(cytherm_driver);
 380
 381 MODULE_AUTHOR(DRIVER_AUTHOR);
 382 MODULE_DESCRIPTION(DRIVER_DESC);
 383 MODULE_LICENSE("GPL");