drivers/hid/hid-thingm.c

   1 /*
   2  * ThingM blink(1) USB RGB LED driver
   3  *
   4  * Copyright 2013-2014 Savoir-faire Linux Inc.
   5  *      Vivien Didelot <vivien.didelot@savoirfairelinux.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation, version 2.
  10  */
  11
  12 #include <linux/hid.h>
  13 #include <linux/hidraw.h>
  14 #include <linux/leds.h>
  15 #include <linux/module.h>
  16 #include <linux/mutex.h>
  17
  18 #include "hid-ids.h"
  19
  20 #define REPORT_ID       1
  21 #define REPORT_SIZE     9
  22
  23 /* Firmware major number of supported devices */
  24 #define THINGM_MAJOR_MK1        '1'
  25 #define THINGM_MAJOR_MK2        '2'
  26
  27 struct thingm_fwinfo {
  28         char major;
  29         unsigned numrgb;
  30         unsigned first;
  31 };
  32
  33 static const struct thingm_fwinfo thingm_fwinfo[] = {
  34         {
  35                 .major = THINGM_MAJOR_MK1,
  36                 .numrgb = 1,
  37                 .first = 0,
  38         }, {
  39                 .major = THINGM_MAJOR_MK2,
  40                 .numrgb = 2,
  41                 .first = 1,
  42         }
  43 };
  44
  45 /* A red, green or blue channel, part of an RGB chip */
  46 struct thingm_led {
  47         struct thingm_rgb *rgb;
  48         struct led_classdev ldev;
  49         char name[32];
  50 };
  51
  52 /* Basically a WS2812 5050 RGB LED chip */
  53 struct thingm_rgb {
  54         struct thingm_device *tdev;
  55         struct thingm_led red;
  56         struct thingm_led green;
  57         struct thingm_led blue;
  58         u8 num;
  59 };
  60
  61 struct thingm_device {
  62         struct hid_device *hdev;
  63         struct {
  64                 char major;
  65                 char minor;
  66         } version;
  67         const struct thingm_fwinfo *fwinfo;
  68         struct mutex lock;
  69         struct thingm_rgb *rgb;
  70 };
  71
  72 static int thingm_send(struct thingm_device *tdev, u8 buf[REPORT_SIZE])
  73 {
  74         int ret;
  75
  76         hid_dbg(tdev->hdev, "-> %d %c %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx\n",
  77                         buf[0], buf[1], buf[2], buf[3], buf[4],
  78                         buf[5], buf[6], buf[7], buf[8]);
  79
  80         mutex_lock(&tdev->lock);
  81
  82         ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
  83                         HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
  84
  85         mutex_unlock(&tdev->lock);
  86
  87         return ret < 0 ? ret : 0;
  88 }
  89
  90 static int thingm_recv(struct thingm_device *tdev, u8 buf[REPORT_SIZE])
  91 {
  92         int ret;
  93
  94         /*
  95          * A read consists of two operations: sending the read command
  96          * and the actual read from the device. Use the mutex to protect
  97          * the full sequence of both operations.
  98          */
  99         mutex_lock(&tdev->lock);
 100
 101         ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
 102                         HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 103         if (ret < 0)
 104                 goto err;
 105
 106         ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
 107                         HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
 108         if (ret < 0)
 109                 goto err;
 110
 111         ret = 0;
 112
 113         hid_dbg(tdev->hdev, "<- %d %c %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx\n",
 114                         buf[0], buf[1], buf[2], buf[3], buf[4],
 115                         buf[5], buf[6], buf[7], buf[8]);
 116 err:
 117         mutex_unlock(&tdev->lock);
 118         return ret;
 119 }
 120
 121 static int thingm_version(struct thingm_device *tdev)
 122 {
 123         u8 buf[REPORT_SIZE] = { REPORT_ID, 'v', 0, 0, 0, 0, 0, 0, 0 };
 124         int err;
 125
 126         err = thingm_recv(tdev, buf);
 127         if (err)
 128                 return err;
 129
 130         tdev->version.major = buf[3];
 131         tdev->version.minor = buf[4];
 132
 133         return 0;
 134 }
 135
 136 static int thingm_write_color(struct thingm_rgb *rgb)
 137 {
 138         u8 buf[REPORT_SIZE] = { REPORT_ID, 'c', 0, 0, 0, 0, 0, rgb->num, 0 };
 139
 140         buf[2] = rgb->red.ldev.brightness;
 141         buf[3] = rgb->green.ldev.brightness;
 142         buf[4] = rgb->blue.ldev.brightness;
 143
 144         return thingm_send(rgb->tdev, buf);
 145 }
 146
 147 static int thingm_led_set(struct led_classdev *ldev,
 148                           enum led_brightness brightness)
 149 {
 150         struct thingm_led *led = container_of(ldev, struct thingm_led, ldev);
 151
 152         return thingm_write_color(led->rgb);
 153 }
 154
 155 static int thingm_init_led(struct thingm_led *led, const char *color_name,
 156                            struct thingm_rgb *rgb, int minor)
 157 {
 158         snprintf(led->name, sizeof(led->name), "thingm%d:%s:led%d",
 159                  minor, color_name, rgb->num);
 160         led->ldev.name = led->name;
 161         led->ldev.max_brightness = 255;
 162         led->ldev.brightness_set_blocking = thingm_led_set;
 163         led->ldev.flags = LED_HW_PLUGGABLE;
 164         led->rgb = rgb;
 165         return devm_led_classdev_register(&rgb->tdev->hdev->dev, &led->ldev);
 166 }
 167
 168 static int thingm_init_rgb(struct thingm_rgb *rgb)
 169 {
 170         const int minor = ((struct hidraw *) rgb->tdev->hdev->hidraw)->minor;
 171         int err;
 172
 173         /* Register the red diode */
 174         err = thingm_init_led(&rgb->red, "red", rgb, minor);
 175         if (err)
 176                 return err;
 177
 178         /* Register the green diode */
 179         err = thingm_init_led(&rgb->green, "green", rgb, minor);
 180         if (err)
 181                 return err;
 182
 183         /* Register the blue diode */
 184         return thingm_init_led(&rgb->blue, "blue", rgb, minor);
 185 }
 186
 187 static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id)
 188 {
 189         struct thingm_device *tdev;
 190         int i, err;
 191
 192         tdev = devm_kzalloc(&hdev->dev, sizeof(struct thingm_device),
 193                         GFP_KERNEL);
 194         if (!tdev)
 195                 return -ENOMEM;
 196
 197         tdev->hdev = hdev;
 198         hid_set_drvdata(hdev, tdev);
 199
 200         err = hid_parse(hdev);
 201         if (err)
 202                 return err;
 203
 204         mutex_init(&tdev->lock);
 205
 206         err = thingm_version(tdev);
 207         if (err)
 208                 return err;
 209
 210         hid_dbg(hdev, "firmware version: %c.%c\n",
 211                         tdev->version.major, tdev->version.minor);
 212
 213         for (i = 0; i < ARRAY_SIZE(thingm_fwinfo) && !tdev->fwinfo; ++i)
 214                 if (thingm_fwinfo[i].major == tdev->version.major)
 215                         tdev->fwinfo = &thingm_fwinfo[i];
 216
 217         if (!tdev->fwinfo) {
 218                 hid_err(hdev, "unsupported firmware %c\n", tdev->version.major);
 219                 return -ENODEV;
 220         }
 221
 222         tdev->rgb = devm_kzalloc(&hdev->dev,
 223                         sizeof(struct thingm_rgb) * tdev->fwinfo->numrgb,
 224                         GFP_KERNEL);
 225         if (!tdev->rgb)
 226                 return -ENOMEM;
 227
 228         err = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 229         if (err)
 230                 return err;
 231
 232         for (i = 0; i < tdev->fwinfo->numrgb; ++i) {
 233                 struct thingm_rgb *rgb = tdev->rgb + i;
 234
 235                 rgb->tdev = tdev;
 236                 rgb->num = tdev->fwinfo->first + i;
 237                 err = thingm_init_rgb(rgb);
 238                 if (err) {
 239                         hid_hw_stop(hdev);
 240                         return err;
 241                 }
 242         }
 243
 244         return 0;
 245 }
 246
 247 static const struct hid_device_id thingm_table[] = {
 248         { HID_USB_DEVICE(USB_VENDOR_ID_THINGM, USB_DEVICE_ID_BLINK1) },
 249         { }
 250 };
 251 MODULE_DEVICE_TABLE(hid, thingm_table);
 252
 253 static struct hid_driver thingm_driver = {
 254         .name = "thingm",
 255         .probe = thingm_probe,
 256         .id_table = thingm_table,
 257 };
 258
 259 module_hid_driver(thingm_driver);
 260
 261 MODULE_LICENSE("GPL");
 262 MODULE_AUTHOR("Vivien Didelot <vivien.didelot@savoirfairelinux.com>");
 263 MODULE_DESCRIPTION("ThingM blink(1) USB RGB LED driver");