drivers/hid/hid-thingm.c

   1 /*
   2  * ThingM blink(1) USB RGB LED driver
   3  *
   4  * Copyright 2013 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/leds.h>
  14 #include <linux/module.h>
  15 #include <linux/usb.h>
  16
  17 #include "hid-ids.h"
  18
  19 #define BLINK1_CMD_SIZE         9
  20
  21 #define blink1_rgb_to_r(rgb)    ((rgb & 0xFF0000) >> 16)
  22 #define blink1_rgb_to_g(rgb)    ((rgb & 0x00FF00) >> 8)
  23 #define blink1_rgb_to_b(rgb)    ((rgb & 0x0000FF) >> 0)
  24
  25 /**
  26  * struct blink1_data - blink(1) device specific data
  27  * @hdev:               HID device.
  28  * @led_cdev:           LED class instance.
  29  * @rgb:                8-bit per channel RGB notation.
  30  * @fade:               fade time in hundredths of a second.
  31  * @brightness:         brightness coefficient.
  32  * @play:               play/pause in-memory patterns.
  33  */
  34 struct blink1_data {
  35         struct hid_device *hdev;
  36         struct led_classdev led_cdev;
  37         u32 rgb;
  38         u16 fade;
  39         u8 brightness;
  40         bool play;
  41 };
  42
  43 static int blink1_send_command(struct blink1_data *data,
  44                 u8 buf[BLINK1_CMD_SIZE])
  45 {
  46         int ret;
  47
  48         hid_dbg(data->hdev, "command: %d%c%.2x%.2x%.2x%.2x%.2x%.2x%.2x\n",
  49                         buf[0], buf[1], buf[2], buf[3], buf[4],
  50                         buf[5], buf[6], buf[7], buf[8]);
  51
  52         ret = data->hdev->hid_output_raw_report(data->hdev, buf,
  53                         BLINK1_CMD_SIZE, HID_FEATURE_REPORT);
  54
  55         return ret < 0 ? ret : 0;
  56 }
  57
  58 static int blink1_update_color(struct blink1_data *data)
  59 {
  60         u8 buf[BLINK1_CMD_SIZE] = { 1, 'n', 0, 0, 0, 0, 0, 0, 0 };
  61
  62         if (data->brightness) {
  63                 unsigned int coef = DIV_ROUND_CLOSEST(255, data->brightness);
  64
  65                 buf[2] = DIV_ROUND_CLOSEST(blink1_rgb_to_r(data->rgb), coef);
  66                 buf[3] = DIV_ROUND_CLOSEST(blink1_rgb_to_g(data->rgb), coef);
  67                 buf[4] = DIV_ROUND_CLOSEST(blink1_rgb_to_b(data->rgb), coef);
  68         }
  69
  70         if (data->fade) {
  71                 buf[1] = 'c';
  72                 buf[5] = (data->fade & 0xFF00) >> 8;
  73                 buf[6] = (data->fade & 0x00FF);
  74         }
  75
  76         return blink1_send_command(data, buf);
  77 }
  78
  79 static void blink1_led_set(struct led_classdev *led_cdev,
  80                 enum led_brightness brightness)
  81 {
  82         struct blink1_data *data = dev_get_drvdata(led_cdev->dev->parent);
  83
  84         data->brightness = brightness;
  85         if (blink1_update_color(data))
  86                 hid_err(data->hdev, "failed to update color\n");
  87 }
  88
  89 static enum led_brightness blink1_led_get(struct led_classdev *led_cdev)
  90 {
  91         struct blink1_data *data = dev_get_drvdata(led_cdev->dev->parent);
  92
  93         return data->brightness;
  94 }
  95
  96 static ssize_t blink1_show_rgb(struct device *dev,
  97                 struct device_attribute *attr, char *buf)
  98 {
  99         struct blink1_data *data = dev_get_drvdata(dev->parent);
 100
 101         return sprintf(buf, "%.6X\n", data->rgb);
 102 }
 103
 104 static ssize_t blink1_store_rgb(struct device *dev,
 105                 struct device_attribute *attr, const char *buf, size_t count)
 106 {
 107         struct blink1_data *data = dev_get_drvdata(dev->parent);
 108         long unsigned int rgb;
 109         int ret;
 110
 111         ret = kstrtoul(buf, 16, &rgb);
 112         if (ret)
 113                 return ret;
 114
 115         /* RGB triplet notation is 24-bit hexadecimal */
 116         if (rgb > 0xFFFFFF)
 117                 return -EINVAL;
 118
 119         data->rgb = rgb;
 120         ret = blink1_update_color(data);
 121
 122         return ret ? ret : count;
 123 }
 124
 125 static DEVICE_ATTR(rgb, S_IRUGO | S_IWUSR, blink1_show_rgb, blink1_store_rgb);
 126
 127 static ssize_t blink1_show_fade(struct device *dev,
 128                 struct device_attribute *attr, char *buf)
 129 {
 130         struct blink1_data *data = dev_get_drvdata(dev->parent);
 131
 132         return sprintf(buf, "%d\n", data->fade * 10);
 133 }
 134
 135 static ssize_t blink1_store_fade(struct device *dev,
 136                 struct device_attribute *attr, const char *buf, size_t count)
 137 {
 138         struct blink1_data *data = dev_get_drvdata(dev->parent);
 139         long unsigned int fade;
 140         int ret;
 141
 142         ret = kstrtoul(buf, 10, &fade);
 143         if (ret)
 144                 return ret;
 145
 146         /* blink(1) accepts 16-bit fade time, number of 10ms ticks */
 147         fade = DIV_ROUND_CLOSEST(fade, 10);
 148         if (fade > 65535)
 149                 return -EINVAL;
 150
 151         data->fade = fade;
 152
 153         return count;
 154 }
 155
 156 static DEVICE_ATTR(fade, S_IRUGO | S_IWUSR,
 157                 blink1_show_fade, blink1_store_fade);
 158
 159 static ssize_t blink1_show_play(struct device *dev,
 160                 struct device_attribute *attr, char *buf)
 161 {
 162         struct blink1_data *data = dev_get_drvdata(dev->parent);
 163
 164         return sprintf(buf, "%d\n", data->play);
 165 }
 166
 167 static ssize_t blink1_store_play(struct device *dev,
 168                 struct device_attribute *attr, const char *buf, size_t count)
 169 {
 170         struct blink1_data *data = dev_get_drvdata(dev->parent);
 171         u8 cmd[BLINK1_CMD_SIZE] = { 1, 'p', 0, 0, 0, 0, 0, 0, 0 };
 172         long unsigned int play;
 173         int ret;
 174
 175         ret = kstrtoul(buf, 10, &play);
 176         if (ret)
 177                 return ret;
 178
 179         data->play = !!play;
 180         cmd[2] = data->play;
 181         ret = blink1_send_command(data, cmd);
 182
 183         return ret ? ret : count;
 184 }
 185
 186 static DEVICE_ATTR(play, S_IRUGO | S_IWUSR,
 187                 blink1_show_play, blink1_store_play);
 188
 189 static const struct attribute_group blink1_sysfs_group = {
 190         .attrs = (struct attribute *[]) {
 191                 &dev_attr_rgb.attr,
 192                 &dev_attr_fade.attr,
 193                 &dev_attr_play.attr,
 194                 NULL
 195         },
 196 };
 197
 198 static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id)
 199 {
 200         struct blink1_data *data;
 201         struct led_classdev *led;
 202         char led_name[13];
 203         int ret;
 204
 205         data = devm_kzalloc(&hdev->dev, sizeof(struct blink1_data), GFP_KERNEL);
 206         if (!data)
 207                 return -ENOMEM;
 208
 209         hid_set_drvdata(hdev, data);
 210         data->hdev = hdev;
 211         data->rgb = 0xFFFFFF; /* set a default white color */
 212
 213         ret = hid_parse(hdev);
 214         if (ret)
 215                 goto error;
 216
 217         ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
 218         if (ret)
 219                 goto error;
 220
 221         /* blink(1) serial numbers range is 0x1A001000 to 0x1A002FFF */
 222         led = &data->led_cdev;
 223         snprintf(led_name, sizeof(led_name), "blink1::%s", hdev->uniq + 4);
 224         led->name = led_name;
 225         led->brightness_set = blink1_led_set;
 226         led->brightness_get = blink1_led_get;
 227         ret = led_classdev_register(&hdev->dev, led);
 228         if (ret)
 229                 goto stop;
 230
 231         ret = sysfs_create_group(&led->dev->kobj, &blink1_sysfs_group);
 232         if (ret)
 233                 goto remove_led;
 234
 235         return 0;
 236
 237 remove_led:
 238         led_classdev_unregister(led);
 239 stop:
 240         hid_hw_stop(hdev);
 241 error:
 242         return ret;
 243 }
 244
 245 static void thingm_remove(struct hid_device *hdev)
 246 {
 247         struct blink1_data *data = hid_get_drvdata(hdev);
 248         struct led_classdev *led = &data->led_cdev;
 249
 250         sysfs_remove_group(&led->dev->kobj, &blink1_sysfs_group);
 251         led_classdev_unregister(led);
 252         hid_hw_stop(hdev);
 253 }
 254
 255 static const struct hid_device_id thingm_table[] = {
 256         { HID_USB_DEVICE(USB_VENDOR_ID_THINGM, USB_DEVICE_ID_BLINK1) },
 257         { }
 258 };
 259 MODULE_DEVICE_TABLE(hid, thingm_table);
 260
 261 static struct hid_driver thingm_driver = {
 262         .name = "thingm",
 263         .probe = thingm_probe,
 264         .remove = thingm_remove,
 265         .id_table = thingm_table,
 266 };
 267
 268 module_hid_driver(thingm_driver);
 269
 270 MODULE_LICENSE("GPL");
 271 MODULE_AUTHOR("Vivien Didelot <vivien.didelot@savoirfairelinux.com>");
 272 MODULE_DESCRIPTION("ThingM blink(1) USB RGB LED driver");