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 #include <linux/workqueue.h>
18
19 #include "hid-ids.h"
20
21 #define REPORT_ID 1
22 #define REPORT_SIZE 9
23
24 /* Firmware major number of supported devices */
25 #define THINGM_MAJOR_MK1 '1'
26 #define THINGM_MAJOR_MK2 '2'
27
28 struct thingm_fwinfo {
29 char major;
30 unsigned numrgb;
31 unsigned first;
32 };
33
34 static const struct thingm_fwinfo thingm_fwinfo[] = {
35 {
36 .major = THINGM_MAJOR_MK1,
37 .numrgb = 1,
38 .first = 0,
39 }, {
40 .major = THINGM_MAJOR_MK2,
41 .numrgb = 2,
42 .first = 1,
43 }
44 };
45
46 /* A red, green or blue channel, part of an RGB chip */
47 struct thingm_led {
48 struct thingm_rgb *rgb;
49 struct led_classdev ldev;
50 char name[32];
51 };
52
53 /* Basically a WS2812 5050 RGB LED chip */
54 struct thingm_rgb {
55 struct thingm_device *tdev;
56 struct thingm_led red;
57 struct thingm_led green;
58 struct thingm_led blue;
59 struct work_struct work;
60 u8 num;
61 };
62
63 struct thingm_device {
64 struct hid_device *hdev;
65 struct {
66 char major;
67 char minor;
68 } version;
69 const struct thingm_fwinfo *fwinfo;
70 struct mutex lock;
71 struct thingm_rgb *rgb;
72 };
73
thingm_send(struct thingm_device * tdev,u8 buf[REPORT_SIZE])74 static int thingm_send(struct thingm_device *tdev, u8 buf[REPORT_SIZE])
75 {
76 int ret;
77
78 hid_dbg(tdev->hdev, "-> %d %c %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx\n",
79 buf[0], buf[1], buf[2], buf[3], buf[4],
80 buf[5], buf[6], buf[7], buf[8]);
81
82 ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
83 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
84
85 return ret < 0 ? ret : 0;
86 }
87
thingm_recv(struct thingm_device * tdev,u8 buf[REPORT_SIZE])88 static int thingm_recv(struct thingm_device *tdev, u8 buf[REPORT_SIZE])
89 {
90 int ret;
91
92 ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
93 HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
94 if (ret < 0)
95 return ret;
96
97 hid_dbg(tdev->hdev, "<- %d %c %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx\n",
98 buf[0], buf[1], buf[2], buf[3], buf[4],
99 buf[5], buf[6], buf[7], buf[8]);
100
101 return 0;
102 }
103
thingm_version(struct thingm_device * tdev)104 static int thingm_version(struct thingm_device *tdev)
105 {
106 u8 buf[REPORT_SIZE] = { REPORT_ID, 'v', 0, 0, 0, 0, 0, 0, 0 };
107 int err;
108
109 err = thingm_send(tdev, buf);
110 if (err)
111 return err;
112
113 err = thingm_recv(tdev, buf);
114 if (err)
115 return err;
116
117 tdev->version.major = buf[3];
118 tdev->version.minor = buf[4];
119
120 return 0;
121 }
122
thingm_write_color(struct thingm_rgb * rgb)123 static int thingm_write_color(struct thingm_rgb *rgb)
124 {
125 u8 buf[REPORT_SIZE] = { REPORT_ID, 'c', 0, 0, 0, 0, 0, rgb->num, 0 };
126
127 buf[2] = rgb->red.ldev.brightness;
128 buf[3] = rgb->green.ldev.brightness;
129 buf[4] = rgb->blue.ldev.brightness;
130
131 return thingm_send(rgb->tdev, buf);
132 }
133
thingm_work(struct work_struct * work)134 static void thingm_work(struct work_struct *work)
135 {
136 struct thingm_rgb *rgb = container_of(work, struct thingm_rgb, work);
137
138 mutex_lock(&rgb->tdev->lock);
139
140 if (thingm_write_color(rgb))
141 hid_err(rgb->tdev->hdev, "failed to write color\n");
142
143 mutex_unlock(&rgb->tdev->lock);
144 }
145
thingm_led_set(struct led_classdev * ldev,enum led_brightness brightness)146 static void thingm_led_set(struct led_classdev *ldev,
147 enum led_brightness brightness)
148 {
149 struct thingm_led *led = container_of(ldev, struct thingm_led, ldev);
150
151 /* the ledclass has already stored the brightness value */
152 schedule_work(&led->rgb->work);
153 }
154
thingm_init_rgb(struct thingm_rgb * rgb)155 static int thingm_init_rgb(struct thingm_rgb *rgb)
156 {
157 const int minor = ((struct hidraw *) rgb->tdev->hdev->hidraw)->minor;
158 int err;
159
160 /* Register the red diode */
161 snprintf(rgb->red.name, sizeof(rgb->red.name),
162 "thingm%d:red:led%d", minor, rgb->num);
163 rgb->red.ldev.name = rgb->red.name;
164 rgb->red.ldev.max_brightness = 255;
165 rgb->red.ldev.brightness_set = thingm_led_set;
166 rgb->red.rgb = rgb;
167
168 err = led_classdev_register(&rgb->tdev->hdev->dev, &rgb->red.ldev);
169 if (err)
170 return err;
171
172 /* Register the green diode */
173 snprintf(rgb->green.name, sizeof(rgb->green.name),
174 "thingm%d:green:led%d", minor, rgb->num);
175 rgb->green.ldev.name = rgb->green.name;
176 rgb->green.ldev.max_brightness = 255;
177 rgb->green.ldev.brightness_set = thingm_led_set;
178 rgb->green.rgb = rgb;
179
180 err = led_classdev_register(&rgb->tdev->hdev->dev, &rgb->green.ldev);
181 if (err)
182 goto unregister_red;
183
184 /* Register the blue diode */
185 snprintf(rgb->blue.name, sizeof(rgb->blue.name),
186 "thingm%d:blue:led%d", minor, rgb->num);
187 rgb->blue.ldev.name = rgb->blue.name;
188 rgb->blue.ldev.max_brightness = 255;
189 rgb->blue.ldev.brightness_set = thingm_led_set;
190 rgb->blue.rgb = rgb;
191
192 err = led_classdev_register(&rgb->tdev->hdev->dev, &rgb->blue.ldev);
193 if (err)
194 goto unregister_green;
195
196 INIT_WORK(&rgb->work, thingm_work);
197
198 return 0;
199
200 unregister_green:
201 led_classdev_unregister(&rgb->green.ldev);
202
203 unregister_red:
204 led_classdev_unregister(&rgb->red.ldev);
205
206 return err;
207 }
208
thingm_remove_rgb(struct thingm_rgb * rgb)209 static void thingm_remove_rgb(struct thingm_rgb *rgb)
210 {
211 led_classdev_unregister(&rgb->red.ldev);
212 led_classdev_unregister(&rgb->green.ldev);
213 led_classdev_unregister(&rgb->blue.ldev);
214 flush_work(&rgb->work);
215 }
216
thingm_probe(struct hid_device * hdev,const struct hid_device_id * id)217 static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id)
218 {
219 struct thingm_device *tdev;
220 int i, err;
221
222 tdev = devm_kzalloc(&hdev->dev, sizeof(struct thingm_device),
223 GFP_KERNEL);
224 if (!tdev)
225 return -ENOMEM;
226
227 tdev->hdev = hdev;
228 hid_set_drvdata(hdev, tdev);
229
230 err = hid_parse(hdev);
231 if (err)
232 goto error;
233
234 err = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
235 if (err)
236 goto error;
237
238 mutex_init(&tdev->lock);
239
240 err = thingm_version(tdev);
241 if (err)
242 goto stop;
243
244 hid_dbg(hdev, "firmware version: %c.%c\n",
245 tdev->version.major, tdev->version.minor);
246
247 for (i = 0; i < ARRAY_SIZE(thingm_fwinfo) && !tdev->fwinfo; ++i)
248 if (thingm_fwinfo[i].major == tdev->version.major)
249 tdev->fwinfo = &thingm_fwinfo[i];
250
251 if (!tdev->fwinfo) {
252 hid_err(hdev, "unsupported firmware %c\n", tdev->version.major);
253 err = -ENODEV;
254 goto stop;
255 }
256
257 tdev->rgb = devm_kzalloc(&hdev->dev,
258 sizeof(struct thingm_rgb) * tdev->fwinfo->numrgb,
259 GFP_KERNEL);
260 if (!tdev->rgb) {
261 err = -ENOMEM;
262 goto stop;
263 }
264
265 for (i = 0; i < tdev->fwinfo->numrgb; ++i) {
266 struct thingm_rgb *rgb = tdev->rgb + i;
267
268 rgb->tdev = tdev;
269 rgb->num = tdev->fwinfo->first + i;
270 err = thingm_init_rgb(rgb);
271 if (err) {
272 while (--i >= 0)
273 thingm_remove_rgb(tdev->rgb + i);
274 goto stop;
275 }
276 }
277
278 return 0;
279 stop:
280 hid_hw_stop(hdev);
281 error:
282 return err;
283 }
284
thingm_remove(struct hid_device * hdev)285 static void thingm_remove(struct hid_device *hdev)
286 {
287 struct thingm_device *tdev = hid_get_drvdata(hdev);
288 int i;
289
290 hid_hw_stop(hdev);
291
292 for (i = 0; i < tdev->fwinfo->numrgb; ++i)
293 thingm_remove_rgb(tdev->rgb + i);
294 }
295
296 static const struct hid_device_id thingm_table[] = {
297 { HID_USB_DEVICE(USB_VENDOR_ID_THINGM, USB_DEVICE_ID_BLINK1) },
298 { }
299 };
300 MODULE_DEVICE_TABLE(hid, thingm_table);
301
302 static struct hid_driver thingm_driver = {
303 .name = "thingm",
304 .probe = thingm_probe,
305 .remove = thingm_remove,
306 .id_table = thingm_table,
307 };
308
309 module_hid_driver(thingm_driver);
310
311 MODULE_LICENSE("GPL");
312 MODULE_AUTHOR("Vivien Didelot <vivien.didelot@savoirfairelinux.com>");
313 MODULE_DESCRIPTION("ThingM blink(1) USB RGB LED driver");
314