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335d7c58 GR |
1 | /* |
2 | * Driver for the Diolan u2c-12 USB-I2C adapter | |
3 | * | |
4 | * Copyright (c) 2010-2011 Ericsson AB | |
5 | * | |
6 | * Derived from: | |
7 | * i2c-tiny-usb.c | |
8 | * Copyright (C) 2006-2007 Till Harbaum (Till@Harbaum.org) | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License as | |
12 | * published by the Free Software Foundation, version 2. | |
13 | */ | |
14 | ||
15 | #include <linux/kernel.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/types.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/usb.h> | |
21 | #include <linux/i2c.h> | |
22 | ||
23 | #define DRIVER_NAME "i2c-diolan-u2c" | |
24 | ||
25 | #define USB_VENDOR_ID_DIOLAN 0x0abf | |
26 | #define USB_DEVICE_ID_DIOLAN_U2C 0x3370 | |
27 | ||
335d7c58 GR |
28 | |
29 | /* commands via USB, must match command ids in the firmware */ | |
30 | #define CMD_I2C_READ 0x01 | |
31 | #define CMD_I2C_WRITE 0x02 | |
32 | #define CMD_I2C_SCAN 0x03 /* Returns list of detected devices */ | |
33 | #define CMD_I2C_RELEASE_SDA 0x04 | |
34 | #define CMD_I2C_RELEASE_SCL 0x05 | |
35 | #define CMD_I2C_DROP_SDA 0x06 | |
36 | #define CMD_I2C_DROP_SCL 0x07 | |
37 | #define CMD_I2C_READ_SDA 0x08 | |
38 | #define CMD_I2C_READ_SCL 0x09 | |
39 | #define CMD_GET_FW_VERSION 0x0a | |
40 | #define CMD_GET_SERIAL 0x0b | |
41 | #define CMD_I2C_START 0x0c | |
42 | #define CMD_I2C_STOP 0x0d | |
43 | #define CMD_I2C_REPEATED_START 0x0e | |
44 | #define CMD_I2C_PUT_BYTE 0x0f | |
45 | #define CMD_I2C_GET_BYTE 0x10 | |
46 | #define CMD_I2C_PUT_ACK 0x11 | |
47 | #define CMD_I2C_GET_ACK 0x12 | |
48 | #define CMD_I2C_PUT_BYTE_ACK 0x13 | |
49 | #define CMD_I2C_GET_BYTE_ACK 0x14 | |
50 | #define CMD_I2C_SET_SPEED 0x1b | |
51 | #define CMD_I2C_GET_SPEED 0x1c | |
52 | #define CMD_I2C_SET_CLK_SYNC 0x24 | |
53 | #define CMD_I2C_GET_CLK_SYNC 0x25 | |
54 | #define CMD_I2C_SET_CLK_SYNC_TO 0x26 | |
55 | #define CMD_I2C_GET_CLK_SYNC_TO 0x27 | |
56 | ||
57 | #define RESP_OK 0x00 | |
58 | #define RESP_FAILED 0x01 | |
59 | #define RESP_BAD_MEMADDR 0x04 | |
60 | #define RESP_DATA_ERR 0x05 | |
61 | #define RESP_NOT_IMPLEMENTED 0x06 | |
62 | #define RESP_NACK 0x07 | |
63 | #define RESP_TIMEOUT 0x09 | |
64 | ||
65 | #define U2C_I2C_SPEED_FAST 0 /* 400 kHz */ | |
66 | #define U2C_I2C_SPEED_STD 1 /* 100 kHz */ | |
67 | #define U2C_I2C_SPEED_2KHZ 242 /* 2 kHz, minimum speed */ | |
68 | #define U2C_I2C_SPEED(f) ((DIV_ROUND_UP(1000000, (f)) - 10) / 2 + 1) | |
69 | ||
70 | #define U2C_I2C_FREQ_FAST 400000 | |
71 | #define U2C_I2C_FREQ_STD 100000 | |
72 | #define U2C_I2C_FREQ(s) (1000000 / (2 * (s - 1) + 10)) | |
73 | ||
74 | #define DIOLAN_USB_TIMEOUT 100 /* in ms */ | |
75 | #define DIOLAN_SYNC_TIMEOUT 20 /* in ms */ | |
76 | ||
77 | #define DIOLAN_OUTBUF_LEN 128 | |
78 | #define DIOLAN_FLUSH_LEN (DIOLAN_OUTBUF_LEN - 4) | |
79 | #define DIOLAN_INBUF_LEN 256 /* Maximum supported receive length */ | |
80 | ||
81 | /* Structure to hold all of our device specific stuff */ | |
82 | struct i2c_diolan_u2c { | |
83 | u8 obuffer[DIOLAN_OUTBUF_LEN]; /* output buffer */ | |
84 | u8 ibuffer[DIOLAN_INBUF_LEN]; /* input buffer */ | |
4e4844cc | 85 | int ep_in, ep_out; /* Endpoints */ |
335d7c58 GR |
86 | struct usb_device *usb_dev; /* the usb device for this device */ |
87 | struct usb_interface *interface;/* the interface for this device */ | |
88 | struct i2c_adapter adapter; /* i2c related things */ | |
89 | int olen; /* Output buffer length */ | |
90 | int ocount; /* Number of enqueued messages */ | |
91 | }; | |
92 | ||
93 | static uint frequency = U2C_I2C_FREQ_STD; /* I2C clock frequency in Hz */ | |
94 | ||
95 | module_param(frequency, uint, S_IRUGO | S_IWUSR); | |
96 | MODULE_PARM_DESC(frequency, "I2C clock frequency in hertz"); | |
97 | ||
98 | /* usb layer */ | |
99 | ||
100 | /* Send command to device, and get response. */ | |
101 | static int diolan_usb_transfer(struct i2c_diolan_u2c *dev) | |
102 | { | |
103 | int ret = 0; | |
104 | int actual; | |
105 | int i; | |
106 | ||
107 | if (!dev->olen || !dev->ocount) | |
108 | return -EINVAL; | |
109 | ||
110 | ret = usb_bulk_msg(dev->usb_dev, | |
4e4844cc | 111 | usb_sndbulkpipe(dev->usb_dev, dev->ep_out), |
335d7c58 GR |
112 | dev->obuffer, dev->olen, &actual, |
113 | DIOLAN_USB_TIMEOUT); | |
114 | if (!ret) { | |
115 | for (i = 0; i < dev->ocount; i++) { | |
116 | int tmpret; | |
117 | ||
118 | tmpret = usb_bulk_msg(dev->usb_dev, | |
119 | usb_rcvbulkpipe(dev->usb_dev, | |
4e4844cc | 120 | dev->ep_in), |
335d7c58 GR |
121 | dev->ibuffer, |
122 | sizeof(dev->ibuffer), &actual, | |
123 | DIOLAN_USB_TIMEOUT); | |
124 | /* | |
125 | * Stop command processing if a previous command | |
126 | * returned an error. | |
127 | * Note that we still need to retrieve all messages. | |
128 | */ | |
129 | if (ret < 0) | |
130 | continue; | |
131 | ret = tmpret; | |
132 | if (ret == 0 && actual > 0) { | |
133 | switch (dev->ibuffer[actual - 1]) { | |
134 | case RESP_NACK: | |
135 | /* | |
136 | * Return ENXIO if NACK was received as | |
137 | * response to the address phase, | |
138 | * EIO otherwise | |
139 | */ | |
140 | ret = i == 1 ? -ENXIO : -EIO; | |
141 | break; | |
142 | case RESP_TIMEOUT: | |
143 | ret = -ETIMEDOUT; | |
144 | break; | |
145 | case RESP_OK: | |
146 | /* strip off return code */ | |
147 | ret = actual - 1; | |
148 | break; | |
149 | default: | |
150 | ret = -EIO; | |
151 | break; | |
152 | } | |
153 | } | |
154 | } | |
155 | } | |
156 | dev->olen = 0; | |
157 | dev->ocount = 0; | |
158 | return ret; | |
159 | } | |
160 | ||
161 | static int diolan_write_cmd(struct i2c_diolan_u2c *dev, bool flush) | |
162 | { | |
163 | if (flush || dev->olen >= DIOLAN_FLUSH_LEN) | |
164 | return diolan_usb_transfer(dev); | |
165 | return 0; | |
166 | } | |
167 | ||
168 | /* Send command (no data) */ | |
169 | static int diolan_usb_cmd(struct i2c_diolan_u2c *dev, u8 command, bool flush) | |
170 | { | |
171 | dev->obuffer[dev->olen++] = command; | |
172 | dev->ocount++; | |
173 | return diolan_write_cmd(dev, flush); | |
174 | } | |
175 | ||
176 | /* Send command with one byte of data */ | |
177 | static int diolan_usb_cmd_data(struct i2c_diolan_u2c *dev, u8 command, u8 data, | |
178 | bool flush) | |
179 | { | |
180 | dev->obuffer[dev->olen++] = command; | |
181 | dev->obuffer[dev->olen++] = data; | |
182 | dev->ocount++; | |
183 | return diolan_write_cmd(dev, flush); | |
184 | } | |
185 | ||
186 | /* Send command with two bytes of data */ | |
187 | static int diolan_usb_cmd_data2(struct i2c_diolan_u2c *dev, u8 command, u8 d1, | |
188 | u8 d2, bool flush) | |
189 | { | |
190 | dev->obuffer[dev->olen++] = command; | |
191 | dev->obuffer[dev->olen++] = d1; | |
192 | dev->obuffer[dev->olen++] = d2; | |
193 | dev->ocount++; | |
194 | return diolan_write_cmd(dev, flush); | |
195 | } | |
196 | ||
197 | /* | |
198 | * Flush input queue. | |
199 | * If we don't do this at startup and the controller has queued up | |
200 | * messages which were not retrieved, it will stop responding | |
201 | * at some point. | |
202 | */ | |
203 | static void diolan_flush_input(struct i2c_diolan_u2c *dev) | |
204 | { | |
205 | int i; | |
206 | ||
207 | for (i = 0; i < 10; i++) { | |
208 | int actual = 0; | |
209 | int ret; | |
210 | ||
211 | ret = usb_bulk_msg(dev->usb_dev, | |
4e4844cc | 212 | usb_rcvbulkpipe(dev->usb_dev, dev->ep_in), |
335d7c58 GR |
213 | dev->ibuffer, sizeof(dev->ibuffer), &actual, |
214 | DIOLAN_USB_TIMEOUT); | |
215 | if (ret < 0 || actual == 0) | |
216 | break; | |
217 | } | |
218 | if (i == 10) | |
219 | dev_err(&dev->interface->dev, "Failed to flush input buffer\n"); | |
220 | } | |
221 | ||
222 | static int diolan_i2c_start(struct i2c_diolan_u2c *dev) | |
223 | { | |
224 | return diolan_usb_cmd(dev, CMD_I2C_START, false); | |
225 | } | |
226 | ||
227 | static int diolan_i2c_repeated_start(struct i2c_diolan_u2c *dev) | |
228 | { | |
229 | return diolan_usb_cmd(dev, CMD_I2C_REPEATED_START, false); | |
230 | } | |
231 | ||
232 | static int diolan_i2c_stop(struct i2c_diolan_u2c *dev) | |
233 | { | |
234 | return diolan_usb_cmd(dev, CMD_I2C_STOP, true); | |
235 | } | |
236 | ||
237 | static int diolan_i2c_get_byte_ack(struct i2c_diolan_u2c *dev, bool ack, | |
238 | u8 *byte) | |
239 | { | |
240 | int ret; | |
241 | ||
242 | ret = diolan_usb_cmd_data(dev, CMD_I2C_GET_BYTE_ACK, ack, true); | |
243 | if (ret > 0) | |
244 | *byte = dev->ibuffer[0]; | |
245 | else if (ret == 0) | |
246 | ret = -EIO; | |
247 | ||
248 | return ret; | |
249 | } | |
250 | ||
251 | static int diolan_i2c_put_byte_ack(struct i2c_diolan_u2c *dev, u8 byte) | |
252 | { | |
253 | return diolan_usb_cmd_data(dev, CMD_I2C_PUT_BYTE_ACK, byte, false); | |
254 | } | |
255 | ||
256 | static int diolan_set_speed(struct i2c_diolan_u2c *dev, u8 speed) | |
257 | { | |
258 | return diolan_usb_cmd_data(dev, CMD_I2C_SET_SPEED, speed, true); | |
259 | } | |
260 | ||
261 | /* Enable or disable clock synchronization (stretching) */ | |
262 | static int diolan_set_clock_synch(struct i2c_diolan_u2c *dev, bool enable) | |
263 | { | |
264 | return diolan_usb_cmd_data(dev, CMD_I2C_SET_CLK_SYNC, enable, true); | |
265 | } | |
266 | ||
267 | /* Set clock synchronization timeout in ms */ | |
268 | static int diolan_set_clock_synch_timeout(struct i2c_diolan_u2c *dev, int ms) | |
269 | { | |
270 | int to_val = ms * 10; | |
271 | ||
272 | return diolan_usb_cmd_data2(dev, CMD_I2C_SET_CLK_SYNC_TO, | |
273 | to_val & 0xff, (to_val >> 8) & 0xff, true); | |
274 | } | |
275 | ||
276 | static void diolan_fw_version(struct i2c_diolan_u2c *dev) | |
277 | { | |
278 | int ret; | |
279 | ||
280 | ret = diolan_usb_cmd(dev, CMD_GET_FW_VERSION, true); | |
281 | if (ret >= 2) | |
282 | dev_info(&dev->interface->dev, | |
283 | "Diolan U2C firmware version %u.%u\n", | |
284 | (unsigned int)dev->ibuffer[0], | |
285 | (unsigned int)dev->ibuffer[1]); | |
286 | } | |
287 | ||
288 | static void diolan_get_serial(struct i2c_diolan_u2c *dev) | |
289 | { | |
290 | int ret; | |
291 | u32 serial; | |
292 | ||
293 | ret = diolan_usb_cmd(dev, CMD_GET_SERIAL, true); | |
294 | if (ret >= 4) { | |
295 | serial = le32_to_cpu(*(u32 *)dev->ibuffer); | |
296 | dev_info(&dev->interface->dev, | |
297 | "Diolan U2C serial number %u\n", serial); | |
298 | } | |
299 | } | |
300 | ||
301 | static int diolan_init(struct i2c_diolan_u2c *dev) | |
302 | { | |
303 | int speed, ret; | |
304 | ||
305 | if (frequency >= 200000) { | |
306 | speed = U2C_I2C_SPEED_FAST; | |
307 | frequency = U2C_I2C_FREQ_FAST; | |
308 | } else if (frequency >= 100000 || frequency == 0) { | |
309 | speed = U2C_I2C_SPEED_STD; | |
310 | frequency = U2C_I2C_FREQ_STD; | |
311 | } else { | |
312 | speed = U2C_I2C_SPEED(frequency); | |
313 | if (speed > U2C_I2C_SPEED_2KHZ) | |
314 | speed = U2C_I2C_SPEED_2KHZ; | |
315 | frequency = U2C_I2C_FREQ(speed); | |
316 | } | |
317 | ||
318 | dev_info(&dev->interface->dev, | |
319 | "Diolan U2C at USB bus %03d address %03d speed %d Hz\n", | |
320 | dev->usb_dev->bus->busnum, dev->usb_dev->devnum, frequency); | |
321 | ||
322 | diolan_flush_input(dev); | |
323 | diolan_fw_version(dev); | |
324 | diolan_get_serial(dev); | |
325 | ||
326 | /* Set I2C speed */ | |
327 | ret = diolan_set_speed(dev, speed); | |
328 | if (ret < 0) | |
329 | return ret; | |
330 | ||
331 | /* Configure I2C clock synchronization */ | |
332 | ret = diolan_set_clock_synch(dev, speed != U2C_I2C_SPEED_FAST); | |
333 | if (ret < 0) | |
334 | return ret; | |
335 | ||
336 | if (speed != U2C_I2C_SPEED_FAST) | |
337 | ret = diolan_set_clock_synch_timeout(dev, DIOLAN_SYNC_TIMEOUT); | |
338 | ||
339 | return ret; | |
340 | } | |
341 | ||
342 | /* i2c layer */ | |
343 | ||
344 | static int diolan_usb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, | |
345 | int num) | |
346 | { | |
347 | struct i2c_diolan_u2c *dev = i2c_get_adapdata(adapter); | |
348 | struct i2c_msg *pmsg; | |
349 | int i, j; | |
350 | int ret, sret; | |
351 | ||
352 | ret = diolan_i2c_start(dev); | |
353 | if (ret < 0) | |
354 | return ret; | |
355 | ||
356 | for (i = 0; i < num; i++) { | |
357 | pmsg = &msgs[i]; | |
358 | if (i) { | |
359 | ret = diolan_i2c_repeated_start(dev); | |
360 | if (ret < 0) | |
361 | goto abort; | |
362 | } | |
363 | if (pmsg->flags & I2C_M_RD) { | |
364 | ret = | |
365 | diolan_i2c_put_byte_ack(dev, (pmsg->addr << 1) | 1); | |
366 | if (ret < 0) | |
367 | goto abort; | |
368 | for (j = 0; j < pmsg->len; j++) { | |
369 | u8 byte; | |
370 | bool ack = j < pmsg->len - 1; | |
371 | ||
372 | /* | |
373 | * Don't send NACK if this is the first byte | |
374 | * of a SMBUS_BLOCK message. | |
375 | */ | |
376 | if (j == 0 && (pmsg->flags & I2C_M_RECV_LEN)) | |
377 | ack = true; | |
378 | ||
379 | ret = diolan_i2c_get_byte_ack(dev, ack, &byte); | |
380 | if (ret < 0) | |
381 | goto abort; | |
382 | /* | |
383 | * Adjust count if first received byte is length | |
384 | */ | |
385 | if (j == 0 && (pmsg->flags & I2C_M_RECV_LEN)) { | |
386 | if (byte == 0 | |
387 | || byte > I2C_SMBUS_BLOCK_MAX) { | |
388 | ret = -EPROTO; | |
389 | goto abort; | |
390 | } | |
391 | pmsg->len += byte; | |
392 | } | |
393 | pmsg->buf[j] = byte; | |
394 | } | |
395 | } else { | |
396 | ret = diolan_i2c_put_byte_ack(dev, pmsg->addr << 1); | |
397 | if (ret < 0) | |
398 | goto abort; | |
399 | for (j = 0; j < pmsg->len; j++) { | |
400 | ret = diolan_i2c_put_byte_ack(dev, | |
401 | pmsg->buf[j]); | |
402 | if (ret < 0) | |
403 | goto abort; | |
404 | } | |
405 | } | |
406 | } | |
ab5625c3 | 407 | ret = num; |
335d7c58 GR |
408 | abort: |
409 | sret = diolan_i2c_stop(dev); | |
410 | if (sret < 0 && ret >= 0) | |
411 | ret = sret; | |
412 | return ret; | |
413 | } | |
414 | ||
415 | /* | |
416 | * Return list of supported functionality. | |
417 | */ | |
418 | static u32 diolan_usb_func(struct i2c_adapter *a) | |
419 | { | |
420 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | | |
421 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL; | |
422 | } | |
423 | ||
424 | static const struct i2c_algorithm diolan_usb_algorithm = { | |
425 | .master_xfer = diolan_usb_xfer, | |
426 | .functionality = diolan_usb_func, | |
427 | }; | |
428 | ||
429 | /* device layer */ | |
430 | ||
431 | static const struct usb_device_id diolan_u2c_table[] = { | |
432 | { USB_DEVICE(USB_VENDOR_ID_DIOLAN, USB_DEVICE_ID_DIOLAN_U2C) }, | |
433 | { } | |
434 | }; | |
435 | ||
436 | MODULE_DEVICE_TABLE(usb, diolan_u2c_table); | |
437 | ||
438 | static void diolan_u2c_free(struct i2c_diolan_u2c *dev) | |
439 | { | |
440 | usb_put_dev(dev->usb_dev); | |
441 | kfree(dev); | |
442 | } | |
443 | ||
444 | static int diolan_u2c_probe(struct usb_interface *interface, | |
445 | const struct usb_device_id *id) | |
446 | { | |
4e4844cc | 447 | struct usb_host_interface *hostif = interface->cur_altsetting; |
335d7c58 GR |
448 | struct i2c_diolan_u2c *dev; |
449 | int ret; | |
450 | ||
4e4844cc MV |
451 | if (hostif->desc.bInterfaceNumber != 0 |
452 | || hostif->desc.bNumEndpoints < 2) | |
453 | return -ENODEV; | |
454 | ||
335d7c58 GR |
455 | /* allocate memory for our device state and initialize it */ |
456 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); | |
457 | if (dev == NULL) { | |
335d7c58 GR |
458 | ret = -ENOMEM; |
459 | goto error; | |
460 | } | |
4e4844cc MV |
461 | dev->ep_out = hostif->endpoint[0].desc.bEndpointAddress; |
462 | dev->ep_in = hostif->endpoint[1].desc.bEndpointAddress; | |
335d7c58 GR |
463 | |
464 | dev->usb_dev = usb_get_dev(interface_to_usbdev(interface)); | |
465 | dev->interface = interface; | |
466 | ||
467 | /* save our data pointer in this interface device */ | |
468 | usb_set_intfdata(interface, dev); | |
469 | ||
470 | /* setup i2c adapter description */ | |
471 | dev->adapter.owner = THIS_MODULE; | |
472 | dev->adapter.class = I2C_CLASS_HWMON; | |
473 | dev->adapter.algo = &diolan_usb_algorithm; | |
474 | i2c_set_adapdata(&dev->adapter, dev); | |
475 | snprintf(dev->adapter.name, sizeof(dev->adapter.name), | |
476 | DRIVER_NAME " at bus %03d device %03d", | |
477 | dev->usb_dev->bus->busnum, dev->usb_dev->devnum); | |
478 | ||
479 | dev->adapter.dev.parent = &dev->interface->dev; | |
480 | ||
481 | /* initialize diolan i2c interface */ | |
482 | ret = diolan_init(dev); | |
483 | if (ret < 0) { | |
484 | dev_err(&interface->dev, "failed to initialize adapter\n"); | |
485 | goto error_free; | |
486 | } | |
487 | ||
488 | /* and finally attach to i2c layer */ | |
489 | ret = i2c_add_adapter(&dev->adapter); | |
ea734404 | 490 | if (ret < 0) |
335d7c58 | 491 | goto error_free; |
335d7c58 GR |
492 | |
493 | dev_dbg(&interface->dev, "connected " DRIVER_NAME "\n"); | |
494 | ||
495 | return 0; | |
496 | ||
497 | error_free: | |
498 | usb_set_intfdata(interface, NULL); | |
499 | diolan_u2c_free(dev); | |
500 | error: | |
501 | return ret; | |
502 | } | |
503 | ||
504 | static void diolan_u2c_disconnect(struct usb_interface *interface) | |
505 | { | |
506 | struct i2c_diolan_u2c *dev = usb_get_intfdata(interface); | |
507 | ||
508 | i2c_del_adapter(&dev->adapter); | |
509 | usb_set_intfdata(interface, NULL); | |
510 | diolan_u2c_free(dev); | |
511 | ||
512 | dev_dbg(&interface->dev, "disconnected\n"); | |
513 | } | |
514 | ||
515 | static struct usb_driver diolan_u2c_driver = { | |
516 | .name = DRIVER_NAME, | |
517 | .probe = diolan_u2c_probe, | |
518 | .disconnect = diolan_u2c_disconnect, | |
519 | .id_table = diolan_u2c_table, | |
520 | }; | |
521 | ||
fe748483 | 522 | module_usb_driver(diolan_u2c_driver); |
335d7c58 | 523 | |
83a638df | 524 | MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); |
335d7c58 GR |
525 | MODULE_DESCRIPTION(DRIVER_NAME " driver"); |
526 | MODULE_LICENSE("GPL"); |