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67a95c21 RG |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * MCP2221A - Microchip USB to I2C Host Protocol Bridge | |
4 | * | |
5 | * Copyright (c) 2020, Rishi Gupta <gupt21@gmail.com> | |
6 | * | |
b266eacf | 7 | * Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf |
67a95c21 RG |
8 | */ |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/err.h> | |
12 | #include <linux/mutex.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/delay.h> | |
15 | #include <linux/hid.h> | |
16 | #include <linux/hidraw.h> | |
17 | #include <linux/i2c.h> | |
328de1c5 | 18 | #include <linux/gpio/driver.h> |
67a95c21 RG |
19 | #include "hid-ids.h" |
20 | ||
21 | /* Commands codes in a raw output report */ | |
22 | enum { | |
23 | MCP2221_I2C_WR_DATA = 0x90, | |
24 | MCP2221_I2C_WR_NO_STOP = 0x94, | |
25 | MCP2221_I2C_RD_DATA = 0x91, | |
26 | MCP2221_I2C_RD_RPT_START = 0x93, | |
27 | MCP2221_I2C_GET_DATA = 0x40, | |
28 | MCP2221_I2C_PARAM_OR_STATUS = 0x10, | |
29 | MCP2221_I2C_SET_SPEED = 0x20, | |
30 | MCP2221_I2C_CANCEL = 0x10, | |
328de1c5 RG |
31 | MCP2221_GPIO_SET = 0x50, |
32 | MCP2221_GPIO_GET = 0x51, | |
67a95c21 RG |
33 | }; |
34 | ||
35 | /* Response codes in a raw input report */ | |
36 | enum { | |
37 | MCP2221_SUCCESS = 0x00, | |
38 | MCP2221_I2C_ENG_BUSY = 0x01, | |
39 | MCP2221_I2C_START_TOUT = 0x12, | |
40 | MCP2221_I2C_STOP_TOUT = 0x62, | |
41 | MCP2221_I2C_WRADDRL_TOUT = 0x23, | |
42 | MCP2221_I2C_WRDATA_TOUT = 0x44, | |
43 | MCP2221_I2C_WRADDRL_NACK = 0x25, | |
44 | MCP2221_I2C_MASK_ADDR_NACK = 0x40, | |
45 | MCP2221_I2C_WRADDRL_SEND = 0x21, | |
46 | MCP2221_I2C_ADDR_NACK = 0x25, | |
47 | MCP2221_I2C_READ_COMPL = 0x55, | |
328de1c5 RG |
48 | MCP2221_ALT_F_NOT_GPIOV = 0xEE, |
49 | MCP2221_ALT_F_NOT_GPIOD = 0xEF, | |
67a95c21 RG |
50 | }; |
51 | ||
567b8e9f LP |
52 | /* MCP GPIO direction encoding */ |
53 | enum { | |
54 | MCP2221_DIR_OUT = 0x00, | |
55 | MCP2221_DIR_IN = 0x01, | |
56 | }; | |
57 | ||
58 | #define MCP_NGPIO 4 | |
59 | ||
60 | /* MCP GPIO set command layout */ | |
61 | struct mcp_set_gpio { | |
62 | u8 cmd; | |
63 | u8 dummy; | |
64 | struct { | |
65 | u8 change_value; | |
66 | u8 value; | |
67 | u8 change_direction; | |
68 | u8 direction; | |
69 | } gpio[MCP_NGPIO]; | |
70 | } __packed; | |
71 | ||
72 | /* MCP GPIO get command layout */ | |
73 | struct mcp_get_gpio { | |
74 | u8 cmd; | |
75 | u8 dummy; | |
76 | struct { | |
77 | u8 direction; | |
78 | u8 value; | |
79 | } gpio[MCP_NGPIO]; | |
80 | } __packed; | |
81 | ||
67a95c21 RG |
82 | /* |
83 | * There is no way to distinguish responses. Therefore next command | |
84 | * is sent only after response to previous has been received. Mutex | |
85 | * lock is used for this purpose mainly. | |
86 | */ | |
87 | struct mcp2221 { | |
88 | struct hid_device *hdev; | |
89 | struct i2c_adapter adapter; | |
90 | struct mutex lock; | |
91 | struct completion wait_in_report; | |
92 | u8 *rxbuf; | |
93 | u8 txbuf[64]; | |
94 | int rxbuf_idx; | |
95 | int status; | |
96 | u8 cur_i2c_clk_div; | |
328de1c5 RG |
97 | struct gpio_chip *gc; |
98 | u8 gp_idx; | |
99 | u8 gpio_dir; | |
67a95c21 RG |
100 | }; |
101 | ||
102 | /* | |
103 | * Default i2c bus clock frequency 400 kHz. Modify this if you | |
104 | * want to set some other frequency (min 50 kHz - max 400 kHz). | |
105 | */ | |
106 | static uint i2c_clk_freq = 400; | |
107 | ||
108 | /* Synchronously send output report to the device */ | |
109 | static int mcp_send_report(struct mcp2221 *mcp, | |
110 | u8 *out_report, size_t len) | |
111 | { | |
112 | u8 *buf; | |
113 | int ret; | |
114 | ||
115 | buf = kmemdup(out_report, len, GFP_KERNEL); | |
116 | if (!buf) | |
117 | return -ENOMEM; | |
118 | ||
119 | /* mcp2221 uses interrupt endpoint for out reports */ | |
120 | ret = hid_hw_output_report(mcp->hdev, buf, len); | |
121 | kfree(buf); | |
122 | ||
123 | if (ret < 0) | |
124 | return ret; | |
125 | return 0; | |
126 | } | |
127 | ||
128 | /* | |
129 | * Send o/p report to the device and wait for i/p report to be | |
130 | * received from the device. If the device does not respond, | |
131 | * we timeout. | |
132 | */ | |
133 | static int mcp_send_data_req_status(struct mcp2221 *mcp, | |
134 | u8 *out_report, int len) | |
135 | { | |
136 | int ret; | |
137 | unsigned long t; | |
138 | ||
139 | reinit_completion(&mcp->wait_in_report); | |
140 | ||
141 | ret = mcp_send_report(mcp, out_report, len); | |
142 | if (ret) | |
143 | return ret; | |
144 | ||
145 | t = wait_for_completion_timeout(&mcp->wait_in_report, | |
146 | msecs_to_jiffies(4000)); | |
147 | if (!t) | |
148 | return -ETIMEDOUT; | |
149 | ||
150 | return mcp->status; | |
151 | } | |
152 | ||
153 | /* Check pass/fail for actual communication with i2c slave */ | |
154 | static int mcp_chk_last_cmd_status(struct mcp2221 *mcp) | |
155 | { | |
156 | memset(mcp->txbuf, 0, 8); | |
157 | mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; | |
158 | ||
159 | return mcp_send_data_req_status(mcp, mcp->txbuf, 8); | |
160 | } | |
161 | ||
162 | /* Cancels last command releasing i2c bus just in case occupied */ | |
163 | static int mcp_cancel_last_cmd(struct mcp2221 *mcp) | |
164 | { | |
165 | memset(mcp->txbuf, 0, 8); | |
166 | mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; | |
167 | mcp->txbuf[2] = MCP2221_I2C_CANCEL; | |
168 | ||
169 | return mcp_send_data_req_status(mcp, mcp->txbuf, 8); | |
170 | } | |
171 | ||
172 | static int mcp_set_i2c_speed(struct mcp2221 *mcp) | |
173 | { | |
174 | int ret; | |
175 | ||
176 | memset(mcp->txbuf, 0, 8); | |
177 | mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; | |
178 | mcp->txbuf[3] = MCP2221_I2C_SET_SPEED; | |
179 | mcp->txbuf[4] = mcp->cur_i2c_clk_div; | |
180 | ||
181 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, 8); | |
182 | if (ret) { | |
183 | /* Small delay is needed here */ | |
184 | usleep_range(980, 1000); | |
185 | mcp_cancel_last_cmd(mcp); | |
186 | } | |
187 | ||
188 | return 0; | |
189 | } | |
190 | ||
191 | /* | |
192 | * An output report can contain minimum 1 and maximum 60 user data | |
193 | * bytes. If the number of data bytes is more then 60, we send it | |
194 | * in chunks of 60 bytes. Last chunk may contain exactly 60 or less | |
195 | * bytes. Total number of bytes is informed in very first report to | |
196 | * mcp2221, from that point onwards it first collect all the data | |
197 | * from host and then send to i2c slave device. | |
198 | */ | |
199 | static int mcp_i2c_write(struct mcp2221 *mcp, | |
200 | struct i2c_msg *msg, int type, u8 last_status) | |
201 | { | |
202 | int ret, len, idx, sent; | |
203 | ||
204 | idx = 0; | |
205 | sent = 0; | |
206 | if (msg->len < 60) | |
207 | len = msg->len; | |
208 | else | |
209 | len = 60; | |
210 | ||
211 | do { | |
212 | mcp->txbuf[0] = type; | |
213 | mcp->txbuf[1] = msg->len & 0xff; | |
214 | mcp->txbuf[2] = msg->len >> 8; | |
215 | mcp->txbuf[3] = (u8)(msg->addr << 1); | |
216 | ||
217 | memcpy(&mcp->txbuf[4], &msg->buf[idx], len); | |
218 | ||
219 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, len + 4); | |
220 | if (ret) | |
221 | return ret; | |
222 | ||
223 | usleep_range(980, 1000); | |
224 | ||
225 | if (last_status) { | |
226 | ret = mcp_chk_last_cmd_status(mcp); | |
227 | if (ret) | |
228 | return ret; | |
229 | } | |
230 | ||
231 | sent = sent + len; | |
232 | if (sent >= msg->len) | |
233 | break; | |
234 | ||
235 | idx = idx + len; | |
236 | if ((msg->len - sent) < 60) | |
237 | len = msg->len - sent; | |
238 | else | |
239 | len = 60; | |
240 | ||
241 | /* | |
242 | * Testing shows delay is needed between successive writes | |
243 | * otherwise next write fails on first-try from i2c core. | |
244 | * This value is obtained through automated stress testing. | |
245 | */ | |
246 | usleep_range(980, 1000); | |
247 | } while (len > 0); | |
248 | ||
249 | return ret; | |
250 | } | |
251 | ||
252 | /* | |
253 | * Device reads all data (0 - 65535 bytes) from i2c slave device and | |
254 | * stores it in device itself. This data is read back from device to | |
255 | * host in multiples of 60 bytes using input reports. | |
256 | */ | |
257 | static int mcp_i2c_smbus_read(struct mcp2221 *mcp, | |
258 | struct i2c_msg *msg, int type, u16 smbus_addr, | |
259 | u8 smbus_len, u8 *smbus_buf) | |
260 | { | |
261 | int ret; | |
262 | u16 total_len; | |
263 | ||
264 | mcp->txbuf[0] = type; | |
265 | if (msg) { | |
266 | mcp->txbuf[1] = msg->len & 0xff; | |
267 | mcp->txbuf[2] = msg->len >> 8; | |
268 | mcp->txbuf[3] = (u8)(msg->addr << 1); | |
269 | total_len = msg->len; | |
270 | mcp->rxbuf = msg->buf; | |
271 | } else { | |
272 | mcp->txbuf[1] = smbus_len; | |
273 | mcp->txbuf[2] = 0; | |
274 | mcp->txbuf[3] = (u8)(smbus_addr << 1); | |
275 | total_len = smbus_len; | |
276 | mcp->rxbuf = smbus_buf; | |
277 | } | |
278 | ||
279 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4); | |
280 | if (ret) | |
281 | return ret; | |
282 | ||
283 | mcp->rxbuf_idx = 0; | |
284 | ||
285 | do { | |
286 | memset(mcp->txbuf, 0, 4); | |
287 | mcp->txbuf[0] = MCP2221_I2C_GET_DATA; | |
288 | ||
289 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); | |
290 | if (ret) | |
291 | return ret; | |
292 | ||
293 | ret = mcp_chk_last_cmd_status(mcp); | |
294 | if (ret) | |
295 | return ret; | |
296 | ||
297 | usleep_range(980, 1000); | |
298 | } while (mcp->rxbuf_idx < total_len); | |
299 | ||
300 | return ret; | |
301 | } | |
302 | ||
303 | static int mcp_i2c_xfer(struct i2c_adapter *adapter, | |
304 | struct i2c_msg msgs[], int num) | |
305 | { | |
306 | int ret; | |
307 | struct mcp2221 *mcp = i2c_get_adapdata(adapter); | |
308 | ||
309 | hid_hw_power(mcp->hdev, PM_HINT_FULLON); | |
310 | ||
311 | mutex_lock(&mcp->lock); | |
312 | ||
313 | /* Setting speed before every transaction is required for mcp2221 */ | |
314 | ret = mcp_set_i2c_speed(mcp); | |
315 | if (ret) | |
316 | goto exit; | |
317 | ||
318 | if (num == 1) { | |
319 | if (msgs->flags & I2C_M_RD) { | |
320 | ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA, | |
321 | 0, 0, NULL); | |
322 | } else { | |
323 | ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1); | |
324 | } | |
325 | if (ret) | |
326 | goto exit; | |
327 | ret = num; | |
328 | } else if (num == 2) { | |
329 | /* Ex transaction; send reg address and read its contents */ | |
330 | if (msgs[0].addr == msgs[1].addr && | |
331 | !(msgs[0].flags & I2C_M_RD) && | |
332 | (msgs[1].flags & I2C_M_RD)) { | |
333 | ||
334 | ret = mcp_i2c_write(mcp, &msgs[0], | |
335 | MCP2221_I2C_WR_NO_STOP, 0); | |
336 | if (ret) | |
337 | goto exit; | |
338 | ||
339 | ret = mcp_i2c_smbus_read(mcp, &msgs[1], | |
340 | MCP2221_I2C_RD_RPT_START, | |
341 | 0, 0, NULL); | |
342 | if (ret) | |
343 | goto exit; | |
344 | ret = num; | |
345 | } else { | |
346 | dev_err(&adapter->dev, | |
347 | "unsupported multi-msg i2c transaction\n"); | |
348 | ret = -EOPNOTSUPP; | |
349 | } | |
350 | } else { | |
351 | dev_err(&adapter->dev, | |
352 | "unsupported multi-msg i2c transaction\n"); | |
353 | ret = -EOPNOTSUPP; | |
354 | } | |
355 | ||
356 | exit: | |
357 | hid_hw_power(mcp->hdev, PM_HINT_NORMAL); | |
358 | mutex_unlock(&mcp->lock); | |
359 | return ret; | |
360 | } | |
361 | ||
362 | static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr, | |
363 | u8 command, u8 *buf, u8 len, int type, | |
364 | u8 last_status) | |
365 | { | |
366 | int data_len, ret; | |
367 | ||
368 | mcp->txbuf[0] = type; | |
369 | mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */ | |
370 | mcp->txbuf[2] = 0; | |
371 | mcp->txbuf[3] = (u8)(addr << 1); | |
372 | mcp->txbuf[4] = command; | |
373 | ||
374 | switch (len) { | |
375 | case 0: | |
376 | data_len = 5; | |
377 | break; | |
378 | case 1: | |
379 | mcp->txbuf[5] = buf[0]; | |
380 | data_len = 6; | |
381 | break; | |
382 | case 2: | |
383 | mcp->txbuf[5] = buf[0]; | |
384 | mcp->txbuf[6] = buf[1]; | |
385 | data_len = 7; | |
386 | break; | |
387 | default: | |
388 | memcpy(&mcp->txbuf[5], buf, len); | |
389 | data_len = len + 5; | |
390 | } | |
391 | ||
392 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len); | |
393 | if (ret) | |
394 | return ret; | |
395 | ||
396 | if (last_status) { | |
397 | usleep_range(980, 1000); | |
398 | ||
399 | ret = mcp_chk_last_cmd_status(mcp); | |
400 | if (ret) | |
401 | return ret; | |
402 | } | |
403 | ||
404 | return ret; | |
405 | } | |
406 | ||
407 | static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr, | |
408 | unsigned short flags, char read_write, | |
409 | u8 command, int size, | |
410 | union i2c_smbus_data *data) | |
411 | { | |
412 | int ret; | |
413 | struct mcp2221 *mcp = i2c_get_adapdata(adapter); | |
414 | ||
415 | hid_hw_power(mcp->hdev, PM_HINT_FULLON); | |
416 | ||
417 | mutex_lock(&mcp->lock); | |
418 | ||
419 | ret = mcp_set_i2c_speed(mcp); | |
420 | if (ret) | |
421 | goto exit; | |
422 | ||
423 | switch (size) { | |
424 | ||
425 | case I2C_SMBUS_QUICK: | |
426 | if (read_write == I2C_SMBUS_READ) | |
427 | ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, | |
428 | addr, 0, &data->byte); | |
429 | else | |
430 | ret = mcp_smbus_write(mcp, addr, command, NULL, | |
431 | 0, MCP2221_I2C_WR_DATA, 1); | |
432 | break; | |
433 | case I2C_SMBUS_BYTE: | |
434 | if (read_write == I2C_SMBUS_READ) | |
435 | ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, | |
436 | addr, 1, &data->byte); | |
437 | else | |
438 | ret = mcp_smbus_write(mcp, addr, command, NULL, | |
439 | 0, MCP2221_I2C_WR_DATA, 1); | |
440 | break; | |
441 | case I2C_SMBUS_BYTE_DATA: | |
442 | if (read_write == I2C_SMBUS_READ) { | |
443 | ret = mcp_smbus_write(mcp, addr, command, NULL, | |
444 | 0, MCP2221_I2C_WR_NO_STOP, 0); | |
445 | if (ret) | |
446 | goto exit; | |
447 | ||
448 | ret = mcp_i2c_smbus_read(mcp, NULL, | |
449 | MCP2221_I2C_RD_RPT_START, | |
450 | addr, 1, &data->byte); | |
451 | } else { | |
452 | ret = mcp_smbus_write(mcp, addr, command, &data->byte, | |
453 | 1, MCP2221_I2C_WR_DATA, 1); | |
454 | } | |
455 | break; | |
456 | case I2C_SMBUS_WORD_DATA: | |
457 | if (read_write == I2C_SMBUS_READ) { | |
458 | ret = mcp_smbus_write(mcp, addr, command, NULL, | |
459 | 0, MCP2221_I2C_WR_NO_STOP, 0); | |
460 | if (ret) | |
461 | goto exit; | |
462 | ||
463 | ret = mcp_i2c_smbus_read(mcp, NULL, | |
464 | MCP2221_I2C_RD_RPT_START, | |
465 | addr, 2, (u8 *)&data->word); | |
466 | } else { | |
467 | ret = mcp_smbus_write(mcp, addr, command, | |
468 | (u8 *)&data->word, 2, | |
469 | MCP2221_I2C_WR_DATA, 1); | |
470 | } | |
471 | break; | |
472 | case I2C_SMBUS_BLOCK_DATA: | |
473 | if (read_write == I2C_SMBUS_READ) { | |
474 | ret = mcp_smbus_write(mcp, addr, command, NULL, | |
475 | 0, MCP2221_I2C_WR_NO_STOP, 1); | |
476 | if (ret) | |
477 | goto exit; | |
478 | ||
479 | mcp->rxbuf_idx = 0; | |
480 | mcp->rxbuf = data->block; | |
481 | mcp->txbuf[0] = MCP2221_I2C_GET_DATA; | |
482 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); | |
483 | if (ret) | |
484 | goto exit; | |
485 | } else { | |
486 | if (!data->block[0]) { | |
487 | ret = -EINVAL; | |
488 | goto exit; | |
489 | } | |
490 | ret = mcp_smbus_write(mcp, addr, command, data->block, | |
491 | data->block[0] + 1, | |
492 | MCP2221_I2C_WR_DATA, 1); | |
493 | } | |
494 | break; | |
495 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
496 | if (read_write == I2C_SMBUS_READ) { | |
497 | ret = mcp_smbus_write(mcp, addr, command, NULL, | |
498 | 0, MCP2221_I2C_WR_NO_STOP, 1); | |
499 | if (ret) | |
500 | goto exit; | |
501 | ||
502 | mcp->rxbuf_idx = 0; | |
503 | mcp->rxbuf = data->block; | |
504 | mcp->txbuf[0] = MCP2221_I2C_GET_DATA; | |
505 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); | |
506 | if (ret) | |
507 | goto exit; | |
508 | } else { | |
509 | if (!data->block[0]) { | |
510 | ret = -EINVAL; | |
511 | goto exit; | |
512 | } | |
513 | ret = mcp_smbus_write(mcp, addr, command, | |
514 | &data->block[1], data->block[0], | |
515 | MCP2221_I2C_WR_DATA, 1); | |
516 | } | |
517 | break; | |
518 | case I2C_SMBUS_PROC_CALL: | |
519 | ret = mcp_smbus_write(mcp, addr, command, | |
520 | (u8 *)&data->word, | |
521 | 2, MCP2221_I2C_WR_NO_STOP, 0); | |
522 | if (ret) | |
523 | goto exit; | |
524 | ||
525 | ret = mcp_i2c_smbus_read(mcp, NULL, | |
526 | MCP2221_I2C_RD_RPT_START, | |
527 | addr, 2, (u8 *)&data->word); | |
528 | break; | |
529 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
530 | ret = mcp_smbus_write(mcp, addr, command, data->block, | |
531 | data->block[0] + 1, | |
532 | MCP2221_I2C_WR_NO_STOP, 0); | |
533 | if (ret) | |
534 | goto exit; | |
535 | ||
536 | ret = mcp_i2c_smbus_read(mcp, NULL, | |
537 | MCP2221_I2C_RD_RPT_START, | |
538 | addr, I2C_SMBUS_BLOCK_MAX, | |
539 | data->block); | |
540 | break; | |
541 | default: | |
542 | dev_err(&mcp->adapter.dev, | |
543 | "unsupported smbus transaction size:%d\n", size); | |
544 | ret = -EOPNOTSUPP; | |
545 | } | |
546 | ||
547 | exit: | |
548 | hid_hw_power(mcp->hdev, PM_HINT_NORMAL); | |
549 | mutex_unlock(&mcp->lock); | |
550 | return ret; | |
551 | } | |
552 | ||
553 | static u32 mcp_i2c_func(struct i2c_adapter *adapter) | |
554 | { | |
555 | return I2C_FUNC_I2C | | |
556 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | | |
557 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | | |
558 | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC); | |
559 | } | |
560 | ||
561 | static const struct i2c_algorithm mcp_i2c_algo = { | |
562 | .master_xfer = mcp_i2c_xfer, | |
563 | .smbus_xfer = mcp_smbus_xfer, | |
564 | .functionality = mcp_i2c_func, | |
565 | }; | |
566 | ||
328de1c5 RG |
567 | static int mcp_gpio_get(struct gpio_chip *gc, |
568 | unsigned int offset) | |
569 | { | |
570 | int ret; | |
571 | struct mcp2221 *mcp = gpiochip_get_data(gc); | |
572 | ||
573 | mcp->txbuf[0] = MCP2221_GPIO_GET; | |
574 | ||
567b8e9f | 575 | mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset].value); |
328de1c5 RG |
576 | |
577 | mutex_lock(&mcp->lock); | |
578 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); | |
579 | mutex_unlock(&mcp->lock); | |
580 | ||
581 | return ret; | |
582 | } | |
583 | ||
584 | static void mcp_gpio_set(struct gpio_chip *gc, | |
585 | unsigned int offset, int value) | |
586 | { | |
587 | struct mcp2221 *mcp = gpiochip_get_data(gc); | |
588 | ||
589 | memset(mcp->txbuf, 0, 18); | |
590 | mcp->txbuf[0] = MCP2221_GPIO_SET; | |
591 | ||
567b8e9f | 592 | mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].value); |
328de1c5 RG |
593 | |
594 | mcp->txbuf[mcp->gp_idx - 1] = 1; | |
595 | mcp->txbuf[mcp->gp_idx] = !!value; | |
596 | ||
597 | mutex_lock(&mcp->lock); | |
598 | mcp_send_data_req_status(mcp, mcp->txbuf, 18); | |
599 | mutex_unlock(&mcp->lock); | |
600 | } | |
601 | ||
602 | static int mcp_gpio_dir_set(struct mcp2221 *mcp, | |
603 | unsigned int offset, u8 val) | |
604 | { | |
605 | memset(mcp->txbuf, 0, 18); | |
606 | mcp->txbuf[0] = MCP2221_GPIO_SET; | |
607 | ||
567b8e9f | 608 | mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].direction); |
328de1c5 RG |
609 | |
610 | mcp->txbuf[mcp->gp_idx - 1] = 1; | |
611 | mcp->txbuf[mcp->gp_idx] = val; | |
612 | ||
613 | return mcp_send_data_req_status(mcp, mcp->txbuf, 18); | |
614 | } | |
615 | ||
616 | static int mcp_gpio_direction_input(struct gpio_chip *gc, | |
617 | unsigned int offset) | |
618 | { | |
619 | int ret; | |
620 | struct mcp2221 *mcp = gpiochip_get_data(gc); | |
621 | ||
622 | mutex_lock(&mcp->lock); | |
567b8e9f | 623 | ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_IN); |
328de1c5 RG |
624 | mutex_unlock(&mcp->lock); |
625 | ||
626 | return ret; | |
627 | } | |
628 | ||
629 | static int mcp_gpio_direction_output(struct gpio_chip *gc, | |
630 | unsigned int offset, int value) | |
631 | { | |
632 | int ret; | |
633 | struct mcp2221 *mcp = gpiochip_get_data(gc); | |
634 | ||
635 | mutex_lock(&mcp->lock); | |
567b8e9f | 636 | ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_OUT); |
328de1c5 RG |
637 | mutex_unlock(&mcp->lock); |
638 | ||
639 | /* Can't configure as output, bailout early */ | |
640 | if (ret) | |
641 | return ret; | |
642 | ||
643 | mcp_gpio_set(gc, offset, value); | |
644 | ||
645 | return 0; | |
646 | } | |
647 | ||
648 | static int mcp_gpio_get_direction(struct gpio_chip *gc, | |
649 | unsigned int offset) | |
650 | { | |
651 | int ret; | |
652 | struct mcp2221 *mcp = gpiochip_get_data(gc); | |
653 | ||
654 | mcp->txbuf[0] = MCP2221_GPIO_GET; | |
655 | ||
567b8e9f | 656 | mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset].direction); |
328de1c5 RG |
657 | |
658 | mutex_lock(&mcp->lock); | |
659 | ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); | |
660 | mutex_unlock(&mcp->lock); | |
661 | ||
662 | if (ret) | |
663 | return ret; | |
664 | ||
567b8e9f | 665 | if (mcp->gpio_dir == MCP2221_DIR_IN) |
328de1c5 RG |
666 | return GPIO_LINE_DIRECTION_IN; |
667 | ||
668 | return GPIO_LINE_DIRECTION_OUT; | |
669 | } | |
670 | ||
67a95c21 RG |
671 | /* Gives current state of i2c engine inside mcp2221 */ |
672 | static int mcp_get_i2c_eng_state(struct mcp2221 *mcp, | |
673 | u8 *data, u8 idx) | |
674 | { | |
675 | int ret; | |
676 | ||
677 | switch (data[idx]) { | |
678 | case MCP2221_I2C_WRADDRL_NACK: | |
679 | case MCP2221_I2C_WRADDRL_SEND: | |
680 | ret = -ENXIO; | |
681 | break; | |
682 | case MCP2221_I2C_START_TOUT: | |
683 | case MCP2221_I2C_STOP_TOUT: | |
684 | case MCP2221_I2C_WRADDRL_TOUT: | |
685 | case MCP2221_I2C_WRDATA_TOUT: | |
686 | ret = -ETIMEDOUT; | |
687 | break; | |
688 | case MCP2221_I2C_ENG_BUSY: | |
689 | ret = -EAGAIN; | |
690 | break; | |
691 | case MCP2221_SUCCESS: | |
692 | ret = 0x00; | |
693 | break; | |
694 | default: | |
695 | ret = -EIO; | |
696 | } | |
697 | ||
698 | return ret; | |
699 | } | |
700 | ||
701 | /* | |
702 | * MCP2221 uses interrupt endpoint for input reports. This function | |
703 | * is called by HID layer when it receives i/p report from mcp2221, | |
704 | * which is actually a response to the previously sent command. | |
705 | * | |
706 | * MCP2221A firmware specific return codes are parsed and 0 or | |
707 | * appropriate negative error code is returned. Delayed response | |
708 | * results in timeout error and stray reponses results in -EIO. | |
709 | */ | |
710 | static int mcp2221_raw_event(struct hid_device *hdev, | |
711 | struct hid_report *report, u8 *data, int size) | |
712 | { | |
713 | u8 *buf; | |
714 | struct mcp2221 *mcp = hid_get_drvdata(hdev); | |
715 | ||
716 | switch (data[0]) { | |
717 | ||
718 | case MCP2221_I2C_WR_DATA: | |
719 | case MCP2221_I2C_WR_NO_STOP: | |
720 | case MCP2221_I2C_RD_DATA: | |
721 | case MCP2221_I2C_RD_RPT_START: | |
722 | switch (data[1]) { | |
723 | case MCP2221_SUCCESS: | |
724 | mcp->status = 0; | |
725 | break; | |
726 | default: | |
727 | mcp->status = mcp_get_i2c_eng_state(mcp, data, 2); | |
728 | } | |
729 | complete(&mcp->wait_in_report); | |
730 | break; | |
731 | ||
732 | case MCP2221_I2C_PARAM_OR_STATUS: | |
733 | switch (data[1]) { | |
734 | case MCP2221_SUCCESS: | |
735 | if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) && | |
736 | (data[3] != MCP2221_I2C_SET_SPEED)) { | |
737 | mcp->status = -EAGAIN; | |
738 | break; | |
739 | } | |
740 | if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) { | |
741 | mcp->status = -ENXIO; | |
742 | break; | |
743 | } | |
744 | mcp->status = mcp_get_i2c_eng_state(mcp, data, 8); | |
745 | break; | |
746 | default: | |
747 | mcp->status = -EIO; | |
748 | } | |
749 | complete(&mcp->wait_in_report); | |
750 | break; | |
751 | ||
752 | case MCP2221_I2C_GET_DATA: | |
753 | switch (data[1]) { | |
754 | case MCP2221_SUCCESS: | |
755 | if (data[2] == MCP2221_I2C_ADDR_NACK) { | |
756 | mcp->status = -ENXIO; | |
757 | break; | |
758 | } | |
759 | if (!mcp_get_i2c_eng_state(mcp, data, 2) | |
760 | && (data[3] == 0)) { | |
761 | mcp->status = 0; | |
762 | break; | |
763 | } | |
764 | if (data[3] == 127) { | |
765 | mcp->status = -EIO; | |
766 | break; | |
767 | } | |
768 | if (data[2] == MCP2221_I2C_READ_COMPL) { | |
769 | buf = mcp->rxbuf; | |
770 | memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]); | |
771 | mcp->rxbuf_idx = mcp->rxbuf_idx + data[3]; | |
772 | mcp->status = 0; | |
773 | break; | |
774 | } | |
775 | mcp->status = -EIO; | |
776 | break; | |
777 | default: | |
778 | mcp->status = -EIO; | |
779 | } | |
780 | complete(&mcp->wait_in_report); | |
781 | break; | |
782 | ||
328de1c5 RG |
783 | case MCP2221_GPIO_GET: |
784 | switch (data[1]) { | |
785 | case MCP2221_SUCCESS: | |
786 | if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) || | |
787 | (data[mcp->gp_idx + 1] == MCP2221_ALT_F_NOT_GPIOD)) { | |
788 | mcp->status = -ENOENT; | |
789 | } else { | |
790 | mcp->status = !!data[mcp->gp_idx]; | |
567b8e9f | 791 | mcp->gpio_dir = data[mcp->gp_idx + 1]; |
328de1c5 RG |
792 | } |
793 | break; | |
794 | default: | |
795 | mcp->status = -EAGAIN; | |
796 | } | |
797 | complete(&mcp->wait_in_report); | |
798 | break; | |
799 | ||
800 | case MCP2221_GPIO_SET: | |
801 | switch (data[1]) { | |
802 | case MCP2221_SUCCESS: | |
803 | if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) || | |
804 | (data[mcp->gp_idx - 1] == MCP2221_ALT_F_NOT_GPIOV)) { | |
805 | mcp->status = -ENOENT; | |
806 | } else { | |
807 | mcp->status = 0; | |
808 | } | |
809 | break; | |
810 | default: | |
811 | mcp->status = -EAGAIN; | |
812 | } | |
813 | complete(&mcp->wait_in_report); | |
814 | break; | |
815 | ||
67a95c21 RG |
816 | default: |
817 | mcp->status = -EIO; | |
818 | complete(&mcp->wait_in_report); | |
819 | } | |
820 | ||
821 | return 1; | |
822 | } | |
823 | ||
824 | static int mcp2221_probe(struct hid_device *hdev, | |
825 | const struct hid_device_id *id) | |
826 | { | |
827 | int ret; | |
828 | struct mcp2221 *mcp; | |
829 | ||
830 | mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL); | |
831 | if (!mcp) | |
832 | return -ENOMEM; | |
833 | ||
834 | ret = hid_parse(hdev); | |
835 | if (ret) { | |
836 | hid_err(hdev, "can't parse reports\n"); | |
837 | return ret; | |
838 | } | |
839 | ||
840 | ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); | |
841 | if (ret) { | |
842 | hid_err(hdev, "can't start hardware\n"); | |
843 | return ret; | |
844 | } | |
845 | ||
846 | ret = hid_hw_open(hdev); | |
847 | if (ret) { | |
848 | hid_err(hdev, "can't open device\n"); | |
849 | goto err_hstop; | |
850 | } | |
851 | ||
852 | mutex_init(&mcp->lock); | |
853 | init_completion(&mcp->wait_in_report); | |
854 | hid_set_drvdata(hdev, mcp); | |
855 | mcp->hdev = hdev; | |
856 | ||
857 | /* Set I2C bus clock diviser */ | |
858 | if (i2c_clk_freq > 400) | |
859 | i2c_clk_freq = 400; | |
860 | if (i2c_clk_freq < 50) | |
861 | i2c_clk_freq = 50; | |
862 | mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3; | |
863 | ||
864 | mcp->adapter.owner = THIS_MODULE; | |
865 | mcp->adapter.class = I2C_CLASS_HWMON; | |
866 | mcp->adapter.algo = &mcp_i2c_algo; | |
867 | mcp->adapter.retries = 1; | |
868 | mcp->adapter.dev.parent = &hdev->dev; | |
869 | snprintf(mcp->adapter.name, sizeof(mcp->adapter.name), | |
870 | "MCP2221 usb-i2c bridge on hidraw%d", | |
871 | ((struct hidraw *)hdev->hidraw)->minor); | |
872 | ||
873 | ret = i2c_add_adapter(&mcp->adapter); | |
874 | if (ret) { | |
875 | hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret); | |
876 | goto err_i2c; | |
877 | } | |
878 | i2c_set_adapdata(&mcp->adapter, mcp); | |
879 | ||
328de1c5 RG |
880 | /* Setup GPIO chip */ |
881 | mcp->gc = devm_kzalloc(&hdev->dev, sizeof(*mcp->gc), GFP_KERNEL); | |
882 | if (!mcp->gc) { | |
883 | ret = -ENOMEM; | |
884 | goto err_gc; | |
885 | } | |
886 | ||
887 | mcp->gc->label = "mcp2221_gpio"; | |
888 | mcp->gc->direction_input = mcp_gpio_direction_input; | |
889 | mcp->gc->direction_output = mcp_gpio_direction_output; | |
890 | mcp->gc->get_direction = mcp_gpio_get_direction; | |
891 | mcp->gc->set = mcp_gpio_set; | |
892 | mcp->gc->get = mcp_gpio_get; | |
567b8e9f | 893 | mcp->gc->ngpio = MCP_NGPIO; |
328de1c5 RG |
894 | mcp->gc->base = -1; |
895 | mcp->gc->can_sleep = 1; | |
896 | mcp->gc->parent = &hdev->dev; | |
897 | ||
898 | ret = devm_gpiochip_add_data(&hdev->dev, mcp->gc, mcp); | |
899 | if (ret) | |
900 | goto err_gc; | |
901 | ||
67a95c21 RG |
902 | return 0; |
903 | ||
328de1c5 RG |
904 | err_gc: |
905 | i2c_del_adapter(&mcp->adapter); | |
67a95c21 RG |
906 | err_i2c: |
907 | hid_hw_close(mcp->hdev); | |
908 | err_hstop: | |
909 | hid_hw_stop(mcp->hdev); | |
910 | return ret; | |
911 | } | |
912 | ||
913 | static void mcp2221_remove(struct hid_device *hdev) | |
914 | { | |
915 | struct mcp2221 *mcp = hid_get_drvdata(hdev); | |
916 | ||
917 | i2c_del_adapter(&mcp->adapter); | |
918 | hid_hw_close(mcp->hdev); | |
919 | hid_hw_stop(mcp->hdev); | |
920 | } | |
921 | ||
922 | static const struct hid_device_id mcp2221_devices[] = { | |
923 | { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) }, | |
924 | { } | |
925 | }; | |
926 | MODULE_DEVICE_TABLE(hid, mcp2221_devices); | |
927 | ||
928 | static struct hid_driver mcp2221_driver = { | |
929 | .name = "mcp2221", | |
930 | .id_table = mcp2221_devices, | |
931 | .probe = mcp2221_probe, | |
932 | .remove = mcp2221_remove, | |
933 | .raw_event = mcp2221_raw_event, | |
934 | }; | |
935 | ||
936 | /* Register with HID core */ | |
937 | module_hid_driver(mcp2221_driver); | |
938 | ||
939 | MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>"); | |
940 | MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge"); | |
941 | MODULE_LICENSE("GPL v2"); |