1 | /* |
2 | * Copyright (c) 2011-2016 Synaptics Incorporated |
3 | * Copyright (c) 2011 Unixphere |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify it |
6 | * under the terms of the GNU General Public License version 2 as published by |
7 | * the Free Software Foundation. |
8 | */ |
9 | |
10 | #include <linux/kernel.h> |
11 | #include <linux/module.h> |
12 | #include <linux/rmi.h> |
13 | #include <linux/slab.h> |
14 | #include <linux/spi/spi.h> |
15 | #include <linux/of.h> |
16 | #include "rmi_driver.h" |
17 | |
18 | #define RMI_SPI_DEFAULT_XFER_BUF_SIZE 64 |
19 | |
20 | #define RMI_PAGE_SELECT_REGISTER 0x00FF |
21 | #define RMI_SPI_PAGE(addr) (((addr) >> 8) & 0x80) |
22 | #define RMI_SPI_XFER_SIZE_LIMIT 255 |
23 | |
24 | #define BUFFER_SIZE_INCREMENT 32 |
25 | |
26 | enum rmi_spi_op { |
27 | RMI_SPI_WRITE = 0, |
28 | RMI_SPI_READ, |
29 | RMI_SPI_V2_READ_UNIFIED, |
30 | RMI_SPI_V2_READ_SPLIT, |
31 | RMI_SPI_V2_WRITE, |
32 | }; |
33 | |
34 | struct rmi_spi_cmd { |
35 | enum rmi_spi_op op; |
36 | u16 addr; |
37 | }; |
38 | |
39 | struct rmi_spi_xport { |
40 | struct rmi_transport_dev xport; |
41 | struct spi_device *spi; |
42 | |
43 | struct mutex page_mutex; |
44 | int page; |
45 | |
46 | u8 *rx_buf; |
47 | u8 *tx_buf; |
48 | int xfer_buf_size; |
49 | |
50 | struct spi_transfer *rx_xfers; |
51 | struct spi_transfer *tx_xfers; |
52 | int rx_xfer_count; |
53 | int tx_xfer_count; |
54 | }; |
55 | |
56 | static int rmi_spi_manage_pools(struct rmi_spi_xport *rmi_spi, int len) |
57 | { |
58 | struct spi_device *spi = rmi_spi->spi; |
59 | int buf_size = rmi_spi->xfer_buf_size |
60 | ? rmi_spi->xfer_buf_size : RMI_SPI_DEFAULT_XFER_BUF_SIZE; |
61 | struct spi_transfer *xfer_buf; |
62 | void *buf; |
63 | void *tmp; |
64 | |
65 | while (buf_size < len) |
66 | buf_size *= 2; |
67 | |
68 | if (buf_size > RMI_SPI_XFER_SIZE_LIMIT) |
69 | buf_size = RMI_SPI_XFER_SIZE_LIMIT; |
70 | |
71 | tmp = rmi_spi->rx_buf; |
72 | buf = devm_kcalloc(&spi->dev, buf_size, 2, |
73 | GFP_KERNEL | GFP_DMA); |
74 | if (!buf) |
75 | return -ENOMEM; |
76 | |
77 | rmi_spi->rx_buf = buf; |
78 | rmi_spi->tx_buf = &rmi_spi->rx_buf[buf_size]; |
79 | rmi_spi->xfer_buf_size = buf_size; |
80 | |
81 | if (tmp) |
82 | devm_kfree(&spi->dev, tmp); |
83 | |
84 | if (rmi_spi->xport.pdata.spi_data.read_delay_us) |
85 | rmi_spi->rx_xfer_count = buf_size; |
86 | else |
87 | rmi_spi->rx_xfer_count = 1; |
88 | |
89 | if (rmi_spi->xport.pdata.spi_data.write_delay_us) |
90 | rmi_spi->tx_xfer_count = buf_size; |
91 | else |
92 | rmi_spi->tx_xfer_count = 1; |
93 | |
94 | /* |
95 | * Allocate a pool of spi_transfer buffers for devices which need |
96 | * per byte delays. |
97 | */ |
98 | tmp = rmi_spi->rx_xfers; |
99 | xfer_buf = devm_kcalloc(&spi->dev, |
100 | rmi_spi->rx_xfer_count + rmi_spi->tx_xfer_count, |
101 | sizeof(struct spi_transfer), |
102 | GFP_KERNEL); |
103 | if (!xfer_buf) |
104 | return -ENOMEM; |
105 | |
106 | rmi_spi->rx_xfers = xfer_buf; |
107 | rmi_spi->tx_xfers = &xfer_buf[rmi_spi->rx_xfer_count]; |
108 | |
109 | if (tmp) |
110 | devm_kfree(&spi->dev, tmp); |
111 | |
112 | return 0; |
113 | } |
114 | |
115 | static int rmi_spi_xfer(struct rmi_spi_xport *rmi_spi, |
116 | const struct rmi_spi_cmd *cmd, const u8 *tx_buf, |
117 | int tx_len, u8 *rx_buf, int rx_len) |
118 | { |
119 | struct spi_device *spi = rmi_spi->spi; |
120 | struct rmi_device_platform_data_spi *spi_data = |
121 | &rmi_spi->xport.pdata.spi_data; |
122 | struct spi_message msg; |
123 | struct spi_transfer *xfer; |
124 | int ret = 0; |
125 | int len; |
126 | int cmd_len = 0; |
127 | int total_tx_len; |
128 | int i; |
129 | u16 addr = cmd->addr; |
130 | |
131 | spi_message_init(&msg); |
132 | |
133 | switch (cmd->op) { |
134 | case RMI_SPI_WRITE: |
135 | case RMI_SPI_READ: |
136 | cmd_len += 2; |
137 | break; |
138 | case RMI_SPI_V2_READ_UNIFIED: |
139 | case RMI_SPI_V2_READ_SPLIT: |
140 | case RMI_SPI_V2_WRITE: |
141 | cmd_len += 4; |
142 | break; |
143 | } |
144 | |
145 | total_tx_len = cmd_len + tx_len; |
146 | len = max(total_tx_len, rx_len); |
147 | |
148 | if (len > RMI_SPI_XFER_SIZE_LIMIT) |
149 | return -EINVAL; |
150 | |
151 | if (rmi_spi->xfer_buf_size < len) { |
152 | ret = rmi_spi_manage_pools(rmi_spi, len); |
153 | if (ret < 0) |
154 | return ret; |
155 | } |
156 | |
157 | if (addr == 0) |
158 | /* |
159 | * SPI needs an address. Use 0x7FF if we want to keep |
160 | * reading from the last position of the register pointer. |
161 | */ |
162 | addr = 0x7FF; |
163 | |
164 | switch (cmd->op) { |
165 | case RMI_SPI_WRITE: |
166 | rmi_spi->tx_buf[0] = (addr >> 8); |
167 | rmi_spi->tx_buf[1] = addr & 0xFF; |
168 | break; |
169 | case RMI_SPI_READ: |
170 | rmi_spi->tx_buf[0] = (addr >> 8) | 0x80; |
171 | rmi_spi->tx_buf[1] = addr & 0xFF; |
172 | break; |
173 | case RMI_SPI_V2_READ_UNIFIED: |
174 | break; |
175 | case RMI_SPI_V2_READ_SPLIT: |
176 | break; |
177 | case RMI_SPI_V2_WRITE: |
178 | rmi_spi->tx_buf[0] = 0x40; |
179 | rmi_spi->tx_buf[1] = (addr >> 8) & 0xFF; |
180 | rmi_spi->tx_buf[2] = addr & 0xFF; |
181 | rmi_spi->tx_buf[3] = tx_len; |
182 | break; |
183 | } |
184 | |
185 | if (tx_buf) |
186 | memcpy(&rmi_spi->tx_buf[cmd_len], tx_buf, tx_len); |
187 | |
188 | if (rmi_spi->tx_xfer_count > 1) { |
189 | for (i = 0; i < total_tx_len; i++) { |
190 | xfer = &rmi_spi->tx_xfers[i]; |
191 | memset(xfer, 0, sizeof(struct spi_transfer)); |
192 | xfer->tx_buf = &rmi_spi->tx_buf[i]; |
193 | xfer->len = 1; |
194 | xfer->delay_usecs = spi_data->write_delay_us; |
195 | spi_message_add_tail(xfer, &msg); |
196 | } |
197 | } else { |
198 | xfer = rmi_spi->tx_xfers; |
199 | memset(xfer, 0, sizeof(struct spi_transfer)); |
200 | xfer->tx_buf = rmi_spi->tx_buf; |
201 | xfer->len = total_tx_len; |
202 | spi_message_add_tail(xfer, &msg); |
203 | } |
204 | |
205 | rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: cmd: %s tx_buf len: %d tx_buf: %*ph\n" , |
206 | __func__, cmd->op == RMI_SPI_WRITE ? "WRITE" : "READ" , |
207 | total_tx_len, total_tx_len, rmi_spi->tx_buf); |
208 | |
209 | if (rx_buf) { |
210 | if (rmi_spi->rx_xfer_count > 1) { |
211 | for (i = 0; i < rx_len; i++) { |
212 | xfer = &rmi_spi->rx_xfers[i]; |
213 | memset(xfer, 0, sizeof(struct spi_transfer)); |
214 | xfer->rx_buf = &rmi_spi->rx_buf[i]; |
215 | xfer->len = 1; |
216 | xfer->delay_usecs = spi_data->read_delay_us; |
217 | spi_message_add_tail(xfer, &msg); |
218 | } |
219 | } else { |
220 | xfer = rmi_spi->rx_xfers; |
221 | memset(xfer, 0, sizeof(struct spi_transfer)); |
222 | xfer->rx_buf = rmi_spi->rx_buf; |
223 | xfer->len = rx_len; |
224 | spi_message_add_tail(xfer, &msg); |
225 | } |
226 | } |
227 | |
228 | ret = spi_sync(spi, &msg); |
229 | if (ret < 0) { |
230 | dev_err(&spi->dev, "spi xfer failed: %d\n" , ret); |
231 | return ret; |
232 | } |
233 | |
234 | if (rx_buf) { |
235 | memcpy(rx_buf, rmi_spi->rx_buf, rx_len); |
236 | rmi_dbg(RMI_DEBUG_XPORT, &spi->dev, "%s: (%d) %*ph\n" , |
237 | __func__, rx_len, rx_len, rx_buf); |
238 | } |
239 | |
240 | return 0; |
241 | } |
242 | |
243 | /* |
244 | * rmi_set_page - Set RMI page |
245 | * @xport: The pointer to the rmi_transport_dev struct |
246 | * @page: The new page address. |
247 | * |
248 | * RMI devices have 16-bit addressing, but some of the transport |
249 | * implementations (like SMBus) only have 8-bit addressing. So RMI implements |
250 | * a page address at 0xff of every page so we can reliable page addresses |
251 | * every 256 registers. |
252 | * |
253 | * The page_mutex lock must be held when this function is entered. |
254 | * |
255 | * Returns zero on success, non-zero on failure. |
256 | */ |
257 | static int rmi_set_page(struct rmi_spi_xport *rmi_spi, u8 page) |
258 | { |
259 | struct rmi_spi_cmd cmd; |
260 | int ret; |
261 | |
262 | cmd.op = RMI_SPI_WRITE; |
263 | cmd.addr = RMI_PAGE_SELECT_REGISTER; |
264 | |
265 | ret = rmi_spi_xfer(rmi_spi, &cmd, &page, 1, NULL, 0); |
266 | |
267 | if (ret) |
268 | rmi_spi->page = page; |
269 | |
270 | return ret; |
271 | } |
272 | |
273 | static int rmi_spi_write_block(struct rmi_transport_dev *xport, u16 addr, |
274 | const void *buf, size_t len) |
275 | { |
276 | struct rmi_spi_xport *rmi_spi = |
277 | container_of(xport, struct rmi_spi_xport, xport); |
278 | struct rmi_spi_cmd cmd; |
279 | int ret; |
280 | |
281 | mutex_lock(&rmi_spi->page_mutex); |
282 | |
283 | if (RMI_SPI_PAGE(addr) != rmi_spi->page) { |
284 | ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr)); |
285 | if (ret) |
286 | goto exit; |
287 | } |
288 | |
289 | cmd.op = RMI_SPI_WRITE; |
290 | cmd.addr = addr; |
291 | |
292 | ret = rmi_spi_xfer(rmi_spi, &cmd, buf, len, NULL, 0); |
293 | |
294 | exit: |
295 | mutex_unlock(&rmi_spi->page_mutex); |
296 | return ret; |
297 | } |
298 | |
299 | static int rmi_spi_read_block(struct rmi_transport_dev *xport, u16 addr, |
300 | void *buf, size_t len) |
301 | { |
302 | struct rmi_spi_xport *rmi_spi = |
303 | container_of(xport, struct rmi_spi_xport, xport); |
304 | struct rmi_spi_cmd cmd; |
305 | int ret; |
306 | |
307 | mutex_lock(&rmi_spi->page_mutex); |
308 | |
309 | if (RMI_SPI_PAGE(addr) != rmi_spi->page) { |
310 | ret = rmi_set_page(rmi_spi, RMI_SPI_PAGE(addr)); |
311 | if (ret) |
312 | goto exit; |
313 | } |
314 | |
315 | cmd.op = RMI_SPI_READ; |
316 | cmd.addr = addr; |
317 | |
318 | ret = rmi_spi_xfer(rmi_spi, &cmd, NULL, 0, buf, len); |
319 | |
320 | exit: |
321 | mutex_unlock(&rmi_spi->page_mutex); |
322 | return ret; |
323 | } |
324 | |
325 | static const struct rmi_transport_ops rmi_spi_ops = { |
326 | .write_block = rmi_spi_write_block, |
327 | .read_block = rmi_spi_read_block, |
328 | }; |
329 | |
330 | #ifdef CONFIG_OF |
331 | static int rmi_spi_of_probe(struct spi_device *spi, |
332 | struct rmi_device_platform_data *pdata) |
333 | { |
334 | struct device *dev = &spi->dev; |
335 | int retval; |
336 | |
337 | retval = rmi_of_property_read_u32(dev, |
338 | &pdata->spi_data.read_delay_us, |
339 | "spi-rx-delay-us" , 1); |
340 | if (retval) |
341 | return retval; |
342 | |
343 | retval = rmi_of_property_read_u32(dev, |
344 | &pdata->spi_data.write_delay_us, |
345 | "spi-tx-delay-us" , 1); |
346 | if (retval) |
347 | return retval; |
348 | |
349 | return 0; |
350 | } |
351 | |
352 | static const struct of_device_id rmi_spi_of_match[] = { |
353 | { .compatible = "syna,rmi4-spi" }, |
354 | {}, |
355 | }; |
356 | MODULE_DEVICE_TABLE(of, rmi_spi_of_match); |
357 | #else |
358 | static inline int rmi_spi_of_probe(struct spi_device *spi, |
359 | struct rmi_device_platform_data *pdata) |
360 | { |
361 | return -ENODEV; |
362 | } |
363 | #endif |
364 | |
365 | static void rmi_spi_unregister_transport(void *data) |
366 | { |
367 | struct rmi_spi_xport *rmi_spi = data; |
368 | |
369 | rmi_unregister_transport_device(&rmi_spi->xport); |
370 | } |
371 | |
372 | static int rmi_spi_probe(struct spi_device *spi) |
373 | { |
374 | struct rmi_spi_xport *rmi_spi; |
375 | struct rmi_device_platform_data *pdata; |
376 | struct rmi_device_platform_data *spi_pdata = spi->dev.platform_data; |
377 | int error; |
378 | |
379 | if (spi->master->flags & SPI_MASTER_HALF_DUPLEX) |
380 | return -EINVAL; |
381 | |
382 | rmi_spi = devm_kzalloc(&spi->dev, sizeof(struct rmi_spi_xport), |
383 | GFP_KERNEL); |
384 | if (!rmi_spi) |
385 | return -ENOMEM; |
386 | |
387 | pdata = &rmi_spi->xport.pdata; |
388 | |
389 | if (spi->dev.of_node) { |
390 | error = rmi_spi_of_probe(spi, pdata); |
391 | if (error) |
392 | return error; |
393 | } else if (spi_pdata) { |
394 | *pdata = *spi_pdata; |
395 | } |
396 | |
397 | if (pdata->spi_data.bits_per_word) |
398 | spi->bits_per_word = pdata->spi_data.bits_per_word; |
399 | |
400 | if (pdata->spi_data.mode) |
401 | spi->mode = pdata->spi_data.mode; |
402 | |
403 | error = spi_setup(spi); |
404 | if (error < 0) { |
405 | dev_err(&spi->dev, "spi_setup failed!\n" ); |
406 | return error; |
407 | } |
408 | |
409 | pdata->irq = spi->irq; |
410 | |
411 | rmi_spi->spi = spi; |
412 | mutex_init(&rmi_spi->page_mutex); |
413 | |
414 | rmi_spi->xport.dev = &spi->dev; |
415 | rmi_spi->xport.proto_name = "spi" ; |
416 | rmi_spi->xport.ops = &rmi_spi_ops; |
417 | |
418 | spi_set_drvdata(spi, rmi_spi); |
419 | |
420 | error = rmi_spi_manage_pools(rmi_spi, RMI_SPI_DEFAULT_XFER_BUF_SIZE); |
421 | if (error) |
422 | return error; |
423 | |
424 | /* |
425 | * Setting the page to zero will (a) make sure the PSR is in a |
426 | * known state, and (b) make sure we can talk to the device. |
427 | */ |
428 | error = rmi_set_page(rmi_spi, 0); |
429 | if (error) { |
430 | dev_err(&spi->dev, "Failed to set page select to 0.\n" ); |
431 | return error; |
432 | } |
433 | |
434 | dev_info(&spi->dev, "registering SPI-connected sensor\n" ); |
435 | |
436 | error = rmi_register_transport_device(&rmi_spi->xport); |
437 | if (error) { |
438 | dev_err(&spi->dev, "failed to register sensor: %d\n" , error); |
439 | return error; |
440 | } |
441 | |
442 | error = devm_add_action_or_reset(&spi->dev, |
443 | rmi_spi_unregister_transport, |
444 | rmi_spi); |
445 | if (error) |
446 | return error; |
447 | |
448 | return 0; |
449 | } |
450 | |
451 | #ifdef CONFIG_PM_SLEEP |
452 | static int rmi_spi_suspend(struct device *dev) |
453 | { |
454 | struct spi_device *spi = to_spi_device(dev); |
455 | struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
456 | int ret; |
457 | |
458 | ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, true); |
459 | if (ret) |
460 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
461 | |
462 | return ret; |
463 | } |
464 | |
465 | static int rmi_spi_resume(struct device *dev) |
466 | { |
467 | struct spi_device *spi = to_spi_device(dev); |
468 | struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
469 | int ret; |
470 | |
471 | ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, true); |
472 | if (ret) |
473 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
474 | |
475 | return ret; |
476 | } |
477 | #endif |
478 | |
479 | #ifdef CONFIG_PM |
480 | static int rmi_spi_runtime_suspend(struct device *dev) |
481 | { |
482 | struct spi_device *spi = to_spi_device(dev); |
483 | struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
484 | int ret; |
485 | |
486 | ret = rmi_driver_suspend(rmi_spi->xport.rmi_dev, false); |
487 | if (ret) |
488 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
489 | |
490 | return 0; |
491 | } |
492 | |
493 | static int rmi_spi_runtime_resume(struct device *dev) |
494 | { |
495 | struct spi_device *spi = to_spi_device(dev); |
496 | struct rmi_spi_xport *rmi_spi = spi_get_drvdata(spi); |
497 | int ret; |
498 | |
499 | ret = rmi_driver_resume(rmi_spi->xport.rmi_dev, false); |
500 | if (ret) |
501 | dev_warn(dev, "Failed to resume device: %d\n" , ret); |
502 | |
503 | return 0; |
504 | } |
505 | #endif |
506 | |
507 | static const struct dev_pm_ops rmi_spi_pm = { |
508 | SET_SYSTEM_SLEEP_PM_OPS(rmi_spi_suspend, rmi_spi_resume) |
509 | SET_RUNTIME_PM_OPS(rmi_spi_runtime_suspend, rmi_spi_runtime_resume, |
510 | NULL) |
511 | }; |
512 | |
513 | static const struct spi_device_id rmi_id[] = { |
514 | { "rmi4_spi" , 0 }, |
515 | { } |
516 | }; |
517 | MODULE_DEVICE_TABLE(spi, rmi_id); |
518 | |
519 | static struct spi_driver rmi_spi_driver = { |
520 | .driver = { |
521 | .name = "rmi4_spi" , |
522 | .pm = &rmi_spi_pm, |
523 | .of_match_table = of_match_ptr(rmi_spi_of_match), |
524 | }, |
525 | .id_table = rmi_id, |
526 | .probe = rmi_spi_probe, |
527 | }; |
528 | |
529 | module_spi_driver(rmi_spi_driver); |
530 | |
531 | MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>" ); |
532 | MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>" ); |
533 | MODULE_DESCRIPTION("RMI SPI driver" ); |
534 | MODULE_LICENSE("GPL" ); |
535 | |