diff options
Diffstat (limited to 'drivers/mmc')
-rw-r--r-- | drivers/mmc/host/Kconfig | 13 | ||||
-rw-r--r-- | drivers/mmc/host/Makefile | 1 | ||||
-rw-r--r-- | drivers/mmc/host/mmc_spi.c | 1408 |
3 files changed, 1422 insertions, 0 deletions
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index e23082fe88d0..68fb052afd3e 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig | |||
@@ -100,3 +100,16 @@ config MMC_TIFM_SD | |||
100 | To compile this driver as a module, choose M here: the | 100 | To compile this driver as a module, choose M here: the |
101 | module will be called tifm_sd. | 101 | module will be called tifm_sd. |
102 | 102 | ||
103 | config MMC_SPI | ||
104 | tristate "MMC/SD over SPI (EXPERIMENTAL)" | ||
105 | depends on MMC && SPI_MASTER && !HIGHMEM && EXPERIMENTAL | ||
106 | select CRC7 | ||
107 | select CRC_ITU_T | ||
108 | help | ||
109 | Some systems accss MMC/SD cards using a SPI controller instead of | ||
110 | using a "native" MMC/SD controller. This has a disadvantage of | ||
111 | being relatively high overhead, but a compensating advantage of | ||
112 | working on many systems without dedicated MMC/SD controllers. | ||
113 | |||
114 | If unsure, or if your system has no SPI master driver, say N. | ||
115 | |||
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile index 6685f64345b4..8dc82ce647b7 100644 --- a/drivers/mmc/host/Makefile +++ b/drivers/mmc/host/Makefile | |||
@@ -15,4 +15,5 @@ obj-$(CONFIG_MMC_AU1X) += au1xmmc.o | |||
15 | obj-$(CONFIG_MMC_OMAP) += omap.o | 15 | obj-$(CONFIG_MMC_OMAP) += omap.o |
16 | obj-$(CONFIG_MMC_AT91) += at91_mci.o | 16 | obj-$(CONFIG_MMC_AT91) += at91_mci.o |
17 | obj-$(CONFIG_MMC_TIFM_SD) += tifm_sd.o | 17 | obj-$(CONFIG_MMC_TIFM_SD) += tifm_sd.o |
18 | obj-$(CONFIG_MMC_SPI) += mmc_spi.o | ||
18 | 19 | ||
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c new file mode 100644 index 000000000000..f30327bba6f6 --- /dev/null +++ b/drivers/mmc/host/mmc_spi.c | |||
@@ -0,0 +1,1408 @@ | |||
1 | /* | ||
2 | * mmc_spi.c - Access SD/MMC cards through SPI master controllers | ||
3 | * | ||
4 | * (C) Copyright 2005, Intec Automation, | ||
5 | * Mike Lavender (mike@steroidmicros) | ||
6 | * (C) Copyright 2006-2007, David Brownell | ||
7 | * (C) Copyright 2007, Axis Communications, | ||
8 | * Hans-Peter Nilsson (hp@axis.com) | ||
9 | * (C) Copyright 2007, ATRON electronic GmbH, | ||
10 | * Jan Nikitenko <jan.nikitenko@gmail.com> | ||
11 | * | ||
12 | * | ||
13 | * This program is free software; you can redistribute it and/or modify | ||
14 | * it under the terms of the GNU General Public License as published by | ||
15 | * the Free Software Foundation; either version 2 of the License, or | ||
16 | * (at your option) any later version. | ||
17 | * | ||
18 | * This program is distributed in the hope that it will be useful, | ||
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
21 | * GNU General Public License for more details. | ||
22 | * | ||
23 | * You should have received a copy of the GNU General Public License | ||
24 | * along with this program; if not, write to the Free Software | ||
25 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | ||
26 | */ | ||
27 | #include <linux/hrtimer.h> | ||
28 | #include <linux/delay.h> | ||
29 | #include <linux/blkdev.h> | ||
30 | #include <linux/dma-mapping.h> | ||
31 | #include <linux/crc7.h> | ||
32 | #include <linux/crc-itu-t.h> | ||
33 | |||
34 | #include <linux/mmc/host.h> | ||
35 | #include <linux/mmc/mmc.h> /* for R1_SPI_* bit values */ | ||
36 | |||
37 | #include <linux/spi/spi.h> | ||
38 | #include <linux/spi/mmc_spi.h> | ||
39 | |||
40 | #include <asm/unaligned.h> | ||
41 | |||
42 | |||
43 | /* NOTES: | ||
44 | * | ||
45 | * - For now, we won't try to interoperate with a real mmc/sd/sdio | ||
46 | * controller, although some of them do have hardware support for | ||
47 | * SPI protocol. The main reason for such configs would be mmc-ish | ||
48 | * cards like DataFlash, which don't support that "native" protocol. | ||
49 | * | ||
50 | * We don't have a "DataFlash/MMC/SD/SDIO card slot" abstraction to | ||
51 | * switch between driver stacks, and in any case if "native" mode | ||
52 | * is available, it will be faster and hence preferable. | ||
53 | * | ||
54 | * - MMC depends on a different chipselect management policy than the | ||
55 | * SPI interface currently supports for shared bus segments: it needs | ||
56 | * to issue multiple spi_message requests with the chipselect active, | ||
57 | * using the results of one message to decide the next one to issue. | ||
58 | * | ||
59 | * Pending updates to the programming interface, this driver expects | ||
60 | * that it not share the bus with other drivers (precluding conflicts). | ||
61 | * | ||
62 | * - We tell the controller to keep the chipselect active from the | ||
63 | * beginning of an mmc_host_ops.request until the end. So beware | ||
64 | * of SPI controller drivers that mis-handle the cs_change flag! | ||
65 | * | ||
66 | * However, many cards seem OK with chipselect flapping up/down | ||
67 | * during that time ... at least on unshared bus segments. | ||
68 | */ | ||
69 | |||
70 | |||
71 | /* | ||
72 | * Local protocol constants, internal to data block protocols. | ||
73 | */ | ||
74 | |||
75 | /* Response tokens used to ack each block written: */ | ||
76 | #define SPI_MMC_RESPONSE_CODE(x) ((x) & 0x1f) | ||
77 | #define SPI_RESPONSE_ACCEPTED ((2 << 1)|1) | ||
78 | #define SPI_RESPONSE_CRC_ERR ((5 << 1)|1) | ||
79 | #define SPI_RESPONSE_WRITE_ERR ((6 << 1)|1) | ||
80 | |||
81 | /* Read and write blocks start with these tokens and end with crc; | ||
82 | * on error, read tokens act like a subset of R2_SPI_* values. | ||
83 | */ | ||
84 | #define SPI_TOKEN_SINGLE 0xfe /* single block r/w, multiblock read */ | ||
85 | #define SPI_TOKEN_MULTI_WRITE 0xfc /* multiblock write */ | ||
86 | #define SPI_TOKEN_STOP_TRAN 0xfd /* terminate multiblock write */ | ||
87 | |||
88 | #define MMC_SPI_BLOCKSIZE 512 | ||
89 | |||
90 | |||
91 | /* These fixed timeouts come from the latest SD specs, which say to ignore | ||
92 | * the CSD values. The R1B value is for card erase (e.g. the "I forgot the | ||
93 | * card's password" scenario); it's mostly applied to STOP_TRANSMISSION after | ||
94 | * reads which takes nowhere near that long. Older cards may be able to use | ||
95 | * shorter timeouts ... but why bother? | ||
96 | */ | ||
97 | #define readblock_timeout ktime_set(0, 100 * 1000 * 1000) | ||
98 | #define writeblock_timeout ktime_set(0, 250 * 1000 * 1000) | ||
99 | #define r1b_timeout ktime_set(3, 0) | ||
100 | |||
101 | |||
102 | /****************************************************************************/ | ||
103 | |||
104 | /* | ||
105 | * Local Data Structures | ||
106 | */ | ||
107 | |||
108 | /* "scratch" is per-{command,block} data exchanged with the card */ | ||
109 | struct scratch { | ||
110 | u8 status[29]; | ||
111 | u8 data_token; | ||
112 | __be16 crc_val; | ||
113 | }; | ||
114 | |||
115 | struct mmc_spi_host { | ||
116 | struct mmc_host *mmc; | ||
117 | struct spi_device *spi; | ||
118 | |||
119 | unsigned char power_mode; | ||
120 | u16 powerup_msecs; | ||
121 | |||
122 | struct mmc_spi_platform_data *pdata; | ||
123 | |||
124 | /* for bulk data transfers */ | ||
125 | struct spi_transfer token, t, crc, early_status; | ||
126 | struct spi_message m; | ||
127 | |||
128 | /* for status readback */ | ||
129 | struct spi_transfer status; | ||
130 | struct spi_message readback; | ||
131 | |||
132 | /* underlying DMA-aware controller, or null */ | ||
133 | struct device *dma_dev; | ||
134 | |||
135 | /* buffer used for commands and for message "overhead" */ | ||
136 | struct scratch *data; | ||
137 | dma_addr_t data_dma; | ||
138 | |||
139 | /* Specs say to write ones most of the time, even when the card | ||
140 | * has no need to read its input data; and many cards won't care. | ||
141 | * This is our source of those ones. | ||
142 | */ | ||
143 | void *ones; | ||
144 | dma_addr_t ones_dma; | ||
145 | }; | ||
146 | |||
147 | |||
148 | /****************************************************************************/ | ||
149 | |||
150 | /* | ||
151 | * MMC-over-SPI protocol glue, used by the MMC stack interface | ||
152 | */ | ||
153 | |||
154 | static inline int mmc_cs_off(struct mmc_spi_host *host) | ||
155 | { | ||
156 | /* chipselect will always be inactive after setup() */ | ||
157 | return spi_setup(host->spi); | ||
158 | } | ||
159 | |||
160 | static int | ||
161 | mmc_spi_readbytes(struct mmc_spi_host *host, unsigned len) | ||
162 | { | ||
163 | int status; | ||
164 | |||
165 | if (len > sizeof(*host->data)) { | ||
166 | WARN_ON(1); | ||
167 | return -EIO; | ||
168 | } | ||
169 | |||
170 | host->status.len = len; | ||
171 | |||
172 | if (host->dma_dev) | ||
173 | dma_sync_single_for_device(host->dma_dev, | ||
174 | host->data_dma, sizeof(*host->data), | ||
175 | DMA_FROM_DEVICE); | ||
176 | |||
177 | status = spi_sync(host->spi, &host->readback); | ||
178 | if (status == 0) | ||
179 | status = host->readback.status; | ||
180 | |||
181 | if (host->dma_dev) | ||
182 | dma_sync_single_for_cpu(host->dma_dev, | ||
183 | host->data_dma, sizeof(*host->data), | ||
184 | DMA_FROM_DEVICE); | ||
185 | |||
186 | return status; | ||
187 | } | ||
188 | |||
189 | static int | ||
190 | mmc_spi_skip(struct mmc_spi_host *host, ktime_t timeout, unsigned n, u8 byte) | ||
191 | { | ||
192 | u8 *cp = host->data->status; | ||
193 | |||
194 | timeout = ktime_add(timeout, ktime_get()); | ||
195 | |||
196 | while (1) { | ||
197 | int status; | ||
198 | unsigned i; | ||
199 | |||
200 | status = mmc_spi_readbytes(host, n); | ||
201 | if (status < 0) | ||
202 | return status; | ||
203 | |||
204 | for (i = 0; i < n; i++) { | ||
205 | if (cp[i] != byte) | ||
206 | return cp[i]; | ||
207 | } | ||
208 | |||
209 | /* REVISIT investigate msleep() to avoid busy-wait I/O | ||
210 | * in at least some cases. | ||
211 | */ | ||
212 | if (ktime_to_ns(ktime_sub(ktime_get(), timeout)) > 0) | ||
213 | break; | ||
214 | } | ||
215 | return -ETIMEDOUT; | ||
216 | } | ||
217 | |||
218 | static inline int | ||
219 | mmc_spi_wait_unbusy(struct mmc_spi_host *host, ktime_t timeout) | ||
220 | { | ||
221 | return mmc_spi_skip(host, timeout, sizeof(host->data->status), 0); | ||
222 | } | ||
223 | |||
224 | static int mmc_spi_readtoken(struct mmc_spi_host *host) | ||
225 | { | ||
226 | return mmc_spi_skip(host, readblock_timeout, 1, 0xff); | ||
227 | } | ||
228 | |||
229 | |||
230 | /* | ||
231 | * Note that for SPI, cmd->resp[0] is not the same data as "native" protocol | ||
232 | * hosts return! The low byte holds R1_SPI bits. The next byte may hold | ||
233 | * R2_SPI bits ... for SEND_STATUS, or after data read errors. | ||
234 | * | ||
235 | * cmd->resp[1] holds any four-byte response, for R3 (READ_OCR) and on | ||
236 | * newer cards R7 (IF_COND). | ||
237 | */ | ||
238 | |||
239 | static char *maptype(struct mmc_command *cmd) | ||
240 | { | ||
241 | switch (mmc_spi_resp_type(cmd)) { | ||
242 | case MMC_RSP_SPI_R1: return "R1"; | ||
243 | case MMC_RSP_SPI_R1B: return "R1B"; | ||
244 | case MMC_RSP_SPI_R2: return "R2/R5"; | ||
245 | case MMC_RSP_SPI_R3: return "R3/R4/R7"; | ||
246 | default: return "?"; | ||
247 | } | ||
248 | } | ||
249 | |||
250 | /* return zero, else negative errno after setting cmd->error */ | ||
251 | static int mmc_spi_response_get(struct mmc_spi_host *host, | ||
252 | struct mmc_command *cmd, int cs_on) | ||
253 | { | ||
254 | u8 *cp = host->data->status; | ||
255 | u8 *end = cp + host->t.len; | ||
256 | int value = 0; | ||
257 | char tag[32]; | ||
258 | |||
259 | snprintf(tag, sizeof(tag), " ... CMD%d response SPI_%s", | ||
260 | cmd->opcode, maptype(cmd)); | ||
261 | |||
262 | /* Except for data block reads, the whole response will already | ||
263 | * be stored in the scratch buffer. It's somewhere after the | ||
264 | * command and the first byte we read after it. We ignore that | ||
265 | * first byte. After STOP_TRANSMISSION command it may include | ||
266 | * two data bits, but otherwise it's all ones. | ||
267 | */ | ||
268 | cp += 8; | ||
269 | while (cp < end && *cp == 0xff) | ||
270 | cp++; | ||
271 | |||
272 | /* Data block reads (R1 response types) may need more data... */ | ||
273 | if (cp == end) { | ||
274 | unsigned i; | ||
275 | |||
276 | cp = host->data->status; | ||
277 | |||
278 | /* Card sends N(CR) (== 1..8) bytes of all-ones then one | ||
279 | * status byte ... and we already scanned 2 bytes. | ||
280 | * | ||
281 | * REVISIT block read paths use nasty byte-at-a-time I/O | ||
282 | * so it can always DMA directly into the target buffer. | ||
283 | * It'd probably be better to memcpy() the first chunk and | ||
284 | * avoid extra i/o calls... | ||
285 | */ | ||
286 | for (i = 2; i < 9; i++) { | ||
287 | value = mmc_spi_readbytes(host, 1); | ||
288 | if (value < 0) | ||
289 | goto done; | ||
290 | if (*cp != 0xff) | ||
291 | goto checkstatus; | ||
292 | } | ||
293 | value = -ETIMEDOUT; | ||
294 | goto done; | ||
295 | } | ||
296 | |||
297 | checkstatus: | ||
298 | if (*cp & 0x80) { | ||
299 | dev_dbg(&host->spi->dev, "%s: INVALID RESPONSE, %02x\n", | ||
300 | tag, *cp); | ||
301 | value = -EBADR; | ||
302 | goto done; | ||
303 | } | ||
304 | |||
305 | cmd->resp[0] = *cp++; | ||
306 | cmd->error = 0; | ||
307 | |||
308 | /* Status byte: the entire seven-bit R1 response. */ | ||
309 | if (cmd->resp[0] != 0) { | ||
310 | if ((R1_SPI_PARAMETER | R1_SPI_ADDRESS | ||
311 | | R1_SPI_ILLEGAL_COMMAND) | ||
312 | & cmd->resp[0]) | ||
313 | value = -EINVAL; | ||
314 | else if (R1_SPI_COM_CRC & cmd->resp[0]) | ||
315 | value = -EILSEQ; | ||
316 | else if ((R1_SPI_ERASE_SEQ | R1_SPI_ERASE_RESET) | ||
317 | & cmd->resp[0]) | ||
318 | value = -EIO; | ||
319 | /* else R1_SPI_IDLE, "it's resetting" */ | ||
320 | } | ||
321 | |||
322 | switch (mmc_spi_resp_type(cmd)) { | ||
323 | |||
324 | /* SPI R1B == R1 + busy; STOP_TRANSMISSION (for multiblock reads) | ||
325 | * and less-common stuff like various erase operations. | ||
326 | */ | ||
327 | case MMC_RSP_SPI_R1B: | ||
328 | /* maybe we read all the busy tokens already */ | ||
329 | while (cp < end && *cp == 0) | ||
330 | cp++; | ||
331 | if (cp == end) | ||
332 | mmc_spi_wait_unbusy(host, r1b_timeout); | ||
333 | break; | ||
334 | |||
335 | /* SPI R2 == R1 + second status byte; SEND_STATUS | ||
336 | * SPI R5 == R1 + data byte; IO_RW_DIRECT | ||
337 | */ | ||
338 | case MMC_RSP_SPI_R2: | ||
339 | cmd->resp[0] |= *cp << 8; | ||
340 | break; | ||
341 | |||
342 | /* SPI R3, R4, or R7 == R1 + 4 bytes */ | ||
343 | case MMC_RSP_SPI_R3: | ||
344 | cmd->resp[1] = be32_to_cpu(get_unaligned((u32 *)cp)); | ||
345 | break; | ||
346 | |||
347 | /* SPI R1 == just one status byte */ | ||
348 | case MMC_RSP_SPI_R1: | ||
349 | break; | ||
350 | |||
351 | default: | ||
352 | dev_dbg(&host->spi->dev, "bad response type %04x\n", | ||
353 | mmc_spi_resp_type(cmd)); | ||
354 | if (value >= 0) | ||
355 | value = -EINVAL; | ||
356 | goto done; | ||
357 | } | ||
358 | |||
359 | if (value < 0) | ||
360 | dev_dbg(&host->spi->dev, "%s: resp %04x %08x\n", | ||
361 | tag, cmd->resp[0], cmd->resp[1]); | ||
362 | |||
363 | /* disable chipselect on errors and some success cases */ | ||
364 | if (value >= 0 && cs_on) | ||
365 | return value; | ||
366 | done: | ||
367 | if (value < 0) | ||
368 | cmd->error = value; | ||
369 | mmc_cs_off(host); | ||
370 | return value; | ||
371 | } | ||
372 | |||
373 | /* Issue command and read its response. | ||
374 | * Returns zero on success, negative for error. | ||
375 | * | ||
376 | * On error, caller must cope with mmc core retry mechanism. That | ||
377 | * means immediate low-level resubmit, which affects the bus lock... | ||
378 | */ | ||
379 | static int | ||
380 | mmc_spi_command_send(struct mmc_spi_host *host, | ||
381 | struct mmc_request *mrq, | ||
382 | struct mmc_command *cmd, int cs_on) | ||
383 | { | ||
384 | struct scratch *data = host->data; | ||
385 | u8 *cp = data->status; | ||
386 | u32 arg = cmd->arg; | ||
387 | int status; | ||
388 | struct spi_transfer *t; | ||
389 | |||
390 | /* We can handle most commands (except block reads) in one full | ||
391 | * duplex I/O operation before either starting the next transfer | ||
392 | * (data block or command) or else deselecting the card. | ||
393 | * | ||
394 | * First, write 7 bytes: | ||
395 | * - an all-ones byte to ensure the card is ready | ||
396 | * - opcode byte (plus start and transmission bits) | ||
397 | * - four bytes of big-endian argument | ||
398 | * - crc7 (plus end bit) ... always computed, it's cheap | ||
399 | * | ||
400 | * We init the whole buffer to all-ones, which is what we need | ||
401 | * to write while we're reading (later) response data. | ||
402 | */ | ||
403 | memset(cp++, 0xff, sizeof(data->status)); | ||
404 | |||
405 | *cp++ = 0x40 | cmd->opcode; | ||
406 | *cp++ = (u8)(arg >> 24); | ||
407 | *cp++ = (u8)(arg >> 16); | ||
408 | *cp++ = (u8)(arg >> 8); | ||
409 | *cp++ = (u8)arg; | ||
410 | *cp++ = (crc7(0, &data->status[1], 5) << 1) | 0x01; | ||
411 | |||
412 | /* Then, read up to 13 bytes (while writing all-ones): | ||
413 | * - N(CR) (== 1..8) bytes of all-ones | ||
414 | * - status byte (for all response types) | ||
415 | * - the rest of the response, either: | ||
416 | * + nothing, for R1 or R1B responses | ||
417 | * + second status byte, for R2 responses | ||
418 | * + four data bytes, for R3 and R7 responses | ||
419 | * | ||
420 | * Finally, read some more bytes ... in the nice cases we know in | ||
421 | * advance how many, and reading 1 more is always OK: | ||
422 | * - N(EC) (== 0..N) bytes of all-ones, before deselect/finish | ||
423 | * - N(RC) (== 1..N) bytes of all-ones, before next command | ||
424 | * - N(WR) (== 1..N) bytes of all-ones, before data write | ||
425 | * | ||
426 | * So in those cases one full duplex I/O of at most 21 bytes will | ||
427 | * handle the whole command, leaving the card ready to receive a | ||
428 | * data block or new command. We do that whenever we can, shaving | ||
429 | * CPU and IRQ costs (especially when using DMA or FIFOs). | ||
430 | * | ||
431 | * There are two other cases, where it's not generally practical | ||
432 | * to rely on a single I/O: | ||
433 | * | ||
434 | * - R1B responses need at least N(EC) bytes of all-zeroes. | ||
435 | * | ||
436 | * In this case we can *try* to fit it into one I/O, then | ||
437 | * maybe read more data later. | ||
438 | * | ||
439 | * - Data block reads are more troublesome, since a variable | ||
440 | * number of padding bytes precede the token and data. | ||
441 | * + N(CX) (== 0..8) bytes of all-ones, before CSD or CID | ||
442 | * + N(AC) (== 1..many) bytes of all-ones | ||
443 | * | ||
444 | * In this case we currently only have minimal speedups here: | ||
445 | * when N(CR) == 1 we can avoid I/O in response_get(). | ||
446 | */ | ||
447 | if (cs_on && (mrq->data->flags & MMC_DATA_READ)) { | ||
448 | cp += 2; /* min(N(CR)) + status */ | ||
449 | /* R1 */ | ||
450 | } else { | ||
451 | cp += 10; /* max(N(CR)) + status + min(N(RC),N(WR)) */ | ||
452 | if (cmd->flags & MMC_RSP_SPI_S2) /* R2/R5 */ | ||
453 | cp++; | ||
454 | else if (cmd->flags & MMC_RSP_SPI_B4) /* R3/R4/R7 */ | ||
455 | cp += 4; | ||
456 | else if (cmd->flags & MMC_RSP_BUSY) /* R1B */ | ||
457 | cp = data->status + sizeof(data->status); | ||
458 | /* else: R1 (most commands) */ | ||
459 | } | ||
460 | |||
461 | dev_dbg(&host->spi->dev, " mmc_spi: CMD%d, resp %s\n", | ||
462 | cmd->opcode, maptype(cmd)); | ||
463 | |||
464 | /* send command, leaving chipselect active */ | ||
465 | spi_message_init(&host->m); | ||
466 | |||
467 | t = &host->t; | ||
468 | memset(t, 0, sizeof(*t)); | ||
469 | t->tx_buf = t->rx_buf = data->status; | ||
470 | t->tx_dma = t->rx_dma = host->data_dma; | ||
471 | t->len = cp - data->status; | ||
472 | t->cs_change = 1; | ||
473 | spi_message_add_tail(t, &host->m); | ||
474 | |||
475 | if (host->dma_dev) { | ||
476 | host->m.is_dma_mapped = 1; | ||
477 | dma_sync_single_for_device(host->dma_dev, | ||
478 | host->data_dma, sizeof(*host->data), | ||
479 | DMA_BIDIRECTIONAL); | ||
480 | } | ||
481 | status = spi_sync(host->spi, &host->m); | ||
482 | if (status == 0) | ||
483 | status = host->m.status; | ||
484 | |||
485 | if (host->dma_dev) | ||
486 | dma_sync_single_for_cpu(host->dma_dev, | ||
487 | host->data_dma, sizeof(*host->data), | ||
488 | DMA_BIDIRECTIONAL); | ||
489 | if (status < 0) { | ||
490 | dev_dbg(&host->spi->dev, " ... write returned %d\n", status); | ||
491 | cmd->error = status; | ||
492 | return status; | ||
493 | } | ||
494 | |||
495 | /* after no-data commands and STOP_TRANSMISSION, chipselect off */ | ||
496 | return mmc_spi_response_get(host, cmd, cs_on); | ||
497 | } | ||
498 | |||
499 | /* Build data message with up to four separate transfers. For TX, we | ||
500 | * start by writing the data token. And in most cases, we finish with | ||
501 | * a status transfer. | ||
502 | * | ||
503 | * We always provide TX data for data and CRC. The MMC/SD protocol | ||
504 | * requires us to write ones; but Linux defaults to writing zeroes; | ||
505 | * so we explicitly initialize it to all ones on RX paths. | ||
506 | * | ||
507 | * We also handle DMA mapping, so the underlying SPI controller does | ||
508 | * not need to (re)do it for each message. | ||
509 | */ | ||
510 | static void | ||
511 | mmc_spi_setup_data_message( | ||
512 | struct mmc_spi_host *host, | ||
513 | int multiple, | ||
514 | enum dma_data_direction direction) | ||
515 | { | ||
516 | struct spi_transfer *t; | ||
517 | struct scratch *scratch = host->data; | ||
518 | dma_addr_t dma = host->data_dma; | ||
519 | |||
520 | spi_message_init(&host->m); | ||
521 | if (dma) | ||
522 | host->m.is_dma_mapped = 1; | ||
523 | |||
524 | /* for reads, readblock() skips 0xff bytes before finding | ||
525 | * the token; for writes, this transfer issues that token. | ||
526 | */ | ||
527 | if (direction == DMA_TO_DEVICE) { | ||
528 | t = &host->token; | ||
529 | memset(t, 0, sizeof(*t)); | ||
530 | t->len = 1; | ||
531 | if (multiple) | ||
532 | scratch->data_token = SPI_TOKEN_MULTI_WRITE; | ||
533 | else | ||
534 | scratch->data_token = SPI_TOKEN_SINGLE; | ||
535 | t->tx_buf = &scratch->data_token; | ||
536 | if (dma) | ||
537 | t->tx_dma = dma + offsetof(struct scratch, data_token); | ||
538 | spi_message_add_tail(t, &host->m); | ||
539 | } | ||
540 | |||
541 | /* Body of transfer is buffer, then CRC ... | ||
542 | * either TX-only, or RX with TX-ones. | ||
543 | */ | ||
544 | t = &host->t; | ||
545 | memset(t, 0, sizeof(*t)); | ||
546 | t->tx_buf = host->ones; | ||
547 | t->tx_dma = host->ones_dma; | ||
548 | /* length and actual buffer info are written later */ | ||
549 | spi_message_add_tail(t, &host->m); | ||
550 | |||
551 | t = &host->crc; | ||
552 | memset(t, 0, sizeof(*t)); | ||
553 | t->len = 2; | ||
554 | if (direction == DMA_TO_DEVICE) { | ||
555 | /* the actual CRC may get written later */ | ||
556 | t->tx_buf = &scratch->crc_val; | ||
557 | if (dma) | ||
558 | t->tx_dma = dma + offsetof(struct scratch, crc_val); | ||
559 | } else { | ||
560 | t->tx_buf = host->ones; | ||
561 | t->tx_dma = host->ones_dma; | ||
562 | t->rx_buf = &scratch->crc_val; | ||
563 | if (dma) | ||
564 | t->rx_dma = dma + offsetof(struct scratch, crc_val); | ||
565 | } | ||
566 | spi_message_add_tail(t, &host->m); | ||
567 | |||
568 | /* | ||
569 | * A single block read is followed by N(EC) [0+] all-ones bytes | ||
570 | * before deselect ... don't bother. | ||
571 | * | ||
572 | * Multiblock reads are followed by N(AC) [1+] all-ones bytes before | ||
573 | * the next block is read, or a STOP_TRANSMISSION is issued. We'll | ||
574 | * collect that single byte, so readblock() doesn't need to. | ||
575 | * | ||
576 | * For a write, the one-byte data response follows immediately, then | ||
577 | * come zero or more busy bytes, then N(WR) [1+] all-ones bytes. | ||
578 | * Then single block reads may deselect, and multiblock ones issue | ||
579 | * the next token (next data block, or STOP_TRAN). We can try to | ||
580 | * minimize I/O ops by using a single read to collect end-of-busy. | ||
581 | */ | ||
582 | if (multiple || direction == DMA_TO_DEVICE) { | ||
583 | t = &host->early_status; | ||
584 | memset(t, 0, sizeof(*t)); | ||
585 | t->len = (direction == DMA_TO_DEVICE) | ||
586 | ? sizeof(scratch->status) | ||
587 | : 1; | ||
588 | t->tx_buf = host->ones; | ||
589 | t->tx_dma = host->ones_dma; | ||
590 | t->rx_buf = scratch->status; | ||
591 | if (dma) | ||
592 | t->rx_dma = dma + offsetof(struct scratch, status); | ||
593 | t->cs_change = 1; | ||
594 | spi_message_add_tail(t, &host->m); | ||
595 | } | ||
596 | } | ||
597 | |||
598 | /* | ||
599 | * Write one block: | ||
600 | * - caller handled preceding N(WR) [1+] all-ones bytes | ||
601 | * - data block | ||
602 | * + token | ||
603 | * + data bytes | ||
604 | * + crc16 | ||
605 | * - an all-ones byte ... card writes a data-response byte | ||
606 | * - followed by N(EC) [0+] all-ones bytes, card writes zero/'busy' | ||
607 | * | ||
608 | * Return negative errno, else success. | ||
609 | */ | ||
610 | static int | ||
611 | mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t) | ||
612 | { | ||
613 | struct spi_device *spi = host->spi; | ||
614 | int status, i; | ||
615 | struct scratch *scratch = host->data; | ||
616 | |||
617 | if (host->mmc->use_spi_crc) | ||
618 | scratch->crc_val = cpu_to_be16( | ||
619 | crc_itu_t(0, t->tx_buf, t->len)); | ||
620 | if (host->dma_dev) | ||
621 | dma_sync_single_for_device(host->dma_dev, | ||
622 | host->data_dma, sizeof(*scratch), | ||
623 | DMA_BIDIRECTIONAL); | ||
624 | |||
625 | status = spi_sync(spi, &host->m); | ||
626 | if (status == 0) | ||
627 | status = host->m.status; | ||
628 | |||
629 | if (status != 0) { | ||
630 | dev_dbg(&spi->dev, "write error (%d)\n", status); | ||
631 | return status; | ||
632 | } | ||
633 | |||
634 | if (host->dma_dev) | ||
635 | dma_sync_single_for_cpu(host->dma_dev, | ||
636 | host->data_dma, sizeof(*scratch), | ||
637 | DMA_BIDIRECTIONAL); | ||
638 | |||
639 | /* | ||
640 | * Get the transmission data-response reply. It must follow | ||
641 | * immediately after the data block we transferred. This reply | ||
642 | * doesn't necessarily tell whether the write operation succeeded; | ||
643 | * it just says if the transmission was ok and whether *earlier* | ||
644 | * writes succeeded; see the standard. | ||
645 | */ | ||
646 | switch (SPI_MMC_RESPONSE_CODE(scratch->status[0])) { | ||
647 | case SPI_RESPONSE_ACCEPTED: | ||
648 | status = 0; | ||
649 | break; | ||
650 | case SPI_RESPONSE_CRC_ERR: | ||
651 | /* host shall then issue MMC_STOP_TRANSMISSION */ | ||
652 | status = -EILSEQ; | ||
653 | break; | ||
654 | case SPI_RESPONSE_WRITE_ERR: | ||
655 | /* host shall then issue MMC_STOP_TRANSMISSION, | ||
656 | * and should MMC_SEND_STATUS to sort it out | ||
657 | */ | ||
658 | status = -EIO; | ||
659 | break; | ||
660 | default: | ||
661 | status = -EPROTO; | ||
662 | break; | ||
663 | } | ||
664 | if (status != 0) { | ||
665 | dev_dbg(&spi->dev, "write error %02x (%d)\n", | ||
666 | scratch->status[0], status); | ||
667 | return status; | ||
668 | } | ||
669 | |||
670 | t->tx_buf += t->len; | ||
671 | if (host->dma_dev) | ||
672 | t->tx_dma += t->len; | ||
673 | |||
674 | /* Return when not busy. If we didn't collect that status yet, | ||
675 | * we'll need some more I/O. | ||
676 | */ | ||
677 | for (i = 1; i < sizeof(scratch->status); i++) { | ||
678 | if (scratch->status[i] != 0) | ||
679 | return 0; | ||
680 | } | ||
681 | return mmc_spi_wait_unbusy(host, writeblock_timeout); | ||
682 | } | ||
683 | |||
684 | /* | ||
685 | * Read one block: | ||
686 | * - skip leading all-ones bytes ... either | ||
687 | * + N(AC) [1..f(clock,CSD)] usually, else | ||
688 | * + N(CX) [0..8] when reading CSD or CID | ||
689 | * - data block | ||
690 | * + token ... if error token, no data or crc | ||
691 | * + data bytes | ||
692 | * + crc16 | ||
693 | * | ||
694 | * After single block reads, we're done; N(EC) [0+] all-ones bytes follow | ||
695 | * before dropping chipselect. | ||
696 | * | ||
697 | * For multiblock reads, caller either reads the next block or issues a | ||
698 | * STOP_TRANSMISSION command. | ||
699 | */ | ||
700 | static int | ||
701 | mmc_spi_readblock(struct mmc_spi_host *host, struct spi_transfer *t) | ||
702 | { | ||
703 | struct spi_device *spi = host->spi; | ||
704 | int status; | ||
705 | struct scratch *scratch = host->data; | ||
706 | |||
707 | /* At least one SD card sends an all-zeroes byte when N(CX) | ||
708 | * applies, before the all-ones bytes ... just cope with that. | ||
709 | */ | ||
710 | status = mmc_spi_readbytes(host, 1); | ||
711 | if (status < 0) | ||
712 | return status; | ||
713 | status = scratch->status[0]; | ||
714 | if (status == 0xff || status == 0) | ||
715 | status = mmc_spi_readtoken(host); | ||
716 | |||
717 | if (status == SPI_TOKEN_SINGLE) { | ||
718 | if (host->dma_dev) { | ||
719 | dma_sync_single_for_device(host->dma_dev, | ||
720 | host->data_dma, sizeof(*scratch), | ||
721 | DMA_BIDIRECTIONAL); | ||
722 | dma_sync_single_for_device(host->dma_dev, | ||
723 | t->rx_dma, t->len, | ||
724 | DMA_FROM_DEVICE); | ||
725 | } | ||
726 | |||
727 | status = spi_sync(spi, &host->m); | ||
728 | if (status == 0) | ||
729 | status = host->m.status; | ||
730 | |||
731 | if (host->dma_dev) { | ||
732 | dma_sync_single_for_cpu(host->dma_dev, | ||
733 | host->data_dma, sizeof(*scratch), | ||
734 | DMA_BIDIRECTIONAL); | ||
735 | dma_sync_single_for_cpu(host->dma_dev, | ||
736 | t->rx_dma, t->len, | ||
737 | DMA_FROM_DEVICE); | ||
738 | } | ||
739 | |||
740 | } else { | ||
741 | dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status); | ||
742 | |||
743 | /* we've read extra garbage, timed out, etc */ | ||
744 | if (status < 0) | ||
745 | return status; | ||
746 | |||
747 | /* low four bits are an R2 subset, fifth seems to be | ||
748 | * vendor specific ... map them all to generic error.. | ||
749 | */ | ||
750 | return -EIO; | ||
751 | } | ||
752 | |||
753 | if (host->mmc->use_spi_crc) { | ||
754 | u16 crc = crc_itu_t(0, t->rx_buf, t->len); | ||
755 | |||
756 | be16_to_cpus(&scratch->crc_val); | ||
757 | if (scratch->crc_val != crc) { | ||
758 | dev_dbg(&spi->dev, "read - crc error: crc_val=0x%04x, " | ||
759 | "computed=0x%04x len=%d\n", | ||
760 | scratch->crc_val, crc, t->len); | ||
761 | return -EILSEQ; | ||
762 | } | ||
763 | } | ||
764 | |||
765 | t->rx_buf += t->len; | ||
766 | if (host->dma_dev) | ||
767 | t->rx_dma += t->len; | ||
768 | |||
769 | return 0; | ||
770 | } | ||
771 | |||
772 | /* | ||
773 | * An MMC/SD data stage includes one or more blocks, optional CRCs, | ||
774 | * and inline handshaking. That handhaking makes it unlike most | ||
775 | * other SPI protocol stacks. | ||
776 | */ | ||
777 | static void | ||
778 | mmc_spi_data_do(struct mmc_spi_host *host, struct mmc_command *cmd, | ||
779 | struct mmc_data *data, u32 blk_size) | ||
780 | { | ||
781 | struct spi_device *spi = host->spi; | ||
782 | struct device *dma_dev = host->dma_dev; | ||
783 | struct spi_transfer *t; | ||
784 | enum dma_data_direction direction; | ||
785 | struct scatterlist *sg; | ||
786 | unsigned n_sg; | ||
787 | int multiple = (data->blocks > 1); | ||
788 | |||
789 | if (data->flags & MMC_DATA_READ) | ||
790 | direction = DMA_FROM_DEVICE; | ||
791 | else | ||
792 | direction = DMA_TO_DEVICE; | ||
793 | mmc_spi_setup_data_message(host, multiple, direction); | ||
794 | t = &host->t; | ||
795 | |||
796 | /* Handle scatterlist segments one at a time, with synch for | ||
797 | * each 512-byte block | ||
798 | */ | ||
799 | for (sg = data->sg, n_sg = data->sg_len; n_sg; n_sg--, sg++) { | ||
800 | int status = 0; | ||
801 | dma_addr_t dma_addr = 0; | ||
802 | void *kmap_addr; | ||
803 | unsigned length = sg->length; | ||
804 | enum dma_data_direction dir = direction; | ||
805 | |||
806 | /* set up dma mapping for controller drivers that might | ||
807 | * use DMA ... though they may fall back to PIO | ||
808 | */ | ||
809 | if (dma_dev) { | ||
810 | /* never invalidate whole *shared* pages ... */ | ||
811 | if ((sg->offset != 0 || length != PAGE_SIZE) | ||
812 | && dir == DMA_FROM_DEVICE) | ||
813 | dir = DMA_BIDIRECTIONAL; | ||
814 | |||
815 | dma_addr = dma_map_page(dma_dev, sg->page, 0, | ||
816 | PAGE_SIZE, dir); | ||
817 | if (direction == DMA_TO_DEVICE) | ||
818 | t->tx_dma = dma_addr + sg->offset; | ||
819 | else | ||
820 | t->rx_dma = dma_addr + sg->offset; | ||
821 | } | ||
822 | |||
823 | /* allow pio too; we don't allow highmem */ | ||
824 | kmap_addr = kmap(sg->page); | ||
825 | if (direction == DMA_TO_DEVICE) | ||
826 | t->tx_buf = kmap_addr + sg->offset; | ||
827 | else | ||
828 | t->rx_buf = kmap_addr + sg->offset; | ||
829 | |||
830 | /* transfer each block, and update request status */ | ||
831 | while (length) { | ||
832 | t->len = min(length, blk_size); | ||
833 | |||
834 | dev_dbg(&host->spi->dev, | ||
835 | " mmc_spi: %s block, %d bytes\n", | ||
836 | (direction == DMA_TO_DEVICE) | ||
837 | ? "write" | ||
838 | : "read", | ||
839 | t->len); | ||
840 | |||
841 | if (direction == DMA_TO_DEVICE) | ||
842 | status = mmc_spi_writeblock(host, t); | ||
843 | else | ||
844 | status = mmc_spi_readblock(host, t); | ||
845 | if (status < 0) | ||
846 | break; | ||
847 | |||
848 | data->bytes_xfered += t->len; | ||
849 | length -= t->len; | ||
850 | |||
851 | if (!multiple) | ||
852 | break; | ||
853 | } | ||
854 | |||
855 | /* discard mappings */ | ||
856 | if (direction == DMA_FROM_DEVICE) | ||
857 | flush_kernel_dcache_page(sg->page); | ||
858 | kunmap(sg->page); | ||
859 | if (dma_dev) | ||
860 | dma_unmap_page(dma_dev, dma_addr, PAGE_SIZE, dir); | ||
861 | |||
862 | if (status < 0) { | ||
863 | data->error = status; | ||
864 | dev_dbg(&spi->dev, "%s status %d\n", | ||
865 | (direction == DMA_TO_DEVICE) | ||
866 | ? "write" : "read", | ||
867 | status); | ||
868 | break; | ||
869 | } | ||
870 | } | ||
871 | |||
872 | /* NOTE some docs describe an MMC-only SET_BLOCK_COUNT (CMD23) that | ||
873 | * can be issued before multiblock writes. Unlike its more widely | ||
874 | * documented analogue for SD cards (SET_WR_BLK_ERASE_COUNT, ACMD23), | ||
875 | * that can affect the STOP_TRAN logic. Complete (and current) | ||
876 | * MMC specs should sort that out before Linux starts using CMD23. | ||
877 | */ | ||
878 | if (direction == DMA_TO_DEVICE && multiple) { | ||
879 | struct scratch *scratch = host->data; | ||
880 | int tmp; | ||
881 | const unsigned statlen = sizeof(scratch->status); | ||
882 | |||
883 | dev_dbg(&spi->dev, " mmc_spi: STOP_TRAN\n"); | ||
884 | |||
885 | /* Tweak the per-block message we set up earlier by morphing | ||
886 | * it to hold single buffer with the token followed by some | ||
887 | * all-ones bytes ... skip N(BR) (0..1), scan the rest for | ||
888 | * "not busy any longer" status, and leave chip selected. | ||
889 | */ | ||
890 | INIT_LIST_HEAD(&host->m.transfers); | ||
891 | list_add(&host->early_status.transfer_list, | ||
892 | &host->m.transfers); | ||
893 | |||
894 | memset(scratch->status, 0xff, statlen); | ||
895 | scratch->status[0] = SPI_TOKEN_STOP_TRAN; | ||
896 | |||
897 | host->early_status.tx_buf = host->early_status.rx_buf; | ||
898 | host->early_status.tx_dma = host->early_status.rx_dma; | ||
899 | host->early_status.len = statlen; | ||
900 | |||
901 | if (host->dma_dev) | ||
902 | dma_sync_single_for_device(host->dma_dev, | ||
903 | host->data_dma, sizeof(*scratch), | ||
904 | DMA_BIDIRECTIONAL); | ||
905 | |||
906 | tmp = spi_sync(spi, &host->m); | ||
907 | if (tmp == 0) | ||
908 | tmp = host->m.status; | ||
909 | |||
910 | if (host->dma_dev) | ||
911 | dma_sync_single_for_cpu(host->dma_dev, | ||
912 | host->data_dma, sizeof(*scratch), | ||
913 | DMA_BIDIRECTIONAL); | ||
914 | |||
915 | if (tmp < 0) { | ||
916 | if (!data->error) | ||
917 | data->error = tmp; | ||
918 | return; | ||
919 | } | ||
920 | |||
921 | /* Ideally we collected "not busy" status with one I/O, | ||
922 | * avoiding wasteful byte-at-a-time scanning... but more | ||
923 | * I/O is often needed. | ||
924 | */ | ||
925 | for (tmp = 2; tmp < statlen; tmp++) { | ||
926 | if (scratch->status[tmp] != 0) | ||
927 | return; | ||
928 | } | ||
929 | tmp = mmc_spi_wait_unbusy(host, writeblock_timeout); | ||
930 | if (tmp < 0 && !data->error) | ||
931 | data->error = tmp; | ||
932 | } | ||
933 | } | ||
934 | |||
935 | /****************************************************************************/ | ||
936 | |||
937 | /* | ||
938 | * MMC driver implementation -- the interface to the MMC stack | ||
939 | */ | ||
940 | |||
941 | static void mmc_spi_request(struct mmc_host *mmc, struct mmc_request *mrq) | ||
942 | { | ||
943 | struct mmc_spi_host *host = mmc_priv(mmc); | ||
944 | int status = -EINVAL; | ||
945 | |||
946 | #ifdef DEBUG | ||
947 | /* MMC core and layered drivers *MUST* issue SPI-aware commands */ | ||
948 | { | ||
949 | struct mmc_command *cmd; | ||
950 | int invalid = 0; | ||
951 | |||
952 | cmd = mrq->cmd; | ||
953 | if (!mmc_spi_resp_type(cmd)) { | ||
954 | dev_dbg(&host->spi->dev, "bogus command\n"); | ||
955 | cmd->error = -EINVAL; | ||
956 | invalid = 1; | ||
957 | } | ||
958 | |||
959 | cmd = mrq->stop; | ||
960 | if (cmd && !mmc_spi_resp_type(cmd)) { | ||
961 | dev_dbg(&host->spi->dev, "bogus STOP command\n"); | ||
962 | cmd->error = -EINVAL; | ||
963 | invalid = 1; | ||
964 | } | ||
965 | |||
966 | if (invalid) { | ||
967 | dump_stack(); | ||
968 | mmc_request_done(host->mmc, mrq); | ||
969 | return; | ||
970 | } | ||
971 | } | ||
972 | #endif | ||
973 | |||
974 | /* issue command; then optionally data and stop */ | ||
975 | status = mmc_spi_command_send(host, mrq, mrq->cmd, mrq->data != NULL); | ||
976 | if (status == 0 && mrq->data) { | ||
977 | mmc_spi_data_do(host, mrq->cmd, mrq->data, mrq->data->blksz); | ||
978 | if (mrq->stop) | ||
979 | status = mmc_spi_command_send(host, mrq, mrq->stop, 0); | ||
980 | else | ||
981 | mmc_cs_off(host); | ||
982 | } | ||
983 | |||
984 | mmc_request_done(host->mmc, mrq); | ||
985 | } | ||
986 | |||
987 | /* See Section 6.4.1, in SD "Simplified Physical Layer Specification 2.0" | ||
988 | * | ||
989 | * NOTE that here we can't know that the card has just been powered up; | ||
990 | * not all MMC/SD sockets support power switching. | ||
991 | * | ||
992 | * FIXME when the card is still in SPI mode, e.g. from a previous kernel, | ||
993 | * this doesn't seem to do the right thing at all... | ||
994 | */ | ||
995 | static void mmc_spi_initsequence(struct mmc_spi_host *host) | ||
996 | { | ||
997 | /* Try to be very sure any previous command has completed; | ||
998 | * wait till not-busy, skip debris from any old commands. | ||
999 | */ | ||
1000 | mmc_spi_wait_unbusy(host, r1b_timeout); | ||
1001 | mmc_spi_readbytes(host, 10); | ||
1002 | |||
1003 | /* | ||
1004 | * Do a burst with chipselect active-high. We need to do this to | ||
1005 | * meet the requirement of 74 clock cycles with both chipselect | ||
1006 | * and CMD (MOSI) high before CMD0 ... after the card has been | ||
1007 | * powered up to Vdd(min), and so is ready to take commands. | ||
1008 | * | ||
1009 | * Some cards are particularly needy of this (e.g. Viking "SD256") | ||
1010 | * while most others don't seem to care. | ||
1011 | * | ||
1012 | * Note that this is one of the places MMC/SD plays games with the | ||
1013 | * SPI protocol. Another is that when chipselect is released while | ||
1014 | * the card returns BUSY status, the clock must issue several cycles | ||
1015 | * with chipselect high before the card will stop driving its output. | ||
1016 | */ | ||
1017 | host->spi->mode |= SPI_CS_HIGH; | ||
1018 | if (spi_setup(host->spi) != 0) { | ||
1019 | /* Just warn; most cards work without it. */ | ||
1020 | dev_warn(&host->spi->dev, | ||
1021 | "can't change chip-select polarity\n"); | ||
1022 | host->spi->mode &= ~SPI_CS_HIGH; | ||
1023 | } else { | ||
1024 | mmc_spi_readbytes(host, 18); | ||
1025 | |||
1026 | host->spi->mode &= ~SPI_CS_HIGH; | ||
1027 | if (spi_setup(host->spi) != 0) { | ||
1028 | /* Wot, we can't get the same setup we had before? */ | ||
1029 | dev_err(&host->spi->dev, | ||
1030 | "can't restore chip-select polarity\n"); | ||
1031 | } | ||
1032 | } | ||
1033 | } | ||
1034 | |||
1035 | static char *mmc_powerstring(u8 power_mode) | ||
1036 | { | ||
1037 | switch (power_mode) { | ||
1038 | case MMC_POWER_OFF: return "off"; | ||
1039 | case MMC_POWER_UP: return "up"; | ||
1040 | case MMC_POWER_ON: return "on"; | ||
1041 | } | ||
1042 | return "?"; | ||
1043 | } | ||
1044 | |||
1045 | static void mmc_spi_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) | ||
1046 | { | ||
1047 | struct mmc_spi_host *host = mmc_priv(mmc); | ||
1048 | |||
1049 | if (host->power_mode != ios->power_mode) { | ||
1050 | int canpower; | ||
1051 | |||
1052 | canpower = host->pdata && host->pdata->setpower; | ||
1053 | |||
1054 | dev_dbg(&host->spi->dev, "mmc_spi: power %s (%d)%s\n", | ||
1055 | mmc_powerstring(ios->power_mode), | ||
1056 | ios->vdd, | ||
1057 | canpower ? ", can switch" : ""); | ||
1058 | |||
1059 | /* switch power on/off if possible, accounting for | ||
1060 | * max 250msec powerup time if needed. | ||
1061 | */ | ||
1062 | if (canpower) { | ||
1063 | switch (ios->power_mode) { | ||
1064 | case MMC_POWER_OFF: | ||
1065 | case MMC_POWER_UP: | ||
1066 | host->pdata->setpower(&host->spi->dev, | ||
1067 | ios->vdd); | ||
1068 | if (ios->power_mode == MMC_POWER_UP) | ||
1069 | msleep(host->powerup_msecs); | ||
1070 | } | ||
1071 | } | ||
1072 | |||
1073 | /* See 6.4.1 in the simplified SD card physical spec 2.0 */ | ||
1074 | if (ios->power_mode == MMC_POWER_ON) | ||
1075 | mmc_spi_initsequence(host); | ||
1076 | |||
1077 | /* If powering down, ground all card inputs to avoid power | ||
1078 | * delivery from data lines! On a shared SPI bus, this | ||
1079 | * will probably be temporary; 6.4.2 of the simplified SD | ||
1080 | * spec says this must last at least 1msec. | ||
1081 | * | ||
1082 | * - Clock low means CPOL 0, e.g. mode 0 | ||
1083 | * - MOSI low comes from writing zero | ||
1084 | * - Chipselect is usually active low... | ||
1085 | */ | ||
1086 | if (canpower && ios->power_mode == MMC_POWER_OFF) { | ||
1087 | int mres; | ||
1088 | |||
1089 | host->spi->mode &= ~(SPI_CPOL|SPI_CPHA); | ||
1090 | mres = spi_setup(host->spi); | ||
1091 | if (mres < 0) | ||
1092 | dev_dbg(&host->spi->dev, | ||
1093 | "switch to SPI mode 0 failed\n"); | ||
1094 | |||
1095 | if (spi_w8r8(host->spi, 0x00) < 0) | ||
1096 | dev_dbg(&host->spi->dev, | ||
1097 | "put spi signals to low failed\n"); | ||
1098 | |||
1099 | /* | ||
1100 | * Now clock should be low due to spi mode 0; | ||
1101 | * MOSI should be low because of written 0x00; | ||
1102 | * chipselect should be low (it is active low) | ||
1103 | * power supply is off, so now MMC is off too! | ||
1104 | * | ||
1105 | * FIXME no, chipselect can be high since the | ||
1106 | * device is inactive and SPI_CS_HIGH is clear... | ||
1107 | */ | ||
1108 | msleep(10); | ||
1109 | if (mres == 0) { | ||
1110 | host->spi->mode |= (SPI_CPOL|SPI_CPHA); | ||
1111 | mres = spi_setup(host->spi); | ||
1112 | if (mres < 0) | ||
1113 | dev_dbg(&host->spi->dev, | ||
1114 | "switch back to SPI mode 3" | ||
1115 | " failed\n"); | ||
1116 | } | ||
1117 | } | ||
1118 | |||
1119 | host->power_mode = ios->power_mode; | ||
1120 | } | ||
1121 | |||
1122 | if (host->spi->max_speed_hz != ios->clock && ios->clock != 0) { | ||
1123 | int status; | ||
1124 | |||
1125 | host->spi->max_speed_hz = ios->clock; | ||
1126 | status = spi_setup(host->spi); | ||
1127 | dev_dbg(&host->spi->dev, | ||
1128 | "mmc_spi: clock to %d Hz, %d\n", | ||
1129 | host->spi->max_speed_hz, status); | ||
1130 | } | ||
1131 | } | ||
1132 | |||
1133 | static int mmc_spi_get_ro(struct mmc_host *mmc) | ||
1134 | { | ||
1135 | struct mmc_spi_host *host = mmc_priv(mmc); | ||
1136 | |||
1137 | if (host->pdata && host->pdata->get_ro) | ||
1138 | return host->pdata->get_ro(mmc->parent); | ||
1139 | /* board doesn't support read only detection; assume writeable */ | ||
1140 | return 0; | ||
1141 | } | ||
1142 | |||
1143 | |||
1144 | static const struct mmc_host_ops mmc_spi_ops = { | ||
1145 | .request = mmc_spi_request, | ||
1146 | .set_ios = mmc_spi_set_ios, | ||
1147 | .get_ro = mmc_spi_get_ro, | ||
1148 | }; | ||
1149 | |||
1150 | |||
1151 | /****************************************************************************/ | ||
1152 | |||
1153 | /* | ||
1154 | * SPI driver implementation | ||
1155 | */ | ||
1156 | |||
1157 | static irqreturn_t | ||
1158 | mmc_spi_detect_irq(int irq, void *mmc) | ||
1159 | { | ||
1160 | struct mmc_spi_host *host = mmc_priv(mmc); | ||
1161 | u16 delay_msec = max(host->pdata->detect_delay, (u16)100); | ||
1162 | |||
1163 | mmc_detect_change(mmc, msecs_to_jiffies(delay_msec)); | ||
1164 | return IRQ_HANDLED; | ||
1165 | } | ||
1166 | |||
1167 | static int mmc_spi_probe(struct spi_device *spi) | ||
1168 | { | ||
1169 | void *ones; | ||
1170 | struct mmc_host *mmc; | ||
1171 | struct mmc_spi_host *host; | ||
1172 | int status; | ||
1173 | |||
1174 | /* MMC and SD specs only seem to care that sampling is on the | ||
1175 | * rising edge ... meaning SPI modes 0 or 3. So either SPI mode | ||
1176 | * should be legit. We'll use mode 0 since it seems to be a | ||
1177 | * bit less troublesome on some hardware ... unclear why. | ||
1178 | */ | ||
1179 | spi->mode = SPI_MODE_0; | ||
1180 | spi->bits_per_word = 8; | ||
1181 | |||
1182 | status = spi_setup(spi); | ||
1183 | if (status < 0) { | ||
1184 | dev_dbg(&spi->dev, "needs SPI mode %02x, %d KHz; %d\n", | ||
1185 | spi->mode, spi->max_speed_hz / 1000, | ||
1186 | status); | ||
1187 | return status; | ||
1188 | } | ||
1189 | |||
1190 | /* We can use the bus safely iff nobody else will interfere with | ||
1191 | * us. That is, either we have the experimental exclusive access | ||
1192 | * primitives ... or else there's nobody to share it with. | ||
1193 | */ | ||
1194 | if (spi->master->num_chipselect > 1) { | ||
1195 | struct device *parent = spi->dev.parent; | ||
1196 | |||
1197 | /* If there are multiple devices on this bus, we | ||
1198 | * can't proceed. | ||
1199 | */ | ||
1200 | spin_lock(&parent->klist_children.k_lock); | ||
1201 | if (parent->klist_children.k_list.next | ||
1202 | != parent->klist_children.k_list.prev) | ||
1203 | status = -EMLINK; | ||
1204 | else | ||
1205 | status = 0; | ||
1206 | spin_unlock(&parent->klist_children.k_lock); | ||
1207 | if (status < 0) { | ||
1208 | dev_err(&spi->dev, "can't share SPI bus\n"); | ||
1209 | return status; | ||
1210 | } | ||
1211 | |||
1212 | /* REVISIT we can't guarantee another device won't | ||
1213 | * be added later. It's uncommon though ... for now, | ||
1214 | * work as if this is safe. | ||
1215 | */ | ||
1216 | dev_warn(&spi->dev, "ASSUMING unshared SPI bus!\n"); | ||
1217 | } | ||
1218 | |||
1219 | /* We need a supply of ones to transmit. This is the only time | ||
1220 | * the CPU touches these, so cache coherency isn't a concern. | ||
1221 | * | ||
1222 | * NOTE if many systems use more than one MMC-over-SPI connector | ||
1223 | * it'd save some memory to share this. That's evidently rare. | ||
1224 | */ | ||
1225 | status = -ENOMEM; | ||
1226 | ones = kmalloc(MMC_SPI_BLOCKSIZE, GFP_KERNEL); | ||
1227 | if (!ones) | ||
1228 | goto nomem; | ||
1229 | memset(ones, 0xff, MMC_SPI_BLOCKSIZE); | ||
1230 | |||
1231 | mmc = mmc_alloc_host(sizeof(*host), &spi->dev); | ||
1232 | if (!mmc) | ||
1233 | goto nomem; | ||
1234 | |||
1235 | mmc->ops = &mmc_spi_ops; | ||
1236 | mmc->max_blk_size = MMC_SPI_BLOCKSIZE; | ||
1237 | |||
1238 | /* As long as we keep track of the number of successfully | ||
1239 | * transmitted blocks, we're good for multiwrite. | ||
1240 | */ | ||
1241 | mmc->caps = MMC_CAP_SPI | MMC_CAP_MULTIWRITE; | ||
1242 | |||
1243 | /* SPI doesn't need the lowspeed device identification thing for | ||
1244 | * MMC or SD cards, since it never comes up in open drain mode. | ||
1245 | * That's good; some SPI masters can't handle very low speeds! | ||
1246 | * | ||
1247 | * However, low speed SDIO cards need not handle over 400 KHz; | ||
1248 | * that's the only reason not to use a few MHz for f_min (until | ||
1249 | * the upper layer reads the target frequency from the CSD). | ||
1250 | */ | ||
1251 | mmc->f_min = 400000; | ||
1252 | mmc->f_max = spi->max_speed_hz; | ||
1253 | |||
1254 | host = mmc_priv(mmc); | ||
1255 | host->mmc = mmc; | ||
1256 | host->spi = spi; | ||
1257 | |||
1258 | host->ones = ones; | ||
1259 | |||
1260 | /* Platform data is used to hook up things like card sensing | ||
1261 | * and power switching gpios. | ||
1262 | */ | ||
1263 | host->pdata = spi->dev.platform_data; | ||
1264 | if (host->pdata) | ||
1265 | mmc->ocr_avail = host->pdata->ocr_mask; | ||
1266 | if (!mmc->ocr_avail) { | ||
1267 | dev_warn(&spi->dev, "ASSUMING 3.2-3.4 V slot power\n"); | ||
1268 | mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34; | ||
1269 | } | ||
1270 | if (host->pdata && host->pdata->setpower) { | ||
1271 | host->powerup_msecs = host->pdata->powerup_msecs; | ||
1272 | if (!host->powerup_msecs || host->powerup_msecs > 250) | ||
1273 | host->powerup_msecs = 250; | ||
1274 | } | ||
1275 | |||
1276 | dev_set_drvdata(&spi->dev, mmc); | ||
1277 | |||
1278 | /* preallocate dma buffers */ | ||
1279 | host->data = kmalloc(sizeof(*host->data), GFP_KERNEL); | ||
1280 | if (!host->data) | ||
1281 | goto fail_nobuf1; | ||
1282 | |||
1283 | if (spi->master->cdev.dev->dma_mask) { | ||
1284 | struct device *dev = spi->master->cdev.dev; | ||
1285 | |||
1286 | host->dma_dev = dev; | ||
1287 | host->ones_dma = dma_map_single(dev, ones, | ||
1288 | MMC_SPI_BLOCKSIZE, DMA_TO_DEVICE); | ||
1289 | host->data_dma = dma_map_single(dev, host->data, | ||
1290 | sizeof(*host->data), DMA_BIDIRECTIONAL); | ||
1291 | |||
1292 | /* REVISIT in theory those map operations can fail... */ | ||
1293 | |||
1294 | dma_sync_single_for_cpu(host->dma_dev, | ||
1295 | host->data_dma, sizeof(*host->data), | ||
1296 | DMA_BIDIRECTIONAL); | ||
1297 | } | ||
1298 | |||
1299 | /* setup message for status/busy readback */ | ||
1300 | spi_message_init(&host->readback); | ||
1301 | host->readback.is_dma_mapped = (host->dma_dev != NULL); | ||
1302 | |||
1303 | spi_message_add_tail(&host->status, &host->readback); | ||
1304 | host->status.tx_buf = host->ones; | ||
1305 | host->status.tx_dma = host->ones_dma; | ||
1306 | host->status.rx_buf = &host->data->status; | ||
1307 | host->status.rx_dma = host->data_dma + offsetof(struct scratch, status); | ||
1308 | host->status.cs_change = 1; | ||
1309 | |||
1310 | /* register card detect irq */ | ||
1311 | if (host->pdata && host->pdata->init) { | ||
1312 | status = host->pdata->init(&spi->dev, mmc_spi_detect_irq, mmc); | ||
1313 | if (status != 0) | ||
1314 | goto fail_glue_init; | ||
1315 | } | ||
1316 | |||
1317 | status = mmc_add_host(mmc); | ||
1318 | if (status != 0) | ||
1319 | goto fail_add_host; | ||
1320 | |||
1321 | dev_info(&spi->dev, "SD/MMC host %s%s%s%s\n", | ||
1322 | mmc->class_dev.bus_id, | ||
1323 | host->dma_dev ? "" : ", no DMA", | ||
1324 | (host->pdata && host->pdata->get_ro) | ||
1325 | ? "" : ", no WP", | ||
1326 | (host->pdata && host->pdata->setpower) | ||
1327 | ? "" : ", no poweroff"); | ||
1328 | return 0; | ||
1329 | |||
1330 | fail_add_host: | ||
1331 | mmc_remove_host (mmc); | ||
1332 | fail_glue_init: | ||
1333 | if (host->dma_dev) | ||
1334 | dma_unmap_single(host->dma_dev, host->data_dma, | ||
1335 | sizeof(*host->data), DMA_BIDIRECTIONAL); | ||
1336 | kfree(host->data); | ||
1337 | |||
1338 | fail_nobuf1: | ||
1339 | mmc_free_host(mmc); | ||
1340 | dev_set_drvdata(&spi->dev, NULL); | ||
1341 | |||
1342 | nomem: | ||
1343 | kfree(ones); | ||
1344 | return status; | ||
1345 | } | ||
1346 | |||
1347 | |||
1348 | static int __devexit mmc_spi_remove(struct spi_device *spi) | ||
1349 | { | ||
1350 | struct mmc_host *mmc = dev_get_drvdata(&spi->dev); | ||
1351 | struct mmc_spi_host *host; | ||
1352 | |||
1353 | if (mmc) { | ||
1354 | host = mmc_priv(mmc); | ||
1355 | |||
1356 | /* prevent new mmc_detect_change() calls */ | ||
1357 | if (host->pdata && host->pdata->exit) | ||
1358 | host->pdata->exit(&spi->dev, mmc); | ||
1359 | |||
1360 | mmc_remove_host(mmc); | ||
1361 | |||
1362 | if (host->dma_dev) { | ||
1363 | dma_unmap_single(host->dma_dev, host->ones_dma, | ||
1364 | MMC_SPI_BLOCKSIZE, DMA_TO_DEVICE); | ||
1365 | dma_unmap_single(host->dma_dev, host->data_dma, | ||
1366 | sizeof(*host->data), DMA_BIDIRECTIONAL); | ||
1367 | } | ||
1368 | |||
1369 | kfree(host->data); | ||
1370 | kfree(host->ones); | ||
1371 | |||
1372 | spi->max_speed_hz = mmc->f_max; | ||
1373 | mmc_free_host(mmc); | ||
1374 | dev_set_drvdata(&spi->dev, NULL); | ||
1375 | } | ||
1376 | return 0; | ||
1377 | } | ||
1378 | |||
1379 | |||
1380 | static struct spi_driver mmc_spi_driver = { | ||
1381 | .driver = { | ||
1382 | .name = "mmc_spi", | ||
1383 | .bus = &spi_bus_type, | ||
1384 | .owner = THIS_MODULE, | ||
1385 | }, | ||
1386 | .probe = mmc_spi_probe, | ||
1387 | .remove = __devexit_p(mmc_spi_remove), | ||
1388 | }; | ||
1389 | |||
1390 | |||
1391 | static int __init mmc_spi_init(void) | ||
1392 | { | ||
1393 | return spi_register_driver(&mmc_spi_driver); | ||
1394 | } | ||
1395 | module_init(mmc_spi_init); | ||
1396 | |||
1397 | |||
1398 | static void __exit mmc_spi_exit(void) | ||
1399 | { | ||
1400 | spi_unregister_driver(&mmc_spi_driver); | ||
1401 | } | ||
1402 | module_exit(mmc_spi_exit); | ||
1403 | |||
1404 | |||
1405 | MODULE_AUTHOR("Mike Lavender, David Brownell, " | ||
1406 | "Hans-Peter Nilsson, Jan Nikitenko"); | ||
1407 | MODULE_DESCRIPTION("SPI SD/MMC host driver"); | ||
1408 | MODULE_LICENSE("GPL"); | ||