diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/mmc/host/mmc_spi.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/mmc/host/mmc_spi.c | 1554 |
1 files changed, 0 insertions, 1554 deletions
diff --git a/ANDROID_3.4.5/drivers/mmc/host/mmc_spi.c b/ANDROID_3.4.5/drivers/mmc/host/mmc_spi.c deleted file mode 100644 index 273306c6..00000000 --- a/ANDROID_3.4.5/drivers/mmc/host/mmc_spi.c +++ /dev/null @@ -1,1554 +0,0 @@ -/* - * mmc_spi.c - Access SD/MMC cards through SPI master controllers - * - * (C) Copyright 2005, Intec Automation, - * Mike Lavender (mike@steroidmicros) - * (C) Copyright 2006-2007, David Brownell - * (C) Copyright 2007, Axis Communications, - * Hans-Peter Nilsson (hp@axis.com) - * (C) Copyright 2007, ATRON electronic GmbH, - * Jan Nikitenko <jan.nikitenko@gmail.com> - * - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - */ -#include <linux/sched.h> -#include <linux/delay.h> -#include <linux/slab.h> -#include <linux/module.h> -#include <linux/bio.h> -#include <linux/dma-mapping.h> -#include <linux/crc7.h> -#include <linux/crc-itu-t.h> -#include <linux/scatterlist.h> - -#include <linux/mmc/host.h> -#include <linux/mmc/mmc.h> /* for R1_SPI_* bit values */ - -#include <linux/spi/spi.h> -#include <linux/spi/mmc_spi.h> - -#include <asm/unaligned.h> - - -/* NOTES: - * - * - For now, we won't try to interoperate with a real mmc/sd/sdio - * controller, although some of them do have hardware support for - * SPI protocol. The main reason for such configs would be mmc-ish - * cards like DataFlash, which don't support that "native" protocol. - * - * We don't have a "DataFlash/MMC/SD/SDIO card slot" abstraction to - * switch between driver stacks, and in any case if "native" mode - * is available, it will be faster and hence preferable. - * - * - MMC depends on a different chipselect management policy than the - * SPI interface currently supports for shared bus segments: it needs - * to issue multiple spi_message requests with the chipselect active, - * using the results of one message to decide the next one to issue. - * - * Pending updates to the programming interface, this driver expects - * that it not share the bus with other drivers (precluding conflicts). - * - * - We tell the controller to keep the chipselect active from the - * beginning of an mmc_host_ops.request until the end. So beware - * of SPI controller drivers that mis-handle the cs_change flag! - * - * However, many cards seem OK with chipselect flapping up/down - * during that time ... at least on unshared bus segments. - */ - - -/* - * Local protocol constants, internal to data block protocols. - */ - -/* Response tokens used to ack each block written: */ -#define SPI_MMC_RESPONSE_CODE(x) ((x) & 0x1f) -#define SPI_RESPONSE_ACCEPTED ((2 << 1)|1) -#define SPI_RESPONSE_CRC_ERR ((5 << 1)|1) -#define SPI_RESPONSE_WRITE_ERR ((6 << 1)|1) - -/* Read and write blocks start with these tokens and end with crc; - * on error, read tokens act like a subset of R2_SPI_* values. - */ -#define SPI_TOKEN_SINGLE 0xfe /* single block r/w, multiblock read */ -#define SPI_TOKEN_MULTI_WRITE 0xfc /* multiblock write */ -#define SPI_TOKEN_STOP_TRAN 0xfd /* terminate multiblock write */ - -#define MMC_SPI_BLOCKSIZE 512 - - -/* These fixed timeouts come from the latest SD specs, which say to ignore - * the CSD values. The R1B value is for card erase (e.g. the "I forgot the - * card's password" scenario); it's mostly applied to STOP_TRANSMISSION after - * reads which takes nowhere near that long. Older cards may be able to use - * shorter timeouts ... but why bother? - */ -#define r1b_timeout (HZ * 3) - -/* One of the critical speed parameters is the amount of data which may - * be transferred in one command. If this value is too low, the SD card - * controller has to do multiple partial block writes (argggh!). With - * today (2008) SD cards there is little speed gain if we transfer more - * than 64 KBytes at a time. So use this value until there is any indication - * that we should do more here. - */ -#define MMC_SPI_BLOCKSATONCE 128 - -/****************************************************************************/ - -/* - * Local Data Structures - */ - -/* "scratch" is per-{command,block} data exchanged with the card */ -struct scratch { - u8 status[29]; - u8 data_token; - __be16 crc_val; -}; - -struct mmc_spi_host { - struct mmc_host *mmc; - struct spi_device *spi; - - unsigned char power_mode; - u16 powerup_msecs; - - struct mmc_spi_platform_data *pdata; - - /* for bulk data transfers */ - struct spi_transfer token, t, crc, early_status; - struct spi_message m; - - /* for status readback */ - struct spi_transfer status; - struct spi_message readback; - - /* underlying DMA-aware controller, or null */ - struct device *dma_dev; - - /* buffer used for commands and for message "overhead" */ - struct scratch *data; - dma_addr_t data_dma; - - /* Specs say to write ones most of the time, even when the card - * has no need to read its input data; and many cards won't care. - * This is our source of those ones. - */ - void *ones; - dma_addr_t ones_dma; -}; - - -/****************************************************************************/ - -/* - * MMC-over-SPI protocol glue, used by the MMC stack interface - */ - -static inline int mmc_cs_off(struct mmc_spi_host *host) -{ - /* chipselect will always be inactive after setup() */ - return spi_setup(host->spi); -} - -static int -mmc_spi_readbytes(struct mmc_spi_host *host, unsigned len) -{ - int status; - - if (len > sizeof(*host->data)) { - WARN_ON(1); - return -EIO; - } - - host->status.len = len; - - if (host->dma_dev) - dma_sync_single_for_device(host->dma_dev, - host->data_dma, sizeof(*host->data), - DMA_FROM_DEVICE); - - status = spi_sync_locked(host->spi, &host->readback); - - if (host->dma_dev) - dma_sync_single_for_cpu(host->dma_dev, - host->data_dma, sizeof(*host->data), - DMA_FROM_DEVICE); - - return status; -} - -static int mmc_spi_skip(struct mmc_spi_host *host, unsigned long timeout, - unsigned n, u8 byte) -{ - u8 *cp = host->data->status; - unsigned long start = jiffies; - - while (1) { - int status; - unsigned i; - - status = mmc_spi_readbytes(host, n); - if (status < 0) - return status; - - for (i = 0; i < n; i++) { - if (cp[i] != byte) - return cp[i]; - } - - if (time_is_before_jiffies(start + timeout)) - break; - - /* If we need long timeouts, we may release the CPU. - * We use jiffies here because we want to have a relation - * between elapsed time and the blocking of the scheduler. - */ - if (time_is_before_jiffies(start+1)) - schedule(); - } - return -ETIMEDOUT; -} - -static inline int -mmc_spi_wait_unbusy(struct mmc_spi_host *host, unsigned long timeout) -{ - return mmc_spi_skip(host, timeout, sizeof(host->data->status), 0); -} - -static int mmc_spi_readtoken(struct mmc_spi_host *host, unsigned long timeout) -{ - return mmc_spi_skip(host, timeout, 1, 0xff); -} - - -/* - * Note that for SPI, cmd->resp[0] is not the same data as "native" protocol - * hosts return! The low byte holds R1_SPI bits. The next byte may hold - * R2_SPI bits ... for SEND_STATUS, or after data read errors. - * - * cmd->resp[1] holds any four-byte response, for R3 (READ_OCR) and on - * newer cards R7 (IF_COND). - */ - -static char *maptype(struct mmc_command *cmd) -{ - switch (mmc_spi_resp_type(cmd)) { - case MMC_RSP_SPI_R1: return "R1"; - case MMC_RSP_SPI_R1B: return "R1B"; - case MMC_RSP_SPI_R2: return "R2/R5"; - case MMC_RSP_SPI_R3: return "R3/R4/R7"; - default: return "?"; - } -} - -/* return zero, else negative errno after setting cmd->error */ -static int mmc_spi_response_get(struct mmc_spi_host *host, - struct mmc_command *cmd, int cs_on) -{ - u8 *cp = host->data->status; - u8 *end = cp + host->t.len; - int value = 0; - int bitshift; - u8 leftover = 0; - unsigned short rotator; - int i; - char tag[32]; - - snprintf(tag, sizeof(tag), " ... CMD%d response SPI_%s", - cmd->opcode, maptype(cmd)); - - /* Except for data block reads, the whole response will already - * be stored in the scratch buffer. It's somewhere after the - * command and the first byte we read after it. We ignore that - * first byte. After STOP_TRANSMISSION command it may include - * two data bits, but otherwise it's all ones. - */ - cp += 8; - while (cp < end && *cp == 0xff) - cp++; - - /* Data block reads (R1 response types) may need more data... */ - if (cp == end) { - cp = host->data->status; - end = cp+1; - - /* Card sends N(CR) (== 1..8) bytes of all-ones then one - * status byte ... and we already scanned 2 bytes. - * - * REVISIT block read paths use nasty byte-at-a-time I/O - * so it can always DMA directly into the target buffer. - * It'd probably be better to memcpy() the first chunk and - * avoid extra i/o calls... - * - * Note we check for more than 8 bytes, because in practice, - * some SD cards are slow... - */ - for (i = 2; i < 16; i++) { - value = mmc_spi_readbytes(host, 1); - if (value < 0) - goto done; - if (*cp != 0xff) - goto checkstatus; - } - value = -ETIMEDOUT; - goto done; - } - -checkstatus: - bitshift = 0; - if (*cp & 0x80) { - /* Houston, we have an ugly card with a bit-shifted response */ - rotator = *cp++ << 8; - /* read the next byte */ - if (cp == end) { - value = mmc_spi_readbytes(host, 1); - if (value < 0) - goto done; - cp = host->data->status; - end = cp+1; - } - rotator |= *cp++; - while (rotator & 0x8000) { - bitshift++; - rotator <<= 1; - } - cmd->resp[0] = rotator >> 8; - leftover = rotator; - } else { - cmd->resp[0] = *cp++; - } - cmd->error = 0; - - /* Status byte: the entire seven-bit R1 response. */ - if (cmd->resp[0] != 0) { - if ((R1_SPI_PARAMETER | R1_SPI_ADDRESS) - & cmd->resp[0]) - value = -EFAULT; /* Bad address */ - else if (R1_SPI_ILLEGAL_COMMAND & cmd->resp[0]) - value = -ENOSYS; /* Function not implemented */ - else if (R1_SPI_COM_CRC & cmd->resp[0]) - value = -EILSEQ; /* Illegal byte sequence */ - else if ((R1_SPI_ERASE_SEQ | R1_SPI_ERASE_RESET) - & cmd->resp[0]) - value = -EIO; /* I/O error */ - /* else R1_SPI_IDLE, "it's resetting" */ - } - - switch (mmc_spi_resp_type(cmd)) { - - /* SPI R1B == R1 + busy; STOP_TRANSMISSION (for multiblock reads) - * and less-common stuff like various erase operations. - */ - case MMC_RSP_SPI_R1B: - /* maybe we read all the busy tokens already */ - while (cp < end && *cp == 0) - cp++; - if (cp == end) - mmc_spi_wait_unbusy(host, r1b_timeout); - break; - - /* SPI R2 == R1 + second status byte; SEND_STATUS - * SPI R5 == R1 + data byte; IO_RW_DIRECT - */ - case MMC_RSP_SPI_R2: - /* read the next byte */ - if (cp == end) { - value = mmc_spi_readbytes(host, 1); - if (value < 0) - goto done; - cp = host->data->status; - end = cp+1; - } - if (bitshift) { - rotator = leftover << 8; - rotator |= *cp << bitshift; - cmd->resp[0] |= (rotator & 0xFF00); - } else { - cmd->resp[0] |= *cp << 8; - } - break; - - /* SPI R3, R4, or R7 == R1 + 4 bytes */ - case MMC_RSP_SPI_R3: - rotator = leftover << 8; - cmd->resp[1] = 0; - for (i = 0; i < 4; i++) { - cmd->resp[1] <<= 8; - /* read the next byte */ - if (cp == end) { - value = mmc_spi_readbytes(host, 1); - if (value < 0) - goto done; - cp = host->data->status; - end = cp+1; - } - if (bitshift) { - rotator |= *cp++ << bitshift; - cmd->resp[1] |= (rotator >> 8); - rotator <<= 8; - } else { - cmd->resp[1] |= *cp++; - } - } - break; - - /* SPI R1 == just one status byte */ - case MMC_RSP_SPI_R1: - break; - - default: - dev_dbg(&host->spi->dev, "bad response type %04x\n", - mmc_spi_resp_type(cmd)); - if (value >= 0) - value = -EINVAL; - goto done; - } - - if (value < 0) - dev_dbg(&host->spi->dev, "%s: resp %04x %08x\n", - tag, cmd->resp[0], cmd->resp[1]); - - /* disable chipselect on errors and some success cases */ - if (value >= 0 && cs_on) - return value; -done: - if (value < 0) - cmd->error = value; - mmc_cs_off(host); - return value; -} - -/* Issue command and read its response. - * Returns zero on success, negative for error. - * - * On error, caller must cope with mmc core retry mechanism. That - * means immediate low-level resubmit, which affects the bus lock... - */ -static int -mmc_spi_command_send(struct mmc_spi_host *host, - struct mmc_request *mrq, - struct mmc_command *cmd, int cs_on) -{ - struct scratch *data = host->data; - u8 *cp = data->status; - u32 arg = cmd->arg; - int status; - struct spi_transfer *t; - - /* We can handle most commands (except block reads) in one full - * duplex I/O operation before either starting the next transfer - * (data block or command) or else deselecting the card. - * - * First, write 7 bytes: - * - an all-ones byte to ensure the card is ready - * - opcode byte (plus start and transmission bits) - * - four bytes of big-endian argument - * - crc7 (plus end bit) ... always computed, it's cheap - * - * We init the whole buffer to all-ones, which is what we need - * to write while we're reading (later) response data. - */ - memset(cp++, 0xff, sizeof(data->status)); - - *cp++ = 0x40 | cmd->opcode; - *cp++ = (u8)(arg >> 24); - *cp++ = (u8)(arg >> 16); - *cp++ = (u8)(arg >> 8); - *cp++ = (u8)arg; - *cp++ = (crc7(0, &data->status[1], 5) << 1) | 0x01; - - /* Then, read up to 13 bytes (while writing all-ones): - * - N(CR) (== 1..8) bytes of all-ones - * - status byte (for all response types) - * - the rest of the response, either: - * + nothing, for R1 or R1B responses - * + second status byte, for R2 responses - * + four data bytes, for R3 and R7 responses - * - * Finally, read some more bytes ... in the nice cases we know in - * advance how many, and reading 1 more is always OK: - * - N(EC) (== 0..N) bytes of all-ones, before deselect/finish - * - N(RC) (== 1..N) bytes of all-ones, before next command - * - N(WR) (== 1..N) bytes of all-ones, before data write - * - * So in those cases one full duplex I/O of at most 21 bytes will - * handle the whole command, leaving the card ready to receive a - * data block or new command. We do that whenever we can, shaving - * CPU and IRQ costs (especially when using DMA or FIFOs). - * - * There are two other cases, where it's not generally practical - * to rely on a single I/O: - * - * - R1B responses need at least N(EC) bytes of all-zeroes. - * - * In this case we can *try* to fit it into one I/O, then - * maybe read more data later. - * - * - Data block reads are more troublesome, since a variable - * number of padding bytes precede the token and data. - * + N(CX) (== 0..8) bytes of all-ones, before CSD or CID - * + N(AC) (== 1..many) bytes of all-ones - * - * In this case we currently only have minimal speedups here: - * when N(CR) == 1 we can avoid I/O in response_get(). - */ - if (cs_on && (mrq->data->flags & MMC_DATA_READ)) { - cp += 2; /* min(N(CR)) + status */ - /* R1 */ - } else { - cp += 10; /* max(N(CR)) + status + min(N(RC),N(WR)) */ - if (cmd->flags & MMC_RSP_SPI_S2) /* R2/R5 */ - cp++; - else if (cmd->flags & MMC_RSP_SPI_B4) /* R3/R4/R7 */ - cp += 4; - else if (cmd->flags & MMC_RSP_BUSY) /* R1B */ - cp = data->status + sizeof(data->status); - /* else: R1 (most commands) */ - } - - dev_dbg(&host->spi->dev, " mmc_spi: CMD%d, resp %s\n", - cmd->opcode, maptype(cmd)); - - /* send command, leaving chipselect active */ - spi_message_init(&host->m); - - t = &host->t; - memset(t, 0, sizeof(*t)); - t->tx_buf = t->rx_buf = data->status; - t->tx_dma = t->rx_dma = host->data_dma; - t->len = cp - data->status; - t->cs_change = 1; - spi_message_add_tail(t, &host->m); - - if (host->dma_dev) { - host->m.is_dma_mapped = 1; - dma_sync_single_for_device(host->dma_dev, - host->data_dma, sizeof(*host->data), - DMA_BIDIRECTIONAL); - } - status = spi_sync_locked(host->spi, &host->m); - - if (host->dma_dev) - dma_sync_single_for_cpu(host->dma_dev, - host->data_dma, sizeof(*host->data), - DMA_BIDIRECTIONAL); - if (status < 0) { - dev_dbg(&host->spi->dev, " ... write returned %d\n", status); - cmd->error = status; - return status; - } - - /* after no-data commands and STOP_TRANSMISSION, chipselect off */ - return mmc_spi_response_get(host, cmd, cs_on); -} - -/* Build data message with up to four separate transfers. For TX, we - * start by writing the data token. And in most cases, we finish with - * a status transfer. - * - * We always provide TX data for data and CRC. The MMC/SD protocol - * requires us to write ones; but Linux defaults to writing zeroes; - * so we explicitly initialize it to all ones on RX paths. - * - * We also handle DMA mapping, so the underlying SPI controller does - * not need to (re)do it for each message. - */ -static void -mmc_spi_setup_data_message( - struct mmc_spi_host *host, - int multiple, - enum dma_data_direction direction) -{ - struct spi_transfer *t; - struct scratch *scratch = host->data; - dma_addr_t dma = host->data_dma; - - spi_message_init(&host->m); - if (dma) - host->m.is_dma_mapped = 1; - - /* for reads, readblock() skips 0xff bytes before finding - * the token; for writes, this transfer issues that token. - */ - if (direction == DMA_TO_DEVICE) { - t = &host->token; - memset(t, 0, sizeof(*t)); - t->len = 1; - if (multiple) - scratch->data_token = SPI_TOKEN_MULTI_WRITE; - else - scratch->data_token = SPI_TOKEN_SINGLE; - t->tx_buf = &scratch->data_token; - if (dma) - t->tx_dma = dma + offsetof(struct scratch, data_token); - spi_message_add_tail(t, &host->m); - } - - /* Body of transfer is buffer, then CRC ... - * either TX-only, or RX with TX-ones. - */ - t = &host->t; - memset(t, 0, sizeof(*t)); - t->tx_buf = host->ones; - t->tx_dma = host->ones_dma; - /* length and actual buffer info are written later */ - spi_message_add_tail(t, &host->m); - - t = &host->crc; - memset(t, 0, sizeof(*t)); - t->len = 2; - if (direction == DMA_TO_DEVICE) { - /* the actual CRC may get written later */ - t->tx_buf = &scratch->crc_val; - if (dma) - t->tx_dma = dma + offsetof(struct scratch, crc_val); - } else { - t->tx_buf = host->ones; - t->tx_dma = host->ones_dma; - t->rx_buf = &scratch->crc_val; - if (dma) - t->rx_dma = dma + offsetof(struct scratch, crc_val); - } - spi_message_add_tail(t, &host->m); - - /* - * A single block read is followed by N(EC) [0+] all-ones bytes - * before deselect ... don't bother. - * - * Multiblock reads are followed by N(AC) [1+] all-ones bytes before - * the next block is read, or a STOP_TRANSMISSION is issued. We'll - * collect that single byte, so readblock() doesn't need to. - * - * For a write, the one-byte data response follows immediately, then - * come zero or more busy bytes, then N(WR) [1+] all-ones bytes. - * Then single block reads may deselect, and multiblock ones issue - * the next token (next data block, or STOP_TRAN). We can try to - * minimize I/O ops by using a single read to collect end-of-busy. - */ - if (multiple || direction == DMA_TO_DEVICE) { - t = &host->early_status; - memset(t, 0, sizeof(*t)); - t->len = (direction == DMA_TO_DEVICE) - ? sizeof(scratch->status) - : 1; - t->tx_buf = host->ones; - t->tx_dma = host->ones_dma; - t->rx_buf = scratch->status; - if (dma) - t->rx_dma = dma + offsetof(struct scratch, status); - t->cs_change = 1; - spi_message_add_tail(t, &host->m); - } -} - -/* - * Write one block: - * - caller handled preceding N(WR) [1+] all-ones bytes - * - data block - * + token - * + data bytes - * + crc16 - * - an all-ones byte ... card writes a data-response byte - * - followed by N(EC) [0+] all-ones bytes, card writes zero/'busy' - * - * Return negative errno, else success. - */ -static int -mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t, - unsigned long timeout) -{ - struct spi_device *spi = host->spi; - int status, i; - struct scratch *scratch = host->data; - u32 pattern; - - if (host->mmc->use_spi_crc) - scratch->crc_val = cpu_to_be16( - crc_itu_t(0, t->tx_buf, t->len)); - if (host->dma_dev) - dma_sync_single_for_device(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - - status = spi_sync_locked(spi, &host->m); - - if (status != 0) { - dev_dbg(&spi->dev, "write error (%d)\n", status); - return status; - } - - if (host->dma_dev) - dma_sync_single_for_cpu(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - - /* - * Get the transmission data-response reply. It must follow - * immediately after the data block we transferred. This reply - * doesn't necessarily tell whether the write operation succeeded; - * it just says if the transmission was ok and whether *earlier* - * writes succeeded; see the standard. - * - * In practice, there are (even modern SDHC-)cards which are late - * in sending the response, and miss the time frame by a few bits, - * so we have to cope with this situation and check the response - * bit-by-bit. Arggh!!! - */ - pattern = scratch->status[0] << 24; - pattern |= scratch->status[1] << 16; - pattern |= scratch->status[2] << 8; - pattern |= scratch->status[3]; - - /* First 3 bit of pattern are undefined */ - pattern |= 0xE0000000; - - /* left-adjust to leading 0 bit */ - while (pattern & 0x80000000) - pattern <<= 1; - /* right-adjust for pattern matching. Code is in bit 4..0 now. */ - pattern >>= 27; - - switch (pattern) { - case SPI_RESPONSE_ACCEPTED: - status = 0; - break; - case SPI_RESPONSE_CRC_ERR: - /* host shall then issue MMC_STOP_TRANSMISSION */ - status = -EILSEQ; - break; - case SPI_RESPONSE_WRITE_ERR: - /* host shall then issue MMC_STOP_TRANSMISSION, - * and should MMC_SEND_STATUS to sort it out - */ - status = -EIO; - break; - default: - status = -EPROTO; - break; - } - if (status != 0) { - dev_dbg(&spi->dev, "write error %02x (%d)\n", - scratch->status[0], status); - return status; - } - - t->tx_buf += t->len; - if (host->dma_dev) - t->tx_dma += t->len; - - /* Return when not busy. If we didn't collect that status yet, - * we'll need some more I/O. - */ - for (i = 4; i < sizeof(scratch->status); i++) { - /* card is non-busy if the most recent bit is 1 */ - if (scratch->status[i] & 0x01) - return 0; - } - return mmc_spi_wait_unbusy(host, timeout); -} - -/* - * Read one block: - * - skip leading all-ones bytes ... either - * + N(AC) [1..f(clock,CSD)] usually, else - * + N(CX) [0..8] when reading CSD or CID - * - data block - * + token ... if error token, no data or crc - * + data bytes - * + crc16 - * - * After single block reads, we're done; N(EC) [0+] all-ones bytes follow - * before dropping chipselect. - * - * For multiblock reads, caller either reads the next block or issues a - * STOP_TRANSMISSION command. - */ -static int -mmc_spi_readblock(struct mmc_spi_host *host, struct spi_transfer *t, - unsigned long timeout) -{ - struct spi_device *spi = host->spi; - int status; - struct scratch *scratch = host->data; - unsigned int bitshift; - u8 leftover; - - /* At least one SD card sends an all-zeroes byte when N(CX) - * applies, before the all-ones bytes ... just cope with that. - */ - status = mmc_spi_readbytes(host, 1); - if (status < 0) - return status; - status = scratch->status[0]; - if (status == 0xff || status == 0) - status = mmc_spi_readtoken(host, timeout); - - if (status < 0) { - dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status); - return status; - } - - /* The token may be bit-shifted... - * the first 0-bit precedes the data stream. - */ - bitshift = 7; - while (status & 0x80) { - status <<= 1; - bitshift--; - } - leftover = status << 1; - - if (host->dma_dev) { - dma_sync_single_for_device(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - dma_sync_single_for_device(host->dma_dev, - t->rx_dma, t->len, - DMA_FROM_DEVICE); - } - - status = spi_sync_locked(spi, &host->m); - - if (host->dma_dev) { - dma_sync_single_for_cpu(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - dma_sync_single_for_cpu(host->dma_dev, - t->rx_dma, t->len, - DMA_FROM_DEVICE); - } - - if (bitshift) { - /* Walk through the data and the crc and do - * all the magic to get byte-aligned data. - */ - u8 *cp = t->rx_buf; - unsigned int len; - unsigned int bitright = 8 - bitshift; - u8 temp; - for (len = t->len; len; len--) { - temp = *cp; - *cp++ = leftover | (temp >> bitshift); - leftover = temp << bitright; - } - cp = (u8 *) &scratch->crc_val; - temp = *cp; - *cp++ = leftover | (temp >> bitshift); - leftover = temp << bitright; - temp = *cp; - *cp = leftover | (temp >> bitshift); - } - - if (host->mmc->use_spi_crc) { - u16 crc = crc_itu_t(0, t->rx_buf, t->len); - - be16_to_cpus(&scratch->crc_val); - if (scratch->crc_val != crc) { - dev_dbg(&spi->dev, "read - crc error: crc_val=0x%04x, " - "computed=0x%04x len=%d\n", - scratch->crc_val, crc, t->len); - return -EILSEQ; - } - } - - t->rx_buf += t->len; - if (host->dma_dev) - t->rx_dma += t->len; - - return 0; -} - -/* - * An MMC/SD data stage includes one or more blocks, optional CRCs, - * and inline handshaking. That handhaking makes it unlike most - * other SPI protocol stacks. - */ -static void -mmc_spi_data_do(struct mmc_spi_host *host, struct mmc_command *cmd, - struct mmc_data *data, u32 blk_size) -{ - struct spi_device *spi = host->spi; - struct device *dma_dev = host->dma_dev; - struct spi_transfer *t; - enum dma_data_direction direction; - struct scatterlist *sg; - unsigned n_sg; - int multiple = (data->blocks > 1); - u32 clock_rate; - unsigned long timeout; - - if (data->flags & MMC_DATA_READ) - direction = DMA_FROM_DEVICE; - else - direction = DMA_TO_DEVICE; - mmc_spi_setup_data_message(host, multiple, direction); - t = &host->t; - - if (t->speed_hz) - clock_rate = t->speed_hz; - else - clock_rate = spi->max_speed_hz; - - timeout = data->timeout_ns + - data->timeout_clks * 1000000 / clock_rate; - timeout = usecs_to_jiffies((unsigned int)(timeout / 1000)) + 1; - - /* Handle scatterlist segments one at a time, with synch for - * each 512-byte block - */ - for (sg = data->sg, n_sg = data->sg_len; n_sg; n_sg--, sg++) { - int status = 0; - dma_addr_t dma_addr = 0; - void *kmap_addr; - unsigned length = sg->length; - enum dma_data_direction dir = direction; - - /* set up dma mapping for controller drivers that might - * use DMA ... though they may fall back to PIO - */ - if (dma_dev) { - /* never invalidate whole *shared* pages ... */ - if ((sg->offset != 0 || length != PAGE_SIZE) - && dir == DMA_FROM_DEVICE) - dir = DMA_BIDIRECTIONAL; - - dma_addr = dma_map_page(dma_dev, sg_page(sg), 0, - PAGE_SIZE, dir); - if (direction == DMA_TO_DEVICE) - t->tx_dma = dma_addr + sg->offset; - else - t->rx_dma = dma_addr + sg->offset; - } - - /* allow pio too; we don't allow highmem */ - kmap_addr = kmap(sg_page(sg)); - if (direction == DMA_TO_DEVICE) - t->tx_buf = kmap_addr + sg->offset; - else - t->rx_buf = kmap_addr + sg->offset; - - /* transfer each block, and update request status */ - while (length) { - t->len = min(length, blk_size); - - dev_dbg(&host->spi->dev, - " mmc_spi: %s block, %d bytes\n", - (direction == DMA_TO_DEVICE) - ? "write" - : "read", - t->len); - - if (direction == DMA_TO_DEVICE) - status = mmc_spi_writeblock(host, t, timeout); - else - status = mmc_spi_readblock(host, t, timeout); - if (status < 0) - break; - - data->bytes_xfered += t->len; - length -= t->len; - - if (!multiple) - break; - } - - /* discard mappings */ - if (direction == DMA_FROM_DEVICE) - flush_kernel_dcache_page(sg_page(sg)); - kunmap(sg_page(sg)); - if (dma_dev) - dma_unmap_page(dma_dev, dma_addr, PAGE_SIZE, dir); - - if (status < 0) { - data->error = status; - dev_dbg(&spi->dev, "%s status %d\n", - (direction == DMA_TO_DEVICE) - ? "write" : "read", - status); - break; - } - } - - /* NOTE some docs describe an MMC-only SET_BLOCK_COUNT (CMD23) that - * can be issued before multiblock writes. Unlike its more widely - * documented analogue for SD cards (SET_WR_BLK_ERASE_COUNT, ACMD23), - * that can affect the STOP_TRAN logic. Complete (and current) - * MMC specs should sort that out before Linux starts using CMD23. - */ - if (direction == DMA_TO_DEVICE && multiple) { - struct scratch *scratch = host->data; - int tmp; - const unsigned statlen = sizeof(scratch->status); - - dev_dbg(&spi->dev, " mmc_spi: STOP_TRAN\n"); - - /* Tweak the per-block message we set up earlier by morphing - * it to hold single buffer with the token followed by some - * all-ones bytes ... skip N(BR) (0..1), scan the rest for - * "not busy any longer" status, and leave chip selected. - */ - INIT_LIST_HEAD(&host->m.transfers); - list_add(&host->early_status.transfer_list, - &host->m.transfers); - - memset(scratch->status, 0xff, statlen); - scratch->status[0] = SPI_TOKEN_STOP_TRAN; - - host->early_status.tx_buf = host->early_status.rx_buf; - host->early_status.tx_dma = host->early_status.rx_dma; - host->early_status.len = statlen; - - if (host->dma_dev) - dma_sync_single_for_device(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - - tmp = spi_sync_locked(spi, &host->m); - - if (host->dma_dev) - dma_sync_single_for_cpu(host->dma_dev, - host->data_dma, sizeof(*scratch), - DMA_BIDIRECTIONAL); - - if (tmp < 0) { - if (!data->error) - data->error = tmp; - return; - } - - /* Ideally we collected "not busy" status with one I/O, - * avoiding wasteful byte-at-a-time scanning... but more - * I/O is often needed. - */ - for (tmp = 2; tmp < statlen; tmp++) { - if (scratch->status[tmp] != 0) - return; - } - tmp = mmc_spi_wait_unbusy(host, timeout); - if (tmp < 0 && !data->error) - data->error = tmp; - } -} - -/****************************************************************************/ - -/* - * MMC driver implementation -- the interface to the MMC stack - */ - -static void mmc_spi_request(struct mmc_host *mmc, struct mmc_request *mrq) -{ - struct mmc_spi_host *host = mmc_priv(mmc); - int status = -EINVAL; - int crc_retry = 5; - struct mmc_command stop; - -#ifdef DEBUG - /* MMC core and layered drivers *MUST* issue SPI-aware commands */ - { - struct mmc_command *cmd; - int invalid = 0; - - cmd = mrq->cmd; - if (!mmc_spi_resp_type(cmd)) { - dev_dbg(&host->spi->dev, "bogus command\n"); - cmd->error = -EINVAL; - invalid = 1; - } - - cmd = mrq->stop; - if (cmd && !mmc_spi_resp_type(cmd)) { - dev_dbg(&host->spi->dev, "bogus STOP command\n"); - cmd->error = -EINVAL; - invalid = 1; - } - - if (invalid) { - dump_stack(); - mmc_request_done(host->mmc, mrq); - return; - } - } -#endif - - /* request exclusive bus access */ - spi_bus_lock(host->spi->master); - -crc_recover: - /* issue command; then optionally data and stop */ - status = mmc_spi_command_send(host, mrq, mrq->cmd, mrq->data != NULL); - if (status == 0 && mrq->data) { - mmc_spi_data_do(host, mrq->cmd, mrq->data, mrq->data->blksz); - - /* - * The SPI bus is not always reliable for large data transfers. - * If an occasional crc error is reported by the SD device with - * data read/write over SPI, it may be recovered by repeating - * the last SD command again. The retry count is set to 5 to - * ensure the driver passes stress tests. - */ - if (mrq->data->error == -EILSEQ && crc_retry) { - stop.opcode = MMC_STOP_TRANSMISSION; - stop.arg = 0; - stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC; - status = mmc_spi_command_send(host, mrq, &stop, 0); - crc_retry--; - mrq->data->error = 0; - goto crc_recover; - } - - if (mrq->stop) - status = mmc_spi_command_send(host, mrq, mrq->stop, 0); - else - mmc_cs_off(host); - } - - /* release the bus */ - spi_bus_unlock(host->spi->master); - - mmc_request_done(host->mmc, mrq); -} - -/* See Section 6.4.1, in SD "Simplified Physical Layer Specification 2.0" - * - * NOTE that here we can't know that the card has just been powered up; - * not all MMC/SD sockets support power switching. - * - * FIXME when the card is still in SPI mode, e.g. from a previous kernel, - * this doesn't seem to do the right thing at all... - */ -static void mmc_spi_initsequence(struct mmc_spi_host *host) -{ - /* Try to be very sure any previous command has completed; - * wait till not-busy, skip debris from any old commands. - */ - mmc_spi_wait_unbusy(host, r1b_timeout); - mmc_spi_readbytes(host, 10); - - /* - * Do a burst with chipselect active-high. We need to do this to - * meet the requirement of 74 clock cycles with both chipselect - * and CMD (MOSI) high before CMD0 ... after the card has been - * powered up to Vdd(min), and so is ready to take commands. - * - * Some cards are particularly needy of this (e.g. Viking "SD256") - * while most others don't seem to care. - * - * Note that this is one of the places MMC/SD plays games with the - * SPI protocol. Another is that when chipselect is released while - * the card returns BUSY status, the clock must issue several cycles - * with chipselect high before the card will stop driving its output. - */ - host->spi->mode |= SPI_CS_HIGH; - if (spi_setup(host->spi) != 0) { - /* Just warn; most cards work without it. */ - dev_warn(&host->spi->dev, - "can't change chip-select polarity\n"); - host->spi->mode &= ~SPI_CS_HIGH; - } else { - mmc_spi_readbytes(host, 18); - - host->spi->mode &= ~SPI_CS_HIGH; - if (spi_setup(host->spi) != 0) { - /* Wot, we can't get the same setup we had before? */ - dev_err(&host->spi->dev, - "can't restore chip-select polarity\n"); - } - } -} - -static char *mmc_powerstring(u8 power_mode) -{ - switch (power_mode) { - case MMC_POWER_OFF: return "off"; - case MMC_POWER_UP: return "up"; - case MMC_POWER_ON: return "on"; - } - return "?"; -} - -static void mmc_spi_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) -{ - struct mmc_spi_host *host = mmc_priv(mmc); - - if (host->power_mode != ios->power_mode) { - int canpower; - - canpower = host->pdata && host->pdata->setpower; - - dev_dbg(&host->spi->dev, "mmc_spi: power %s (%d)%s\n", - mmc_powerstring(ios->power_mode), - ios->vdd, - canpower ? ", can switch" : ""); - - /* switch power on/off if possible, accounting for - * max 250msec powerup time if needed. - */ - if (canpower) { - switch (ios->power_mode) { - case MMC_POWER_OFF: - case MMC_POWER_UP: - host->pdata->setpower(&host->spi->dev, - ios->vdd); - if (ios->power_mode == MMC_POWER_UP) - msleep(host->powerup_msecs); - } - } - - /* See 6.4.1 in the simplified SD card physical spec 2.0 */ - if (ios->power_mode == MMC_POWER_ON) - mmc_spi_initsequence(host); - - /* If powering down, ground all card inputs to avoid power - * delivery from data lines! On a shared SPI bus, this - * will probably be temporary; 6.4.2 of the simplified SD - * spec says this must last at least 1msec. - * - * - Clock low means CPOL 0, e.g. mode 0 - * - MOSI low comes from writing zero - * - Chipselect is usually active low... - */ - if (canpower && ios->power_mode == MMC_POWER_OFF) { - int mres; - u8 nullbyte = 0; - - host->spi->mode &= ~(SPI_CPOL|SPI_CPHA); - mres = spi_setup(host->spi); - if (mres < 0) - dev_dbg(&host->spi->dev, - "switch to SPI mode 0 failed\n"); - - if (spi_write(host->spi, &nullbyte, 1) < 0) - dev_dbg(&host->spi->dev, - "put spi signals to low failed\n"); - - /* - * Now clock should be low due to spi mode 0; - * MOSI should be low because of written 0x00; - * chipselect should be low (it is active low) - * power supply is off, so now MMC is off too! - * - * FIXME no, chipselect can be high since the - * device is inactive and SPI_CS_HIGH is clear... - */ - msleep(10); - if (mres == 0) { - host->spi->mode |= (SPI_CPOL|SPI_CPHA); - mres = spi_setup(host->spi); - if (mres < 0) - dev_dbg(&host->spi->dev, - "switch back to SPI mode 3" - " failed\n"); - } - } - - host->power_mode = ios->power_mode; - } - - if (host->spi->max_speed_hz != ios->clock && ios->clock != 0) { - int status; - - host->spi->max_speed_hz = ios->clock; - status = spi_setup(host->spi); - dev_dbg(&host->spi->dev, - "mmc_spi: clock to %d Hz, %d\n", - host->spi->max_speed_hz, status); - } -} - -static int mmc_spi_get_ro(struct mmc_host *mmc) -{ - struct mmc_spi_host *host = mmc_priv(mmc); - - if (host->pdata && host->pdata->get_ro) - return !!host->pdata->get_ro(mmc->parent); - /* - * Board doesn't support read only detection; let the mmc core - * decide what to do. - */ - return -ENOSYS; -} - -static int mmc_spi_get_cd(struct mmc_host *mmc) -{ - struct mmc_spi_host *host = mmc_priv(mmc); - - if (host->pdata && host->pdata->get_cd) - return !!host->pdata->get_cd(mmc->parent); - return -ENOSYS; -} - -static const struct mmc_host_ops mmc_spi_ops = { - .request = mmc_spi_request, - .set_ios = mmc_spi_set_ios, - .get_ro = mmc_spi_get_ro, - .get_cd = mmc_spi_get_cd, -}; - - -/****************************************************************************/ - -/* - * SPI driver implementation - */ - -static irqreturn_t -mmc_spi_detect_irq(int irq, void *mmc) -{ - struct mmc_spi_host *host = mmc_priv(mmc); - u16 delay_msec = max(host->pdata->detect_delay, (u16)100); - - mmc_detect_change(mmc, msecs_to_jiffies(delay_msec)); - return IRQ_HANDLED; -} - -static int mmc_spi_probe(struct spi_device *spi) -{ - void *ones; - struct mmc_host *mmc; - struct mmc_spi_host *host; - int status; - - /* We rely on full duplex transfers, mostly to reduce - * per-transfer overheads (by making fewer transfers). - */ - if (spi->master->flags & SPI_MASTER_HALF_DUPLEX) - return -EINVAL; - - /* MMC and SD specs only seem to care that sampling is on the - * rising edge ... meaning SPI modes 0 or 3. So either SPI mode - * should be legit. We'll use mode 0 since the steady state is 0, - * which is appropriate for hotplugging, unless the platform data - * specify mode 3 (if hardware is not compatible to mode 0). - */ - if (spi->mode != SPI_MODE_3) - spi->mode = SPI_MODE_0; - spi->bits_per_word = 8; - - status = spi_setup(spi); - if (status < 0) { - dev_dbg(&spi->dev, "needs SPI mode %02x, %d KHz; %d\n", - spi->mode, spi->max_speed_hz / 1000, - status); - return status; - } - - /* We need a supply of ones to transmit. This is the only time - * the CPU touches these, so cache coherency isn't a concern. - * - * NOTE if many systems use more than one MMC-over-SPI connector - * it'd save some memory to share this. That's evidently rare. - */ - status = -ENOMEM; - ones = kmalloc(MMC_SPI_BLOCKSIZE, GFP_KERNEL); - if (!ones) - goto nomem; - memset(ones, 0xff, MMC_SPI_BLOCKSIZE); - - mmc = mmc_alloc_host(sizeof(*host), &spi->dev); - if (!mmc) - goto nomem; - - mmc->ops = &mmc_spi_ops; - mmc->max_blk_size = MMC_SPI_BLOCKSIZE; - mmc->max_segs = MMC_SPI_BLOCKSATONCE; - mmc->max_req_size = MMC_SPI_BLOCKSATONCE * MMC_SPI_BLOCKSIZE; - mmc->max_blk_count = MMC_SPI_BLOCKSATONCE; - - mmc->caps = MMC_CAP_SPI; - - /* SPI doesn't need the lowspeed device identification thing for - * MMC or SD cards, since it never comes up in open drain mode. - * That's good; some SPI masters can't handle very low speeds! - * - * However, low speed SDIO cards need not handle over 400 KHz; - * that's the only reason not to use a few MHz for f_min (until - * the upper layer reads the target frequency from the CSD). - */ - mmc->f_min = 400000; - mmc->f_max = spi->max_speed_hz; - - host = mmc_priv(mmc); - host->mmc = mmc; - host->spi = spi; - - host->ones = ones; - - /* Platform data is used to hook up things like card sensing - * and power switching gpios. - */ - host->pdata = mmc_spi_get_pdata(spi); - if (host->pdata) - mmc->ocr_avail = host->pdata->ocr_mask; - if (!mmc->ocr_avail) { - dev_warn(&spi->dev, "ASSUMING 3.2-3.4 V slot power\n"); - mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34; - } - if (host->pdata && host->pdata->setpower) { - host->powerup_msecs = host->pdata->powerup_msecs; - if (!host->powerup_msecs || host->powerup_msecs > 250) - host->powerup_msecs = 250; - } - - dev_set_drvdata(&spi->dev, mmc); - - /* preallocate dma buffers */ - host->data = kmalloc(sizeof(*host->data), GFP_KERNEL); - if (!host->data) - goto fail_nobuf1; - - if (spi->master->dev.parent->dma_mask) { - struct device *dev = spi->master->dev.parent; - - host->dma_dev = dev; - host->ones_dma = dma_map_single(dev, ones, - MMC_SPI_BLOCKSIZE, DMA_TO_DEVICE); - host->data_dma = dma_map_single(dev, host->data, - sizeof(*host->data), DMA_BIDIRECTIONAL); - - /* REVISIT in theory those map operations can fail... */ - - dma_sync_single_for_cpu(host->dma_dev, - host->data_dma, sizeof(*host->data), - DMA_BIDIRECTIONAL); - } - - /* setup message for status/busy readback */ - spi_message_init(&host->readback); - host->readback.is_dma_mapped = (host->dma_dev != NULL); - - spi_message_add_tail(&host->status, &host->readback); - host->status.tx_buf = host->ones; - host->status.tx_dma = host->ones_dma; - host->status.rx_buf = &host->data->status; - host->status.rx_dma = host->data_dma + offsetof(struct scratch, status); - host->status.cs_change = 1; - - /* register card detect irq */ - if (host->pdata && host->pdata->init) { - status = host->pdata->init(&spi->dev, mmc_spi_detect_irq, mmc); - if (status != 0) - goto fail_glue_init; - } - - /* pass platform capabilities, if any */ - if (host->pdata) - mmc->caps |= host->pdata->caps; - - status = mmc_add_host(mmc); - if (status != 0) - goto fail_add_host; - - dev_info(&spi->dev, "SD/MMC host %s%s%s%s%s\n", - dev_name(&mmc->class_dev), - host->dma_dev ? "" : ", no DMA", - (host->pdata && host->pdata->get_ro) - ? "" : ", no WP", - (host->pdata && host->pdata->setpower) - ? "" : ", no poweroff", - (mmc->caps & MMC_CAP_NEEDS_POLL) - ? ", cd polling" : ""); - return 0; - -fail_add_host: - mmc_remove_host (mmc); -fail_glue_init: - if (host->dma_dev) - dma_unmap_single(host->dma_dev, host->data_dma, - sizeof(*host->data), DMA_BIDIRECTIONAL); - kfree(host->data); - -fail_nobuf1: - mmc_free_host(mmc); - mmc_spi_put_pdata(spi); - dev_set_drvdata(&spi->dev, NULL); - -nomem: - kfree(ones); - return status; -} - - -static int __devexit mmc_spi_remove(struct spi_device *spi) -{ - struct mmc_host *mmc = dev_get_drvdata(&spi->dev); - struct mmc_spi_host *host; - - if (mmc) { - host = mmc_priv(mmc); - - /* prevent new mmc_detect_change() calls */ - if (host->pdata && host->pdata->exit) - host->pdata->exit(&spi->dev, mmc); - - mmc_remove_host(mmc); - - if (host->dma_dev) { - dma_unmap_single(host->dma_dev, host->ones_dma, - MMC_SPI_BLOCKSIZE, DMA_TO_DEVICE); - dma_unmap_single(host->dma_dev, host->data_dma, - sizeof(*host->data), DMA_BIDIRECTIONAL); - } - - kfree(host->data); - kfree(host->ones); - - spi->max_speed_hz = mmc->f_max; - mmc_free_host(mmc); - mmc_spi_put_pdata(spi); - dev_set_drvdata(&spi->dev, NULL); - } - return 0; -} - -static struct of_device_id mmc_spi_of_match_table[] __devinitdata = { - { .compatible = "mmc-spi-slot", }, - {}, -}; - -static struct spi_driver mmc_spi_driver = { - .driver = { - .name = "mmc_spi", - .owner = THIS_MODULE, - .of_match_table = mmc_spi_of_match_table, - }, - .probe = mmc_spi_probe, - .remove = __devexit_p(mmc_spi_remove), -}; - - -static int __init mmc_spi_init(void) -{ - return spi_register_driver(&mmc_spi_driver); -} -module_init(mmc_spi_init); - - -static void __exit mmc_spi_exit(void) -{ - spi_unregister_driver(&mmc_spi_driver); -} -module_exit(mmc_spi_exit); - - -MODULE_AUTHOR("Mike Lavender, David Brownell, " - "Hans-Peter Nilsson, Jan Nikitenko"); -MODULE_DESCRIPTION("SPI SD/MMC host driver"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("spi:mmc_spi"); |