diff options
Diffstat (limited to 'drivers/mmc/host/mmc_spi.c')
| -rw-r--r-- | drivers/mmc/host/mmc_spi.c | 228 |
1 files changed, 166 insertions, 62 deletions
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c index 87e211df68ac..f48349d18c92 100644 --- a/drivers/mmc/host/mmc_spi.c +++ b/drivers/mmc/host/mmc_spi.c @@ -24,7 +24,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include <linux/hrtimer.h> +#include <linux/sched.h> #include <linux/delay.h> #include <linux/bio.h> #include <linux/dma-mapping.h> @@ -95,7 +95,7 @@ * reads which takes nowhere near that long. Older cards may be able to use * shorter timeouts ... but why bother? */ -#define r1b_timeout ktime_set(3, 0) +#define r1b_timeout (HZ * 3) /****************************************************************************/ @@ -183,12 +183,11 @@ mmc_spi_readbytes(struct mmc_spi_host *host, unsigned len) return status; } -static int -mmc_spi_skip(struct mmc_spi_host *host, ktime_t timeout, unsigned n, u8 byte) +static int mmc_spi_skip(struct mmc_spi_host *host, unsigned long timeout, + unsigned n, u8 byte) { u8 *cp = host->data->status; - - timeout = ktime_add(timeout, ktime_get()); + unsigned long start = jiffies; while (1) { int status; @@ -203,22 +202,26 @@ mmc_spi_skip(struct mmc_spi_host *host, ktime_t timeout, unsigned n, u8 byte) return cp[i]; } - /* REVISIT investigate msleep() to avoid busy-wait I/O - * in at least some cases. - */ - if (ktime_to_ns(ktime_sub(ktime_get(), timeout)) > 0) + 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, ktime_t timeout) +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, ktime_t timeout) +static int mmc_spi_readtoken(struct mmc_spi_host *host, unsigned long timeout) { return mmc_spi_skip(host, timeout, 1, 0xff); } @@ -251,6 +254,10 @@ static int mmc_spi_response_get(struct mmc_spi_host *host, 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", @@ -268,9 +275,8 @@ static int mmc_spi_response_get(struct mmc_spi_host *host, /* Data block reads (R1 response types) may need more data... */ if (cp == end) { - unsigned i; - 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. @@ -279,8 +285,11 @@ static int mmc_spi_response_get(struct mmc_spi_host *host, * 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 < 9; i++) { + for (i = 2; i < 16; i++) { value = mmc_spi_readbytes(host, 1); if (value < 0) goto done; @@ -292,20 +301,34 @@ static int mmc_spi_response_get(struct mmc_spi_host *host, } checkstatus: - if (*cp & 0x80) { - dev_dbg(&host->spi->dev, "%s: INVALID RESPONSE, %02x\n", - tag, *cp); - value = -EBADR; - goto done; + 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->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 - | R1_SPI_ILLEGAL_COMMAND) + | R1_SPI_ILLEGAL_COMMAND) & cmd->resp[0]) value = -EINVAL; else if (R1_SPI_COM_CRC & cmd->resp[0]) @@ -333,12 +356,45 @@ checkstatus: * SPI R5 == R1 + data byte; IO_RW_DIRECT */ case MMC_RSP_SPI_R2: - cmd->resp[0] |= *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; + } + 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: - cmd->resp[1] = get_unaligned_be32(cp); + 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 */ @@ -604,11 +660,12 @@ mmc_spi_setup_data_message( */ static int mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t, - ktime_t timeout) + 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( @@ -636,8 +693,27 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t, * 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!!! */ - switch (SPI_MMC_RESPONSE_CODE(scratch->status[0])) { + 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; @@ -668,8 +744,9 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t, /* Return when not busy. If we didn't collect that status yet, * we'll need some more I/O. */ - for (i = 1; i < sizeof(scratch->status); i++) { - if (scratch->status[i] != 0) + 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); @@ -693,11 +770,13 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t, */ static int mmc_spi_readblock(struct mmc_spi_host *host, struct spi_transfer *t, - ktime_t timeout) + 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. @@ -709,38 +788,60 @@ mmc_spi_readblock(struct mmc_spi_host *host, struct spi_transfer *t, if (status == 0xff || status == 0) status = mmc_spi_readtoken(host, timeout); - if (status == SPI_TOKEN_SINGLE) { - 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); - } + if (status < 0) { + dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status); + return status; + } - status = spi_sync(spi, &host->m); + /* 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_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 (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); + } - } else { - dev_dbg(&spi->dev, "read error %02x (%d)\n", status, status); + status = spi_sync(spi, &host->m); - /* we've read extra garbage, timed out, etc */ - if (status < 0) - return status; + 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); + } - /* low four bits are an R2 subset, fifth seems to be - * vendor specific ... map them all to generic error.. + if (bitshift) { + /* Walk through the data and the crc and do + * all the magic to get byte-aligned data. */ - return -EIO; + 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) { @@ -779,7 +880,7 @@ mmc_spi_data_do(struct mmc_spi_host *host, struct mmc_command *cmd, unsigned n_sg; int multiple = (data->blocks > 1); u32 clock_rate; - ktime_t timeout; + unsigned long timeout; if (data->flags & MMC_DATA_READ) direction = DMA_FROM_DEVICE; @@ -793,8 +894,9 @@ mmc_spi_data_do(struct mmc_spi_host *host, struct mmc_command *cmd, else clock_rate = spi->max_speed_hz; - timeout = ktime_add_ns(ktime_set(0, 0), data->timeout_ns + - data->timeout_clks * 1000000 / clock_rate); + 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 @@ -1204,10 +1306,12 @@ static int mmc_spi_probe(struct spi_device *spi) /* 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 it seems to be a - * bit less troublesome on some hardware ... unclear why. + * 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). */ - spi->mode = SPI_MODE_0; + if (spi->mode != SPI_MODE_3) + spi->mode = SPI_MODE_0; spi->bits_per_word = 8; status = spi_setup(spi); |