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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-14 11:54:09 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-14 11:54:09 -0700 |
commit | b171aa27700c78511086a759383b033949c9d7f0 (patch) | |
tree | 2775b0682ea342dd49c5b997de248da73ec83049 /drivers/mmc/host/mmc_spi.c | |
parent | 11ac552477e32835cb6970bf0a70c210807f5673 (diff) | |
parent | b4225885deb569f7afcf1f3a9f069f74cc9db591 (diff) | |
download | blackbird-op-linux-b171aa27700c78511086a759383b033949c9d7f0.tar.gz blackbird-op-linux-b171aa27700c78511086a759383b033949c9d7f0.zip |
Merge branch 'next-spi' of git://git.secretlab.ca/git/linux-2.6
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6:
spi/amba_pl022: Fix probe and remove hook section annotations.
spi/mpc5121: change annotations for probe and remove functions
spi/bitbang: reinitialize transfer parameters for every message
spi/spi-gpio: add support for controllers without MISO or MOSI pin
spi/bitbang: add support for SPI_MASTER_NO_{TX, RX} modes
SPI100k: Fix 8-bit and RX-only transfers
spi/mmc_spi: mmc_spi adaptations for SPI bus locking API
spi/mmc_spi: SPI bus locking API, using mutex
Fix trivial conflict in drivers/spi/mpc512x_psc_spi.c due to 'struct
of_device' => 'struct platform_device' rename and __init/__exit to
__devinit/__devexit fix.
Diffstat (limited to 'drivers/mmc/host/mmc_spi.c')
-rw-r--r-- | drivers/mmc/host/mmc_spi.c | 59 |
1 files changed, 11 insertions, 48 deletions
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c index 1145ea0792e6..62a35822003e 100644 --- a/drivers/mmc/host/mmc_spi.c +++ b/drivers/mmc/host/mmc_spi.c @@ -182,7 +182,7 @@ mmc_spi_readbytes(struct mmc_spi_host *host, unsigned len) host->data_dma, sizeof(*host->data), DMA_FROM_DEVICE); - status = spi_sync(host->spi, &host->readback); + status = spi_sync_locked(host->spi, &host->readback); if (host->dma_dev) dma_sync_single_for_cpu(host->dma_dev, @@ -541,7 +541,7 @@ mmc_spi_command_send(struct mmc_spi_host *host, host->data_dma, sizeof(*host->data), DMA_BIDIRECTIONAL); } - status = spi_sync(host->spi, &host->m); + status = spi_sync_locked(host->spi, &host->m); if (host->dma_dev) dma_sync_single_for_cpu(host->dma_dev, @@ -685,7 +685,7 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t, host->data_dma, sizeof(*scratch), DMA_BIDIRECTIONAL); - status = spi_sync(spi, &host->m); + status = spi_sync_locked(spi, &host->m); if (status != 0) { dev_dbg(&spi->dev, "write error (%d)\n", status); @@ -822,7 +822,7 @@ mmc_spi_readblock(struct mmc_spi_host *host, struct spi_transfer *t, DMA_FROM_DEVICE); } - status = spi_sync(spi, &host->m); + status = spi_sync_locked(spi, &host->m); if (host->dma_dev) { dma_sync_single_for_cpu(host->dma_dev, @@ -1018,7 +1018,7 @@ mmc_spi_data_do(struct mmc_spi_host *host, struct mmc_command *cmd, host->data_dma, sizeof(*scratch), DMA_BIDIRECTIONAL); - tmp = spi_sync(spi, &host->m); + tmp = spi_sync_locked(spi, &host->m); if (host->dma_dev) dma_sync_single_for_cpu(host->dma_dev, @@ -1084,6 +1084,9 @@ static void mmc_spi_request(struct mmc_host *mmc, struct mmc_request *mrq) } #endif + /* request exclusive bus access */ + spi_bus_lock(host->spi->master); + /* issue command; then optionally data and stop */ status = mmc_spi_command_send(host, mrq, mrq->cmd, mrq->data != NULL); if (status == 0 && mrq->data) { @@ -1094,6 +1097,9 @@ static void mmc_spi_request(struct mmc_host *mmc, struct mmc_request *mrq) mmc_cs_off(host); } + /* release the bus */ + spi_bus_unlock(host->spi->master); + mmc_request_done(host->mmc, mrq); } @@ -1290,23 +1296,6 @@ mmc_spi_detect_irq(int irq, void *mmc) return IRQ_HANDLED; } -struct count_children { - unsigned n; - struct bus_type *bus; -}; - -static int maybe_count_child(struct device *dev, void *c) -{ - struct count_children *ccp = c; - - if (dev->bus == ccp->bus) { - if (ccp->n) - return -EBUSY; - ccp->n++; - } - return 0; -} - static int mmc_spi_probe(struct spi_device *spi) { void *ones; @@ -1338,32 +1327,6 @@ static int mmc_spi_probe(struct spi_device *spi) return status; } - /* We can use the bus safely iff nobody else will interfere with us. - * Most commands consist of one SPI message to issue a command, then - * several more to collect its response, then possibly more for data - * transfer. Clocking access to other devices during that period will - * corrupt the command execution. - * - * Until we have software primitives which guarantee non-interference, - * we'll aim for a hardware-level guarantee. - * - * REVISIT we can't guarantee another device won't be added later... - */ - if (spi->master->num_chipselect > 1) { - struct count_children cc; - - cc.n = 0; - cc.bus = spi->dev.bus; - status = device_for_each_child(spi->dev.parent, &cc, - maybe_count_child); - if (status < 0) { - dev_err(&spi->dev, "can't share SPI bus\n"); - return status; - } - - dev_warn(&spi->dev, "ASSUMING SPI bus stays unshared!\n"); - } - /* We need a supply of ones to transmit. This is the only time * the CPU touches these, so cache coherency isn't a concern. * |