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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-14 11:54:09 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-14 11:54:09 -0700
commitb171aa27700c78511086a759383b033949c9d7f0 (patch)
tree2775b0682ea342dd49c5b997de248da73ec83049 /drivers/mmc/host/mmc_spi.c
parent11ac552477e32835cb6970bf0a70c210807f5673 (diff)
parentb4225885deb569f7afcf1f3a9f069f74cc9db591 (diff)
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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.c59
1 files changed, 11 insertions, 48 deletions
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 1145ea0..62a3582 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.
*