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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-25 00:22:33 +0400 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-25 00:22:33 +0400 |
commit | baea7b946f00a291b166ccae7fcfed6c01530cc6 (patch) | |
tree | 4aa275fbdbec9c7b9b4629e8bee2bbecd3c6a6af /drivers/spi/spi.c | |
parent | ae19ffbadc1b2100285a5b5b3d0a4e0a11390904 (diff) | |
parent | 94e0fb086fc5663c38bbc0fe86d698be8314f82f (diff) | |
download | linux-baea7b946f00a291b166ccae7fcfed6c01530cc6.tar.xz |
Merge branch 'origin' into for-linus
Conflicts:
MAINTAINERS
Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r-- | drivers/spi/spi.c | 85 |
1 files changed, 84 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 70845ccd85c3..b76f2468a84a 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -23,6 +23,7 @@ #include <linux/init.h> #include <linux/cache.h> #include <linux/mutex.h> +#include <linux/mod_devicetable.h> #include <linux/spi/spi.h> @@ -59,9 +60,32 @@ static struct device_attribute spi_dev_attrs[] = { * and the sysfs version makes coldplug work too. */ +static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, + const struct spi_device *sdev) +{ + while (id->name[0]) { + if (!strcmp(sdev->modalias, id->name)) + return id; + id++; + } + return NULL; +} + +const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) +{ + const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); + + return spi_match_id(sdrv->id_table, sdev); +} +EXPORT_SYMBOL_GPL(spi_get_device_id); + static int spi_match_device(struct device *dev, struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); + const struct spi_driver *sdrv = to_spi_driver(drv); + + if (sdrv->id_table) + return !!spi_match_id(sdrv->id_table, spi); return strcmp(spi->modalias, drv->name) == 0; } @@ -70,7 +94,7 @@ static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) { const struct spi_device *spi = to_spi_device(dev); - add_uevent_var(env, "MODALIAS=%s", spi->modalias); + add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); return 0; } @@ -639,6 +663,65 @@ int spi_setup(struct spi_device *spi) } EXPORT_SYMBOL_GPL(spi_setup); +/** + * spi_async - asynchronous SPI transfer + * @spi: device with which data will be exchanged + * @message: describes the data transfers, including completion callback + * Context: any (irqs may be blocked, etc) + * + * This call may be used in_irq and other contexts which can't sleep, + * as well as from task contexts which can sleep. + * + * The completion callback is invoked in a context which can't sleep. + * Before that invocation, the value of message->status is undefined. + * When the callback is issued, message->status holds either zero (to + * indicate complete success) or a negative error code. After that + * callback returns, the driver which issued the transfer request may + * deallocate the associated memory; it's no longer in use by any SPI + * core or controller driver code. + * + * Note that although all messages to a spi_device are handled in + * FIFO order, messages may go to different devices in other orders. + * Some device might be higher priority, or have various "hard" access + * time requirements, for example. + * + * On detection of any fault during the transfer, processing of + * the entire message is aborted, and the device is deselected. + * Until returning from the associated message completion callback, + * no other spi_message queued to that device will be processed. + * (This rule applies equally to all the synchronous transfer calls, + * which are wrappers around this core asynchronous primitive.) + */ +int spi_async(struct spi_device *spi, struct spi_message *message) +{ + struct spi_master *master = spi->master; + + /* Half-duplex links include original MicroWire, and ones with + * only one data pin like SPI_3WIRE (switches direction) or where + * either MOSI or MISO is missing. They can also be caused by + * software limitations. + */ + if ((master->flags & SPI_MASTER_HALF_DUPLEX) + || (spi->mode & SPI_3WIRE)) { + struct spi_transfer *xfer; + unsigned flags = master->flags; + + list_for_each_entry(xfer, &message->transfers, transfer_list) { + if (xfer->rx_buf && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) + return -EINVAL; + } + } + + message->spi = spi; + message->status = -EINPROGRESS; + return master->transfer(spi, message); +} +EXPORT_SYMBOL_GPL(spi_async); + /*-------------------------------------------------------------------------*/ |