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,
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,
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);
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,
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,
}
#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) {
mmc_cs_off(host);
}
+ /* release the bus */
+ spi_bus_unlock(host->spi->master);
+
mmc_request_done(host->mmc, mrq);
}
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;
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.
*
return 0;
}
+#if defined(CONFIG_OF)
+static struct of_device_id mmc_spi_of_match_table[] __devinitdata = {
+ { .compatible = "mmc-spi-slot", },
+ {},
+};
+#endif
static struct spi_driver mmc_spi_driver = {
.driver = {
.name = "mmc_spi",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
+#if defined(CONFIG_OF)
+ .of_match_table = mmc_spi_of_match_table,
+#endif
},
.probe = mmc_spi_probe,
.remove = __devexit_p(mmc_spi_remove),
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
+#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
}
/* bus_num is used only for the case dev->platform_data == NULL */
- static int __init mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
- u32 size, unsigned int irq,
- s16 bus_num)
+ static int __devinit mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
+ u32 size, unsigned int irq,
+ s16 bus_num)
{
struct fsl_spi_platform_data *pdata = dev->platform_data;
struct mpc512x_psc_spi *mps;
master->setup = mpc512x_psc_spi_setup;
master->transfer = mpc512x_psc_spi_transfer;
master->cleanup = mpc512x_psc_spi_cleanup;
+ master->dev.of_node = dev->of_node;
tempp = ioremap(regaddr, size);
if (!tempp) {
return ret;
}
- static int __exit mpc512x_psc_spi_do_remove(struct device *dev)
+ static int __devexit mpc512x_psc_spi_do_remove(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
return 0;
}
- static int __init mpc512x_psc_spi_of_probe(struct platform_device *op,
- const struct of_device_id *match)
-static int __devinit mpc512x_psc_spi_of_probe(struct of_device *op,
++static int __devinit mpc512x_psc_spi_of_probe(struct platform_device *op,
+ const struct of_device_id *match)
{
const u32 *regaddr_p;
u64 regaddr64, size64;
irq_of_parse_and_map(op->dev.of_node, 0), id);
}
- static int __exit mpc512x_psc_spi_of_remove(struct platform_device *op)
-static int __devexit mpc512x_psc_spi_of_remove(struct of_device *op)
++static int __devexit mpc512x_psc_spi_of_remove(struct platform_device *op)
{
return mpc512x_psc_spi_do_remove(&op->dev);
}
static struct of_platform_driver mpc512x_psc_spi_of_driver = {
.probe = mpc512x_psc_spi_of_probe,
- .remove = __exit_p(mpc512x_psc_spi_of_remove),
+ .remove = __devexit_p(mpc512x_psc_spi_of_remove),
.driver = {
.name = "mpc512x-psc-spi",
.owner = THIS_MODULE,
#include <linux/slab.h>
#include <linux/mod_devicetable.h>
#include <linux/spi/spi.h>
+#include <linux/of_spi.h>
/* SPI bustype and spi_master class are registered after board init code
dynamic = 1;
}
+ spin_lock_init(&master->bus_lock_spinlock);
+ mutex_init(&master->bus_lock_mutex);
+ master->bus_lock_flag = 0;
+
/* register the device, then userspace will see it.
* registration fails if the bus ID is in use.
*/
/* populate children from any spi device tables */
scan_boardinfo(master);
status = 0;
+
+ /* Register devices from the device tree */
+ of_register_spi_devices(master);
done:
return status;
}
}
EXPORT_SYMBOL_GPL(spi_setup);
+ static 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);
+ }
+
/**
* spi_async - asynchronous SPI transfer
* @spi: device with which data will be exchanged
int spi_async(struct spi_device *spi, struct spi_message *message)
{
struct spi_master *master = spi->master;
+ int ret;
+ unsigned long flags;
- /* 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;
+ spin_lock_irqsave(&master->bus_lock_spinlock, 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;
- }
- }
+ if (master->bus_lock_flag)
+ ret = -EBUSY;
+ else
+ ret = __spi_async(spi, message);
- message->spi = spi;
- message->status = -EINPROGRESS;
- return master->transfer(spi, message);
+ spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(spi_async);
+ /**
+ * spi_async_locked - version of spi_async with exclusive bus usage
+ * @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_locked(struct spi_device *spi, struct spi_message *message)
+ {
+ struct spi_master *master = spi->master;
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+
+ ret = __spi_async(spi, message);
+
+ spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+
+ return ret;
+
+ }
+ EXPORT_SYMBOL_GPL(spi_async_locked);
+
/*-------------------------------------------------------------------------*/
complete(arg);
}
+ static int __spi_sync(struct spi_device *spi, struct spi_message *message,
+ int bus_locked)
+ {
+ DECLARE_COMPLETION_ONSTACK(done);
+ int status;
+ struct spi_master *master = spi->master;
+
+ message->complete = spi_complete;
+ message->context = &done;
+
+ if (!bus_locked)
+ mutex_lock(&master->bus_lock_mutex);
+
+ status = spi_async_locked(spi, message);
+
+ if (!bus_locked)
+ mutex_unlock(&master->bus_lock_mutex);
+
+ if (status == 0) {
+ wait_for_completion(&done);
+ status = message->status;
+ }
+ message->context = NULL;
+ return status;
+ }
+
/**
* spi_sync - blocking/synchronous SPI data transfers
* @spi: device with which data will be exchanged
*/
int spi_sync(struct spi_device *spi, struct spi_message *message)
{
- DECLARE_COMPLETION_ONSTACK(done);
- int status;
-
- message->complete = spi_complete;
- message->context = &done;
- status = spi_async(spi, message);
- if (status == 0) {
- wait_for_completion(&done);
- status = message->status;
- }
- message->context = NULL;
- return status;
+ return __spi_sync(spi, message, 0);
}
EXPORT_SYMBOL_GPL(spi_sync);
+ /**
+ * spi_sync_locked - version of spi_sync with exclusive bus usage
+ * @spi: device with which data will be exchanged
+ * @message: describes the data transfers
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep. The sleep
+ * is non-interruptible, and has no timeout. Low-overhead controller
+ * drivers may DMA directly into and out of the message buffers.
+ *
+ * This call should be used by drivers that require exclusive access to the
+ * SPI bus. It has to be preceeded by a spi_bus_lock call. The SPI bus must
+ * be released by a spi_bus_unlock call when the exclusive access is over.
+ *
+ * It returns zero on success, else a negative error code.
+ */
+ int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
+ {
+ return __spi_sync(spi, message, 1);
+ }
+ EXPORT_SYMBOL_GPL(spi_sync_locked);
+
+ /**
+ * spi_bus_lock - obtain a lock for exclusive SPI bus usage
+ * @master: SPI bus master that should be locked for exclusive bus access
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep. The sleep
+ * is non-interruptible, and has no timeout.
+ *
+ * This call should be used by drivers that require exclusive access to the
+ * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
+ * exclusive access is over. Data transfer must be done by spi_sync_locked
+ * and spi_async_locked calls when the SPI bus lock is held.
+ *
+ * It returns zero on success, else a negative error code.
+ */
+ int spi_bus_lock(struct spi_master *master)
+ {
+ unsigned long flags;
+
+ mutex_lock(&master->bus_lock_mutex);
+
+ spin_lock_irqsave(&master->bus_lock_spinlock, flags);
+ master->bus_lock_flag = 1;
+ spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
+
+ /* mutex remains locked until spi_bus_unlock is called */
+
+ return 0;
+ }
+ EXPORT_SYMBOL_GPL(spi_bus_lock);
+
+ /**
+ * spi_bus_unlock - release the lock for exclusive SPI bus usage
+ * @master: SPI bus master that was locked for exclusive bus access
+ * Context: can sleep
+ *
+ * This call may only be used from a context that may sleep. The sleep
+ * is non-interruptible, and has no timeout.
+ *
+ * This call releases an SPI bus lock previously obtained by an spi_bus_lock
+ * call.
+ *
+ * It returns zero on success, else a negative error code.
+ */
+ int spi_bus_unlock(struct spi_master *master)
+ {
+ master->bus_lock_flag = 0;
+
+ mutex_unlock(&master->bus_lock_mutex);
+
+ return 0;
+ }
+ EXPORT_SYMBOL_GPL(spi_bus_unlock);
+
/* portable code must never pass more than 32 bytes */
#define SPI_BUFSIZ max(32,SMP_CACHE_BYTES)
git.samba.org / sfrench / cifs-2.6.git / commitdiff