#include <linux/init.h>
#include <linux/cache.h>
#include <linux/mutex.h>
+#include <linux/mod_devicetable.h>
#include <linux/spi/spi.h>
* 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;
}
{
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;
}
* normally rely on the device being setup. Devices
* using SPI_CS_HIGH can't coexist well otherwise...
*/
- status = spi->master->setup(spi);
+ status = spi_setup(spi);
if (status < 0) {
dev_err(dev, "can't %s %s, status %d\n",
"setup", dev_name(&spi->dev), status);
/*-------------------------------------------------------------------------*/
+/* Core methods for SPI master protocol drivers. Some of the
+ * other core methods are currently defined as inline functions.
+ */
+
+/**
+ * spi_setup - setup SPI mode and clock rate
+ * @spi: the device whose settings are being modified
+ * Context: can sleep, and no requests are queued to the device
+ *
+ * SPI protocol drivers may need to update the transfer mode if the
+ * device doesn't work with its default. They may likewise need
+ * to update clock rates or word sizes from initial values. This function
+ * changes those settings, and must be called from a context that can sleep.
+ * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
+ * effect the next time the device is selected and data is transferred to
+ * or from it. When this function returns, the spi device is deselected.
+ *
+ * Note that this call will fail if the protocol driver specifies an option
+ * that the underlying controller or its driver does not support. For
+ * example, not all hardware supports wire transfers using nine bit words,
+ * LSB-first wire encoding, or active-high chipselects.
+ */
+int spi_setup(struct spi_device *spi)
+{
+ unsigned bad_bits;
+ int status;
+
+ /* help drivers fail *cleanly* when they need options
+ * that aren't supported with their current master
+ */
+ bad_bits = spi->mode & ~spi->master->mode_bits;
+ if (bad_bits) {
+ dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+ bad_bits);
+ return -EINVAL;
+ }
+
+ if (!spi->bits_per_word)
+ spi->bits_per_word = 8;
+
+ status = spi->master->setup(spi);
+
+ dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s"
+ "%u bits/w, %u Hz max --> %d\n",
+ (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
+ (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
+ (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
+ (spi->mode & SPI_3WIRE) ? "3wire, " : "",
+ (spi->mode & SPI_LOOP) ? "loopback, " : "",
+ spi->bits_per_word, spi->max_speed_hz,
+ status);
+
+ return status;
+}
+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);
+
+
+/*-------------------------------------------------------------------------*/
+
+/* Utility methods for SPI master protocol drivers, layered on
+ * top of the core. Some other utility methods are defined as
+ * inline functions.
+ */
+
static void spi_complete(void *arg)
{
complete(arg);
* @spi: device with which data will be exchanged
* @txbuf: data to be written (need not be dma-safe)
* @n_tx: size of txbuf, in bytes
- * @rxbuf: buffer into which data will be read
- * @n_rx: size of rxbuf, in bytes (need not be dma-safe)
+ * @rxbuf: buffer into which data will be read (need not be dma-safe)
+ * @n_rx: size of rxbuf, in bytes
* Context: can sleep
*
* This performs a half duplex MicroWire style transaction with the
int status;
struct spi_message message;
- struct spi_transfer x;
+ struct spi_transfer x[2];
u8 *local_buf;
/* Use preallocated DMA-safe buffer. We can't avoid copying here,
return -EINVAL;
spi_message_init(&message);
- memset(&x, 0, sizeof x);
- x.len = n_tx + n_rx;
- spi_message_add_tail(&x, &message);
+ memset(x, 0, sizeof x);
+ if (n_tx) {
+ x[0].len = n_tx;
+ spi_message_add_tail(&x[0], &message);
+ }
+ if (n_rx) {
+ x[1].len = n_rx;
+ spi_message_add_tail(&x[1], &message);
+ }
/* ... unless someone else is using the pre-allocated buffer */
if (!mutex_trylock(&lock)) {
local_buf = buf;
memcpy(local_buf, txbuf, n_tx);
- x.tx_buf = local_buf;
- x.rx_buf = local_buf;
+ x[0].tx_buf = local_buf;
+ x[1].rx_buf = local_buf + n_tx;
/* do the i/o */
status = spi_sync(spi, &message);
if (status == 0)
- memcpy(rxbuf, x.rx_buf + n_tx, n_rx);
+ memcpy(rxbuf, x[1].rx_buf, n_rx);
- if (x.tx_buf == buf)
+ if (x[0].tx_buf == buf)
mutex_unlock(&lock);
else
kfree(local_buf);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff