static LIST_HEAD(board_list);
static DEFINE_MUTEX(board_lock);
+/**
+ * spi_alloc_device - Allocate a new SPI device
+ * @master: Controller to which device is connected
+ * Context: can sleep
+ *
+ * Allows a driver to allocate and initialize a spi_device without
+ * registering it immediately. This allows a driver to directly
+ * fill the spi_device with device parameters before calling
+ * spi_add_device() on it.
+ *
+ * Caller is responsible to call spi_add_device() on the returned
+ * spi_device structure to add it to the SPI master. If the caller
+ * needs to discard the spi_device without adding it, then it should
+ * call spi_dev_put() on it.
+ *
+ * Returns a pointer to the new device, or NULL.
+ */
+struct spi_device *spi_alloc_device(struct spi_master *master)
+{
+ struct spi_device *spi;
+ struct device *dev = master->dev.parent;
+
+ if (!spi_master_get(master))
+ return NULL;
+
+ spi = kzalloc(sizeof *spi, GFP_KERNEL);
+ if (!spi) {
+ dev_err(dev, "cannot alloc spi_device\n");
+ spi_master_put(master);
+ return NULL;
+ }
+
+ spi->master = master;
+ spi->dev.parent = dev;
+ spi->dev.bus = &spi_bus_type;
+ spi->dev.release = spidev_release;
+ device_initialize(&spi->dev);
+ return spi;
+}
+EXPORT_SYMBOL_GPL(spi_alloc_device);
+
+/**
+ * spi_add_device - Add spi_device allocated with spi_alloc_device
+ * @spi: spi_device to register
+ *
+ * Companion function to spi_alloc_device. Devices allocated with
+ * spi_alloc_device can be added onto the spi bus with this function.
+ *
+ * Returns 0 on success; negative errno on failure
+ */
+int spi_add_device(struct spi_device *spi)
+{
+ static DEFINE_MUTEX(spi_add_lock);
+ struct device *dev = spi->master->dev.parent;
+ int status;
+
+ /* Chipselects are numbered 0..max; validate. */
+ if (spi->chip_select >= spi->master->num_chipselect) {
+ dev_err(dev, "cs%d >= max %d\n",
+ spi->chip_select,
+ spi->master->num_chipselect);
+ return -EINVAL;
+ }
+
+ /* Set the bus ID string */
+ snprintf(spi->dev.bus_id, sizeof spi->dev.bus_id,
+ "%s.%u", spi->master->dev.bus_id,
+ spi->chip_select);
+
+
+ /* We need to make sure there's no other device with this
+ * chipselect **BEFORE** we call setup(), else we'll trash
+ * its configuration. Lock against concurrent add() calls.
+ */
+ mutex_lock(&spi_add_lock);
+
+ if (bus_find_device_by_name(&spi_bus_type, NULL, spi->dev.bus_id)
+ != NULL) {
+ dev_err(dev, "chipselect %d already in use\n",
+ spi->chip_select);
+ status = -EBUSY;
+ goto done;
+ }
+
+ /* Drivers may modify this initial i/o setup, but will
+ * normally rely on the device being setup. Devices
+ * using SPI_CS_HIGH can't coexist well otherwise...
+ */
+ status = spi->master->setup(spi);
+ if (status < 0) {
+ dev_err(dev, "can't %s %s, status %d\n",
+ "setup", spi->dev.bus_id, status);
+ goto done;
+ }
+
+ /* Device may be bound to an active driver when this returns */
+ status = device_add(&spi->dev);
+ if (status < 0)
+ dev_err(dev, "can't %s %s, status %d\n",
+ "add", spi->dev.bus_id, status);
+ else
+ dev_dbg(dev, "registered child %s\n", spi->dev.bus_id);
+
+done:
+ mutex_unlock(&spi_add_lock);
+ return status;
+}
+EXPORT_SYMBOL_GPL(spi_add_device);
/**
* spi_new_device - instantiate one new SPI device
struct spi_board_info *chip)
{
struct spi_device *proxy;
- struct device *dev = master->dev.parent;
int status;
/* NOTE: caller did any chip->bus_num checks necessary.
* suggests syslogged diagnostics are best here (ugh).
*/
- /* Chipselects are numbered 0..max; validate. */
- if (chip->chip_select >= master->num_chipselect) {
- dev_err(dev, "cs%d > max %d\n",
- chip->chip_select,
- master->num_chipselect);
- return NULL;
- }
-
- if (!spi_master_get(master))
+ proxy = spi_alloc_device(master);
+ if (!proxy)
return NULL;
WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
- proxy = kzalloc(sizeof *proxy, GFP_KERNEL);
- if (!proxy) {
- dev_err(dev, "can't alloc dev for cs%d\n",
- chip->chip_select);
- goto fail;
- }
- proxy->master = master;
proxy->chip_select = chip->chip_select;
proxy->max_speed_hz = chip->max_speed_hz;
proxy->mode = chip->mode;
proxy->irq = chip->irq;
strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
-
- snprintf(proxy->dev.bus_id, sizeof proxy->dev.bus_id,
- "%s.%u", master->dev.bus_id,
- chip->chip_select);
- proxy->dev.parent = dev;
- proxy->dev.bus = &spi_bus_type;
proxy->dev.platform_data = (void *) chip->platform_data;
proxy->controller_data = chip->controller_data;
proxy->controller_state = NULL;
- proxy->dev.release = spidev_release;
- /* drivers may modify this initial i/o setup */
- status = master->setup(proxy);
+ status = spi_add_device(proxy);
if (status < 0) {
- dev_err(dev, "can't %s %s, status %d\n",
- "setup", proxy->dev.bus_id, status);
- goto fail;
+ spi_dev_put(proxy);
+ return NULL;
}
- /* driver core catches callers that misbehave by defining
- * devices that already exist.
- */
- status = device_register(&proxy->dev);
- if (status < 0) {
- dev_err(dev, "can't %s %s, status %d\n",
- "add", proxy->dev.bus_id, status);
- goto fail;
- }
- dev_dbg(dev, "registered child %s\n", proxy->dev.bus_id);
return proxy;
-
-fail:
- spi_master_put(master);
- kfree(proxy);
- return NULL;
}
EXPORT_SYMBOL_GPL(spi_new_device);
int status;
struct spi_message message;
- struct spi_transfer x[2];
+ struct spi_transfer x;
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);
- 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);
- }
+ memset(&x, 0, sizeof x);
+ x.len = n_tx + n_rx;
+ spi_message_add_tail(&x, &message);
/* ... unless someone else is using the pre-allocated buffer */
if (!mutex_trylock(&lock)) {
local_buf = buf;
memcpy(local_buf, txbuf, n_tx);
- x[0].tx_buf = local_buf;
- x[1].rx_buf = local_buf + n_tx;
+ x.tx_buf = local_buf;
+ x.rx_buf = local_buf;
/* do the i/o */
status = spi_sync(spi, &message);
if (status == 0)
- memcpy(rxbuf, x[1].rx_buf, n_rx);
+ memcpy(rxbuf, x.rx_buf + n_tx, n_rx);
- if (x[0].tx_buf == buf)
+ if (x.tx_buf == buf)
mutex_unlock(&lock);
else
kfree(local_buf);
* driver registration) _could_ be dynamically linked (modular) ... costs
* include needing to have boardinfo data structures be much more public.
*/
-subsys_initcall(spi_init);
+postcore_initcall(spi_init);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff