summaryrefslogtreecommitdiffstats
path: root/drivers/dma/acpi-dma.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/dma/acpi-dma.c')
-rw-r--r--drivers/dma/acpi-dma.c36
1 files changed, 22 insertions, 14 deletions
diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c
index 5a635646e05c..16d0daa058a5 100644
--- a/drivers/dma/acpi-dma.c
+++ b/drivers/dma/acpi-dma.c
@@ -21,6 +21,7 @@
#include <linux/ioport.h>
#include <linux/acpi.h>
#include <linux/acpi_dma.h>
+#include <linux/property.h>
static LIST_HEAD(acpi_dma_list);
static DEFINE_MUTEX(acpi_dma_lock);
@@ -160,10 +161,8 @@ int acpi_dma_controller_register(struct device *dev,
return -EINVAL;
/* Check if the device was enumerated by ACPI */
- if (!ACPI_HANDLE(dev))
- return -EINVAL;
-
- if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev))
+ adev = ACPI_COMPANION(dev);
+ if (!adev)
return -EINVAL;
adma = kzalloc(sizeof(*adma), GFP_KERNEL);
@@ -358,10 +357,11 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
int found;
/* Check if the device was enumerated by ACPI */
- if (!dev || !ACPI_HANDLE(dev))
+ if (!dev)
return ERR_PTR(-ENODEV);
- if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev))
+ adev = ACPI_COMPANION(dev);
+ if (!adev)
return ERR_PTR(-ENODEV);
memset(&pdata, 0, sizeof(pdata));
@@ -413,21 +413,29 @@ EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
* translate the names "tx" and "rx" here based on the most common case where
* the first FixedDMA descriptor is TX and second is RX.
*
+ * If the device has "dma-names" property the FixedDMA descriptor indices
+ * are retrieved based on those. Otherwise the function falls back using
+ * hardcoded indices.
+ *
* Return:
* Pointer to appropriate dma channel on success or an error pointer.
*/
struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
const char *name)
{
- size_t index;
-
- if (!strcmp(name, "tx"))
- index = 0;
- else if (!strcmp(name, "rx"))
- index = 1;
- else
- return ERR_PTR(-ENODEV);
+ int index;
+
+ index = device_property_match_string(dev, "dma-names", name);
+ if (index < 0) {
+ if (!strcmp(name, "tx"))
+ index = 0;
+ else if (!strcmp(name, "rx"))
+ index = 1;
+ else
+ return ERR_PTR(-ENODEV);
+ }
+ dev_dbg(dev, "found DMA channel \"%s\" at index %d\n", name, index);
return acpi_dma_request_slave_chan_by_index(dev, index);
}
EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name);