diff options
| -rw-r--r-- | drivers/dma/acpi-dma.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index 5a635646e05c..981a38fc4cb8 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); @@ -413,21 +414,29 @@ 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); |