diff options
Diffstat (limited to 'drivers/rapidio')
| -rw-r--r-- | drivers/rapidio/Kconfig | 14 | ||||
| -rw-r--r-- | drivers/rapidio/rio.c | 81 |
2 files changed, 95 insertions, 0 deletions
diff --git a/drivers/rapidio/Kconfig b/drivers/rapidio/Kconfig index bc8719238793..6194d35ebb97 100644 --- a/drivers/rapidio/Kconfig +++ b/drivers/rapidio/Kconfig @@ -22,6 +22,20 @@ config RAPIDIO_ENABLE_RX_TX_PORTS ports for Input/Output direction to allow other traffic than Maintenance transfers. +config RAPIDIO_DMA_ENGINE + bool "DMA Engine support for RapidIO" + depends on RAPIDIO + select DMADEVICES + select DMA_ENGINE + help + Say Y here if you want to use DMA Engine frameork for RapidIO data + transfers to/from target RIO devices. RapidIO uses NREAD and + NWRITE (NWRITE_R, SWRITE) requests to transfer data between local + memory and memory on remote target device. You need a DMA controller + capable to perform data transfers to/from RapidIO. + + If you are unsure about this, say Y here. + config RAPIDIO_DEBUG bool "RapidIO subsystem debug messages" depends on RAPIDIO diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c index 86c9a091a2ff..c40665a4fa33 100644 --- a/drivers/rapidio/rio.c +++ b/drivers/rapidio/rio.c @@ -1121,6 +1121,87 @@ int rio_std_route_clr_table(struct rio_mport *mport, u16 destid, u8 hopcount, return 0; } +#ifdef CONFIG_RAPIDIO_DMA_ENGINE + +static bool rio_chan_filter(struct dma_chan *chan, void *arg) +{ + struct rio_dev *rdev = arg; + + /* Check that DMA device belongs to the right MPORT */ + return (rdev->net->hport == + container_of(chan->device, struct rio_mport, dma)); +} + +/** + * rio_request_dma - request RapidIO capable DMA channel that supports + * specified target RapidIO device. + * @rdev: RIO device control structure + * + * Returns pointer to allocated DMA channel or NULL if failed. + */ +struct dma_chan *rio_request_dma(struct rio_dev *rdev) +{ + dma_cap_mask_t mask; + struct dma_chan *dchan; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + dchan = dma_request_channel(mask, rio_chan_filter, rdev); + + return dchan; +} +EXPORT_SYMBOL_GPL(rio_request_dma); + +/** + * rio_release_dma - release specified DMA channel + * @dchan: DMA channel to release + */ +void rio_release_dma(struct dma_chan *dchan) +{ + dma_release_channel(dchan); +} +EXPORT_SYMBOL_GPL(rio_release_dma); + +/** + * rio_dma_prep_slave_sg - RapidIO specific wrapper + * for device_prep_slave_sg callback defined by DMAENGINE. + * @rdev: RIO device control structure + * @dchan: DMA channel to configure + * @data: RIO specific data descriptor + * @direction: DMA data transfer direction (TO or FROM the device) + * @flags: dmaengine defined flags + * + * Initializes RapidIO capable DMA channel for the specified data transfer. + * Uses DMA channel private extension to pass information related to remote + * target RIO device. + * Returns pointer to DMA transaction descriptor or NULL if failed. + */ +struct dma_async_tx_descriptor *rio_dma_prep_slave_sg(struct rio_dev *rdev, + struct dma_chan *dchan, struct rio_dma_data *data, + enum dma_transfer_direction direction, unsigned long flags) +{ + struct dma_async_tx_descriptor *txd = NULL; + struct rio_dma_ext rio_ext; + + if (dchan->device->device_prep_slave_sg == NULL) { + pr_err("%s: prep_rio_sg == NULL\n", __func__); + return NULL; + } + + rio_ext.destid = rdev->destid; + rio_ext.rio_addr_u = data->rio_addr_u; + rio_ext.rio_addr = data->rio_addr; + rio_ext.wr_type = data->wr_type; + + txd = dmaengine_prep_rio_sg(dchan, data->sg, data->sg_len, + direction, flags, &rio_ext); + + return txd; +} +EXPORT_SYMBOL_GPL(rio_dma_prep_slave_sg); + +#endif /* CONFIG_RAPIDIO_DMA_ENGINE */ + static void rio_fixup_device(struct rio_dev *dev) { } |