| Message ID | 1414531573-18807-11-git-send-email-maxime.ripard@free-electrons.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
Hi Maxime, Thank you for the patch. On Tuesday 28 October 2014 22:25:25 Maxime Ripard wrote: > dma_slave_caps is very important to the generic layers that might interact > with dmaengine, such as ASoC. Unfortunately, it has been added as yet > another dma_device callback, and most of the existing drivers haven't > implemented it, reducing its reliability. > > Introduce a generic behaviour to implement this, that rely on both the split > of device_control to derive which functions are supported and on new > variables to be set in the dma_device structure. > > These variables holds what used to be the capabilities, that were set > per-channel. However, this proved to be a bit overkill, since every driver > filling these so far were hardcoding it, disregarding which channel was > actually given. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> You might want to consider adding "dmaengine: Move dma_get_slave_caps() implementation to dmaengine.c" to this series. > --- > include/linux/dmaengine.h | 41 +++++++++++++++++++++++++++++++++++++---- > 1 file changed, 37 insertions(+), 4 deletions(-) > > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > index b0efc805937a..be9e60aa8f5e 100644 > --- a/include/linux/dmaengine.h > +++ b/include/linux/dmaengine.h > @@ -593,6 +593,14 @@ struct dma_tx_state { > * @fill_align: alignment shift for memset operations > * @dev_id: unique device ID > * @dev: struct device reference for dma mapping api > + * @src_addr_widths: bit mask of src addr widths the device supports > + * @dst_addr_widths: bit mask of dst addr widths the device supports > + * @directions: bit mask of slave direction the device supports since > + * the enum dma_transfer_direction is not defined as bits for > + * each type of direction, the dma controller should fill (1 << > + * <TYPE>) and same should be checked by controller as well > + * @residue_granularity: granularity of the transfer residue reported > + * by tx_status > * @device_alloc_chan_resources: allocate resources and return the > * number of allocated descriptors > * @device_free_chan_resources: release DMA channel's resources > @@ -642,6 +650,11 @@ struct dma_device { > int dev_id; > struct device *dev; > > + u32 src_addr_widths; > + u32 dst_addr_widths; > + u32 directions; > + enum dma_residue_granularity residue_granularity; > + > int (*device_alloc_chan_resources)(struct dma_chan *chan); > void (*device_free_chan_resources)(struct dma_chan *chan); > > @@ -783,17 +796,37 @@ static inline struct dma_async_tx_descriptor > *dmaengine_prep_dma_sg( > > static inline int dma_get_slave_caps(struct dma_chan *chan, struct > dma_slave_caps *caps) { > + struct dma_device *device; > + > if (!chan || !caps) > return -EINVAL; > > + device = chan->device; > + > /* check if the channel supports slave transactions */ > - if (!test_bit(DMA_SLAVE, chan->device->cap_mask.bits)) > + if (!test_bit(DMA_SLAVE, device->cap_mask.bits)) > + return -ENXIO; > + > + if (device->device_slave_caps) > + return device->device_slave_caps(chan, caps); > + > + /* > + * Check whether it reports it uses the generic slave > + * capabilities, if not, that means it doesn't support any > + * kind of slave capabilities reporting. > + */ > + if (!device->directions) > return -ENXIO; > > - if (chan->device->device_slave_caps) > - return chan->device->device_slave_caps(chan, caps); > + caps->src_addr_widths = device->src_addr_widths; > + caps->dst_addr_widths = device->dst_addr_widths; > + caps->directions = device->directions; > + caps->residue_granularity = device->residue_granularity; > + > + caps->cmd_pause = !!device->device_pause; > + caps->cmd_terminate = !!device->device_terminate_all; > > - return -ENXIO; > + return 0; > } > > static inline int dmaengine_terminate_all(struct dma_chan *chan)
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index b0efc805937a..be9e60aa8f5e 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -593,6 +593,14 @@ struct dma_tx_state { * @fill_align: alignment shift for memset operations * @dev_id: unique device ID * @dev: struct device reference for dma mapping api + * @src_addr_widths: bit mask of src addr widths the device supports + * @dst_addr_widths: bit mask of dst addr widths the device supports + * @directions: bit mask of slave direction the device supports since + * the enum dma_transfer_direction is not defined as bits for + * each type of direction, the dma controller should fill (1 << + * <TYPE>) and same should be checked by controller as well + * @residue_granularity: granularity of the transfer residue reported + * by tx_status * @device_alloc_chan_resources: allocate resources and return the * number of allocated descriptors * @device_free_chan_resources: release DMA channel's resources @@ -642,6 +650,11 @@ struct dma_device { int dev_id; struct device *dev; + u32 src_addr_widths; + u32 dst_addr_widths; + u32 directions; + enum dma_residue_granularity residue_granularity; + int (*device_alloc_chan_resources)(struct dma_chan *chan); void (*device_free_chan_resources)(struct dma_chan *chan); @@ -783,17 +796,37 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg( static inline int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) { + struct dma_device *device; + if (!chan || !caps) return -EINVAL; + device = chan->device; + /* check if the channel supports slave transactions */ - if (!test_bit(DMA_SLAVE, chan->device->cap_mask.bits)) + if (!test_bit(DMA_SLAVE, device->cap_mask.bits)) + return -ENXIO; + + if (device->device_slave_caps) + return device->device_slave_caps(chan, caps); + + /* + * Check whether it reports it uses the generic slave + * capabilities, if not, that means it doesn't support any + * kind of slave capabilities reporting. + */ + if (!device->directions) return -ENXIO; - if (chan->device->device_slave_caps) - return chan->device->device_slave_caps(chan, caps); + caps->src_addr_widths = device->src_addr_widths; + caps->dst_addr_widths = device->dst_addr_widths; + caps->directions = device->directions; + caps->residue_granularity = device->residue_granularity; + + caps->cmd_pause = !!device->device_pause; + caps->cmd_terminate = !!device->device_terminate_all; - return -ENXIO; + return 0; } static inline int dmaengine_terminate_all(struct dma_chan *chan)
dma_slave_caps is very important to the generic layers that might interact with dmaengine, such as ASoC. Unfortunately, it has been added as yet another dma_device callback, and most of the existing drivers haven't implemented it, reducing its reliability. Introduce a generic behaviour to implement this, that rely on both the split of device_control to derive which functions are supported and on new variables to be set in the dma_device structure. These variables holds what used to be the capabilities, that were set per-channel. However, this proved to be a bit overkill, since every driver filling these so far were hardcoding it, disregarding which channel was actually given. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> --- include/linux/dmaengine.h | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-)