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author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2015-12-14 22:47:40 +0200 |
---|---|---|
committer | Vinod Koul <vinod.koul@intel.com> | 2015-12-18 11:17:26 +0530 |
commit | a8135d0d79e9d0ad3a4ff494fceeaae838becf38 (patch) | |
tree | 3aba1f9650cf172838575013e74ce905c67418fc /include/linux/dmaengine.h | |
parent | 7bd903c5ca47fde5ad52370a47776491813c772e (diff) | |
download | linux-stable-a8135d0d79e9d0ad3a4ff494fceeaae838becf38.tar.gz linux-stable-a8135d0d79e9d0ad3a4ff494fceeaae838becf38.tar.bz2 linux-stable-a8135d0d79e9d0ad3a4ff494fceeaae838becf38.zip |
dmaengine: core: Introduce new, universal API to request a channel
The two API function can cover most, if not all current APIs used to
request a channel. With minimal effort dmaengine drivers, platforms and
dmaengine user drivers can be converted to use the two function.
struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask);
To request any channel matching with the requested capabilities, can be
used to request channel for memcpy, memset, xor, etc where no hardware
synchronization is needed.
struct dma_chan *dma_request_chan(struct device *dev, const char *name);
To request a slave channel. The dma_request_chan() will try to find the
channel via DT, ACPI or in case if the kernel booted in non DT/ACPI mode
it will use a filter lookup table and retrieves the needed information from
the dma_slave_map provided by the DMA drivers.
This legacy mode needs changes in platform code, in dmaengine drivers and
finally the dmaengine user drivers can be converted:
For each dmaengine driver an array of DMA device, slave and the parameter
for the filter function needs to be added:
static const struct dma_slave_map da830_edma_map[] = {
{ "davinci-mcasp.0", "rx", EDMA_FILTER_PARAM(0, 0) },
{ "davinci-mcasp.0", "tx", EDMA_FILTER_PARAM(0, 1) },
{ "davinci-mcasp.1", "rx", EDMA_FILTER_PARAM(0, 2) },
{ "davinci-mcasp.1", "tx", EDMA_FILTER_PARAM(0, 3) },
{ "davinci-mcasp.2", "rx", EDMA_FILTER_PARAM(0, 4) },
{ "davinci-mcasp.2", "tx", EDMA_FILTER_PARAM(0, 5) },
{ "spi_davinci.0", "rx", EDMA_FILTER_PARAM(0, 14) },
{ "spi_davinci.0", "tx", EDMA_FILTER_PARAM(0, 15) },
{ "da830-mmc.0", "rx", EDMA_FILTER_PARAM(0, 16) },
{ "da830-mmc.0", "tx", EDMA_FILTER_PARAM(0, 17) },
{ "spi_davinci.1", "rx", EDMA_FILTER_PARAM(0, 18) },
{ "spi_davinci.1", "tx", EDMA_FILTER_PARAM(0, 19) },
};
This information is going to be needed by the dmaengine driver, so
modification to the platform_data is needed, and the driver map should be
added to the pdata of the DMA driver:
da8xx_edma0_pdata.slave_map = da830_edma_map;
da8xx_edma0_pdata.slavecnt = ARRAY_SIZE(da830_edma_map);
The DMA driver then needs to configure the needed device -> filter_fn
mapping before it registers with dma_async_device_register() :
ecc->dma_slave.filter_map.map = info->slave_map;
ecc->dma_slave.filter_map.mapcnt = info->slavecnt;
ecc->dma_slave.filter_map.fn = edma_filter_fn;
When neither DT or ACPI lookup is available the dma_request_chan() will
try to match the requester's device name with the filter_map's list of
device names, when a match found it will use the information from the
dma_slave_map to get the channel with the dma_get_channel() internal
function.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'include/linux/dmaengine.h')
-rw-r--r-- | include/linux/dmaengine.h | 51 |
1 files changed, 44 insertions, 7 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index c47c68e535e8..d50a6b51a73d 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -607,11 +607,38 @@ enum dmaengine_alignment { }; /** + * struct dma_slave_map - associates slave device and it's slave channel with + * parameter to be used by a filter function + * @devname: name of the device + * @slave: slave channel name + * @param: opaque parameter to pass to struct dma_filter.fn + */ +struct dma_slave_map { + const char *devname; + const char *slave; + void *param; +}; + +/** + * struct dma_filter - information for slave device/channel to filter_fn/param + * mapping + * @fn: filter function callback + * @mapcnt: number of slave device/channel in the map + * @map: array of channel to filter mapping data + */ +struct dma_filter { + dma_filter_fn fn; + int mapcnt; + const struct dma_slave_map *map; +}; + +/** * struct dma_device - info on the entity supplying DMA services * @chancnt: how many DMA channels are supported * @privatecnt: how many DMA channels are requested by dma_request_channel * @channels: the list of struct dma_chan * @global_node: list_head for global dma_device_list + * @filter: information for device/slave to filter function/param mapping * @cap_mask: one or more dma_capability flags * @max_xor: maximum number of xor sources, 0 if no capability * @max_pq: maximum number of PQ sources and PQ-continue capability @@ -666,6 +693,7 @@ struct dma_device { unsigned int privatecnt; struct list_head channels; struct list_head global_node; + struct dma_filter filter; dma_cap_mask_t cap_mask; unsigned short max_xor; unsigned short max_pq; @@ -1140,9 +1168,11 @@ enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx); void dma_issue_pending_all(void); struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param); -struct dma_chan *dma_request_slave_channel_reason(struct device *dev, - const char *name); struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name); + +struct dma_chan *dma_request_chan(struct device *dev, const char *name); +struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask); + void dma_release_channel(struct dma_chan *chan); int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps); #else @@ -1166,16 +1196,21 @@ static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, { return NULL; } -static inline struct dma_chan *dma_request_slave_channel_reason( - struct device *dev, const char *name) -{ - return ERR_PTR(-ENODEV); -} static inline struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name) { return NULL; } +static inline struct dma_chan *dma_request_chan(struct device *dev, + const char *name) +{ + return ERR_PTR(-ENODEV); +} +static inline struct dma_chan *dma_request_chan_by_mask( + const dma_cap_mask_t *mask) +{ + return ERR_PTR(-ENODEV); +} static inline void dma_release_channel(struct dma_chan *chan) { } @@ -1186,6 +1221,8 @@ static inline int dma_get_slave_caps(struct dma_chan *chan, } #endif +#define dma_request_slave_channel_reason(dev, name) dma_request_chan(dev, name) + static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx) { struct dma_slave_caps caps; |