From 221a27c76033a3a4196b3da09848bc5f237f3f94 Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Mon, 8 Jul 2013 14:15:25 +0530 Subject: dmaengine: add dma_slave_get_caps api add new device callback .device_slave_caps api which can be used by clients to query the dma channel capablties before they program the channel. This can help is removing errors during the channel programming. Also add helper dma_slave_get_caps API This patch folds the work done by Matt earlier https://patchwork.kernel.org/patch/2094891/ Signed-off-by: Vinod Koul --- include/linux/dmaengine.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'include/linux/dmaengine.h') diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index cb286b1acdb6..5692bc3afd39 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -370,6 +370,33 @@ struct dma_slave_config { unsigned int slave_id; }; +/* struct dma_slave_caps - expose capabilities of a slave channel only + * + * @src_addr_widths: bit mask of src addr widths the channel supports + * @dstn_addr_widths: bit mask of dstn addr widths the channel supports + * @directions: bit mask of slave direction the channel supported + * since the enum dma_transfer_direction is not defined as bits for each + * type of direction, the dma controller should fill (1 << ) and same + * should be checked by controller as well + * @cmd_pause: true, if pause and thereby resume is supported + * @cmd_terminate: true, if terminate cmd is supported + * + * @max_sg_nr: maximum number of SG segments supported + * 0 for no maximum + * @max_sg_len: maximum length of a SG segment supported + * 0 for no maximum + */ +struct dma_slave_caps { + u32 src_addr_widths; + u32 dstn_addr_widths; + u32 directions; + bool cmd_pause; + bool cmd_terminate; + + u32 max_sg_nr; + u32 max_sg_len; +}; + static inline const char *dma_chan_name(struct dma_chan *chan) { return dev_name(&chan->dev->device); @@ -532,6 +559,7 @@ struct dma_tx_state { * struct with auxiliary transfer status information, otherwise the call * will just return a simple status code * @device_issue_pending: push pending transactions to hardware + * @device_slave_caps: return the slave channel capabilities */ struct dma_device { @@ -597,6 +625,7 @@ struct dma_device { dma_cookie_t cookie, struct dma_tx_state *txstate); void (*device_issue_pending)(struct dma_chan *chan); + int (*device_slave_caps)(struct dma_chan *chan, struct dma_slave_caps *caps); }; static inline int dmaengine_device_control(struct dma_chan *chan, @@ -670,6 +699,21 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma( return chan->device->device_prep_interleaved_dma(chan, xt, flags); } +static inline int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) +{ + if (!chan || !caps) + return -EINVAL; + + /* check if the channel supports slave transactions */ + if (!test_bit(DMA_SLAVE, chan->device->cap_mask.bits)) + return -ENXIO; + + if (chan->device->device_slave_caps) + return chan->device->device_slave_caps(chan, caps); + + return -ENXIO; +} + static inline int dmaengine_terminate_all(struct dma_chan *chan) { return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0); -- cgit v1.2.3 From 7bb587f4eef8f71ce589f360ab99bb54ab0fc85d Mon Sep 17 00:00:00 2001 From: Zhangfei Gao Date: Fri, 28 Jun 2013 20:39:12 +0800 Subject: dmaengine: add interface of dma_get_slave_channel Suggested by Arnd, add dma_get_slave_channel interface Dma host driver could get specific channel specificied by request line, rather than filter. host example: static struct dma_chan *xx_of_dma_simple_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct xx_dma_dev *d = ofdma->of_dma_data; unsigned int request = dma_spec->args[0]; if (request > d->dma_requests) return NULL; return dma_get_slave_channel(&(d->chans[request].vc.chan)); } probe: of_dma_controller_register((&op->dev)->of_node, xx_of_dma_simple_xlate, d); Signed-off-by: Zhangfei Gao Acked-by: Arnd Bergmann Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.c | 26 ++++++++++++++++++++++++++ include/linux/dmaengine.h | 1 + 2 files changed, 27 insertions(+) (limited to 'include/linux/dmaengine.h') diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 9e56745f87bf..5932ab164ace 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -503,6 +503,32 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, return NULL; } +/** + * dma_request_channel - try to get specific channel exclusively + * @chan: target channel + */ +struct dma_chan *dma_get_slave_channel(struct dma_chan *chan) +{ + int err = -EBUSY; + + /* lock against __dma_request_channel */ + mutex_lock(&dma_list_mutex); + + if (chan->client_count == 0) + err = dma_chan_get(chan); + else + chan = NULL; + + mutex_unlock(&dma_list_mutex); + + if (err) + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + + return chan; +} +EXPORT_SYMBOL_GPL(dma_get_slave_channel); + /** * dma_request_channel - try to allocate an exclusive channel * @mask: capabilities that the channel must satisfy diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index cb286b1acdb6..c271608e862e 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -995,6 +995,7 @@ int dma_async_device_register(struct dma_device *device); void dma_async_device_unregister(struct dma_device *device); void dma_run_dependencies(struct dma_async_tx_descriptor *tx); struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type); +struct dma_chan *dma_get_slave_channel(struct dma_chan *chan); struct dma_chan *net_dma_find_channel(void); #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y) #define dma_request_slave_channel_compat(mask, x, y, dev, name) \ -- cgit v1.2.3 From 14f00c74f787a263e443b6901083187ffae641de Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Mon, 2 Sep 2013 17:47:33 +0530 Subject: dmaengine: dma_slave_caps: remove sg entries As pointed by Russell in [1], the sg properties are already availble in struct device, so no need to duplicate here. [1]: http://marc.info/?l=linux-omap&m=137416733628831 Signed-off-by: Vinod Koul --- include/linux/dmaengine.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include/linux/dmaengine.h') diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 5692bc3afd39..4310b8972867 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -380,11 +380,6 @@ struct dma_slave_config { * should be checked by controller as well * @cmd_pause: true, if pause and thereby resume is supported * @cmd_terminate: true, if terminate cmd is supported - * - * @max_sg_nr: maximum number of SG segments supported - * 0 for no maximum - * @max_sg_len: maximum length of a SG segment supported - * 0 for no maximum */ struct dma_slave_caps { u32 src_addr_widths; @@ -392,9 +387,6 @@ struct dma_slave_caps { u32 directions; bool cmd_pause; bool cmd_terminate; - - u32 max_sg_nr; - u32 max_sg_len; }; static inline const char *dma_chan_name(struct dma_chan *chan) -- cgit v1.2.3