diff options
Diffstat (limited to 'drivers/dma/sh')
| -rw-r--r-- | drivers/dma/sh/shdma-base.c | 114 | ||||
| -rw-r--r-- | drivers/dma/sh/shdma.c | 5 |
2 files changed, 92 insertions, 27 deletions
diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index 73db282a1436..27f5c781fd73 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -171,6 +171,65 @@ static struct shdma_desc *shdma_get_desc(struct shdma_chan *schan) return NULL; } +static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) +{ + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + int ret; + + if (slave_id < 0 || slave_id >= slave_num) + return -EINVAL; + + if (test_and_set_bit(slave_id, shdma_slave_used)) + return -EBUSY; + + ret = ops->set_slave(schan, slave_id, false); + if (ret < 0) { + clear_bit(slave_id, shdma_slave_used); + return ret; + } + + schan->slave_id = slave_id; + + return 0; +} + +/* + * This is the standard shdma filter function to be used as a replacement to the + * "old" method, using the .private pointer. If for some reason you allocate a + * channel without slave data, use something like ERR_PTR(-EINVAL) as a filter + * parameter. If this filter is used, the slave driver, after calling + * dma_request_channel(), will also have to call dmaengine_slave_config() with + * .slave_id, .direction, and either .src_addr or .dst_addr set. + * NOTE: this filter doesn't support multiple DMAC drivers with the DMA_SLAVE + * capability! If this becomes a requirement, hardware glue drivers, using this + * services would have to provide their own filters, which first would check + * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do + * this, and only then, in case of a match, call this common filter. + */ +bool shdma_chan_filter(struct dma_chan *chan, void *arg) +{ + struct shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + int slave_id = (int)arg; + int ret; + + if (slave_id < 0) + /* No slave requested - arbitrary channel */ + return true; + + if (slave_id >= slave_num) + return false; + + ret = ops->set_slave(schan, slave_id, true); + if (ret < 0) + return false; + + return true; +} +EXPORT_SYMBOL(shdma_chan_filter); + static int shdma_alloc_chan_resources(struct dma_chan *chan) { struct shdma_chan *schan = to_shdma_chan(chan); @@ -185,21 +244,10 @@ static int shdma_alloc_chan_resources(struct dma_chan *chan) * never runs concurrently with itself or free_chan_resources. */ if (slave) { - if (slave->slave_id < 0 || slave->slave_id >= slave_num) { - ret = -EINVAL; - goto evalid; - } - - if (test_and_set_bit(slave->slave_id, shdma_slave_used)) { - ret = -EBUSY; - goto etestused; - } - - ret = ops->set_slave(schan, slave->slave_id); + /* Legacy mode: .private is set in filter */ + ret = shdma_setup_slave(schan, slave->slave_id); if (ret < 0) goto esetslave; - - schan->slave_id = slave->slave_id; } else { schan->slave_id = -EINVAL; } @@ -228,8 +276,6 @@ edescalloc: if (slave) esetslave: clear_bit(slave->slave_id, shdma_slave_used); -etestused: -evalid: chan->private = NULL; return ret; } @@ -587,22 +633,40 @@ static int shdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, struct shdma_chan *schan = to_shdma_chan(chan); struct shdma_dev *sdev = to_shdma_dev(chan->device); const struct shdma_ops *ops = sdev->ops; + struct dma_slave_config *config; unsigned long flags; - - /* Only supports DMA_TERMINATE_ALL */ - if (cmd != DMA_TERMINATE_ALL) - return -ENXIO; + int ret; if (!chan) return -EINVAL; - spin_lock_irqsave(&schan->chan_lock, flags); - - ops->halt_channel(schan); - - spin_unlock_irqrestore(&schan->chan_lock, flags); + switch (cmd) { + case DMA_TERMINATE_ALL: + spin_lock_irqsave(&schan->chan_lock, flags); + ops->halt_channel(schan); + spin_unlock_irqrestore(&schan->chan_lock, flags); - shdma_chan_ld_cleanup(schan, true); + shdma_chan_ld_cleanup(schan, true); + break; + case DMA_SLAVE_CONFIG: + /* + * So far only .slave_id is used, but the slave drivers are + * encouraged to also set a transfer direction and an address. + */ + if (!arg) + return -EINVAL; + /* + * We could lock this, but you shouldn't be configuring the + * channel, while using it... + */ + config = (struct dma_slave_config *)arg; + ret = shdma_setup_slave(schan, config->slave_id); + if (ret < 0) + return ret; + break; + default: + return -ENXIO; + } return 0; } diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c index 9a10d8bbdef2..027c9be97654 100644 --- a/drivers/dma/sh/shdma.c +++ b/drivers/dma/sh/shdma.c @@ -320,7 +320,7 @@ static const struct sh_dmae_slave_config *dmae_find_slave( } static int sh_dmae_set_slave(struct shdma_chan *schan, - int slave_id) + int slave_id, bool try) { struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan, shdma_chan); @@ -328,7 +328,8 @@ static int sh_dmae_set_slave(struct shdma_chan *schan, if (!cfg) return -ENODEV; - sh_chan->config = cfg; + if (!try) + sh_chan->config = cfg; return 0; } |