diff options
Diffstat (limited to 'drivers/dma/sh/shdma-base.c')
| -rw-r--r-- | drivers/dma/sh/shdma-base.c | 73 |
1 files changed, 53 insertions, 20 deletions
diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index 8ee383d339a5..10fcabad80f3 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -171,8 +171,7 @@ 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, - dma_addr_t slave_addr) +static int shdma_setup_slave(struct shdma_chan *schan, dma_addr_t slave_addr) { struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); const struct shdma_ops *ops = sdev->ops; @@ -183,25 +182,23 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id, ret = ops->set_slave(schan, match, slave_addr, true); if (ret < 0) return ret; - - slave_id = schan->slave_id; } else { - match = slave_id; + match = schan->real_slave_id; } - if (slave_id < 0 || slave_id >= slave_num) + if (schan->real_slave_id < 0 || schan->real_slave_id >= slave_num) return -EINVAL; - if (test_and_set_bit(slave_id, shdma_slave_used)) + if (test_and_set_bit(schan->real_slave_id, shdma_slave_used)) return -EBUSY; ret = ops->set_slave(schan, match, slave_addr, false); if (ret < 0) { - clear_bit(slave_id, shdma_slave_used); + clear_bit(schan->real_slave_id, shdma_slave_used); return ret; } - schan->slave_id = slave_id; + schan->slave_id = schan->real_slave_id; return 0; } @@ -221,10 +218,12 @@ static int shdma_alloc_chan_resources(struct dma_chan *chan) */ if (slave) { /* Legacy mode: .private is set in filter */ - ret = shdma_setup_slave(schan, slave->slave_id, 0); + schan->real_slave_id = slave->slave_id; + ret = shdma_setup_slave(schan, 0); if (ret < 0) goto esetslave; } else { + /* Normal mode: real_slave_id was set by filter */ schan->slave_id = -EINVAL; } @@ -258,11 +257,14 @@ esetslave: /* * 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 + * "old" method, using the .private pointer. + * You always have to pass a valid slave id as the argument, old drivers that + * pass ERR_PTR(-EINVAL) as a filter parameter and set it up in dma_slave_config + * need to be updated so we can remove the slave_id field from dma_slave_config. * 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. + * .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 @@ -276,7 +278,7 @@ bool shdma_chan_filter(struct dma_chan *chan, void *arg) { struct shdma_chan *schan; struct shdma_dev *sdev; - int match = (long)arg; + int slave_id = (long)arg; int ret; /* Only support channels handled by this driver. */ @@ -284,19 +286,39 @@ bool shdma_chan_filter(struct dma_chan *chan, void *arg) shdma_alloc_chan_resources) return false; - if (match < 0) + schan = to_shdma_chan(chan); + sdev = to_shdma_dev(chan->device); + + /* + * For DT, the schan->slave_id field is generated by the + * set_slave function from the slave ID that is passed in + * from xlate. For the non-DT case, the slave ID is + * directly passed into the filter function by the driver + */ + if (schan->dev->of_node) { + ret = sdev->ops->set_slave(schan, slave_id, 0, true); + if (ret < 0) + return false; + + schan->real_slave_id = schan->slave_id; + return true; + } + + if (slave_id < 0) { /* No slave requested - arbitrary channel */ + dev_warn(sdev->dma_dev.dev, "invalid slave ID passed to dma_request_slave\n"); return true; + } - schan = to_shdma_chan(chan); - if (!schan->dev->of_node && match >= slave_num) + if (slave_id >= slave_num) return false; - sdev = to_shdma_dev(schan->dma_chan.device); - ret = sdev->ops->set_slave(schan, match, 0, true); + ret = sdev->ops->set_slave(schan, slave_id, 0, true); if (ret < 0) return false; + schan->real_slave_id = slave_id; + return true; } EXPORT_SYMBOL(shdma_chan_filter); @@ -452,6 +474,8 @@ static void shdma_free_chan_resources(struct dma_chan *chan) chan->private = NULL; } + schan->real_slave_id = 0; + spin_lock_irq(&schan->chan_lock); list_splice_init(&schan->ld_free, &list); @@ -764,11 +788,20 @@ static int shdma_config(struct dma_chan *chan, */ if (!config) return -EINVAL; + + /* + * overriding the slave_id through dma_slave_config is deprecated, + * but possibly some out-of-tree drivers still do it. + */ + if (WARN_ON_ONCE(config->slave_id && + config->slave_id != schan->real_slave_id)) + schan->real_slave_id = config->slave_id; + /* * We could lock this, but you shouldn't be configuring the * channel, while using it... */ - return shdma_setup_slave(schan, config->slave_id, + return shdma_setup_slave(schan, config->direction == DMA_DEV_TO_MEM ? config->src_addr : config->dst_addr); } |