diff options
| -rw-r--r-- | drivers/dma/ti/edma.c | 59 |
1 files changed, 53 insertions, 6 deletions
diff --git a/drivers/dma/ti/edma.c b/drivers/dma/ti/edma.c index 54fd981e3db5..0ecfc2e1d798 100644 --- a/drivers/dma/ti/edma.c +++ b/drivers/dma/ti/edma.c @@ -260,6 +260,13 @@ struct edma_cc { */ unsigned long *slot_inuse; + /* + * For tracking reserved channels used by DSP. + * If the bit is cleared, the channel is allocated to be used by DSP + * and Linux must not touch it. + */ + unsigned long *channels_mask; + struct dma_device dma_slave; struct dma_device *dma_memcpy; struct edma_chan *slave_chans; @@ -716,6 +723,12 @@ static int edma_alloc_channel(struct edma_chan *echan, struct edma_cc *ecc = echan->ecc; int channel = EDMA_CHAN_SLOT(echan->ch_num); + if (!test_bit(echan->ch_num, ecc->channels_mask)) { + dev_err(ecc->dev, "Channel%d is reserved, can not be used!\n", + echan->ch_num); + return -EINVAL; + } + /* ensure access through shadow region 0 */ edma_or_array2(ecc, EDMA_DRAE, 0, EDMA_REG_ARRAY_INDEX(channel), EDMA_CHANNEL_BIT(channel)); @@ -2249,7 +2262,7 @@ static int edma_probe(struct platform_device *pdev) { struct edma_soc_info *info = pdev->dev.platform_data; s8 (*queue_priority_mapping)[2]; - const s16 (*rsv_slots)[2]; + const s16 (*reserved)[2]; int i, irq; char *irq_name; struct resource *mem; @@ -2329,15 +2342,32 @@ static int edma_probe(struct platform_device *pdev) if (!ecc->slot_inuse) return -ENOMEM; + ecc->channels_mask = devm_kcalloc(dev, + BITS_TO_LONGS(ecc->num_channels), + sizeof(unsigned long), GFP_KERNEL); + if (!ecc->channels_mask) + return -ENOMEM; + + /* Mark all channels available initially */ + bitmap_fill(ecc->channels_mask, ecc->num_channels); + ecc->default_queue = info->default_queue; if (info->rsv) { /* Set the reserved slots in inuse list */ - rsv_slots = info->rsv->rsv_slots; - if (rsv_slots) { - for (i = 0; rsv_slots[i][0] != -1; i++) - bitmap_set(ecc->slot_inuse, rsv_slots[i][0], - rsv_slots[i][1]); + reserved = info->rsv->rsv_slots; + if (reserved) { + for (i = 0; reserved[i][0] != -1; i++) + bitmap_set(ecc->slot_inuse, reserved[i][0], + reserved[i][1]); + } + + /* Clear channels not usable for Linux */ + reserved = info->rsv->rsv_chans; + if (reserved) { + for (i = 0; reserved[i][0] != -1; i++) + bitmap_clear(ecc->channels_mask, reserved[i][0], + reserved[i][1]); } } @@ -2389,6 +2419,7 @@ static int edma_probe(struct platform_device *pdev) if (!ecc->legacy_mode) { int lowest_priority = 0; + unsigned int array_max; struct of_phandle_args tc_args; ecc->tc_list = devm_kcalloc(dev, ecc->num_tc, @@ -2410,6 +2441,18 @@ static int edma_probe(struct platform_device *pdev) info->default_queue = i; } } + + /* See if we have optional dma-channel-mask array */ + array_max = DIV_ROUND_UP(ecc->num_channels, BITS_PER_TYPE(u32)); + ret = of_property_read_variable_u32_array(node, + "dma-channel-mask", + (u32 *)ecc->channels_mask, + 1, array_max); + if (ret > 0 && ret != array_max) + dev_warn(dev, "dma-channel-mask is not complete.\n"); + else if (ret == -EOVERFLOW || ret == -ENODATA) + dev_warn(dev, + "dma-channel-mask is out of range or empty\n"); } /* Event queue priority mapping */ @@ -2427,6 +2470,10 @@ static int edma_probe(struct platform_device *pdev) edma_dma_init(ecc, legacy_mode); for (i = 0; i < ecc->num_channels; i++) { + /* Do not touch reserved channels */ + if (!test_bit(i, ecc->channels_mask)) + continue; + /* Assign all channels to the default queue */ edma_assign_channel_eventq(&ecc->slave_chans[i], info->default_queue); |