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Diffstat (limited to 'arch/arm/mach-davinci/dma.c')
-rw-r--r--arch/arm/mach-davinci/dma.c67
1 files changed, 51 insertions, 16 deletions
diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c
index 648fbb760ae..15dd886df04 100644
--- a/arch/arm/mach-davinci/dma.c
+++ b/arch/arm/mach-davinci/dma.c
@@ -226,11 +226,11 @@ struct edma {
*/
DECLARE_BITMAP(edma_inuse, EDMA_MAX_PARAMENTRY);
- /* The edma_noevent bit for each channel is clear unless
- * it doesn't trigger DMA events on this platform. It uses a
- * bit of SOC-specific initialization code.
+ /* The edma_unused bit for each channel is clear unless
+ * it is not being used on this platform. It uses a bit
+ * of SOC-specific initialization code.
*/
- DECLARE_BITMAP(edma_noevent, EDMA_MAX_DMACH);
+ DECLARE_BITMAP(edma_unused, EDMA_MAX_DMACH);
unsigned irq_res_start;
unsigned irq_res_end;
@@ -243,6 +243,7 @@ struct edma {
};
static struct edma *edma_info[EDMA_MAX_CC];
+static int arch_num_cc;
/* dummy param set used to (re)initialize parameter RAM slots */
static const struct edmacc_param dummy_paramset = {
@@ -555,8 +556,27 @@ static int reserve_contiguous_slots(int ctlr, unsigned int id,
return EDMA_CTLR_CHAN(ctlr, i - num_slots + 1);
}
+static int prepare_unused_channel_list(struct device *dev, void *data)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ int i, ctlr;
+
+ for (i = 0; i < pdev->num_resources; i++) {
+ if ((pdev->resource[i].flags & IORESOURCE_DMA) &&
+ (int)pdev->resource[i].start >= 0) {
+ ctlr = EDMA_CTLR(pdev->resource[i].start);
+ clear_bit(EDMA_CHAN_SLOT(pdev->resource[i].start),
+ edma_info[ctlr]->edma_unused);
+ }
+ }
+
+ return 0;
+}
+
/*-----------------------------------------------------------------------*/
+static bool unused_chan_list_done;
+
/* Resource alloc/free: dma channels, parameter RAM slots */
/**
@@ -594,7 +614,22 @@ int edma_alloc_channel(int channel,
void *data,
enum dma_event_q eventq_no)
{
- unsigned i, done, ctlr = 0;
+ unsigned i, done = 0, ctlr = 0;
+ int ret = 0;
+
+ if (!unused_chan_list_done) {
+ /*
+ * Scan all the platform devices to find out the EDMA channels
+ * used and clear them in the unused list, making the rest
+ * available for ARM usage.
+ */
+ ret = bus_for_each_dev(&platform_bus_type, NULL, NULL,
+ prepare_unused_channel_list);
+ if (ret < 0)
+ return ret;
+
+ unused_chan_list_done = true;
+ }
if (channel >= 0) {
ctlr = EDMA_CTLR(channel);
@@ -602,15 +637,15 @@ int edma_alloc_channel(int channel,
}
if (channel < 0) {
- for (i = 0; i < EDMA_MAX_CC; i++) {
+ for (i = 0; i < arch_num_cc; i++) {
channel = 0;
for (;;) {
channel = find_next_bit(edma_info[i]->
- edma_noevent,
+ edma_unused,
edma_info[i]->num_channels,
channel);
if (channel == edma_info[i]->num_channels)
- return -ENOMEM;
+ break;
if (!test_and_set_bit(channel,
edma_info[i]->edma_inuse)) {
done = 1;
@@ -622,6 +657,8 @@ int edma_alloc_channel(int channel,
if (done)
break;
}
+ if (!done)
+ return -ENOMEM;
} else if (channel >= edma_info[ctlr]->num_channels) {
return -EINVAL;
} else if (test_and_set_bit(channel, edma_info[ctlr]->edma_inuse)) {
@@ -642,7 +679,7 @@ int edma_alloc_channel(int channel,
map_dmach_queue(ctlr, channel, eventq_no);
- return channel;
+ return EDMA_CTLR_CHAN(ctlr, channel);
}
EXPORT_SYMBOL(edma_alloc_channel);
@@ -1219,7 +1256,7 @@ int edma_start(unsigned channel)
unsigned int mask = (1 << (channel & 0x1f));
/* EDMA channels without event association */
- if (test_bit(channel, edma_info[ctlr]->edma_noevent)) {
+ if (test_bit(channel, edma_info[ctlr]->edma_unused)) {
pr_debug("EDMA: ESR%d %08x\n", j,
edma_shadow0_read_array(ctlr, SH_ESR, j));
edma_shadow0_write_array(ctlr, SH_ESR, j, mask);
@@ -1344,7 +1381,6 @@ static int __init edma_probe(struct platform_device *pdev)
const s8 (*queue_tc_mapping)[2];
int i, j, found = 0;
int status = -1;
- const s8 *noevent;
int irq[EDMA_MAX_CC] = {0, 0};
int err_irq[EDMA_MAX_CC] = {0, 0};
struct resource *r[EDMA_MAX_CC] = {NULL};
@@ -1407,11 +1443,9 @@ static int __init edma_probe(struct platform_device *pdev)
memcpy_toio(edmacc_regs_base[j] + PARM_OFFSET(i),
&dummy_paramset, PARM_SIZE);
- noevent = info[j].noevent;
- if (noevent) {
- while (*noevent != -1)
- set_bit(*noevent++, edma_info[j]->edma_noevent);
- }
+ /* Mark all channels as unused */
+ memset(edma_info[j]->edma_unused, 0xff,
+ sizeof(edma_info[j]->edma_unused));
sprintf(irq_name, "edma%d", j);
irq[j] = platform_get_irq_byname(pdev, irq_name);
@@ -1467,6 +1501,7 @@ static int __init edma_probe(struct platform_device *pdev)
edma_write_array2(j, EDMA_DRAE, i, 1, 0x0);
edma_write_array(j, EDMA_QRAE, i, 0x0);
}
+ arch_num_cc++;
}
if (tc_errs_handled) {