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部分内核源码：
static void *pl330_request_channel(const struct pl330_info *pi)
{
struct pl330_thread *thrd = NULL;
struct pl330_dmac *pl330;
unsigned long flags;
int chans, i;
if (!pi || !pi->pl330_data)
return NULL;
pl330 = pi->pl330_data;
if (pl330->state == DYING)
return NULL;
chans = pi->pcfg.num_chan;
spin_lock_irqsave(&pl330->lock, flags);
for (i = 0; i < chans; i++) {
thrd = &pl330->channels[i];
if ((thrd->free) && (!_manager_ns(thrd) ||
_chan_ns(pi, i))) {
thrd->ev = _alloc_event(thrd);
if (thrd->ev >= 0) {
thrd->free = false;
thrd->lstenq = 1;
thrd->req[0].r = NULL;
mark_free(thrd, 0);
thrd->req[1].r = NULL;
mark_free(thrd, 1);
break;
}
}
thrd = NULL;
}
spin_unlock_irqrestore(&pl330->lock, flags);
pm_runtime_get_sync(pl330->pinfo->dev);
return thrd;
}
static void pl330_release_channel(void *ch_id)
{
struct pl330_thread *thrd = ch_id;
struct pl330_dmac *pl330;
unsigned long flags;
if (!thrd || thrd->free)
return;
_stop(thrd);
_callback(thrd->req[1 - thrd->lstenq].r, PL330_ERR_ABORT);
_callback(thrd->req[thrd->lstenq].r, PL330_ERR_ABORT);
pl330 = thrd->dmac;
spin_lock_irqsave(&pl330->lock, flags);
_free_event(thrd, thrd->ev);
thrd->free = true;
spin_unlock_irqrestore(&pl330->lock, flags);
pm_runtime_put(pl330->pinfo->dev);
}
static int __devinit
pl330_probe(struct amba_device *adev, const struct amba_id *id)
{
struct dma_pl330_platdata *pdat;
struct dma_pl330_dmac *pdmac;
struct dma_pl330_chan *pch;
struct pl330_info *pi;
struct dma_device *pd;
struct resource *res;
int i, ret, irq;
int num_chan;
pdat = adev->dev.platform_data;
/* Allocate a new DMAC and its Channels */
pdmac = kzalloc(sizeof(*pdmac), GFP_KERNEL);
if (!pdmac) {
dev_err(&adev->dev, "unable to allocate mem\n");
return -ENOMEM;
}
pi = &pdmac->pif;
pi->dev = &adev->dev;
pi->pl330_data = NULL;
pi->mcbufsz = pdat ? pdat->mcbuf_sz : 0;
res = &adev->res;
request_mem_region(res->start, resource_size(res), "dma-pl330");
pi->base = ioremap(res->start, resource_size(res));
if (!pi->base) {
ret = -ENXIO;
goto probe_err1;
}
pdmac->clk = clk_get(&adev->dev, "dma");
if (IS_ERR(pdmac->clk)) {
dev_err(&adev->dev, "Cannot get operation clock.\n");
ret = -EINVAL;
goto probe_err2;
}
amba_set_drvdata(adev, pdmac);
#ifndef CONFIG_PM_RUNTIME
/* enable dma clk */
clk_enable(pdmac->clk);
#endif
irq = adev->irq[0];
ret = request_irq(irq, pl330_irq_handler, 0,
dev_name(&adev->dev), pi);
if (ret)
goto probe_err3;
ret = pl330_add(pi);
if (ret)
goto probe_err4;
INIT_LIST_HEAD(&pdmac->desc_pool);
spin_lock_init(&pdmac->pool_lock);
/* Create a descriptor pool of default size */
if (!add_desc(pdmac, GFP_KERNEL, NR_DEFAULT_DESC))
dev_warn(&adev->dev, "unable to allocate desc\n");
pd = &pdmac->ddma;
INIT_LIST_HEAD(&pd->channels);
/* Initialize channel parameters */
if (pdat)
num_chan = max_t(int, pdat->nr_valid_peri, pi->pcfg.num_chan);
else
num_chan = max_t(int, pi->pcfg.num_peri, pi->pcfg.num_chan);
pdmac->peripherals = kzalloc(num_chan * sizeof(*pch), GFP_KERNEL);
for (i = 0; i < num_chan; i++) {
pch = &pdmac->peripherals[i];
if (!adev->dev.of_node)
pch->chan.private = pdat ? &pdat->peri_id[i] : NULL;
else
pch->chan.private = adev->dev.of_node;
INIT_LIST_HEAD(&pch->work_list);
spin_lock_init(&pch->lock);
pch->pl330_chid = NULL;
pch->chan.device = pd;
pch->dmac = pdmac;
/* Add the channel to the DMAC list */
list_add_tail(&pch->chan.device_node, &pd->channels);
}
pd->dev = &adev->dev;
if (pdat) {
pd->cap_mask = pdat->cap_mask;
} else {
dma_cap_set(DMA_MEMCPY, pd->cap_mask);
if (pi->pcfg.num_peri) {
dma_cap_set(DMA_SLAVE, pd->cap_mask);
dma_cap_set(DMA_CYCLIC, pd->cap_mask);
}
}
pd->device_alloc_chan_resources = pl330_alloc_chan_resources;
pd->device_free_chan_resources = pl330_free_chan_resources;
pd->device_prep_dma_memcpy = pl330_prep_dma_memcpy;
pd->device_prep_dma_cyclic = pl330_prep_dma_cyclic;
pd->device_tx_status = pl330_tx_status;
pd->device_prep_slave_sg = pl330_prep_slave_sg;
pd->device_control = pl330_control;
pd->device_issue_pending = pl330_issue_pending;
ret = dma_async_device_register(pd);
if (ret) {
dev_err(&adev->dev, "unable to register DMAC\n");
goto probe_err5;
}
dev_info(&adev->dev,
"Loaded driver for PL330 DMAC-%d\n", adev->periphid);
dev_info(&adev->dev,
"\tDBUFF-%ux%ubytes Num_Chans-%u Num_Peri-%u Num_Events-%u\n",
pi->pcfg.data_buf_dep,
pi->pcfg.data_bus_width / 8, pi->pcfg.num_chan,
pi->pcfg.num_peri, pi->pcfg.num_events);
pm_runtime_put(&adev->dev);
return 0;
probe_err5:
pl330_del(pi);
probe_err4:
free_irq(irq, pi);
probe_err3:
#ifndef CONFIG_PM_RUNTIME
clk_disable(pdmac->clk);
#endif
clk_put(pdmac->clk);
probe_err2:
iounmap(pi->base);
probe_err1:
release_mem_region(res->start, resource_size(res));
kfree(pdmac);
return ret;
}
这些都是没有屏蔽的。 |
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发表于 2015-06-05 16:47
