in sh/shdmac.c [668:885]
static int sh_dmae_probe(struct platform_device *pdev)
{
const enum dma_slave_buswidth widths =
DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES |
DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES |
DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES;
const struct sh_dmae_pdata *pdata;
unsigned long chan_flag[SH_DMAE_MAX_CHANNELS] = {};
int chan_irq[SH_DMAE_MAX_CHANNELS];
unsigned long irqflags = 0;
int err, errirq, i, irq_cnt = 0, irqres = 0, irq_cap = 0;
struct sh_dmae_device *shdev;
struct dma_device *dma_dev;
struct resource *chan, *dmars, *errirq_res, *chanirq_res;
if (pdev->dev.of_node)
pdata = of_device_get_match_data(&pdev->dev);
else
pdata = dev_get_platdata(&pdev->dev);
/* get platform data */
if (!pdata || !pdata->channel_num)
return -ENODEV;
chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
/* DMARS area is optional */
dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
/*
* IRQ resources:
* 1. there always must be at least one IRQ IO-resource. On SH4 it is
* the error IRQ, in which case it is the only IRQ in this resource:
* start == end. If it is the only IRQ resource, all channels also
* use the same IRQ.
* 2. DMA channel IRQ resources can be specified one per resource or in
* ranges (start != end)
* 3. iff all events (channels and, optionally, error) on this
* controller use the same IRQ, only one IRQ resource can be
* specified, otherwise there must be one IRQ per channel, even if
* some of them are equal
* 4. if all IRQs on this controller are equal or if some specific IRQs
* specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be
* requested with the IRQF_SHARED flag
*/
errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!chan || !errirq_res)
return -ENODEV;
shdev = devm_kzalloc(&pdev->dev, sizeof(struct sh_dmae_device),
GFP_KERNEL);
if (!shdev)
return -ENOMEM;
dma_dev = &shdev->shdma_dev.dma_dev;
shdev->chan_reg = devm_ioremap_resource(&pdev->dev, chan);
if (IS_ERR(shdev->chan_reg))
return PTR_ERR(shdev->chan_reg);
if (dmars) {
shdev->dmars = devm_ioremap_resource(&pdev->dev, dmars);
if (IS_ERR(shdev->dmars))
return PTR_ERR(shdev->dmars);
}
dma_dev->src_addr_widths = widths;
dma_dev->dst_addr_widths = widths;
dma_dev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
if (!pdata->slave_only)
dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
if (pdata->slave && pdata->slave_num)
dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
/* Default transfer size of 32 bytes requires 32-byte alignment */
dma_dev->copy_align = LOG2_DEFAULT_XFER_SIZE;
shdev->shdma_dev.ops = &sh_dmae_shdma_ops;
shdev->shdma_dev.desc_size = sizeof(struct sh_dmae_desc);
err = shdma_init(&pdev->dev, &shdev->shdma_dev,
pdata->channel_num);
if (err < 0)
goto eshdma;
/* platform data */
shdev->pdata = pdata;
if (pdata->chcr_offset)
shdev->chcr_offset = pdata->chcr_offset;
else
shdev->chcr_offset = CHCR;
if (pdata->chcr_ie_bit)
shdev->chcr_ie_bit = pdata->chcr_ie_bit;
else
shdev->chcr_ie_bit = CHCR_IE;
platform_set_drvdata(pdev, shdev);
pm_runtime_enable(&pdev->dev);
err = pm_runtime_get_sync(&pdev->dev);
if (err < 0)
dev_err(&pdev->dev, "%s(): GET = %d\n", __func__, err);
spin_lock_irq(&sh_dmae_lock);
list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
spin_unlock_irq(&sh_dmae_lock);
/* reset dma controller - only needed as a test */
err = sh_dmae_rst(shdev);
if (err)
goto rst_err;
if (IS_ENABLED(CONFIG_CPU_SH4) || IS_ENABLED(CONFIG_ARCH_RENESAS)) {
chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
if (!chanirq_res)
chanirq_res = errirq_res;
else
irqres++;
if (chanirq_res == errirq_res ||
(errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE)
irqflags = IRQF_SHARED;
errirq = errirq_res->start;
err = devm_request_irq(&pdev->dev, errirq, sh_dmae_err,
irqflags, "DMAC Address Error", shdev);
if (err) {
dev_err(&pdev->dev,
"DMA failed requesting irq #%d, error %d\n",
errirq, err);
goto eirq_err;
}
} else {
chanirq_res = errirq_res;
}
if (chanirq_res->start == chanirq_res->end &&
!platform_get_resource(pdev, IORESOURCE_IRQ, 1)) {
/* Special case - all multiplexed */
for (; irq_cnt < pdata->channel_num; irq_cnt++) {
if (irq_cnt < SH_DMAE_MAX_CHANNELS) {
chan_irq[irq_cnt] = chanirq_res->start;
chan_flag[irq_cnt] = IRQF_SHARED;
} else {
irq_cap = 1;
break;
}
}
} else {
do {
for (i = chanirq_res->start; i <= chanirq_res->end; i++) {
if (irq_cnt >= SH_DMAE_MAX_CHANNELS) {
irq_cap = 1;
break;
}
if ((errirq_res->flags & IORESOURCE_BITS) ==
IORESOURCE_IRQ_SHAREABLE)
chan_flag[irq_cnt] = IRQF_SHARED;
else
chan_flag[irq_cnt] = 0;
dev_dbg(&pdev->dev,
"Found IRQ %d for channel %d\n",
i, irq_cnt);
chan_irq[irq_cnt++] = i;
}
if (irq_cnt >= SH_DMAE_MAX_CHANNELS)
break;
chanirq_res = platform_get_resource(pdev,
IORESOURCE_IRQ, ++irqres);
} while (irq_cnt < pdata->channel_num && chanirq_res);
}
/* Create DMA Channel */
for (i = 0; i < irq_cnt; i++) {
err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]);
if (err)
goto chan_probe_err;
}
if (irq_cap)
dev_notice(&pdev->dev, "Attempting to register %d DMA "
"channels when a maximum of %d are supported.\n",
pdata->channel_num, SH_DMAE_MAX_CHANNELS);
pm_runtime_put(&pdev->dev);
err = dma_async_device_register(&shdev->shdma_dev.dma_dev);
if (err < 0)
goto edmadevreg;
return err;
edmadevreg:
pm_runtime_get(&pdev->dev);
chan_probe_err:
sh_dmae_chan_remove(shdev);
eirq_err:
rst_err:
spin_lock_irq(&sh_dmae_lock);
list_del_rcu(&shdev->node);
spin_unlock_irq(&sh_dmae_lock);
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
shdma_cleanup(&shdev->shdma_dev);
eshdma:
synchronize_rcu();
return err;
}