in dw/core.c [1068:1277]
int do_dma_probe(struct dw_dma_chip *chip)
{
struct dw_dma *dw = chip->dw;
struct dw_dma_platform_data *pdata;
bool autocfg = false;
unsigned int dw_params;
unsigned int i;
int err;
dw->pdata = devm_kzalloc(chip->dev, sizeof(*dw->pdata), GFP_KERNEL);
if (!dw->pdata)
return -ENOMEM;
dw->regs = chip->regs;
pm_runtime_get_sync(chip->dev);
if (!chip->pdata) {
dw_params = dma_readl(dw, DW_PARAMS);
dev_dbg(chip->dev, "DW_PARAMS: 0x%08x\n", dw_params);
autocfg = dw_params >> DW_PARAMS_EN & 1;
if (!autocfg) {
err = -EINVAL;
goto err_pdata;
}
/* Reassign the platform data pointer */
pdata = dw->pdata;
/* Get hardware configuration parameters */
pdata->nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 7) + 1;
pdata->nr_masters = (dw_params >> DW_PARAMS_NR_MASTER & 3) + 1;
for (i = 0; i < pdata->nr_masters; i++) {
pdata->data_width[i] =
4 << (dw_params >> DW_PARAMS_DATA_WIDTH(i) & 3);
}
pdata->block_size = dma_readl(dw, MAX_BLK_SIZE);
/* Fill platform data with the default values */
pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
} else if (chip->pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
err = -EINVAL;
goto err_pdata;
} else {
memcpy(dw->pdata, chip->pdata, sizeof(*dw->pdata));
/* Reassign the platform data pointer */
pdata = dw->pdata;
}
dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
GFP_KERNEL);
if (!dw->chan) {
err = -ENOMEM;
goto err_pdata;
}
/* Calculate all channel mask before DMA setup */
dw->all_chan_mask = (1 << pdata->nr_channels) - 1;
/* Force dma off, just in case */
dw->disable(dw);
/* Device and instance ID for IRQ and DMA pool */
dw->set_device_name(dw, chip->id);
/* Create a pool of consistent memory blocks for hardware descriptors */
dw->desc_pool = dmam_pool_create(dw->name, chip->dev,
sizeof(struct dw_desc), 4, 0);
if (!dw->desc_pool) {
dev_err(chip->dev, "No memory for descriptors dma pool\n");
err = -ENOMEM;
goto err_pdata;
}
tasklet_setup(&dw->tasklet, dw_dma_tasklet);
err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
dw->name, dw);
if (err)
goto err_pdata;
INIT_LIST_HEAD(&dw->dma.channels);
for (i = 0; i < pdata->nr_channels; i++) {
struct dw_dma_chan *dwc = &dw->chan[i];
dwc->chan.device = &dw->dma;
dma_cookie_init(&dwc->chan);
if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
list_add_tail(&dwc->chan.device_node,
&dw->dma.channels);
else
list_add(&dwc->chan.device_node, &dw->dma.channels);
/* 7 is highest priority & 0 is lowest. */
if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
dwc->priority = pdata->nr_channels - i - 1;
else
dwc->priority = i;
dwc->ch_regs = &__dw_regs(dw)->CHAN[i];
spin_lock_init(&dwc->lock);
dwc->mask = 1 << i;
INIT_LIST_HEAD(&dwc->active_list);
INIT_LIST_HEAD(&dwc->queue);
channel_clear_bit(dw, CH_EN, dwc->mask);
dwc->direction = DMA_TRANS_NONE;
/* Hardware configuration */
if (autocfg) {
unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
void __iomem *addr = &__dw_regs(dw)->DWC_PARAMS[r];
unsigned int dwc_params = readl(addr);
dev_dbg(chip->dev, "DWC_PARAMS[%d]: 0x%08x\n", i,
dwc_params);
/*
* Decode maximum block size for given channel. The
* stored 4 bit value represents blocks from 0x00 for 3
* up to 0x0a for 4095.
*/
dwc->block_size =
(4 << ((pdata->block_size >> 4 * i) & 0xf)) - 1;
/*
* According to the DW DMA databook the true scatter-
* gether LLPs aren't available if either multi-block
* config is disabled (CHx_MULTI_BLK_EN == 0) or the
* LLP register is hard-coded to zeros
* (CHx_HC_LLP == 1).
*/
dwc->nollp =
(dwc_params >> DWC_PARAMS_MBLK_EN & 0x1) == 0 ||
(dwc_params >> DWC_PARAMS_HC_LLP & 0x1) == 1;
dwc->max_burst =
(0x4 << (dwc_params >> DWC_PARAMS_MSIZE & 0x7));
} else {
dwc->block_size = pdata->block_size;
dwc->nollp = !pdata->multi_block[i];
dwc->max_burst = pdata->max_burst[i] ?: DW_DMA_MAX_BURST;
}
}
/* Clear all interrupts on all channels. */
dma_writel(dw, CLEAR.XFER, dw->all_chan_mask);
dma_writel(dw, CLEAR.BLOCK, dw->all_chan_mask);
dma_writel(dw, CLEAR.SRC_TRAN, dw->all_chan_mask);
dma_writel(dw, CLEAR.DST_TRAN, dw->all_chan_mask);
dma_writel(dw, CLEAR.ERROR, dw->all_chan_mask);
/* Set capabilities */
dma_cap_set(DMA_SLAVE, dw->dma.cap_mask);
dma_cap_set(DMA_PRIVATE, dw->dma.cap_mask);
dma_cap_set(DMA_MEMCPY, dw->dma.cap_mask);
dw->dma.dev = chip->dev;
dw->dma.device_alloc_chan_resources = dwc_alloc_chan_resources;
dw->dma.device_free_chan_resources = dwc_free_chan_resources;
dw->dma.device_prep_dma_memcpy = dwc_prep_dma_memcpy;
dw->dma.device_prep_slave_sg = dwc_prep_slave_sg;
dw->dma.device_caps = dwc_caps;
dw->dma.device_config = dwc_config;
dw->dma.device_pause = dwc_pause;
dw->dma.device_resume = dwc_resume;
dw->dma.device_terminate_all = dwc_terminate_all;
dw->dma.device_tx_status = dwc_tx_status;
dw->dma.device_issue_pending = dwc_issue_pending;
/* DMA capabilities */
dw->dma.min_burst = DW_DMA_MIN_BURST;
dw->dma.max_burst = DW_DMA_MAX_BURST;
dw->dma.src_addr_widths = DW_DMA_BUSWIDTHS;
dw->dma.dst_addr_widths = DW_DMA_BUSWIDTHS;
dw->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
BIT(DMA_MEM_TO_MEM);
dw->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
/*
* For now there is no hardware with non uniform maximum block size
* across all of the device channels, so we set the maximum segment
* size as the block size found for the very first channel.
*/
dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size);
err = dma_async_device_register(&dw->dma);
if (err)
goto err_dma_register;
dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
pdata->nr_channels);
pm_runtime_put_sync_suspend(chip->dev);
return 0;
err_dma_register:
free_irq(chip->irq, dw);
err_pdata:
pm_runtime_put_sync_suspend(chip->dev);
return err;
}