diff options
Diffstat (limited to 'arch/blackfin/kernel/bfin_dma_5xx.c')
| -rw-r--r-- | arch/blackfin/kernel/bfin_dma_5xx.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c index 8531693fb48d..763ed84ba459 100644 --- a/arch/blackfin/kernel/bfin_dma_5xx.c +++ b/arch/blackfin/kernel/bfin_dma_5xx.c @@ -20,6 +20,11 @@ #include <asm/dma.h> #include <asm/uaccess.h> +/* + * To make sure we work around 05000119 - we always check DMA_DONE bit, + * never the DMA_RUN bit + */ + struct dma_channel dma_ch[MAX_DMA_CHANNELS]; EXPORT_SYMBOL(dma_ch); @@ -232,6 +237,87 @@ void blackfin_dma_resume(void) void __init blackfin_dma_early_init(void) { bfin_write_MDMA_S0_CONFIG(0); + bfin_write_MDMA_S1_CONFIG(0); +} + +void __init early_dma_memcpy(void *pdst, const void *psrc, size_t size) +{ + unsigned long dst = (unsigned long)pdst; + unsigned long src = (unsigned long)psrc; + struct dma_register *dst_ch, *src_ch; + + /* We assume that everything is 4 byte aligned, so include + * a basic sanity check + */ + BUG_ON(dst % 4); + BUG_ON(src % 4); + BUG_ON(size % 4); + + /* Force a sync in case a previous config reset on this channel + * occurred. This is needed so subsequent writes to DMA registers + * are not spuriously lost/corrupted. + */ + __builtin_bfin_ssync(); + + src_ch = 0; + /* Find an avalible memDMA channel */ + while (1) { + if (!src_ch || src_ch == (struct dma_register *)MDMA_S1_NEXT_DESC_PTR) { + dst_ch = (struct dma_register *)MDMA_D0_NEXT_DESC_PTR; + src_ch = (struct dma_register *)MDMA_S0_NEXT_DESC_PTR; + } else { + dst_ch = (struct dma_register *)MDMA_D1_NEXT_DESC_PTR; + src_ch = (struct dma_register *)MDMA_S1_NEXT_DESC_PTR; + } + + if (!bfin_read16(&src_ch->cfg)) { + break; + } else { + if (bfin_read16(&src_ch->irq_status) & DMA_DONE) + bfin_write16(&src_ch->cfg, 0); + } + + } + + /* Destination */ + bfin_write32(&dst_ch->start_addr, dst); + bfin_write16(&dst_ch->x_count, size >> 2); + bfin_write16(&dst_ch->x_modify, 1 << 2); + bfin_write16(&dst_ch->irq_status, DMA_DONE | DMA_ERR); + + /* Source */ + bfin_write32(&src_ch->start_addr, src); + bfin_write16(&src_ch->x_count, size >> 2); + bfin_write16(&src_ch->x_modify, 1 << 2); + bfin_write16(&src_ch->irq_status, DMA_DONE | DMA_ERR); + + /* Enable */ + bfin_write16(&src_ch->cfg, DMAEN | WDSIZE_32); + bfin_write16(&dst_ch->cfg, WNR | DI_EN | DMAEN | WDSIZE_32); + + /* Since we are atomic now, don't use the workaround ssync */ + __builtin_bfin_ssync(); +} + +void __init early_dma_memcpy_done(void) +{ + while ((bfin_read_MDMA_S0_CONFIG() && !(bfin_read_MDMA_D0_IRQ_STATUS() & DMA_DONE)) || + (bfin_read_MDMA_S1_CONFIG() && !(bfin_read_MDMA_D1_IRQ_STATUS() & DMA_DONE))) + continue; + + bfin_write_MDMA_D0_IRQ_STATUS(DMA_DONE | DMA_ERR); + bfin_write_MDMA_D1_IRQ_STATUS(DMA_DONE | DMA_ERR); + /* + * Now that DMA is done, we would normally flush cache, but + * i/d cache isn't running this early, so we don't bother, + * and just clear out the DMA channel for next time + */ + bfin_write_MDMA_S0_CONFIG(0); + bfin_write_MDMA_S1_CONFIG(0); + bfin_write_MDMA_D0_CONFIG(0); + bfin_write_MDMA_D1_CONFIG(0); + + __builtin_bfin_ssync(); } /** |