diff options
Diffstat (limited to 'drivers/dma/dw/dw.c')
| -rw-r--r-- | drivers/dma/dw/dw.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/dma/dw/dw.c b/drivers/dma/dw/dw.c new file mode 100644 index 000000000..a4862263f --- /dev/null +++ b/drivers/dma/dw/dw.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2007-2008 Atmel Corporation +// Copyright (C) 2010-2011 ST Microelectronics +// Copyright (C) 2013,2018 Intel Corporation + +#include <linux/bitops.h> +#include <linux/dmaengine.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/types.h> + +#include "internal.h" + +static void dw_dma_initialize_chan(struct dw_dma_chan *dwc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + u32 cfghi = is_slave_direction(dwc->direction) ? 0 : DWC_CFGH_FIFO_MODE; + u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority); + bool hs_polarity = dwc->dws.hs_polarity; + + cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id); + cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id); + cfghi |= DWC_CFGH_PROTCTL(dw->pdata->protctl); + + /* Set polarity of handshake interface */ + cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0; + + channel_writel(dwc, CFG_LO, cfglo); + channel_writel(dwc, CFG_HI, cfghi); +} + +static void dw_dma_suspend_chan(struct dw_dma_chan *dwc, bool drain) +{ + u32 cfglo = channel_readl(dwc, CFG_LO); + + channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP); +} + +static void dw_dma_resume_chan(struct dw_dma_chan *dwc, bool drain) +{ + u32 cfglo = channel_readl(dwc, CFG_LO); + + channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP); +} + +static u32 dw_dma_bytes2block(struct dw_dma_chan *dwc, + size_t bytes, unsigned int width, size_t *len) +{ + u32 block; + + if ((bytes >> width) > dwc->block_size) { + block = dwc->block_size; + *len = dwc->block_size << width; + } else { + block = bytes >> width; + *len = bytes; + } + + return block; +} + +static size_t dw_dma_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width) +{ + return DWC_CTLH_BLOCK_TS(block) << width; +} + +static u32 dw_dma_prepare_ctllo(struct dw_dma_chan *dwc) +{ + struct dma_slave_config *sconfig = &dwc->dma_sconfig; + u8 smsize = (dwc->direction == DMA_DEV_TO_MEM) ? sconfig->src_maxburst : 0; + u8 dmsize = (dwc->direction == DMA_MEM_TO_DEV) ? sconfig->dst_maxburst : 0; + u8 p_master = dwc->dws.p_master; + u8 m_master = dwc->dws.m_master; + u8 dms = (dwc->direction == DMA_MEM_TO_DEV) ? p_master : m_master; + u8 sms = (dwc->direction == DMA_DEV_TO_MEM) ? p_master : m_master; + + return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN | + DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize) | + DWC_CTLL_DMS(dms) | DWC_CTLL_SMS(sms); +} + +static void dw_dma_encode_maxburst(struct dw_dma_chan *dwc, u32 *maxburst) +{ + /* + * Fix burst size according to dw_dmac. We need to convert them as: + * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3. + */ + *maxburst = *maxburst > 1 ? fls(*maxburst) - 2 : 0; +} + +static void dw_dma_set_device_name(struct dw_dma *dw, int id) +{ + snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", id); +} + +static void dw_dma_disable(struct dw_dma *dw) +{ + do_dw_dma_off(dw); +} + +static void dw_dma_enable(struct dw_dma *dw) +{ + do_dw_dma_on(dw); +} + +int dw_dma_probe(struct dw_dma_chip *chip) +{ + struct dw_dma *dw; + + dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL); + if (!dw) + return -ENOMEM; + + /* Channel operations */ + dw->initialize_chan = dw_dma_initialize_chan; + dw->suspend_chan = dw_dma_suspend_chan; + dw->resume_chan = dw_dma_resume_chan; + dw->prepare_ctllo = dw_dma_prepare_ctllo; + dw->encode_maxburst = dw_dma_encode_maxburst; + dw->bytes2block = dw_dma_bytes2block; + dw->block2bytes = dw_dma_block2bytes; + + /* Device operations */ + dw->set_device_name = dw_dma_set_device_name; + dw->disable = dw_dma_disable; + dw->enable = dw_dma_enable; + + chip->dw = dw; + return do_dma_probe(chip); +} +EXPORT_SYMBOL_GPL(dw_dma_probe); + +int dw_dma_remove(struct dw_dma_chip *chip) +{ + return do_dma_remove(chip); +} +EXPORT_SYMBOL_GPL(dw_dma_remove); |