WSL2-Linux-Kernel/drivers/dma/dw/dw.c

138 строки
3.6 KiB
C

// 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);