LXR linux/drivers/dma/dw/dw.c

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (C) 2007-2008 Atmel Corporation
   3// Copyright (C) 2010-2011 ST Microelectronics
   4// Copyright (C) 2013,2018 Intel Corporation
   5
   6#include <linux/bitops.h>
   7#include <linux/dmaengine.h>
   8#include <linux/errno.h>
   9#include <linux/slab.h>
  10#include <linux/types.h>
  11
  12#include "internal.h"
  13
  14static void dw_dma_initialize_chan(struct dw_dma_chan *dwc)
  15{
  16        struct dw_dma *dw = to_dw_dma(dwc->chan.device);
  17        u32 cfghi = is_slave_direction(dwc->direction) ? 0 : DWC_CFGH_FIFO_MODE;
  18        u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
  19        bool hs_polarity = dwc->dws.hs_polarity;
  20
  21        cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
  22        cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
  23        cfghi |= DWC_CFGH_PROTCTL(dw->pdata->protctl);
  24
  25        /* Set polarity of handshake interface */
  26        cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
  27
  28        channel_writel(dwc, CFG_LO, cfglo);
  29        channel_writel(dwc, CFG_HI, cfghi);
  30}
  31
  32static void dw_dma_suspend_chan(struct dw_dma_chan *dwc, bool drain)
  33{
  34        u32 cfglo = channel_readl(dwc, CFG_LO);
  35
  36        channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
  37}
  38
  39static void dw_dma_resume_chan(struct dw_dma_chan *dwc, bool drain)
  40{
  41        u32 cfglo = channel_readl(dwc, CFG_LO);
  42
  43        channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
  44}
  45
  46static u32 dw_dma_bytes2block(struct dw_dma_chan *dwc,
  47                              size_t bytes, unsigned int width, size_t *len)
  48{
  49        u32 block;
  50
  51        if ((bytes >> width) > dwc->block_size) {
  52                block = dwc->block_size;
  53                *len = dwc->block_size << width;
  54        } else {
  55                block = bytes >> width;
  56                *len = bytes;
  57        }
  58
  59        return block;
  60}
  61
  62static size_t dw_dma_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
  63{
  64        return DWC_CTLH_BLOCK_TS(block) << width;
  65}
  66
  67static u32 dw_dma_prepare_ctllo(struct dw_dma_chan *dwc)
  68{
  69        struct dma_slave_config *sconfig = &dwc->dma_sconfig;
  70        u8 smsize = (dwc->direction == DMA_DEV_TO_MEM) ? sconfig->src_maxburst : 0;
  71        u8 dmsize = (dwc->direction == DMA_MEM_TO_DEV) ? sconfig->dst_maxburst : 0;
  72        u8 p_master = dwc->dws.p_master;
  73        u8 m_master = dwc->dws.m_master;
  74        u8 dms = (dwc->direction == DMA_MEM_TO_DEV) ? p_master : m_master;
  75        u8 sms = (dwc->direction == DMA_DEV_TO_MEM) ? p_master : m_master;
  76
  77        return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
  78               DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize) |
  79               DWC_CTLL_DMS(dms) | DWC_CTLL_SMS(sms);
  80}
  81
  82static void dw_dma_encode_maxburst(struct dw_dma_chan *dwc, u32 *maxburst)
  83{
  84        /*
  85         * Fix burst size according to dw_dmac. We need to convert them as:
  86         * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
  87         */
  88        *maxburst = *maxburst > 1 ? fls(*maxburst) - 2 : 0;
  89}
  90
  91static void dw_dma_set_device_name(struct dw_dma *dw, int id)
  92{
  93        snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", id);
  94}
  95
  96static void dw_dma_disable(struct dw_dma *dw)
  97{
  98        do_dw_dma_off(dw);
  99}
 100
 101static void dw_dma_enable(struct dw_dma *dw)
 102{
 103        do_dw_dma_on(dw);
 104}
 105
 106int dw_dma_probe(struct dw_dma_chip *chip)
 107{
 108        struct dw_dma *dw;
 109
 110        dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
 111        if (!dw)
 112                return -ENOMEM;
 113
 114        /* Channel operations */
 115        dw->initialize_chan = dw_dma_initialize_chan;
 116        dw->suspend_chan = dw_dma_suspend_chan;
 117        dw->resume_chan = dw_dma_resume_chan;
 118        dw->prepare_ctllo = dw_dma_prepare_ctllo;
 119        dw->encode_maxburst = dw_dma_encode_maxburst;
 120        dw->bytes2block = dw_dma_bytes2block;
 121        dw->block2bytes = dw_dma_block2bytes;
 122
 123        /* Device operations */
 124        dw->set_device_name = dw_dma_set_device_name;
 125        dw->disable = dw_dma_disable;
 126        dw->enable = dw_dma_enable;
 127
 128        chip->dw = dw;
 129        return do_dma_probe(chip);
 130}
 131EXPORT_SYMBOL_GPL(dw_dma_probe);
 132
 133int dw_dma_remove(struct dw_dma_chip *chip)
 134{
 135        return do_dma_remove(chip);
 136}
 137EXPORT_SYMBOL_GPL(dw_dma_remove);
 138