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
  14 static 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
  32 static 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
  39 static 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
  46 static 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
  62 static 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
  67 static inline u8 dw_dma_encode_maxburst(u32 maxburst)
  68 {
  69         /*
  70          * Fix burst size according to dw_dmac. We need to convert them as:
  71          * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
  72          */
  73         return maxburst > 1 ? fls(maxburst) - 2 : 0;
  74 }
  75
  76 static u32 dw_dma_prepare_ctllo(struct dw_dma_chan *dwc)
  77 {
  78         struct dma_slave_config *sconfig = &dwc->dma_sconfig;
  79         u8 smsize = 0, dmsize = 0;
  80         u8 sms, dms;
  81
  82         if (dwc->direction == DMA_MEM_TO_DEV) {
  83                 sms = dwc->dws.m_master;
  84                 dms = dwc->dws.p_master;
  85                 dmsize = dw_dma_encode_maxburst(sconfig->dst_maxburst);
  86         } else if (dwc->direction == DMA_DEV_TO_MEM) {
  87                 sms = dwc->dws.p_master;
  88                 dms = dwc->dws.m_master;
  89                 smsize = dw_dma_encode_maxburst(sconfig->src_maxburst);
  90         } else /* DMA_MEM_TO_MEM */ {
  91                 sms = dwc->dws.m_master;
  92                 dms = dwc->dws.m_master;
  93         }
  94
  95         return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
  96                DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize) |
  97                DWC_CTLL_DMS(dms) | DWC_CTLL_SMS(sms);
  98 }
  99
 100 static void dw_dma_set_device_name(struct dw_dma *dw, int id)
 101 {
 102         snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", id);
 103 }
 104
 105 static void dw_dma_disable(struct dw_dma *dw)
 106 {
 107         do_dw_dma_off(dw);
 108 }
 109
 110 static void dw_dma_enable(struct dw_dma *dw)
 111 {
 112         do_dw_dma_on(dw);
 113 }
 114
 115 int dw_dma_probe(struct dw_dma_chip *chip)
 116 {
 117         struct dw_dma *dw;
 118
 119         dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
 120         if (!dw)
 121                 return -ENOMEM;
 122
 123         /* Channel operations */
 124         dw->initialize_chan = dw_dma_initialize_chan;
 125         dw->suspend_chan = dw_dma_suspend_chan;
 126         dw->resume_chan = dw_dma_resume_chan;
 127         dw->prepare_ctllo = dw_dma_prepare_ctllo;
 128         dw->bytes2block = dw_dma_bytes2block;
 129         dw->block2bytes = dw_dma_block2bytes;
 130
 131         /* Device operations */
 132         dw->set_device_name = dw_dma_set_device_name;
 133         dw->disable = dw_dma_disable;
 134         dw->enable = dw_dma_enable;
 135
 136         chip->dw = dw;
 137         return do_dma_probe(chip);
 138 }
 139 EXPORT_SYMBOL_GPL(dw_dma_probe);
 140
 141 int dw_dma_remove(struct dw_dma_chip *chip)
 142 {
 143         return do_dma_remove(chip);
 144 }
 145 EXPORT_SYMBOL_GPL(dw_dma_remove);