drivers/media/pci/mgb4/mgb4_dma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2021-2022 Digiteq Automotive
   4  *     author: Martin Tuma <[email protected]>
   5  *
   6  * This module handles the DMA transfers. A standard dmaengine API as provided
   7  * by the XDMA module is used.
   8  */
   9
  10 #include <linux/pci.h>
  11 #include <linux/dma-direction.h>
  12 #include "mgb4_core.h"
  13 #include "mgb4_dma.h"
  14
  15 static void chan_irq(void *param)
  16 {
  17         struct mgb4_dma_channel *chan = param;
  18
  19         complete(&chan->req_compl);
  20 }
  21
  22 int mgb4_dma_transfer(struct mgb4_dev *mgbdev, u32 channel, bool write,
  23                       u64 paddr, struct sg_table *sgt)
  24 {
  25         struct dma_slave_config cfg;
  26         struct mgb4_dma_channel *chan;
  27         struct dma_async_tx_descriptor *tx;
  28         struct pci_dev *pdev = mgbdev->pdev;
  29         int ret;
  30
  31         memset(&cfg, 0, sizeof(cfg));
  32
  33         if (write) {
  34                 cfg.direction = DMA_MEM_TO_DEV;
  35                 cfg.dst_addr = paddr;
  36                 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  37                 chan = &mgbdev->h2c_chan[channel];
  38         } else {
  39                 cfg.direction = DMA_DEV_TO_MEM;
  40                 cfg.src_addr = paddr;
  41                 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  42                 chan = &mgbdev->c2h_chan[channel];
  43         }
  44
  45         ret = dmaengine_slave_config(chan->chan, &cfg);
  46         if (ret) {
  47                 dev_err(&pdev->dev, "failed to config dma: %d\n", ret);
  48                 return ret;
  49         }
  50
  51         tx = dmaengine_prep_slave_sg(chan->chan, sgt->sgl, sgt->nents,
  52                                      cfg.direction, 0);
  53         if (!tx) {
  54                 dev_err(&pdev->dev, "failed to prep slave sg\n");
  55                 return -EIO;
  56         }
  57
  58         tx->callback = chan_irq;
  59         tx->callback_param = chan;
  60
  61         ret = dma_submit_error(dmaengine_submit(tx));
  62         if (ret) {
  63                 dev_err(&pdev->dev, "failed to submit sg\n");
  64                 return -EIO;
  65         }
  66
  67         dma_async_issue_pending(chan->chan);
  68
  69         if (!wait_for_completion_timeout(&chan->req_compl,
  70                                          msecs_to_jiffies(10000))) {
  71                 dev_err(&pdev->dev, "dma timeout\n");
  72                 dmaengine_terminate_sync(chan->chan);
  73                 return -EIO;
  74         }
  75
  76         return 0;
  77 }
  78
  79 int mgb4_dma_channel_init(struct mgb4_dev *mgbdev)
  80 {
  81         int i, ret;
  82         char name[16];
  83         struct pci_dev *pdev = mgbdev->pdev;
  84
  85         for (i = 0; i < MGB4_VIN_DEVICES; i++) {
  86                 sprintf(name, "c2h%d", i);
  87                 mgbdev->c2h_chan[i].chan = dma_request_chan(&pdev->dev, name);
  88                 if (IS_ERR(mgbdev->c2h_chan[i].chan)) {
  89                         dev_err(&pdev->dev, "failed to initialize %s", name);
  90                         ret = PTR_ERR(mgbdev->c2h_chan[i].chan);
  91                         mgbdev->c2h_chan[i].chan = NULL;
  92                         return ret;
  93                 }
  94                 init_completion(&mgbdev->c2h_chan[i].req_compl);
  95         }
  96         for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
  97                 sprintf(name, "h2c%d", i);
  98                 mgbdev->h2c_chan[i].chan = dma_request_chan(&pdev->dev, name);
  99                 if (IS_ERR(mgbdev->h2c_chan[i].chan)) {
 100                         dev_err(&pdev->dev, "failed to initialize %s", name);
 101                         ret = PTR_ERR(mgbdev->h2c_chan[i].chan);
 102                         mgbdev->h2c_chan[i].chan = NULL;
 103                         return ret;
 104                 }
 105                 init_completion(&mgbdev->h2c_chan[i].req_compl);
 106         }
 107
 108         return 0;
 109 }
 110
 111 void mgb4_dma_channel_free(struct mgb4_dev *mgbdev)
 112 {
 113         int i;
 114
 115         for (i = 0; i < MGB4_VIN_DEVICES; i++) {
 116                 if (mgbdev->c2h_chan[i].chan)
 117                         dma_release_channel(mgbdev->c2h_chan[i].chan);
 118         }
 119         for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
 120                 if (mgbdev->h2c_chan[i].chan)
 121                         dma_release_channel(mgbdev->h2c_chan[i].chan);
 122         }
 123 }