1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2021-2022 Digiteq Automotive
4 * author: Martin Tuma <martin.tuma@digiteqautomotive.com>
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
15static void chan_irq(void *param)
16{
17 struct mgb4_dma_channel *chan = param;
18
19 complete(&chan->req_compl);
20}
21
22int 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->chan, config: &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->chan, sgl: sgt->sgl, sg_len: sgt->nents,
52 dir: cfg.direction, flags: 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(cookie: dmaengine_submit(desc: 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->chan);
68
69 if (!wait_for_completion_timeout(x: &chan->req_compl,
70 timeout: msecs_to_jiffies(m: 10000))) {
71 dev_err(&pdev->dev, "dma timeout\n");
72 dmaengine_terminate_sync(chan: chan->chan);
73 return -EIO;
74 }
75
76 return 0;
77}
78
79int 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(buf: name, fmt: "c2h%d", i);
87 mgbdev->c2h_chan[i].chan = dma_request_chan(dev: &pdev->dev, name);
88 if (IS_ERR(ptr: mgbdev->c2h_chan[i].chan)) {
89 dev_err(&pdev->dev, "failed to initialize %s", name);
90 ret = PTR_ERR(ptr: mgbdev->c2h_chan[i].chan);
91 mgbdev->c2h_chan[i].chan = NULL;
92 return ret;
93 }
94 init_completion(x: &mgbdev->c2h_chan[i].req_compl);
95 }
96 for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
97 sprintf(buf: name, fmt: "h2c%d", i);
98 mgbdev->h2c_chan[i].chan = dma_request_chan(dev: &pdev->dev, name);
99 if (IS_ERR(ptr: mgbdev->h2c_chan[i].chan)) {
100 dev_err(&pdev->dev, "failed to initialize %s", name);
101 ret = PTR_ERR(ptr: mgbdev->h2c_chan[i].chan);
102 mgbdev->h2c_chan[i].chan = NULL;
103 return ret;
104 }
105 init_completion(x: &mgbdev->h2c_chan[i].req_compl);
106 }
107
108 return 0;
109}
110
111void 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(chan: 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(chan: mgbdev->h2c_chan[i].chan);
122 }
123}
124

source code of linux/drivers/media/pci/mgb4/mgb4_dma.c