tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 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
76static 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
100static 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
105static void dw_dma_disable(struct dw_dma *dw)
106{
107 do_dw_dma_off(dw);
108}
109
110static void dw_dma_enable(struct dw_dma *dw)
111{
112 do_dw_dma_on(dw);
113}
114
115int 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}
139EXPORT_SYMBOL_GPL(dw_dma_probe);
140
141int dw_dma_remove(struct dw_dma_chip *chip)
142{
143 return do_dma_remove(chip);
144}
145EXPORT_SYMBOL_GPL(dw_dma_remove);