summaryrefslogtreecommitdiff
path: root/drivers/media/pci/pt3/pt3_dma.c
blob: f0ce90437fac4006ce7c2c433ef6275120272daa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
/*
 * Earthsoft PT3 driver
 *
 * Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/pci.h>

#include "pt3.h"

#define PT3_ACCESS_UNIT (TS_PACKET_SZ * 128)
#define PT3_BUF_CANARY  (0x74)

static u32 get_dma_base(int idx)
{
	int i;

	i = (idx == 1 || idx == 2) ? 3 - idx : idx;
	return REG_DMA_BASE + 0x18 * i;
}

int pt3_stop_dma(struct pt3_adapter *adap)
{
	struct pt3_board *pt3 = adap->dvb_adap.priv;
	u32 base;
	u32 stat;
	int retry;

	base = get_dma_base(adap->adap_idx);
	stat = ioread32(pt3->regs[0] + base + OFST_STATUS);
	if (!(stat & 0x01))
		return 0;

	iowrite32(0x02, pt3->regs[0] + base + OFST_DMA_CTL);
	for (retry = 0; retry < 5; retry++) {
		stat = ioread32(pt3->regs[0] + base + OFST_STATUS);
		if (!(stat & 0x01))
			return 0;
		msleep(50);
	}
	return -EIO;
}

int pt3_start_dma(struct pt3_adapter *adap)
{
	struct pt3_board *pt3 = adap->dvb_adap.priv;
	u32 base = get_dma_base(adap->adap_idx);

	iowrite32(0x02, pt3->regs[0] + base + OFST_DMA_CTL);
	iowrite32(lower_32_bits(adap->desc_buf[0].b_addr),
			pt3->regs[0] + base + OFST_DMA_DESC_L);
	iowrite32(upper_32_bits(adap->desc_buf[0].b_addr),
			pt3->regs[0] + base + OFST_DMA_DESC_H);
	iowrite32(0x01, pt3->regs[0] + base + OFST_DMA_CTL);
	return 0;
}


static u8 *next_unit(struct pt3_adapter *adap, int *idx, int *ofs)
{
	*ofs += PT3_ACCESS_UNIT;
	if (*ofs >= DATA_BUF_SZ) {
		*ofs -= DATA_BUF_SZ;
		(*idx)++;
		if (*idx == adap->num_bufs)
			*idx = 0;
	}
	return &adap->buffer[*idx].data[*ofs];
}

int pt3_proc_dma(struct pt3_adapter *adap)
{
	int idx, ofs;

	idx = adap->buf_idx;
	ofs = adap->buf_ofs;

	if (adap->buffer[idx].data[ofs] == PT3_BUF_CANARY)
		return 0;

	while (*next_unit(adap, &idx, &ofs) != PT3_BUF_CANARY) {
		u8 *p;

		p = &adap->buffer[adap->buf_idx].data[adap->buf_ofs];
		if (adap->num_discard > 0)
			adap->num_discard--;
		else if (adap->buf_ofs + PT3_ACCESS_UNIT > DATA_BUF_SZ) {
			dvb_dmx_swfilter_packets(&adap->demux, p,
				(DATA_BUF_SZ - adap->buf_ofs) / TS_PACKET_SZ);
			dvb_dmx_swfilter_packets(&adap->demux,
				adap->buffer[idx].data, ofs / TS_PACKET_SZ);
		} else
			dvb_dmx_swfilter_packets(&adap->demux, p,
				PT3_ACCESS_UNIT / TS_PACKET_SZ);

		*p = PT3_BUF_CANARY;
		adap->buf_idx = idx;
		adap->buf_ofs = ofs;
	}
	return 0;
}

void pt3_init_dmabuf(struct pt3_adapter *adap)
{
	int idx, ofs;
	u8 *p;

	idx = 0;
	ofs = 0;
	p = adap->buffer[0].data;
	/* mark the whole buffers as "not written yet" */
	while (idx < adap->num_bufs) {
		p[ofs] = PT3_BUF_CANARY;
		ofs += PT3_ACCESS_UNIT;
		if (ofs >= DATA_BUF_SZ) {
			ofs -= DATA_BUF_SZ;
			idx++;
			p = adap->buffer[idx].data;
		}
	}
	adap->buf_idx = 0;
	adap->buf_ofs = 0;
}

void pt3_free_dmabuf(struct pt3_adapter *adap)
{
	struct pt3_board *pt3;
	int i;

	pt3 = adap->dvb_adap.priv;
	for (i = 0; i < adap->num_bufs; i++)
		dma_free_coherent(&pt3->pdev->dev, DATA_BUF_SZ,
			adap->buffer[i].data, adap->buffer[i].b_addr);
	adap->num_bufs = 0;

	for (i = 0; i < adap->num_desc_bufs; i++)
		dma_free_coherent(&pt3->pdev->dev, PAGE_SIZE,
			adap->desc_buf[i].descs, adap->desc_buf[i].b_addr);
	adap->num_desc_bufs = 0;
}


int pt3_alloc_dmabuf(struct pt3_adapter *adap)
{
	struct pt3_board *pt3;
	void *p;
	int i, j;
	int idx, ofs;
	int num_desc_bufs;
	dma_addr_t data_addr, desc_addr;
	struct xfer_desc *d;

	pt3 = adap->dvb_adap.priv;
	adap->num_bufs = 0;
	adap->num_desc_bufs = 0;
	for (i = 0; i < pt3->num_bufs; i++) {
		p = dma_alloc_coherent(&pt3->pdev->dev, DATA_BUF_SZ,
					&adap->buffer[i].b_addr, GFP_KERNEL);
		if (p == NULL)
			goto failed;
		adap->buffer[i].data = p;
		adap->num_bufs++;
	}
	pt3_init_dmabuf(adap);

	/* build circular-linked pointers (xfer_desc) to the data buffers*/
	idx = 0;
	ofs = 0;
	num_desc_bufs =
		DIV_ROUND_UP(adap->num_bufs * DATA_BUF_XFERS, DESCS_IN_PAGE);
	for (i = 0; i < num_desc_bufs; i++) {
		p = dma_alloc_coherent(&pt3->pdev->dev, PAGE_SIZE,
					&desc_addr, GFP_KERNEL);
		if (p == NULL)
			goto failed;
		adap->num_desc_bufs++;
		adap->desc_buf[i].descs = p;
		adap->desc_buf[i].b_addr = desc_addr;

		if (i > 0) {
			d = &adap->desc_buf[i - 1].descs[DESCS_IN_PAGE - 1];
			d->next_l = lower_32_bits(desc_addr);
			d->next_h = upper_32_bits(desc_addr);
		}
		for (j = 0; j < DESCS_IN_PAGE; j++) {
			data_addr = adap->buffer[idx].b_addr + ofs;
			d = &adap->desc_buf[i].descs[j];
			d->addr_l = lower_32_bits(data_addr);
			d->addr_h = upper_32_bits(data_addr);
			d->size = DATA_XFER_SZ;

			desc_addr += sizeof(struct xfer_desc);
			d->next_l = lower_32_bits(desc_addr);
			d->next_h = upper_32_bits(desc_addr);

			ofs += DATA_XFER_SZ;
			if (ofs >= DATA_BUF_SZ) {
				ofs -= DATA_BUF_SZ;
				idx++;
				if (idx >= adap->num_bufs) {
					desc_addr = adap->desc_buf[0].b_addr;
					d->next_l = lower_32_bits(desc_addr);
					d->next_h = upper_32_bits(desc_addr);
					return 0;
				}
			}
		}
	}
	return 0;

failed:
	pt3_free_dmabuf(adap);
	return -ENOMEM;
}