1 /*
2 * Earthsoft PT3 driver
3 *
4 * Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation version 2.
9 *
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16 #include <linux/dma-mapping.h>
17 #include <linux/kernel.h>
18 #include <linux/pci.h>
19
20 #include "pt3.h"
21
22 #define PT3_ACCESS_UNIT (TS_PACKET_SZ * 128)
23 #define PT3_BUF_CANARY (0x74)
24
get_dma_base(int idx)25 static u32 get_dma_base(int idx)
26 {
27 int i;
28
29 i = (idx == 1 || idx == 2) ? 3 - idx : idx;
30 return REG_DMA_BASE + 0x18 * i;
31 }
32
pt3_stop_dma(struct pt3_adapter * adap)33 int pt3_stop_dma(struct pt3_adapter *adap)
34 {
35 struct pt3_board *pt3 = adap->dvb_adap.priv;
36 u32 base;
37 u32 stat;
38 int retry;
39
40 base = get_dma_base(adap->adap_idx);
41 stat = ioread32(pt3->regs[0] + base + OFST_STATUS);
42 if (!(stat & 0x01))
43 return 0;
44
45 iowrite32(0x02, pt3->regs[0] + base + OFST_DMA_CTL);
46 for (retry = 0; retry < 5; retry++) {
47 stat = ioread32(pt3->regs[0] + base + OFST_STATUS);
48 if (!(stat & 0x01))
49 return 0;
50 msleep(50);
51 }
52 return -EIO;
53 }
54
pt3_start_dma(struct pt3_adapter * adap)55 int pt3_start_dma(struct pt3_adapter *adap)
56 {
57 struct pt3_board *pt3 = adap->dvb_adap.priv;
58 u32 base = get_dma_base(adap->adap_idx);
59
60 iowrite32(0x02, pt3->regs[0] + base + OFST_DMA_CTL);
61 iowrite32(lower_32_bits(adap->desc_buf[0].b_addr),
62 pt3->regs[0] + base + OFST_DMA_DESC_L);
63 iowrite32(upper_32_bits(adap->desc_buf[0].b_addr),
64 pt3->regs[0] + base + OFST_DMA_DESC_H);
65 iowrite32(0x01, pt3->regs[0] + base + OFST_DMA_CTL);
66 return 0;
67 }
68
69
next_unit(struct pt3_adapter * adap,int * idx,int * ofs)70 static u8 *next_unit(struct pt3_adapter *adap, int *idx, int *ofs)
71 {
72 *ofs += PT3_ACCESS_UNIT;
73 if (*ofs >= DATA_BUF_SZ) {
74 *ofs -= DATA_BUF_SZ;
75 (*idx)++;
76 if (*idx == adap->num_bufs)
77 *idx = 0;
78 }
79 return &adap->buffer[*idx].data[*ofs];
80 }
81
pt3_proc_dma(struct pt3_adapter * adap)82 int pt3_proc_dma(struct pt3_adapter *adap)
83 {
84 int idx, ofs;
85
86 idx = adap->buf_idx;
87 ofs = adap->buf_ofs;
88
89 if (adap->buffer[idx].data[ofs] == PT3_BUF_CANARY)
90 return 0;
91
92 while (*next_unit(adap, &idx, &ofs) != PT3_BUF_CANARY) {
93 u8 *p;
94
95 p = &adap->buffer[adap->buf_idx].data[adap->buf_ofs];
96 if (adap->num_discard > 0)
97 adap->num_discard--;
98 else if (adap->buf_ofs + PT3_ACCESS_UNIT > DATA_BUF_SZ) {
99 dvb_dmx_swfilter_packets(&adap->demux, p,
100 (DATA_BUF_SZ - adap->buf_ofs) / TS_PACKET_SZ);
101 dvb_dmx_swfilter_packets(&adap->demux,
102 adap->buffer[idx].data, ofs / TS_PACKET_SZ);
103 } else
104 dvb_dmx_swfilter_packets(&adap->demux, p,
105 PT3_ACCESS_UNIT / TS_PACKET_SZ);
106
107 *p = PT3_BUF_CANARY;
108 adap->buf_idx = idx;
109 adap->buf_ofs = ofs;
110 }
111 return 0;
112 }
113
pt3_init_dmabuf(struct pt3_adapter * adap)114 void pt3_init_dmabuf(struct pt3_adapter *adap)
115 {
116 int idx, ofs;
117 u8 *p;
118
119 idx = 0;
120 ofs = 0;
121 p = adap->buffer[0].data;
122 /* mark the whole buffers as "not written yet" */
123 while (idx < adap->num_bufs) {
124 p[ofs] = PT3_BUF_CANARY;
125 ofs += PT3_ACCESS_UNIT;
126 if (ofs >= DATA_BUF_SZ) {
127 ofs -= DATA_BUF_SZ;
128 idx++;
129 p = adap->buffer[idx].data;
130 }
131 }
132 adap->buf_idx = 0;
133 adap->buf_ofs = 0;
134 }
135
pt3_free_dmabuf(struct pt3_adapter * adap)136 void pt3_free_dmabuf(struct pt3_adapter *adap)
137 {
138 struct pt3_board *pt3;
139 int i;
140
141 pt3 = adap->dvb_adap.priv;
142 for (i = 0; i < adap->num_bufs; i++)
143 dma_free_coherent(&pt3->pdev->dev, DATA_BUF_SZ,
144 adap->buffer[i].data, adap->buffer[i].b_addr);
145 adap->num_bufs = 0;
146
147 for (i = 0; i < adap->num_desc_bufs; i++)
148 dma_free_coherent(&pt3->pdev->dev, PAGE_SIZE,
149 adap->desc_buf[i].descs, adap->desc_buf[i].b_addr);
150 adap->num_desc_bufs = 0;
151 }
152
153
pt3_alloc_dmabuf(struct pt3_adapter * adap)154 int pt3_alloc_dmabuf(struct pt3_adapter *adap)
155 {
156 struct pt3_board *pt3;
157 void *p;
158 int i, j;
159 int idx, ofs;
160 int num_desc_bufs;
161 dma_addr_t data_addr, desc_addr;
162 struct xfer_desc *d;
163
164 pt3 = adap->dvb_adap.priv;
165 adap->num_bufs = 0;
166 adap->num_desc_bufs = 0;
167 for (i = 0; i < pt3->num_bufs; i++) {
168 p = dma_alloc_coherent(&pt3->pdev->dev, DATA_BUF_SZ,
169 &adap->buffer[i].b_addr, GFP_KERNEL);
170 if (p == NULL)
171 goto failed;
172 adap->buffer[i].data = p;
173 adap->num_bufs++;
174 }
175 pt3_init_dmabuf(adap);
176
177 /* build circular-linked pointers (xfer_desc) to the data buffers*/
178 idx = 0;
179 ofs = 0;
180 num_desc_bufs =
181 DIV_ROUND_UP(adap->num_bufs * DATA_BUF_XFERS, DESCS_IN_PAGE);
182 for (i = 0; i < num_desc_bufs; i++) {
183 p = dma_alloc_coherent(&pt3->pdev->dev, PAGE_SIZE,
184 &desc_addr, GFP_KERNEL);
185 if (p == NULL)
186 goto failed;
187 adap->num_desc_bufs++;
188 adap->desc_buf[i].descs = p;
189 adap->desc_buf[i].b_addr = desc_addr;
190
191 if (i > 0) {
192 d = &adap->desc_buf[i - 1].descs[DESCS_IN_PAGE - 1];
193 d->next_l = lower_32_bits(desc_addr);
194 d->next_h = upper_32_bits(desc_addr);
195 }
196 for (j = 0; j < DESCS_IN_PAGE; j++) {
197 data_addr = adap->buffer[idx].b_addr + ofs;
198 d = &adap->desc_buf[i].descs[j];
199 d->addr_l = lower_32_bits(data_addr);
200 d->addr_h = upper_32_bits(data_addr);
201 d->size = DATA_XFER_SZ;
202
203 desc_addr += sizeof(struct xfer_desc);
204 d->next_l = lower_32_bits(desc_addr);
205 d->next_h = upper_32_bits(desc_addr);
206
207 ofs += DATA_XFER_SZ;
208 if (ofs >= DATA_BUF_SZ) {
209 ofs -= DATA_BUF_SZ;
210 idx++;
211 if (idx >= adap->num_bufs) {
212 desc_addr = adap->desc_buf[0].b_addr;
213 d->next_l = lower_32_bits(desc_addr);
214 d->next_h = upper_32_bits(desc_addr);
215 return 0;
216 }
217 }
218 }
219 }
220 return 0;
221
222 failed:
223 pt3_free_dmabuf(adap);
224 return -ENOMEM;
225 }
226