1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Earthsoft PT3 driver
4 *
5 * Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com>
6 */
7 #include <linux/dma-mapping.h>
8 #include <linux/kernel.h>
9 #include <linux/pci.h>
10
11 #include "pt3.h"
12
13 #define PT3_ACCESS_UNIT (TS_PACKET_SZ * 128)
14 #define PT3_BUF_CANARY (0x74)
15
get_dma_base(int idx)16 static u32 get_dma_base(int idx)
17 {
18 int i;
19
20 i = (idx == 1 || idx == 2) ? 3 - idx : idx;
21 return REG_DMA_BASE + 0x18 * i;
22 }
23
pt3_stop_dma(struct pt3_adapter * adap)24 int pt3_stop_dma(struct pt3_adapter *adap)
25 {
26 struct pt3_board *pt3 = adap->dvb_adap.priv;
27 u32 base;
28 u32 stat;
29 int retry;
30
31 base = get_dma_base(adap->adap_idx);
32 stat = ioread32(pt3->regs[0] + base + OFST_STATUS);
33 if (!(stat & 0x01))
34 return 0;
35
36 iowrite32(0x02, pt3->regs[0] + base + OFST_DMA_CTL);
37 for (retry = 0; retry < 5; retry++) {
38 stat = ioread32(pt3->regs[0] + base + OFST_STATUS);
39 if (!(stat & 0x01))
40 return 0;
41 msleep(50);
42 }
43 return -EIO;
44 }
45
pt3_start_dma(struct pt3_adapter * adap)46 int pt3_start_dma(struct pt3_adapter *adap)
47 {
48 struct pt3_board *pt3 = adap->dvb_adap.priv;
49 u32 base = get_dma_base(adap->adap_idx);
50
51 iowrite32(0x02, pt3->regs[0] + base + OFST_DMA_CTL);
52 iowrite32(lower_32_bits(adap->desc_buf[0].b_addr),
53 pt3->regs[0] + base + OFST_DMA_DESC_L);
54 iowrite32(upper_32_bits(adap->desc_buf[0].b_addr),
55 pt3->regs[0] + base + OFST_DMA_DESC_H);
56 iowrite32(0x01, pt3->regs[0] + base + OFST_DMA_CTL);
57 return 0;
58 }
59
60
next_unit(struct pt3_adapter * adap,int * idx,int * ofs)61 static u8 *next_unit(struct pt3_adapter *adap, int *idx, int *ofs)
62 {
63 *ofs += PT3_ACCESS_UNIT;
64 if (*ofs >= DATA_BUF_SZ) {
65 *ofs -= DATA_BUF_SZ;
66 (*idx)++;
67 if (*idx == adap->num_bufs)
68 *idx = 0;
69 }
70 return &adap->buffer[*idx].data[*ofs];
71 }
72
pt3_proc_dma(struct pt3_adapter * adap)73 int pt3_proc_dma(struct pt3_adapter *adap)
74 {
75 int idx, ofs;
76
77 idx = adap->buf_idx;
78 ofs = adap->buf_ofs;
79
80 if (adap->buffer[idx].data[ofs] == PT3_BUF_CANARY)
81 return 0;
82
83 while (*next_unit(adap, &idx, &ofs) != PT3_BUF_CANARY) {
84 u8 *p;
85
86 p = &adap->buffer[adap->buf_idx].data[adap->buf_ofs];
87 if (adap->num_discard > 0)
88 adap->num_discard--;
89 else if (adap->buf_ofs + PT3_ACCESS_UNIT > DATA_BUF_SZ) {
90 dvb_dmx_swfilter_packets(&adap->demux, p,
91 (DATA_BUF_SZ - adap->buf_ofs) / TS_PACKET_SZ);
92 dvb_dmx_swfilter_packets(&adap->demux,
93 adap->buffer[idx].data, ofs / TS_PACKET_SZ);
94 } else
95 dvb_dmx_swfilter_packets(&adap->demux, p,
96 PT3_ACCESS_UNIT / TS_PACKET_SZ);
97
98 *p = PT3_BUF_CANARY;
99 adap->buf_idx = idx;
100 adap->buf_ofs = ofs;
101 }
102 return 0;
103 }
104
pt3_init_dmabuf(struct pt3_adapter * adap)105 void pt3_init_dmabuf(struct pt3_adapter *adap)
106 {
107 int idx, ofs;
108 u8 *p;
109
110 idx = 0;
111 ofs = 0;
112 p = adap->buffer[0].data;
113 /* mark the whole buffers as "not written yet" */
114 while (idx < adap->num_bufs) {
115 p[ofs] = PT3_BUF_CANARY;
116 ofs += PT3_ACCESS_UNIT;
117 if (ofs >= DATA_BUF_SZ) {
118 ofs -= DATA_BUF_SZ;
119 idx++;
120 p = adap->buffer[idx].data;
121 }
122 }
123 adap->buf_idx = 0;
124 adap->buf_ofs = 0;
125 }
126
pt3_free_dmabuf(struct pt3_adapter * adap)127 void pt3_free_dmabuf(struct pt3_adapter *adap)
128 {
129 struct pt3_board *pt3;
130 int i;
131
132 pt3 = adap->dvb_adap.priv;
133 for (i = 0; i < adap->num_bufs; i++)
134 dma_free_coherent(&pt3->pdev->dev, DATA_BUF_SZ,
135 adap->buffer[i].data, adap->buffer[i].b_addr);
136 adap->num_bufs = 0;
137
138 for (i = 0; i < adap->num_desc_bufs; i++)
139 dma_free_coherent(&pt3->pdev->dev, PAGE_SIZE,
140 adap->desc_buf[i].descs, adap->desc_buf[i].b_addr);
141 adap->num_desc_bufs = 0;
142 }
143
144
pt3_alloc_dmabuf(struct pt3_adapter * adap)145 int pt3_alloc_dmabuf(struct pt3_adapter *adap)
146 {
147 struct pt3_board *pt3;
148 void *p;
149 int i, j;
150 int idx, ofs;
151 int num_desc_bufs;
152 dma_addr_t data_addr, desc_addr;
153 struct xfer_desc *d;
154
155 pt3 = adap->dvb_adap.priv;
156 adap->num_bufs = 0;
157 adap->num_desc_bufs = 0;
158 for (i = 0; i < pt3->num_bufs; i++) {
159 p = dma_alloc_coherent(&pt3->pdev->dev, DATA_BUF_SZ,
160 &adap->buffer[i].b_addr, GFP_KERNEL);
161 if (p == NULL)
162 goto failed;
163 adap->buffer[i].data = p;
164 adap->num_bufs++;
165 }
166 pt3_init_dmabuf(adap);
167
168 /* build circular-linked pointers (xfer_desc) to the data buffers*/
169 idx = 0;
170 ofs = 0;
171 num_desc_bufs =
172 DIV_ROUND_UP(adap->num_bufs * DATA_BUF_XFERS, DESCS_IN_PAGE);
173 for (i = 0; i < num_desc_bufs; i++) {
174 p = dma_alloc_coherent(&pt3->pdev->dev, PAGE_SIZE,
175 &desc_addr, GFP_KERNEL);
176 if (p == NULL)
177 goto failed;
178 adap->num_desc_bufs++;
179 adap->desc_buf[i].descs = p;
180 adap->desc_buf[i].b_addr = desc_addr;
181
182 if (i > 0) {
183 d = &adap->desc_buf[i - 1].descs[DESCS_IN_PAGE - 1];
184 d->next_l = lower_32_bits(desc_addr);
185 d->next_h = upper_32_bits(desc_addr);
186 }
187 for (j = 0; j < DESCS_IN_PAGE; j++) {
188 data_addr = adap->buffer[idx].b_addr + ofs;
189 d = &adap->desc_buf[i].descs[j];
190 d->addr_l = lower_32_bits(data_addr);
191 d->addr_h = upper_32_bits(data_addr);
192 d->size = DATA_XFER_SZ;
193
194 desc_addr += sizeof(struct xfer_desc);
195 d->next_l = lower_32_bits(desc_addr);
196 d->next_h = upper_32_bits(desc_addr);
197
198 ofs += DATA_XFER_SZ;
199 if (ofs >= DATA_BUF_SZ) {
200 ofs -= DATA_BUF_SZ;
201 idx++;
202 if (idx >= adap->num_bufs) {
203 desc_addr = adap->desc_buf[0].b_addr;
204 d->next_l = lower_32_bits(desc_addr);
205 d->next_h = upper_32_bits(desc_addr);
206 return 0;
207 }
208 }
209 }
210 }
211 return 0;
212
213 failed:
214 pt3_free_dmabuf(adap);
215 return -ENOMEM;
216 }
217