pt3_dma.c (4997B)
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 16static 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 24int 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 46int 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 61static 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 73int 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 105void 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 127void 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 145int 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 213failed: 214 pt3_free_dmabuf(adap); 215 return -ENOMEM; 216}