drivers/media/pci/pt3/pt3_dma.c

   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
  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
  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
  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
  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
  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
 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
 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
 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 }