linux/drivers/media/pci/pt3/pt3_dma.c

217 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Earthsoft PT3 driver
*
* Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com>
*/
#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;
}