diff options
Diffstat (limited to 'drivers/media/pci/pt3/pt3_dma.c')
| -rw-r--r-- | drivers/media/pci/pt3/pt3_dma.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/drivers/media/pci/pt3/pt3_dma.c b/drivers/media/pci/pt3/pt3_dma.c new file mode 100644 index 000000000000..f0ce90437fac --- /dev/null +++ b/drivers/media/pci/pt3/pt3_dma.c @@ -0,0 +1,225 @@ +/* + * Earthsoft PT3 driver + * + * Copyright (C) 2014 Akihiro Tsukada <tskd08@gmail.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#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; +} |