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path: root/drivers/media/pci/pt3/pt3_dma.c
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Diffstat (limited to 'drivers/media/pci/pt3/pt3_dma.c')
-rw-r--r--drivers/media/pci/pt3/pt3_dma.c225
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 0000000..f0ce904
--- /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;
+}

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