mantis_dma.c

Go to the documentation of this file.

/*
    Mantis PCI bridge driver

    Copyright (C) Manu Abraham ([email protected])

    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; either version 2 of the License, or
    (at your option) any later version.

    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.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <linux/kernel.h>
#include <asm/page.h>
#include <linux/vmalloc.h>
#include <linux/pci.h>

#include <asm/irq.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/interrupt.h>

#include "dmxdev.h"
#include "dvbdev.h"
#include "dvb_demux.h"
#include "dvb_frontend.h"
#include "dvb_net.h"

#include "mantis_common.h"
#include "mantis_reg.h"
#include "mantis_dma.h"

#define RISC_WRITE      (0x01 << 28)
#define RISC_JUMP       (0x07 << 28)
#define RISC_IRQ        (0x01 << 24)

#define RISC_STATUS(status) ((((~status) & 0x0f) << 20) | ((status & 0x0f) << 16))
#define RISC_FLUSH(risc_pos)        (risc_pos = 0)
#define RISC_INSTR(risc_pos, opcode)    (mantis->risc_cpu[risc_pos++] = cpu_to_le32(opcode))

#define MANTIS_BUF_SIZE     (64 * 1024)
#define MANTIS_BLOCK_BYTES      (MANTIS_BUF_SIZE / 4)
#define MANTIS_DMA_TR_BYTES     (2 * 1024) /* upper limit: 4095 bytes. */
#define MANTIS_BLOCK_COUNT  (MANTIS_BUF_SIZE / MANTIS_BLOCK_BYTES)

#define MANTIS_DMA_TR_UNITS     (MANTIS_BLOCK_BYTES / MANTIS_DMA_TR_BYTES)
/* MANTIS_BUF_SIZE / MANTIS_DMA_TR_UNITS must not exceed MANTIS_RISC_SIZE (4k RISC cmd buffer) */
#define MANTIS_RISC_SIZE    PAGE_SIZE /* RISC program must fit here. */

int mantis_dma_exit(struct mantis_pci *mantis)
{
    if (mantis->buf_cpu) {
        dprintk(MANTIS_ERROR, 1,
            "DMA=0x%lx cpu=0x%p size=%d",
            (unsigned long) mantis->buf_dma,
             mantis->buf_cpu,
             MANTIS_BUF_SIZE);

        pci_free_consistent(mantis->pdev, MANTIS_BUF_SIZE,
                    mantis->buf_cpu, mantis->buf_dma);

        mantis->buf_cpu = NULL;
    }
    if (mantis->risc_cpu) {
        dprintk(MANTIS_ERROR, 1,
            "RISC=0x%lx cpu=0x%p size=%lx",
            (unsigned long) mantis->risc_dma,
            mantis->risc_cpu,
            MANTIS_RISC_SIZE);

        pci_free_consistent(mantis->pdev, MANTIS_RISC_SIZE,
                    mantis->risc_cpu, mantis->risc_dma);

        mantis->risc_cpu = NULL;
    }

    return 0;
}
EXPORT_SYMBOL_GPL(mantis_dma_exit);

static inline int mantis_alloc_buffers(struct mantis_pci *mantis)
{
    if (!mantis->buf_cpu) {
        mantis->buf_cpu = pci_alloc_consistent(mantis->pdev,
                               MANTIS_BUF_SIZE,
                               &mantis->buf_dma);
        if (!mantis->buf_cpu) {
            dprintk(MANTIS_ERROR, 1,
                "DMA buffer allocation failed");

            goto err;
        }
        dprintk(MANTIS_ERROR, 1,
            "DMA=0x%lx cpu=0x%p size=%d",
            (unsigned long) mantis->buf_dma,
            mantis->buf_cpu, MANTIS_BUF_SIZE);
    }
    if (!mantis->risc_cpu) {
        mantis->risc_cpu = pci_alloc_consistent(mantis->pdev,
                            MANTIS_RISC_SIZE,
                            &mantis->risc_dma);

        if (!mantis->risc_cpu) {
            dprintk(MANTIS_ERROR, 1,
                "RISC program allocation failed");

            mantis_dma_exit(mantis);

            goto err;
        }
        dprintk(MANTIS_ERROR, 1,
            "RISC=0x%lx cpu=0x%p size=%lx",
            (unsigned long) mantis->risc_dma,
            mantis->risc_cpu, MANTIS_RISC_SIZE);
    }

    return 0;
err:
    dprintk(MANTIS_ERROR, 1, "Out of memory (?) .....");
    return -ENOMEM;
}

int mantis_dma_init(struct mantis_pci *mantis)
{
    int err = 0;

    dprintk(MANTIS_DEBUG, 1, "Mantis DMA init");
    if (mantis_alloc_buffers(mantis) < 0) {
        dprintk(MANTIS_ERROR, 1, "Error allocating DMA buffer");

        /* Stop RISC Engine */
        mmwrite(0, MANTIS_DMA_CTL);

        goto err;
    }

    return 0;
err:
    return err;
}
EXPORT_SYMBOL_GPL(mantis_dma_init);

static inline void mantis_risc_program(struct mantis_pci *mantis)
{
    u32 buf_pos = 0;
    u32 line, step;
    u32 risc_pos;

    dprintk(MANTIS_DEBUG, 1, "Mantis create RISC program");
    RISC_FLUSH(risc_pos);

    dprintk(MANTIS_DEBUG, 1, "risc len lines %u, bytes per line %u, bytes per DMA tr %u",
        MANTIS_BLOCK_COUNT, MANTIS_BLOCK_BYTES, MANTIS_DMA_TR_BYTES);

    for (line = 0; line < MANTIS_BLOCK_COUNT; line++) {
        for (step = 0; step < MANTIS_DMA_TR_UNITS; step++) {
            dprintk(MANTIS_DEBUG, 1, "RISC PROG line=[%d], step=[%d]", line, step);
            if (step == 0) {
                RISC_INSTR(risc_pos, RISC_WRITE |
                       RISC_IRQ |
                       RISC_STATUS(line) |
                       MANTIS_DMA_TR_BYTES);
            } else {
                RISC_INSTR(risc_pos, RISC_WRITE | MANTIS_DMA_TR_BYTES);
            }
            RISC_INSTR(risc_pos, mantis->buf_dma + buf_pos);
            buf_pos += MANTIS_DMA_TR_BYTES;
          }
    }
    RISC_INSTR(risc_pos, RISC_JUMP);
    RISC_INSTR(risc_pos, mantis->risc_dma);
}

void mantis_dma_start(struct mantis_pci *mantis)
{
    dprintk(MANTIS_DEBUG, 1, "Mantis Start DMA engine");

    mantis_risc_program(mantis);
    mmwrite(mantis->risc_dma, MANTIS_RISC_START);
    mmwrite(mmread(MANTIS_GPIF_ADDR) | MANTIS_GPIF_HIFRDWRN, MANTIS_GPIF_ADDR);

    mmwrite(0, MANTIS_DMA_CTL);
    mantis->last_block = mantis->busy_block = 0;

    mmwrite(mmread(MANTIS_INT_MASK) | MANTIS_INT_RISCI, MANTIS_INT_MASK);

    mmwrite(MANTIS_FIFO_EN | MANTIS_DCAP_EN
                   | MANTIS_RISC_EN, MANTIS_DMA_CTL);

}

void mantis_dma_stop(struct mantis_pci *mantis)
{
    dprintk(MANTIS_DEBUG, 1, "Mantis Stop DMA engine");

    mmwrite((mmread(MANTIS_GPIF_ADDR) & (~(MANTIS_GPIF_HIFRDWRN))), MANTIS_GPIF_ADDR);

    mmwrite((mmread(MANTIS_DMA_CTL) & ~(MANTIS_FIFO_EN |
                        MANTIS_DCAP_EN |
                        MANTIS_RISC_EN)), MANTIS_DMA_CTL);

    mmwrite(mmread(MANTIS_INT_STAT), MANTIS_INT_STAT);

    mmwrite(mmread(MANTIS_INT_MASK) & ~(MANTIS_INT_RISCI |
                        MANTIS_INT_RISCEN), MANTIS_INT_MASK);
}


void mantis_dma_xfer(unsigned long data)
{
    struct mantis_pci *mantis = (struct mantis_pci *) data;
    struct mantis_hwconfig *config = mantis->hwconfig;

    while (mantis->last_block != mantis->busy_block) {
        dprintk(MANTIS_DEBUG, 1, "last block=[%d] finished block=[%d]",
            mantis->last_block, mantis->busy_block);

        (config->ts_size ? dvb_dmx_swfilter_204 : dvb_dmx_swfilter)
        (&mantis->demux, &mantis->buf_cpu[mantis->last_block * MANTIS_BLOCK_BYTES], MANTIS_BLOCK_BYTES);
        mantis->last_block = (mantis->last_block + 1) % MANTIS_BLOCK_COUNT;
    }
}