saa7164-cmd.c

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/*
 *  Driver for the NXP SAA7164 PCIe bridge
 *
 *  Copyright (c) 2010 Steven Toth <[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/wait.h>

#include "saa7164.h"

int saa7164_cmd_alloc_seqno(struct saa7164_dev *dev)
{
    int i, ret = -1;

    mutex_lock(&dev->lock);
    for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
        if (dev->cmds[i].inuse == 0) {
            dev->cmds[i].inuse = 1;
            dev->cmds[i].signalled = 0;
            dev->cmds[i].timeout = 0;
            ret = dev->cmds[i].seqno;
            break;
        }
    }
    mutex_unlock(&dev->lock);

    return ret;
}

void saa7164_cmd_free_seqno(struct saa7164_dev *dev, u8 seqno)
{
    mutex_lock(&dev->lock);
    if ((dev->cmds[seqno].inuse == 1) &&
        (dev->cmds[seqno].seqno == seqno)) {
        dev->cmds[seqno].inuse = 0;
        dev->cmds[seqno].signalled = 0;
        dev->cmds[seqno].timeout = 0;
    }
    mutex_unlock(&dev->lock);
}

void saa7164_cmd_timeout_seqno(struct saa7164_dev *dev, u8 seqno)
{
    mutex_lock(&dev->lock);
    if ((dev->cmds[seqno].inuse == 1) &&
        (dev->cmds[seqno].seqno == seqno)) {
        dev->cmds[seqno].timeout = 1;
    }
    mutex_unlock(&dev->lock);
}

u32 saa7164_cmd_timeout_get(struct saa7164_dev *dev, u8 seqno)
{
    int ret = 0;

    mutex_lock(&dev->lock);
    if ((dev->cmds[seqno].inuse == 1) &&
        (dev->cmds[seqno].seqno == seqno)) {
        ret = dev->cmds[seqno].timeout;
    }
    mutex_unlock(&dev->lock);

    return ret;
}

/* Commands to the f/w get marshelled to/from this code then onto the PCI
 * -bus/c running buffer. */
int saa7164_irq_dequeue(struct saa7164_dev *dev)
{
    int ret = SAA_OK, i = 0;
    u32 timeout;
    wait_queue_head_t *q = NULL;
    u8 tmp[512];
    dprintk(DBGLVL_CMD, "%s()\n", __func__);

    /* While any outstand message on the bus exists... */
    do {

        /* Peek the msg bus */
        struct tmComResInfo tRsp = { 0, 0, 0, 0, 0, 0 };
        ret = saa7164_bus_get(dev, &tRsp, NULL, 1);
        if (ret != SAA_OK)
            break;

        q = &dev->cmds[tRsp.seqno].wait;
        timeout = saa7164_cmd_timeout_get(dev, tRsp.seqno);
        dprintk(DBGLVL_CMD, "%s() timeout = %d\n", __func__, timeout);
        if (!timeout) {
            dprintk(DBGLVL_CMD,
                "%s() signalled seqno(%d) (for dequeue)\n",
                __func__, tRsp.seqno);
            dev->cmds[tRsp.seqno].signalled = 1;
            wake_up(q);
        } else {
            printk(KERN_ERR
                "%s() found timed out command on the bus\n",
                    __func__);

            /* Clean the bus */
            ret = saa7164_bus_get(dev, &tRsp, &tmp, 0);
            printk(KERN_ERR "%s() ret = %x\n", __func__, ret);
            if (ret == SAA_ERR_EMPTY)
                /* Someone else already fetched the response */
                return SAA_OK;

            if (ret != SAA_OK)
                return ret;
        }

        /* It's unlikely to have more than 4 or 5 pending messages,
         * ensure we exit at some point regardless.
         */
    } while (i++ < 32);

    return ret;
}

/* Commands to the f/w get marshelled to/from this code then onto the PCI
 * -bus/c running buffer. */
int saa7164_cmd_dequeue(struct saa7164_dev *dev)
{
    int loop = 1;
    int ret;
    u32 timeout;
    wait_queue_head_t *q = NULL;
    u8 tmp[512];
    dprintk(DBGLVL_CMD, "%s()\n", __func__);

    while (loop) {

        struct tmComResInfo tRsp = { 0, 0, 0, 0, 0, 0 };
        ret = saa7164_bus_get(dev, &tRsp, NULL, 1);
        if (ret == SAA_ERR_EMPTY)
            return SAA_OK;

        if (ret != SAA_OK)
            return ret;

        q = &dev->cmds[tRsp.seqno].wait;
        timeout = saa7164_cmd_timeout_get(dev, tRsp.seqno);
        dprintk(DBGLVL_CMD, "%s() timeout = %d\n", __func__, timeout);
        if (timeout) {
            printk(KERN_ERR "found timed out command on the bus\n");

            /* Clean the bus */
            ret = saa7164_bus_get(dev, &tRsp, &tmp, 0);
            printk(KERN_ERR "ret = %x\n", ret);
            if (ret == SAA_ERR_EMPTY)
                /* Someone else already fetched the response */
                return SAA_OK;

            if (ret != SAA_OK)
                return ret;

            if (tRsp.flags & PVC_CMDFLAG_CONTINUE)
                printk(KERN_ERR "split response\n");
            else
                saa7164_cmd_free_seqno(dev, tRsp.seqno);

            printk(KERN_ERR " timeout continue\n");
            continue;
        }

        dprintk(DBGLVL_CMD, "%s() signalled seqno(%d) (for dequeue)\n",
            __func__, tRsp.seqno);
        dev->cmds[tRsp.seqno].signalled = 1;
        wake_up(q);
        return SAA_OK;
    }

    return SAA_OK;
}

int saa7164_cmd_set(struct saa7164_dev *dev, struct tmComResInfo *msg,
    void *buf)
{
    struct tmComResBusInfo *bus = &dev->bus;
    u8 cmd_sent;
    u16 size, idx;
    u32 cmds;
    void *tmp;
    int ret = -1;

    if (!msg) {
        printk(KERN_ERR "%s() !msg\n", __func__);
        return SAA_ERR_BAD_PARAMETER;
    }

    mutex_lock(&dev->cmds[msg->id].lock);

    size = msg->size;
    idx = 0;
    cmds = size / bus->m_wMaxReqSize;
    if (size % bus->m_wMaxReqSize == 0)
        cmds -= 1;

    cmd_sent = 0;

    /* Split the request into smaller chunks */
    for (idx = 0; idx < cmds; idx++) {

        msg->flags |= SAA_CMDFLAG_CONTINUE;
        msg->size = bus->m_wMaxReqSize;
        tmp = buf + idx * bus->m_wMaxReqSize;

        ret = saa7164_bus_set(dev, msg, tmp);
        if (ret != SAA_OK) {
            printk(KERN_ERR "%s() set failed %d\n", __func__, ret);

            if (cmd_sent) {
                ret = SAA_ERR_BUSY;
                goto out;
            }
            ret = SAA_ERR_OVERFLOW;
            goto out;
        }
        cmd_sent = 1;
    }

    /* If not the last command... */
    if (idx != 0)
        msg->flags &= ~SAA_CMDFLAG_CONTINUE;

    msg->size = size - idx * bus->m_wMaxReqSize;

    ret = saa7164_bus_set(dev, msg, buf + idx * bus->m_wMaxReqSize);
    if (ret != SAA_OK) {
        printk(KERN_ERR "%s() set last failed %d\n", __func__, ret);

        if (cmd_sent) {
            ret = SAA_ERR_BUSY;
            goto out;
        }
        ret = SAA_ERR_OVERFLOW;
        goto out;
    }
    ret = SAA_OK;

out:
    mutex_unlock(&dev->cmds[msg->id].lock);
    return ret;
}

/* Wait for a signal event, without holding a mutex. Either return TIMEOUT if
 * the event never occurred, or SAA_OK if it was signaled during the wait.
 */
int saa7164_cmd_wait(struct saa7164_dev *dev, u8 seqno)
{
    wait_queue_head_t *q = NULL;
    int ret = SAA_BUS_TIMEOUT;
    unsigned long stamp;
    int r;

    if (saa_debug >= 4)
        saa7164_bus_dump(dev);

    dprintk(DBGLVL_CMD, "%s(seqno=%d)\n", __func__, seqno);

    mutex_lock(&dev->lock);
    if ((dev->cmds[seqno].inuse == 1) &&
        (dev->cmds[seqno].seqno == seqno)) {
        q = &dev->cmds[seqno].wait;
    }
    mutex_unlock(&dev->lock);

    if (q) {
        /* If we haven't been signalled we need to wait */
        if (dev->cmds[seqno].signalled == 0) {
            stamp = jiffies;
            dprintk(DBGLVL_CMD,
                "%s(seqno=%d) Waiting (signalled=%d)\n",
                __func__, seqno, dev->cmds[seqno].signalled);

            /* Wait for signalled to be flagged or timeout */
            /* In a highly stressed system this can easily extend
             * into multiple seconds before the deferred worker
             * is scheduled, and we're woken up via signal.
             * We typically are signalled in < 50ms but it can
             * take MUCH longer.
             */
            wait_event_timeout(*q, dev->cmds[seqno].signalled,
                (HZ * waitsecs));
            r = time_before(jiffies, stamp + (HZ * waitsecs));
            if (r)
                ret = SAA_OK;
            else
                saa7164_cmd_timeout_seqno(dev, seqno);

            dprintk(DBGLVL_CMD, "%s(seqno=%d) Waiting res = %d "
                "(signalled=%d)\n", __func__, seqno, r,
                dev->cmds[seqno].signalled);
        } else
            ret = SAA_OK;
    } else
        printk(KERN_ERR "%s(seqno=%d) seqno is invalid\n",
            __func__, seqno);

    return ret;
}

void saa7164_cmd_signal(struct saa7164_dev *dev, u8 seqno)
{
    int i;
    dprintk(DBGLVL_CMD, "%s()\n", __func__);

    mutex_lock(&dev->lock);
    for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
        if (dev->cmds[i].inuse == 1) {
            dprintk(DBGLVL_CMD,
                "seqno %d inuse, sig = %d, t/out = %d\n",
                dev->cmds[i].seqno,
                dev->cmds[i].signalled,
                dev->cmds[i].timeout);
        }
    }

    for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
        if ((dev->cmds[i].inuse == 1) && ((i == 0) ||
            (dev->cmds[i].signalled) || (dev->cmds[i].timeout))) {
            dprintk(DBGLVL_CMD, "%s(seqno=%d) calling wake_up\n",
                __func__, i);
            dev->cmds[i].signalled = 1;
            wake_up(&dev->cmds[i].wait);
        }
    }
    mutex_unlock(&dev->lock);
}

int saa7164_cmd_send(struct saa7164_dev *dev, u8 id, enum tmComResCmd command,
    u16 controlselector, u16 size, void *buf)
{
    struct tmComResInfo command_t, *pcommand_t;
    struct tmComResInfo response_t, *presponse_t;
    u8 errdata[256];
    u16 resp_dsize;
    u16 data_recd;
    u32 loop;
    int ret;
    int safety = 0;

    dprintk(DBGLVL_CMD, "%s(unitid = %s (%d) , command = 0x%x, "
        "sel = 0x%x)\n", __func__, saa7164_unitid_name(dev, id), id,
        command, controlselector);

    if ((size == 0) || (buf == NULL)) {
        printk(KERN_ERR "%s() Invalid param\n", __func__);
        return SAA_ERR_BAD_PARAMETER;
    }

    /* Prepare some basic command/response structures */
    memset(&command_t, 0, sizeof(command_t));
    memset(&response_t, 0, sizeof(response_t));
    pcommand_t = &command_t;
    presponse_t = &response_t;
    command_t.id = id;
    command_t.command = command;
    command_t.controlselector = controlselector;
    command_t.size = size;

    /* Allocate a unique sequence number */
    ret = saa7164_cmd_alloc_seqno(dev);
    if (ret < 0) {
        printk(KERN_ERR "%s() No free sequences\n", __func__);
        ret = SAA_ERR_NO_RESOURCES;
        goto out;
    }

    command_t.seqno = (u8)ret;

    /* Send Command */
    resp_dsize = size;
    pcommand_t->size = size;

    dprintk(DBGLVL_CMD, "%s() pcommand_t.seqno = %d\n",
        __func__, pcommand_t->seqno);

    dprintk(DBGLVL_CMD, "%s() pcommand_t.size = %d\n",
        __func__, pcommand_t->size);

    ret = saa7164_cmd_set(dev, pcommand_t, buf);
    if (ret != SAA_OK) {
        printk(KERN_ERR "%s() set command failed %d\n", __func__, ret);

        if (ret != SAA_ERR_BUSY)
            saa7164_cmd_free_seqno(dev, pcommand_t->seqno);
        else
            /* Flag a timeout, because at least one
             * command was sent */
            saa7164_cmd_timeout_seqno(dev, pcommand_t->seqno);

        goto out;
    }

    /* With split responses we have to collect the msgs piece by piece */
    data_recd = 0;
    loop = 1;
    while (loop) {
        dprintk(DBGLVL_CMD, "%s() loop\n", __func__);

        ret = saa7164_cmd_wait(dev, pcommand_t->seqno);
        dprintk(DBGLVL_CMD, "%s() loop ret = %d\n", __func__, ret);

        /* if power is down and this is not a power command ... */

        if (ret == SAA_BUS_TIMEOUT) {
            printk(KERN_ERR "Event timed out\n");
            saa7164_cmd_timeout_seqno(dev, pcommand_t->seqno);
            return ret;
        }

        if (ret != SAA_OK) {
            printk(KERN_ERR "spurious error\n");
            return ret;
        }

        /* Peek response */
        ret = saa7164_bus_get(dev, presponse_t, NULL, 1);
        if (ret == SAA_ERR_EMPTY) {
            dprintk(4, "%s() SAA_ERR_EMPTY\n", __func__);
            continue;
        }
        if (ret != SAA_OK) {
            printk(KERN_ERR "peek failed\n");
            return ret;
        }

        dprintk(DBGLVL_CMD, "%s() presponse_t->seqno = %d\n",
            __func__, presponse_t->seqno);

        dprintk(DBGLVL_CMD, "%s() presponse_t->flags = 0x%x\n",
            __func__, presponse_t->flags);

        dprintk(DBGLVL_CMD, "%s() presponse_t->size = %d\n",
            __func__, presponse_t->size);

        /* Check if the response was for our command */
        if (presponse_t->seqno != pcommand_t->seqno) {

            dprintk(DBGLVL_CMD,
                "wrong event: seqno = %d, "
                "expected seqno = %d, "
                "will dequeue regardless\n",
                presponse_t->seqno, pcommand_t->seqno);

            ret = saa7164_cmd_dequeue(dev);
            if (ret != SAA_OK) {
                printk(KERN_ERR "dequeue failed, ret = %d\n",
                    ret);
                if (safety++ > 16) {
                    printk(KERN_ERR
                    "dequeue exceeded, safety exit\n");
                    return SAA_ERR_BUSY;
                }
            }

            continue;
        }

        if ((presponse_t->flags & PVC_RESPONSEFLAG_ERROR) != 0) {

            memset(&errdata[0], 0, sizeof(errdata));

            ret = saa7164_bus_get(dev, presponse_t, &errdata[0], 0);
            if (ret != SAA_OK) {
                printk(KERN_ERR "get error(2)\n");
                return ret;
            }

            saa7164_cmd_free_seqno(dev, pcommand_t->seqno);

            dprintk(DBGLVL_CMD, "%s() errdata %02x%02x%02x%02x\n",
                __func__, errdata[0], errdata[1], errdata[2],
                errdata[3]);

            /* Map error codes */
            dprintk(DBGLVL_CMD, "%s() cmd, error code  = 0x%x\n",
                __func__, errdata[0]);

            switch (errdata[0]) {
            case PVC_ERRORCODE_INVALID_COMMAND:
                dprintk(DBGLVL_CMD, "%s() INVALID_COMMAND\n",
                    __func__);
                ret = SAA_ERR_INVALID_COMMAND;
                break;
            case PVC_ERRORCODE_INVALID_DATA:
                dprintk(DBGLVL_CMD, "%s() INVALID_DATA\n",
                    __func__);
                ret = SAA_ERR_BAD_PARAMETER;
                break;
            case PVC_ERRORCODE_TIMEOUT:
                dprintk(DBGLVL_CMD, "%s() TIMEOUT\n", __func__);
                ret = SAA_ERR_TIMEOUT;
                break;
            case PVC_ERRORCODE_NAK:
                dprintk(DBGLVL_CMD, "%s() NAK\n", __func__);
                ret = SAA_ERR_NULL_PACKET;
                break;
            case PVC_ERRORCODE_UNKNOWN:
            case PVC_ERRORCODE_INVALID_CONTROL:
                dprintk(DBGLVL_CMD,
                    "%s() UNKNOWN OR INVALID CONTROL\n",
                    __func__);
            default:
                dprintk(DBGLVL_CMD, "%s() UNKNOWN\n", __func__);
                ret = SAA_ERR_NOT_SUPPORTED;
            }

            /* See of other commands are on the bus */
            if (saa7164_cmd_dequeue(dev) != SAA_OK)
                printk(KERN_ERR "dequeue(2) failed\n");

            return ret;
        }

        /* If response is invalid */
        if ((presponse_t->id != pcommand_t->id) ||
            (presponse_t->command != pcommand_t->command) ||
            (presponse_t->controlselector !=
                pcommand_t->controlselector) ||
            (((resp_dsize - data_recd) != presponse_t->size) &&
                !(presponse_t->flags & PVC_CMDFLAG_CONTINUE)) ||
            ((resp_dsize - data_recd) < presponse_t->size)) {

            /* Invalid */
            dprintk(DBGLVL_CMD, "%s() Invalid\n", __func__);
            ret = saa7164_bus_get(dev, presponse_t, NULL, 0);
            if (ret != SAA_OK) {
                printk(KERN_ERR "get failed\n");
                return ret;
            }

            /* See of other commands are on the bus */
            if (saa7164_cmd_dequeue(dev) != SAA_OK)
                printk(KERN_ERR "dequeue(3) failed\n");
            continue;
        }

        /* OK, now we're actually getting out correct response */
        ret = saa7164_bus_get(dev, presponse_t, buf + data_recd, 0);
        if (ret != SAA_OK) {
            printk(KERN_ERR "get failed\n");
            return ret;
        }

        data_recd = presponse_t->size + data_recd;
        if (resp_dsize == data_recd) {
            dprintk(DBGLVL_CMD, "%s() Resp recd\n", __func__);
            break;
        }

        /* See of other commands are on the bus */
        if (saa7164_cmd_dequeue(dev) != SAA_OK)
            printk(KERN_ERR "dequeue(3) failed\n");

        continue;

    } /* (loop) */

    /* Release the sequence number allocation */
    saa7164_cmd_free_seqno(dev, pcommand_t->seqno);

    /* if powerdown signal all pending commands */

    dprintk(DBGLVL_CMD, "%s() Calling dequeue then exit\n", __func__);

    /* See of other commands are on the bus */
    if (saa7164_cmd_dequeue(dev) != SAA_OK)
        printk(KERN_ERR "dequeue(4) failed\n");

    ret = SAA_OK;
out:
    return ret;
}