linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 * Connection Management Procedures (IEC 61883-1) helper functions

 *

 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>

 */

​

#include <linux/device.h>

#include <linux/firewire.h>

#include <linux/firewire-constants.h>

#include <linux/module.h>

#include <linux/sched.h>

#include "lib.h"

#include "iso-resources.h"

#include "cmp.h"

​

/* MPR common fields */

#define MPR_SPEED_MASK      0xc0000000

#define MPR_SPEED_SHIFT     30

#define MPR_XSPEED_MASK     0x00000060

#define MPR_XSPEED_SHIFT    5

#define MPR_PLUGS_MASK      0x0000001f

​

/* PCR common fields */

#define PCR_ONLINE      0x80000000

#define PCR_BCAST_CONN      0x40000000

#define PCR_P2P_CONN_MASK   0x3f000000

#define PCR_P2P_CONN_SHIFT  24

#define PCR_CHANNEL_MASK    0x003f0000

#define PCR_CHANNEL_SHIFT   16

​

/* oPCR specific fields */

#define OPCR_XSPEED_MASK    0x00C00000

#define OPCR_XSPEED_SHIFT   22

#define OPCR_SPEED_MASK     0x0000C000

#define OPCR_SPEED_SHIFT    14

#define OPCR_OVERHEAD_ID_MASK   0x00003C00

#define OPCR_OVERHEAD_ID_SHIFT  10

​

enum bus_reset_handling {

    ABORT_ON_BUS_RESET,

    SUCCEED_ON_BUS_RESET,

};

​

static __printf(2, 3)

void cmp_error(struct cmp_connection *c, const char *fmt, ...)

{

    va_list va;

​

    va_start(va, fmt);

    dev_err(&c->resources.unit->device, "%cPCR%u: %pV",

        (c->direction == CMP_INPUT) ? 'i' : 'o',

        c->pcr_index, &(struct va_format){ fmt, &va });

    va_end(va);

}

​

static u64 mpr_address(struct cmp_connection *c)

{

    if (c->direction == CMP_INPUT)

        return CSR_REGISTER_BASE + CSR_IMPR;

    else

        return CSR_REGISTER_BASE + CSR_OMPR;

}

​

static u64 pcr_address(struct cmp_connection *c)

{

    if (c->direction == CMP_INPUT)

        return CSR_REGISTER_BASE + CSR_IPCR(c->pcr_index);

    else

        return CSR_REGISTER_BASE + CSR_OPCR(c->pcr_index);

}

​

static int pcr_modify(struct cmp_connection *c,

              __be32 (*modify)(struct cmp_connection *c, __be32 old),

              int (*check)(struct cmp_connection *c, __be32 pcr),

              enum bus_reset_handling bus_reset_handling)

{

    __be32 old_arg, buffer[2];

    int err;

​

    buffer[0] = c->last_pcr_value;

    for (;;) {

        old_arg = buffer[0];

        buffer[1] = modify(c, buffer[0]);

​

        err = snd_fw_transaction(

                c->resources.unit, TCODE_LOCK_COMPARE_SWAP,

                pcr_address(c), buffer, 8,

                FW_FIXED_GENERATION | c->resources.generation);

​

        if (err < 0) {

            if (err == -EAGAIN &&