LXR linux/sound/firewire/motu/motu-transaction.c

   1/*
   2 * motu-transaction.c - a part of driver for MOTU FireWire series
   3 *
   4 * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
   5 *
   6 * Licensed under the terms of the GNU General Public License, version 2.
   7 */
   8
   9
  10#include "motu.h"
  11
  12#define SND_MOTU_ADDR_BASE      0xfffff0000000ULL
  13#define ASYNC_ADDR_HI  0x0b04
  14#define ASYNC_ADDR_LO  0x0b08
  15
  16int snd_motu_transaction_read(struct snd_motu *motu, u32 offset, __be32 *reg,
  17                              size_t size)
  18{
  19        int tcode;
  20
  21        if (size % sizeof(__be32) > 0 || size <= 0)
  22                return -EINVAL;
  23        if (size == sizeof(__be32))
  24                tcode = TCODE_READ_QUADLET_REQUEST;
  25        else
  26                tcode = TCODE_READ_BLOCK_REQUEST;
  27
  28        return snd_fw_transaction(motu->unit, tcode,
  29                                  SND_MOTU_ADDR_BASE + offset, reg, size, 0);
  30}
  31
  32int snd_motu_transaction_write(struct snd_motu *motu, u32 offset, __be32 *reg,
  33                               size_t size)
  34{
  35        int tcode;
  36
  37        if (size % sizeof(__be32) > 0 || size <= 0)
  38                return -EINVAL;
  39        if (size == sizeof(__be32))
  40                tcode = TCODE_WRITE_QUADLET_REQUEST;
  41        else
  42                tcode = TCODE_WRITE_BLOCK_REQUEST;
  43
  44        return snd_fw_transaction(motu->unit, tcode,
  45                                  SND_MOTU_ADDR_BASE + offset, reg, size, 0);
  46}
  47
  48static void handle_message(struct fw_card *card, struct fw_request *request,
  49                           int tcode, int destination, int source,
  50                           int generation, unsigned long long offset,
  51                           void *data, size_t length, void *callback_data)
  52{
  53        struct snd_motu *motu = callback_data;
  54        __be32 *buf = (__be32 *)data;
  55        unsigned long flags;
  56
  57        if (tcode != TCODE_WRITE_QUADLET_REQUEST) {
  58                fw_send_response(card, request, RCODE_COMPLETE);
  59                return;
  60        }
  61
  62        if (offset != motu->async_handler.offset || length != 4) {
  63                fw_send_response(card, request, RCODE_ADDRESS_ERROR);
  64                return;
  65        }
  66
  67        spin_lock_irqsave(&motu->lock, flags);
  68        motu->msg = be32_to_cpu(*buf);
  69        spin_unlock_irqrestore(&motu->lock, flags);
  70
  71        fw_send_response(card, request, RCODE_COMPLETE);
  72
  73        wake_up(&motu->hwdep_wait);
  74}
  75
  76int snd_motu_transaction_reregister(struct snd_motu *motu)
  77{
  78        struct fw_device *device = fw_parent_device(motu->unit);
  79        __be32 data;
  80        int err;
  81
  82        if (motu->async_handler.callback_data == NULL)
  83                return -EINVAL;
  84
  85        /* Register messaging address. Block transaction is not allowed. */
  86        data = cpu_to_be32((device->card->node_id << 16) |
  87                           (motu->async_handler.offset >> 32));
  88        err = snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data,
  89                                         sizeof(data));
  90        if (err < 0)
  91                return err;
  92
  93        data = cpu_to_be32(motu->async_handler.offset);
  94        return snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data,
  95                                          sizeof(data));
  96}
  97
  98int snd_motu_transaction_register(struct snd_motu *motu)
  99{
 100        static const struct fw_address_region resp_register_region = {
 101                .start  = 0xffffe0000000ull,
 102                .end    = 0xffffe000ffffull,
 103        };
 104        int err;
 105
 106        /* Perhaps, 4 byte messages are transferred. */
 107        motu->async_handler.length = 4;
 108        motu->async_handler.address_callback = handle_message;
 109        motu->async_handler.callback_data = motu;
 110
 111        err = fw_core_add_address_handler(&motu->async_handler,
 112                                          &resp_register_region);
 113        if (err < 0)
 114                return err;
 115
 116        err = snd_motu_transaction_reregister(motu);
 117        if (err < 0) {
 118                fw_core_remove_address_handler(&motu->async_handler);
 119                motu->async_handler.address_callback = NULL;
 120        }
 121
 122        return err;
 123}
 124
 125void snd_motu_transaction_unregister(struct snd_motu *motu)
 126{
 127        __be32 data;
 128
 129        if (motu->async_handler.address_callback != NULL)
 130                fw_core_remove_address_handler(&motu->async_handler);
 131        motu->async_handler.address_callback = NULL;
 132
 133        /* Unregister the address. */
 134        data = cpu_to_be32(0x00000000);
 135        snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data, sizeof(data));
 136        snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data, sizeof(data));
 137}
 138