* better

[mascara-docs.git] / i386 / linux-2.3.21 / drivers / sbus / audio / amd7930.c

/*
 * drivers/sbus/audio/amd7930.c
 *
 * Copyright (C) 1996,1997 Thomas K. Dyas (tdyas@eden.rutgers.edu)
 *
 * This is the lowlevel driver for the AMD7930 audio chip found on all
 * sun4c machines and some sun4m machines.
 *
 * The amd7930 is actually an ISDN chip which has a very simple
 * integrated audio encoder/decoder. When Sun decided on what chip to
 * use for audio, they had the brilliant idea of using the amd7930 and
 * only connecting the audio encoder/decoder pins.
 *
 * Thanks to the AMD engineer who was able to get us the AMD79C30
 * databook which has all the programming information and gain tables.
 *
 * Advanced Micro Devices' Am79C30A is an ISDN/audio chip used in the
 * SparcStation 1+.  The chip provides microphone and speaker interfaces
 * which provide mono-channel audio at 8K samples per second via either
 * 8-bit A-law or 8-bit mu-law encoding.  Also, the chip features an
 * ISDN BRI Line Interface Unit (LIU), I.430 S/T physical interface,
 * which performs basic D channel LAPD processing and provides raw
 * B channel data.  The digital audio channel, the two ISDN B channels,
 * and two 64 Kbps channels to the microprocessor are all interconnected
 * via a multiplexer.
 *
 * This driver interfaces to the Linux HiSax ISDN driver, which performs
 * all high-level Q.921 and Q.931 ISDN functions.  The file is not
 * itself a hardware driver; rather it uses functions exported by
 * the AMD7930 driver in the sparcaudio subsystem (drivers/sbus/audio),
 * allowing the chip to be simultaneously used for both audio and ISDN data.
 * The hardware driver does _no_ buffering, but provides several callbacks
 * which are called during interrupt service and should therefore run quickly.
 *
 * D channel transmission is performed by passing the hardware driver the
 * address and size of an skb's data area, then waiting for a callback
 * to signal successful transmission of the packet.  A task is then
 * queued to notify the HiSax driver that another packet may be transmitted.
 *
 * D channel reception is quite simple, mainly because of:
 *   1) the slow speed of the D channel - 16 kbps, and
 *   2) the presence of an 8- or 32-byte (depending on chip version) FIFO
 *      to buffer the D channel data on the chip
 * Worst case scenario of back-to-back packets with the 8 byte buffer
 * at 16 kbps yields an service time of 4 ms - long enough to preclude
 * the need for fancy buffering.  We queue a background task that copies
 * data out of the receive buffer into an skb, and the hardware driver
 * simply does nothing until we're done with the receive buffer and
 * reset it for a new packet.
 *
 * B channel processing is more complex, because of:
 *   1) the faster speed - 64 kbps,
 *   2) the lack of any on-chip buffering (it interrupts for every byte), and
 *   3) the lack of any chip support for HDLC encapsulation
 *
 * The HiSax driver can put each B channel into one of three modes -
 * L1_MODE_NULL (channel disabled), L1_MODE_TRANS (transparent data relay),
 * and L1_MODE_HDLC (HDLC encapsulation by low-level driver).
 * L1_MODE_HDLC is the most common, used for almost all "pure" digital
 * data sessions.  L1_MODE_TRANS is used for ISDN audio.
 *
 * HDLC B channel transmission is performed via a large buffer into
 * which the skb is copied while performing HDLC bit-stuffing.  A CRC
 * is computed and attached to the end of the buffer, which is then
 * passed to the low-level routines for raw transmission.  Once
 * transmission is complete, the hardware driver is set to enter HDLC
 * idle by successive transmission of mark (all 1) bytes, waiting for
 * the ISDN driver to prepare another packet for transmission and
 * deliver it.
 *
 * HDLC B channel reception is performed via an X-byte ring buffer
 * divided into N sections of X/N bytes each.  Defaults: X=256 bytes, N=4.
 * As the hardware driver notifies us that each section is full, we
 * hand it the next section and schedule a background task to peruse
 * the received section, bit-by-bit, with an HDLC decoder.  As
 * packets are detected, they are copied into a large buffer while
 * decoding HDLC bit-stuffing.  The ending CRC is verified, and if
 * it is correct, we alloc a new skb of the correct length (which we
 * now know), copy the packet into it, and hand it to the upper layers.
 * Optimization: for large packets, we hand the buffer (which also
 * happens to be an skb) directly to the upper layer after an skb_trim,
 * and alloc a new large buffer for future packets, thus avoiding a copy.
 * Then we return to HDLC processing; state is saved between calls.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/malloc.h>
#include <linux/init.h>
#include <linux/version.h>
#include <linux/soundcard.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/sbus.h>

#include <asm/audioio.h>
#include "amd7930.h"

static __u8  bilinear2mulaw(__u8 data);
static __u8  mulaw2bilinear(__u8 data);
static __u8  linear2mulaw(__u16 data);
static __u16 mulaw2linear(__u8 data);

#if defined (AMD79C30_ISDN) || defined (LINUX_VERSION_CODE) && LINUX_VERSION_CODE > 0x200ff 
#include "../../isdn/hisax/hisax.h"
#include "../../isdn/hisax/isdnl1.h"
#include "../../isdn/hisax/foreign.h"
#endif

#define MAX_DRIVERS 1

static struct sparcaudio_driver drivers[MAX_DRIVERS];
static int num_drivers;

/* Each amd7930 chip has two bi-directional B channels and a D
 * channel available to the uproc.  This structure handles all
 * the buffering needed to transmit and receive via a single channel.
 */

#define CHANNEL_AVAILABLE       0x00
#define CHANNEL_INUSE_AUDIO_IN  0x01
#define CHANNEL_INUSE_AUDIO_OUT 0x02
#define CHANNEL_INUSE_ISDN_B1   0x04
#define CHANNEL_INUSE_ISDN_B2   0x08
#define CHANNEL_INUSE           0xff

struct amd7930_channel {
        /* Channel status */
        unsigned char channel_status;

        /* Current buffer that the driver is playing on channel */
        volatile __u8 * output_ptr;
        volatile unsigned long output_count;
        unsigned char xmit_idle_char;

        /* Callback routine (and argument) when output is done on */
        void (*output_callback)();
        void * output_callback_arg;

        /* Current buffer that the driver is recording on channel */
        volatile __u8 * input_ptr;
        volatile unsigned long input_count;
        volatile unsigned long input_limit;

        /* Callback routine (and argument) when input is done on */
        void (*input_callback)();
        void * input_callback_arg;

        int input_format;
        int output_format;
};


/* Private information we store for each amd7930 chip. */
struct amd7930_info {
        struct amd7930_channel D;
        struct amd7930_channel Bb;
        struct amd7930_channel Bc;

        /* Pointers to which B channels are being used for what
         * These three fields (Baudio, Bisdn[0], and Bisdn[1]) will either
         * be NULL or point to one of the Bb/Bc structures above.
         */
        struct amd7930_channel *Baudio;
        struct amd7930_channel *Bisdn[2];

        /* Device registers information. */
        struct amd7930 *regs;
        unsigned long regs_size;
        struct amd7930_map map;

        /* Volume information. */
        int pgain, rgain, mgain;

        /* Device interrupt information. */
        int irq;
        volatile int ints_on;

        /* Format type */
        int format_type;


        /* Someone to signal when the ISDN LIU state changes */
        int liu_state;
        void (*liu_callback)(void *);
        void *liu_callback_arg;
};



/* Output a 16-bit quantity in the order that the amd7930 expects. */
#define amd7930_out16(regs,v) ({ regs->dr = v & 0xFF; regs->dr = (v >> 8) & 0xFF; })


/*
 * gx, gr & stg gains.  this table must contain 256 elements with
 * the 0th being "infinity" (the magic value 9008).  The remaining
 * elements match sun's gain curve (but with higher resolution):
 * -18 to 0dB in .16dB steps then 0 to 12dB in .08dB steps.
 */
static __const__ __u16 gx_coeff[256] = {
        0x9008, 0x8b7c, 0x8b51, 0x8b45, 0x8b42, 0x8b3b, 0x8b36, 0x8b33,
        0x8b32, 0x8b2a, 0x8b2b, 0x8b2c, 0x8b25, 0x8b23, 0x8b22, 0x8b22,
        0x9122, 0x8b1a, 0x8aa3, 0x8aa3, 0x8b1c, 0x8aa6, 0x912d, 0x912b,
        0x8aab, 0x8b12, 0x8aaa, 0x8ab2, 0x9132, 0x8ab4, 0x913c, 0x8abb,
        0x9142, 0x9144, 0x9151, 0x8ad5, 0x8aeb, 0x8a79, 0x8a5a, 0x8a4a,
        0x8b03, 0x91c2, 0x91bb, 0x8a3f, 0x8a33, 0x91b2, 0x9212, 0x9213,
        0x8a2c, 0x921d, 0x8a23, 0x921a, 0x9222, 0x9223, 0x922d, 0x9231,
        0x9234, 0x9242, 0x925b, 0x92dd, 0x92c1, 0x92b3, 0x92ab, 0x92a4,
        0x92a2, 0x932b, 0x9341, 0x93d3, 0x93b2, 0x93a2, 0x943c, 0x94b2,
        0x953a, 0x9653, 0x9782, 0x9e21, 0x9d23, 0x9cd2, 0x9c23, 0x9baa,
        0x9bde, 0x9b33, 0x9b22, 0x9b1d, 0x9ab2, 0xa142, 0xa1e5, 0x9a3b,
        0xa213, 0xa1a2, 0xa231, 0xa2eb, 0xa313, 0xa334, 0xa421, 0xa54b,
        0xada4, 0xac23, 0xab3b, 0xaaab, 0xaa5c, 0xb1a3, 0xb2ca, 0xb3bd,
        0xbe24, 0xbb2b, 0xba33, 0xc32b, 0xcb5a, 0xd2a2, 0xe31d, 0x0808,
        0x72ba, 0x62c2, 0x5c32, 0x52db, 0x513e, 0x4cce, 0x43b2, 0x4243,
        0x41b4, 0x3b12, 0x3bc3, 0x3df2, 0x34bd, 0x3334, 0x32c2, 0x3224,
        0x31aa, 0x2a7b, 0x2aaa, 0x2b23, 0x2bba, 0x2c42, 0x2e23, 0x25bb,
        0x242b, 0x240f, 0x231a, 0x22bb, 0x2241, 0x2223, 0x221f, 0x1a33,
        0x1a4a, 0x1acd, 0x2132, 0x1b1b, 0x1b2c, 0x1b62, 0x1c12, 0x1c32,
        0x1d1b, 0x1e71, 0x16b1, 0x1522, 0x1434, 0x1412, 0x1352, 0x1323,
        0x1315, 0x12bc, 0x127a, 0x1235, 0x1226, 0x11a2, 0x1216, 0x0a2a,
        0x11bc, 0x11d1, 0x1163, 0x0ac2, 0x0ab2, 0x0aab, 0x0b1b, 0x0b23,
        0x0b33, 0x0c0f, 0x0bb3, 0x0c1b, 0x0c3e, 0x0cb1, 0x0d4c, 0x0ec1,
        0x079a, 0x0614, 0x0521, 0x047c, 0x0422, 0x03b1, 0x03e3, 0x0333,
        0x0322, 0x031c, 0x02aa, 0x02ba, 0x02f2, 0x0242, 0x0232, 0x0227,
        0x0222, 0x021b, 0x01ad, 0x0212, 0x01b2, 0x01bb, 0x01cb, 0x01f6,
        0x0152, 0x013a, 0x0133, 0x0131, 0x012c, 0x0123, 0x0122, 0x00a2,
        0x011b, 0x011e, 0x0114, 0x00b1, 0x00aa, 0x00b3, 0x00bd, 0x00ba,
        0x00c5, 0x00d3, 0x00f3, 0x0062, 0x0051, 0x0042, 0x003b, 0x0033,
        0x0032, 0x002a, 0x002c, 0x0025, 0x0023, 0x0022, 0x001a, 0x0021,
        0x001b, 0x001b, 0x001d, 0x0015, 0x0013, 0x0013, 0x0012, 0x0012,
        0x000a, 0x000a, 0x0011, 0x0011, 0x000b, 0x000b, 0x000c, 0x000e,
};

static __const__ __u16 ger_coeff[] = {
        0x431f, /* 5. dB */
        0x331f, /* 5.5 dB */
        0x40dd, /* 6. dB */
        0x11dd, /* 6.5 dB */
        0x440f, /* 7. dB */
        0x411f, /* 7.5 dB */
        0x311f, /* 8. dB */
        0x5520, /* 8.5 dB */
        0x10dd, /* 9. dB */
        0x4211, /* 9.5 dB */
        0x410f, /* 10. dB */
        0x111f, /* 10.5 dB */
        0x600b, /* 11. dB */
        0x00dd, /* 11.5 dB */
        0x4210, /* 12. dB */
        0x110f, /* 13. dB */
        0x7200, /* 14. dB */
        0x2110, /* 15. dB */
        0x2200, /* 15.9 dB */
        0x000b, /* 16.9 dB */
        0x000f  /* 18. dB */
};
#define NR_GER_COEFFS (sizeof(ger_coeff) / sizeof(ger_coeff[0]))

/* Enable amd7930 interrupts atomically. */
static __inline__ void amd7930_enable_ints(struct amd7930_info *info)
{
        register unsigned long flags;

        if (info->ints_on)
                return;

        save_and_cli(flags);
        info->regs->cr = AMR_INIT;
        info->regs->dr = AM_INIT_ACTIVE;
        restore_flags(flags);

        info->ints_on = 1;
}

/* Disable amd7930 interrupts atomically. */
static __inline__ void amd7930_disable_ints(struct amd7930_info *info)
{
        register unsigned long flags;

        if (!info->ints_on)
                return;

        save_and_cli(flags);
        info->regs->cr = AMR_INIT;
        info->regs->dr = AM_INIT_ACTIVE | AM_INIT_DISABLE_INTS;
        restore_flags(flags);

        info->ints_on = 0;
}  

/* Idle amd7930 (no interrupts, no audio, no data) */
static __inline__ void amd7930_idle(struct amd7930_info *info)
{
        register unsigned long flags;

        if (!info->ints_on)
                return;

        save_and_cli(flags);
        info->regs->cr = AMR_INIT;
        info->regs->dr = 0;
        restore_flags(flags);

        info->ints_on = 0;
}  

/* Commit the local copy of the MAP registers to the amd7930. */
static void amd7930_write_map(struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;
        struct amd7930      *regs = info->regs;
        struct amd7930_map  *map  = &info->map;
        unsigned long flags;

        save_and_cli(flags);

        regs->cr = AMR_MAP_GX;
        amd7930_out16(regs, map->gx);

        regs->cr = AMR_MAP_GR;
        amd7930_out16(regs, map->gr);

        regs->cr = AMR_MAP_STGR;
        amd7930_out16(regs, map->stgr);

        regs->cr = AMR_MAP_GER;
        amd7930_out16(regs, map->ger);

        regs->cr = AMR_MAP_MMR1;
        regs->dr = map->mmr1;

        regs->cr = AMR_MAP_MMR2;
        regs->dr = map->mmr2;

        restore_flags(flags);
}

/* Update the MAP registers with new settings. */
static void amd7930_update_map(struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;
        struct amd7930_map  *map  = &info->map;
        int level;

        map->gx = gx_coeff[info->rgain];
        map->stgr = gx_coeff[info->mgain];

        level = (info->pgain * (256 + NR_GER_COEFFS)) >> 8;
        if (level >= 256) {
                map->ger = ger_coeff[level - 256];
                map->gr = gx_coeff[255];
        } else {
                map->ger = ger_coeff[0];
                map->gr = gx_coeff[level];
        }

        amd7930_write_map(drv);
}

/* Bit of a hack here - if the HISAX ISDN driver has got INTSTAT debugging
 * turned on, we send debugging characters to the ISDN driver:
 *
 *   i# - Interrupt received - number from 0 to 7 is low three bits of IR
 *   >  - Loaded a single char into the Dchan xmit FIFO
 *   +  - Finished loading an xmit packet into the Dchan xmit FIFO
 *   <  - Read a single char from the Dchan recv FIFO
 *   !  - Finished reading a packet from the Dchan recv FIFO
 *
 * This code needs to be removed if anything other than HISAX uses the ISDN
 * driver, since D.output_callback_arg is assumed to be a certain struct ptr
 */

#ifdef L2FRAME_DEBUG

inline void debug_info(struct amd7930_info *info, char c) {
        struct IsdnCardState *cs;

        if (!info || !info->D.output_callback_arg) return;

        cs = (struct IsdnCardState *)info->D.output_callback_arg;

        if (!cs || !cs->status_write) return;

        if (cs->debug & L1_DEB_INTSTAT) {
                *(cs->status_write++) = c;
                if (cs->status_write > cs->status_end)
                        cs->status_write = cs->status_buf;
        }
}

#else

#define debug_info(info,c)

#endif


static void fill_D_xmit_fifo(struct amd7930_info *info)
{
        /* Send next byte(s) of outgoing data. */
        while (info->D.output_ptr && info->D.output_count > 0 &&
               (info->regs->dsr2 & AMR_DSR2_TBE)) {

                /* Send the next byte and advance buffer pointer. */
                info->regs->dctb = *(info->D.output_ptr);
                info->D.output_ptr++;
                info->D.output_count--;

                debug_info(info, '>');
        }
}

static void transceive_Dchannel(struct amd7930_info *info)
{
        __u8 dummy;

#define D_XMIT_ERRORS (AMR_DER_COLLISION | AMR_DER_UNRN)
#define D_RECV_ERRORS (AMR_DER_RABRT | AMR_DER_RFRAME | AMR_DER_FCS | \
                        AMR_DER_OVFL | AMR_DER_UNFL | AMR_DER_OVRN)

        /* Transmit if we can */
        fill_D_xmit_fifo(info);

        /* Done with the xmit buffer? Notify the midlevel driver. */
        if (info->D.output_ptr != NULL && info->D.output_count == 0) {
                info->D.output_ptr = NULL;
                info->D.output_count = 0;
                debug_info(info, '+');
                if (info->D.output_callback)
                        (*info->D.output_callback)
                                (info->D.output_callback_arg,
                                 info->regs->der);
                                 /* info->regs->der & D_XMIT_ERRORS); */
        }

        /* Read the next byte(s) of incoming data. */

        while (info->regs->dsr2 & AMR_DSR2_RBA) {

                if (info->D.input_ptr &&
                    (info->D.input_count < info->D.input_limit)) {

                        /* Get the next byte and advance buffer pointer. */

                        *(info->D.input_ptr) = info->regs->dcrb;
                        info->D.input_ptr++;
                        info->D.input_count++;

                } else {

                        /* Overflow - should be detected by chip via RBLR
                         * so we'll just consume data until we see LBRP
                         */

                        dummy = info->regs->dcrb;

                }

                debug_info(info, '<');

                if (info->regs->dsr2 & AMR_DSR2_LBRP) {

                        /* End of recv packet? Notify the midlevel driver. */

                        __u8 der;

                        debug_info(info, '!');

                        info->D.input_ptr = NULL;

                        der = info->regs->der & D_RECV_ERRORS;

                        /* Read receive byte count - advances FIFOs */
                        info->regs->cr = AMR_DLC_DRCR;
                        dummy = info->regs->dr;
                        dummy = info->regs->dr;

                        if (info->D.input_callback)
                                (*info->D.input_callback)
                                        (info->D.input_callback_arg, der,
                                         info->D.input_count);
                }

        }
}

long amd7930_xmit_idles=0;

static void transceive_Bchannel(struct amd7930_channel *channel,
        __volatile__ __u8 *io_reg)
{
        /* Send the next byte of outgoing data. */
        if (channel->output_ptr && channel->output_count > 0) {

                /* Send the next byte and advance buffer pointer. */
                switch(channel->output_format) {
                case AUDIO_ENCODING_ULAW:
                case AUDIO_ENCODING_ALAW:
                        *io_reg = *(channel->output_ptr);
                        break;
                case AUDIO_ENCODING_LINEAR8:
                        *io_reg = bilinear2mulaw(*(channel->output_ptr));
                        break;
                case AUDIO_ENCODING_LINEAR:
                        if (channel->output_count >= 2) {
                                *io_reg = linear2mulaw(*((__u16*)(channel->output_ptr)));
                                channel->output_ptr++;
                                channel->output_count--;
                        };
                };
                channel->output_ptr++;
                channel->output_count--;


                /* Done with the buffer? Notify the midlevel driver. */
                if (channel->output_count == 0) {
                        channel->output_ptr = NULL;
                        channel->output_count = 0;
                        if (channel->output_callback)
                                (*channel->output_callback)
                                        (channel->output_callback_arg,1);
                }
        } else {
                *io_reg = channel->xmit_idle_char;
                amd7930_xmit_idles++;
        }

        /* Read the next byte of incoming data. */
        if (channel->input_ptr && channel->input_count > 0) {

                /* Get the next byte and advance buffer pointer. */
                switch(channel->input_format) {
                case AUDIO_ENCODING_ULAW:
                case AUDIO_ENCODING_ALAW:
                        *(channel->input_ptr) = *io_reg;
                        break;
                case AUDIO_ENCODING_LINEAR8:
                        *(channel->input_ptr) = mulaw2bilinear(*io_reg);
                        break;
                case AUDIO_ENCODING_LINEAR:
                        if (channel->input_count >= 2) {
                                *((__u16*)(channel->input_ptr)) = mulaw2linear(*io_reg);
                                channel->input_ptr++;
                                channel->input_count--;
                        } else *(channel->input_ptr) = 0;
                };
                channel->input_ptr++;
                channel->input_count--;

                /* Done with the buffer? Notify the midlevel driver. */
                if (channel->input_count == 0) {
                        channel->input_ptr = NULL;
                        channel->input_count = 0;
                        if (channel->input_callback)
                                (*channel->input_callback)
                                        (channel->input_callback_arg, 1);
                }
        }
}

/* Interrupt handler (The chip takes only one byte per interrupt. Grrr!) */
static void amd7930_interrupt(int irq, void *dev_id, struct pt_regs *intr_regs)
{
        struct sparcaudio_driver *drv = (struct sparcaudio_driver *)dev_id;
        struct amd7930_info *info = (struct amd7930_info *)drv->private;
        struct amd7930 *regs = info->regs;
        __u8 ir;
        __u8 lsr;

        /* Clear the interrupt. */
        ir = regs->ir;

        if (ir & AMR_IR_BBUF) {
                if (info->Bb.channel_status == CHANNEL_INUSE)
                        transceive_Bchannel(&info->Bb, &info->regs->bbtb);
                if (info->Bc.channel_status == CHANNEL_INUSE)
                        transceive_Bchannel(&info->Bc, &info->regs->bctb);
        }

        if (ir & (AMR_IR_DRTHRSH | AMR_IR_DTTHRSH | AMR_IR_DSRI)) {
                debug_info(info, 'i');
                debug_info(info, '0' + (ir&7));
                transceive_Dchannel(info);
        }

        if (ir & AMR_IR_LSRI) {
                regs->cr = AMR_LIU_LSR;
                lsr = regs->dr;

                info->liu_state = (lsr&0x7) + 2;

                if (info->liu_callback)
                        (*info->liu_callback)(info->liu_callback_arg);
        }
}


static int amd7930_open(struct inode * inode, struct file * file,
                        struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        switch(MINOR(inode->i_rdev) & 0xf) {
        case SPARCAUDIO_AUDIO_MINOR:
                info->format_type = AUDIO_ENCODING_ULAW;
                break;
        case SPARCAUDIO_DSP_MINOR:
                info->format_type = AUDIO_ENCODING_LINEAR8;
                break;
        case SPARCAUDIO_DSP16_MINOR:
                info->format_type = AUDIO_ENCODING_LINEAR;
                break;
        };

        MOD_INC_USE_COUNT;
        return 0;
}

static void amd7930_release(struct inode * inode, struct file * file,
                            struct sparcaudio_driver *drv)
{
        /* amd7930_disable_ints(drv->private); */
        MOD_DEC_USE_COUNT;
}

static void request_Baudio(struct amd7930_info *info)
{
        if (info->Bb.channel_status == CHANNEL_AVAILABLE) {

                info->Bb.channel_status = CHANNEL_INUSE;
                info->Baudio = &info->Bb;

                /* Multiplexor map - audio (Ba) to Bb */
                info->regs->cr = AMR_MUX_MCR1;
                info->regs->dr = AM_MUX_CHANNEL_Ba | (AM_MUX_CHANNEL_Bb << 4);

                /* Enable B channel interrupts */
                info->regs->cr = AMR_MUX_MCR4;
                info->regs->dr = AM_MUX_MCR4_ENABLE_INTS;

        } else if (info->Bc.channel_status == CHANNEL_AVAILABLE) {

                info->Bc.channel_status = CHANNEL_INUSE;
                info->Baudio = &info->Bc;

                /* Multiplexor map - audio (Ba) to Bc */
                info->regs->cr = AMR_MUX_MCR1;
                info->regs->dr = AM_MUX_CHANNEL_Ba | (AM_MUX_CHANNEL_Bc << 4);

                /* Enable B channel interrupts */
                info->regs->cr = AMR_MUX_MCR4;
                info->regs->dr = AM_MUX_MCR4_ENABLE_INTS;

        }
}

static void release_Baudio(struct amd7930_info *info)
{
        if (info->Baudio) {
                info->Baudio->channel_status = CHANNEL_AVAILABLE;
                info->regs->cr = AMR_MUX_MCR1;
                info->regs->dr = 0;
                info->Baudio = NULL;

                if (info->Bb.channel_status == CHANNEL_AVAILABLE &&
                    info->Bc.channel_status == CHANNEL_AVAILABLE) {

                        /* Disable B channel interrupts */
                        info->regs->cr = AMR_MUX_MCR4;
                        info->regs->dr = 0;
                }
        }
}

static void amd7930_start_output(struct sparcaudio_driver *drv,
                                 __u8 * buffer, unsigned long count)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        if (! info->Baudio) {
                request_Baudio(info);
        }

        if (info->Baudio) {
                info->Baudio->output_ptr = buffer;
                info->Baudio->output_count = count;
                info->Baudio->output_format = info->format_type;
        info->Baudio->output_callback = (void *) &sparcaudio_output_done;
        info->Baudio->output_callback_arg = (void *) drv;
                info->Baudio->xmit_idle_char = 0;
        }
}

static void amd7930_stop_output(struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        if (info->Baudio) {
                info->Baudio->output_ptr = NULL;
                info->Baudio->output_count = 0;
                if (! info->Baudio->input_ptr)
                        release_Baudio(info);
        }
}

static void amd7930_start_input(struct sparcaudio_driver *drv,
                                __u8 * buffer, unsigned long count)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        if (! info->Baudio) {
                request_Baudio(info);
        }

        if (info->Baudio) {
                info->Baudio->input_ptr = buffer;
                info->Baudio->input_count = count;
                info->Baudio->input_format = info->format_type;
                info->Baudio->input_callback = (void *) &sparcaudio_input_done;
                info->Baudio->input_callback_arg = (void *) drv;
        }
}

static void amd7930_stop_input(struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        if (info->Baudio) {
                info->Baudio->input_ptr = NULL;
                info->Baudio->input_count = 0;
                if (! info->Baudio->output_ptr)
                        release_Baudio(info);
        }

}

static void amd7930_sunaudio_getdev(struct sparcaudio_driver *drv,
                                 audio_device_t * audinfo)
{
        strncpy(audinfo->name, "SUNW,am79c30", sizeof(audinfo->name) - 1);
        strncpy(audinfo->version, "a", sizeof(audinfo->version) - 1);
        strncpy(audinfo->config, "onboard1", sizeof(audinfo->config) - 1);
}

static int amd7930_sunaudio_getdev_sunos(struct sparcaudio_driver *drv)
{
        return AUDIO_DEV_AMD;
}

static int amd7930_get_formats(struct sparcaudio_driver *drv)
{
      return (AFMT_MU_LAW | AFMT_A_LAW | AFMT_U8 | AFMT_S16_BE);
}

static int amd7930_get_output_ports(struct sparcaudio_driver *drv)
{
      return (AUDIO_SPEAKER | AUDIO_HEADPHONE);
}

static int amd7930_get_input_ports(struct sparcaudio_driver *drv)
{
      return (AUDIO_MICROPHONE);
}

static int amd7930_set_output_volume(struct sparcaudio_driver *drv, int vol)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        info->pgain = vol;
        amd7930_update_map(drv);
        return 0;
}

static int amd7930_get_output_volume(struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        return info->pgain;
}

static int amd7930_set_input_volume(struct sparcaudio_driver *drv, int vol)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        info->rgain = vol;
        amd7930_update_map(drv);
        return 0;
}

static int amd7930_get_input_volume(struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        return info->rgain;
}

static int amd7930_set_monitor_volume(struct sparcaudio_driver *drv, int vol)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        info->mgain = vol;
        amd7930_update_map(drv);
        return 0;
}

static int amd7930_get_monitor_volume(struct sparcaudio_driver *drv)
{
      struct amd7930_info *info = (struct amd7930_info *)drv->private;

      return info->mgain;
}

/* Cheats. The amd has the minimum capabilities we support */
static int amd7930_get_output_balance(struct sparcaudio_driver *drv)
{
        return AUDIO_MID_BALANCE;
}

static int amd7930_get_input_balance(struct sparcaudio_driver *drv)
{
        return AUDIO_MID_BALANCE;
}

static int amd7930_get_output_channels(struct sparcaudio_driver *drv)
{
        return AUDIO_MIN_PLAY_CHANNELS;
}

static int amd7930_set_output_channels(struct sparcaudio_driver *drv, 
                                       int value)
{
  return (value == AUDIO_MIN_PLAY_CHANNELS) ? 0 : -EINVAL;
}

static int amd7930_get_input_channels(struct sparcaudio_driver *drv)
{
        return AUDIO_MIN_REC_CHANNELS;
}

static int 
amd7930_set_input_channels(struct sparcaudio_driver *drv, int value)
{
  return (value == AUDIO_MIN_REC_CHANNELS) ? 0 : -EINVAL;
}

static int amd7930_get_output_precision(struct sparcaudio_driver *drv)
{
        return AUDIO_MIN_PLAY_PRECISION;
}

static int 
amd7930_set_output_precision(struct sparcaudio_driver *drv, int value)
{
  return (value == AUDIO_MIN_PLAY_PRECISION) ? 0 : -EINVAL;
}

static int amd7930_get_input_precision(struct sparcaudio_driver *drv)
{
        return AUDIO_MIN_REC_PRECISION;
}

static int 
amd7930_set_input_precision(struct sparcaudio_driver *drv, int value)
{
  return (value == AUDIO_MIN_REC_PRECISION) ? 0 : -EINVAL;
}

static int amd7930_get_output_port(struct sparcaudio_driver *drv)
{
  struct amd7930_info *info = (struct amd7930_info *)drv->private;
  if (info->map.mmr2 & AM_MAP_MMR2_LS)
    return AUDIO_SPEAKER; 
  return AUDIO_HEADPHONE;
}

static int amd7930_set_output_port(struct sparcaudio_driver *drv, int value)
{
  struct amd7930_info *info = (struct amd7930_info *)drv->private;
  switch (value) {
  case AUDIO_HEADPHONE:
    info->map.mmr2 &= ~AM_MAP_MMR2_LS;
    break;
  case AUDIO_SPEAKER:
    info->map.mmr2 |= AM_MAP_MMR2_LS;
    break;
  default:
    return -EINVAL;
  }
  amd7930_update_map(drv);
  return 0;
}

/* Only a microphone here, so no troubles */
static int amd7930_get_input_port(struct sparcaudio_driver *drv)
{
        return AUDIO_MICROPHONE;
}

static int amd7930_get_encoding(struct sparcaudio_driver *drv)
{
  struct amd7930_info *info = (struct amd7930_info *)drv->private;
  if ((info->map.mmr1 & AM_MAP_MMR1_ALAW) && 
      (info->format_type == AUDIO_ENCODING_ALAW))
    return AUDIO_ENCODING_ALAW;

  return info->format_type;
}

static int 
amd7930_set_encoding(struct sparcaudio_driver *drv, int value)
{
  struct amd7930_info *info = (struct amd7930_info *)drv->private;

  switch (value) {
  case AUDIO_ENCODING_ALAW:
    info->map.mmr1 |= AM_MAP_MMR1_ALAW;
    break;
  case AUDIO_ENCODING_LINEAR8:
  case AUDIO_ENCODING_LINEAR:
  case AUDIO_ENCODING_ULAW:
    info->map.mmr1 &= ~AM_MAP_MMR1_ALAW;
    break;
  default:
    return -EINVAL;
  };

  info->format_type = value;

  amd7930_update_map(drv);
  return 0;
}

/* This is what you get. Take it or leave it */
static int amd7930_get_output_rate(struct sparcaudio_driver *drv)
{
        return AMD7930_RATE;
}

static int 
amd7930_set_output_rate(struct sparcaudio_driver *drv, int value)
{
  return (value == AMD7930_RATE) ? 0 : -EINVAL;
}

static int amd7930_get_input_rate(struct sparcaudio_driver *drv)
{
        return AMD7930_RATE;
}

static int
amd7930_set_input_rate(struct sparcaudio_driver *drv, int value)
{
  return (value == AMD7930_RATE) ? 0 : -EINVAL;
}

static int amd7930_get_output_muted(struct sparcaudio_driver *drv)
{
      return 0;
}

static void amd7930_loopback(struct sparcaudio_driver *drv, unsigned int value)
{
  struct amd7930_info *info = (struct amd7930_info *)drv->private;

  if (value)
    info->map.mmr1 |= AM_MAP_MMR1_LOOPBACK;
  else
    info->map.mmr1 &= ~AM_MAP_MMR1_LOOPBACK;
  amd7930_update_map(drv);
  return;
}

static int amd7930_ioctl(struct inode * inode, struct file * file,
                         unsigned int cmd, unsigned long arg, 
                         struct sparcaudio_driver *drv)
{
  int retval = 0;
  
  switch (cmd) {
  case AUDIO_DIAG_LOOPBACK:
    amd7930_loopback(drv, (unsigned int)arg);
    break;
  default:
    retval = -EINVAL;
  }

  return retval;
}


/*
 *       ISDN operations
 *
 * Many of these routines take an "int dev" argument, which is simply
 * an index into the drivers[] array.  Currently, we only support a
 * single AMD 7930 chip, so the value should always be 0.  B channel
 * operations require an "int chan", which should be 0 for channel B1
 * and 1 for channel B2
 *
 * int amd7930_get_irqnum(int dev)
 *
 *   returns the interrupt number being used by the chip.  ISDN4linux
 *   uses this number to watch the interrupt during initialization and
 *   make sure something is happening.
 *
 * int amd7930_get_liu_state(int dev)
 *
 *   returns the current state of the ISDN Line Interface Unit (LIU)
 *   as a number between 2 (state F2) and 7 (state F7).  0 may also be
 *   returned if the chip doesn't exist or the LIU hasn't been
 *   activated.  The meanings of the states are defined in I.430, ISDN
 *   BRI Physical Layer Interface.  The most important two states are
 *   F3 (shutdown) and F7 (syncronized).
 *
 * void amd7930_liu_init(int dev, void (*callback)(), void *callback_arg)
 *
 *   initializes the LIU and optionally registers a callback to be
 *   signaled upon a change of LIU state.  The callback will be called
 *   with a single opaque callback_arg Once the callback has been
 *   triggered, amd7930_get_liu_state can be used to determine the LIU
 *   current state.
 *
 * void amd7930_liu_activate(int dev, int priority)
 *
 *   requests LIU activation at a given D-channel priority.
 *   Successful activatation is achieved upon entering state F7, which
 *   will trigger any callback previously registered with
 *   amd7930_liu_init.
 *
 * void amd7930_liu_deactivate(int dev)
 *
 *   deactivates LIU.  Outstanding D and B channel transactions are
 *   terminated rudely and without callback notification.  LIU change
 *   of state callback will be triggered, however.
 *
 * void amd7930_dxmit(int dev, __u8 *buffer, unsigned int count,
 *               void (*callback)(void *, int), void *callback_arg)
 *
 *   transmits a packet - specified with buffer, count - over the D-channel
 *   interface.  Buffer should begin with the LAPD address field and
 *   end with the information field.  FCS and flag sequences should not
 *   be included, nor is bit-stuffing required - all these functions are
 *   performed by the chip.  The callback function will be called
 *   DURING THE TOP HALF OF AN INTERRUPT HANDLER and will be passed
 *   both the arbitrary callback_arg and an integer error indication:
 *
 *       0 - successful transmission; ready for next packet
 *   non-0 - error value from chip's DER (D-Channel Error Register):
 *       4 - collision detect
 *     128 - underrun; irq routine didn't service chip fast enough
 *
 *   The callback routine should defer any time-consuming operations
 *   to a bottom-half handler; however, amd7930_dxmit may be called
 *   from within the callback to request back-to-back transmission of
 *   a second packet (without repeating the priority/collision mechanism)
 *
 *   A comment about the "collision detect" error, which is signalled
 *   whenever the echoed D-channel data didn't match the transmitted
 *   data.  This is part of ISDN's normal multi-drop T-interface
 *   operation, indicating that another device has attempted simultaneous
 *   transmission, but can also result from line noise.  An immediate
 *   requeue via amd7930_dxmit is suggested, but repeated collision
 *   errors may indicate a more serious problem.
 *
 * void amd7930_drecv(int dev, __u8 *buffer, unsigned int size,
 *               void (*callback)(void *, int, unsigned int),
 *               void *callback_arg)
 *
 *   register a buffer - buffer, size - into which a D-channel packet
 *   can be received.  The callback function will be called DURING
 *   THE TOP HALF OF AN INTERRUPT HANDLER and will be passed an
 *   arbitrary callback_arg, an integer error indication and the length
 *   of the received packet, which will start with the address field,
 *   end with the information field, and not contain flag or FCS
 *   bytes.  Bit-stuffing will already have been corrected for.
 *   Possible values of second callback argument "error":
 *
 *       0 - successful reception
 *   non-0 - error value from chip's DER (D-Channel Error Register):
 *       1 - received packet abort
 *       2 - framing error; non-integer number of bytes received
 *       8 - FCS error; CRC sequence indicated corrupted data
 *      16 - overflow error; packet exceeded size of buffer
 *      32 - underflow error; packet smaller than required five bytes
 *      64 - overrun error; irq routine didn't service chip fast enough
 *
 * int amd7930_bopen(int dev, int chan, u_char xmit_idle_char)
 *
 *   This function should be called before any other operations on a B
 *   channel.  In addition to arranging for interrupt handling and
 *   channel multiplexing, it sets the xmit_idle_char which is
 *   transmitted on the interface when no data buffer is available.
 *   Suggested values are: 0 for ISDN audio; FF for HDLC mark idle; 7E
 *   for HDLC flag idle.  Returns 0 on a successful open; -1 on error,
 *   which is quite possible if audio and the other ISDN channel are
 *   already in use, since the Am7930 can only send two of the three
 *   channels to the processor
 *
 * void amd7930_bclose(int dev, int chan)
 *
 *   Shuts down a B channel when no longer in use.
 *
 * void amd7930_bxmit(int dev, int chan, __u8 *buffer, unsigned int count,
 *               void (*callback)(void *), void *callback_arg)
 *
 *   transmits a raw data block - specified with buffer, count - over
 *   the B channel interface specified by dev/chan.  The callback
 *   function will be called DURING THE TOP HALF OF AN INTERRUPT
 *   HANDLER and will be passed the arbitrary callback_arg
 *
 *   The callback routine should defer any time-consuming operations
 *   to a bottom-half handler; however, amd7930_bxmit may be called
 *   from within the callback to request back-to-back transmission of
 *   another data block
 *
 * void amd7930_brecv(int dev, int chan, __u8 *buffer, unsigned int size,
 *               void (*callback)(void *), void *callback_arg)
 *
 *   receive a raw data block - specified with buffer, size - over the
 *   B channel interface specified by dev/chan.  The callback function
 *   will be called DURING THE TOP HALF OF AN INTERRUPT HANDLER and
 *   will be passed the arbitrary callback_arg
 *
 *   The callback routine should defer any time-consuming operations
 *   to a bottom-half handler; however, amd7930_brecv may be called
 *   from within the callback to register another buffer and ensure
 *   continuous B channel reception without loss of data
 *
 */

#if defined (AMD79C30_ISDN) || defined (LINUX_VERSION_CODE) && LINUX_VERSION_CODE > 0x200ff 
static int amd7930_get_irqnum(int dev)
{
        struct amd7930_info *info;

        if (dev > num_drivers) {
                return(0);
        }

        info = (struct amd7930_info *) drivers[dev].private;

        return info->irq;
}

static int amd7930_get_liu_state(int dev)
{
        struct amd7930_info *info;

        if (dev > num_drivers) {
                return(0);
        }

        info = (struct amd7930_info *) drivers[dev].private;

        return info->liu_state;
}

static void amd7930_liu_init(int dev, void (*callback)(), void *callback_arg)
{
        struct amd7930_info *info;
        register unsigned long flags;

        if (dev > num_drivers) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;

        save_and_cli(flags);

        /* Set callback for LIU state change */
        info->liu_callback = callback;
        info->liu_callback_arg = callback_arg;

        /* De-activate the ISDN Line Interface Unit (LIU) */
        info->regs->cr = AMR_LIU_LMR1;
        info->regs->dr = 0;

        /* Request interrupt when LIU changes state from/to F3/F7/F8 */
        info->regs->cr = AMR_LIU_LMR2;
        info->regs->dr = AM_LIU_LMR2_EN_F3_INT |
          AM_LIU_LMR2_EN_F7_INT | AM_LIU_LMR2_EN_F8_INT;

        /* amd7930_enable_ints(info); */

        /* Activate the ISDN Line Interface Unit (LIU) */
        info->regs->cr = AMR_LIU_LMR1;
        info->regs->dr = AM_LIU_LMR1_LIU_ENABL;

        restore_flags(flags);
}

static void amd7930_liu_activate(int dev, int priority)
{
        struct amd7930_info *info;
        register unsigned long flags;

        if (dev > num_drivers) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;

        save_and_cli(flags);

        /* Set D-channel access priority
         *
         * I.430 defines a priority mechanism based on counting 1s
         * in the echo channel before transmitting
         *
         * Priority 0 is eight 1s; priority 1 is ten 1s; etc
         */

        info->regs->cr = AMR_LIU_LPR;
        info->regs->dr = priority & 0x0f;

        /* request LIU activation */

        info->regs->cr = AMR_LIU_LMR1;
        info->regs->dr = AM_LIU_LMR1_LIU_ENABL | AM_LIU_LMR1_REQ_ACTIV;

        restore_flags(flags);
}

static void amd7930_liu_deactivate(int dev)
{
        struct amd7930_info *info;
        register unsigned long flags;

        if (dev > num_drivers) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;

        save_and_cli(flags);

        /* deactivate LIU */

        info->regs->cr = AMR_LIU_LMR1;
        info->regs->dr = 0;

        restore_flags(flags);
}

static void amd7930_dxmit(int dev, __u8 *buffer, unsigned int count,
                          void (*callback)(void *, int), void *callback_arg)
{
        struct amd7930_info *info;
        register unsigned long flags;
        __u8 dmr1;

        if (dev > num_drivers) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;

        save_and_cli(flags);

        if (info->D.output_ptr) {
                restore_flags(flags);
                printk("amd7930_dxmit: transmitter in use\n");
                return;
        }

        info->D.output_ptr = buffer;
        info->D.output_count = count;
        info->D.output_callback = callback;
        info->D.output_callback_arg = callback_arg;

        /* Enable D-channel Transmit Threshold interrupt; disable addressing */
        info->regs->cr = AMR_DLC_DMR1;
        dmr1 = info->regs->dr;
        dmr1 |= AMR_DLC_DMR1_DTTHRSH_INT;
        dmr1 &= ~AMR_DLC_DMR1_EN_ADDRS;
        info->regs->dr = dmr1;

        /* Begin xmit by setting D-channel Transmit Byte Count Reg (DTCR) */
        info->regs->cr = AMR_DLC_DTCR;
        info->regs->dr = count & 0xff;
        info->regs->dr = (count >> 8) & 0xff;

        /* Prime xmit FIFO */
        /* fill_D_xmit_fifo(info); */
        transceive_Dchannel(info);

        restore_flags(flags);
}

static void amd7930_drecv(int dev, __u8 *buffer, unsigned int size,
                          void (*callback)(void *, int, unsigned int),
                          void *callback_arg)
{
        struct amd7930_info *info;
        register unsigned long flags;
        __u8 dmr1;

        if (dev > num_drivers) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;

        save_and_cli(flags);

        if (info->D.input_ptr) {
                restore_flags(flags);
                printk("amd7930_drecv: receiver already has buffer!\n");
                return;
        }

        info->D.input_ptr = buffer;
        info->D.input_count = 0;
        info->D.input_limit = size;
        info->D.input_callback = callback;
        info->D.input_callback_arg = callback_arg;

        /* Enable D-channel Receive Threshold interrupt;
         * Enable D-channel End of Receive Packet interrupt;
         * Disable address recognition
         */
        info->regs->cr = AMR_DLC_DMR1;
        dmr1 = info->regs->dr;
        dmr1 |= AMR_DLC_DMR1_DRTHRSH_INT | AMR_DLC_DMR1_EORP_INT;
        dmr1 &= ~AMR_DLC_DMR1_EN_ADDRS;
        info->regs->dr = dmr1;

        /* Set D-channel Receive Byte Count Limit Register */
        info->regs->cr = AMR_DLC_DRCR;
        info->regs->dr = size & 0xff;
        info->regs->dr = (size >> 8) & 0xff;

        restore_flags(flags);
}

static int amd7930_bopen(int dev, unsigned int chan, 
                         int mode, u_char xmit_idle_char)
{
        struct amd7930_info *info;
        register unsigned long flags;

        if (dev > num_drivers || chan<0 || chan>1) {
                return -1;
        }

         if (mode == L1_MODE_HDLC) {
                 return -1;
         }
 
        info = (struct amd7930_info *) drivers[dev].private;

        save_and_cli(flags);

        if (info->Bb.channel_status == CHANNEL_AVAILABLE) {

                info->Bb.channel_status = CHANNEL_INUSE;
                info->Bb.xmit_idle_char = xmit_idle_char;
                info->Bisdn[chan] = &info->Bb;

                /* Multiplexor map - isdn (B1/2) to Bb */
                info->regs->cr = AMR_MUX_MCR2 + chan;
                info->regs->dr = (AM_MUX_CHANNEL_B1 + chan) |
                                 (AM_MUX_CHANNEL_Bb << 4);

        } else if (info->Bc.channel_status == CHANNEL_AVAILABLE) {

                info->Bc.channel_status = CHANNEL_INUSE;
                info->Bc.xmit_idle_char = xmit_idle_char;
                info->Bisdn[chan] = &info->Bc;

                /* Multiplexor map - isdn (B1/2) to Bc */
                info->regs->cr = AMR_MUX_MCR2 + chan;
                info->regs->dr = (AM_MUX_CHANNEL_B1 + chan) |
                                 (AM_MUX_CHANNEL_Bc << 4);

        } else {
                restore_flags(flags);
                return (-1);
        }

        /* Enable B channel transmit */
        info->regs->cr = AMR_LIU_LMR1;
        info->regs->dr |= AM_LIU_LMR1_B1_ENABL + chan;

        /* Enable B channel interrupts */
        info->regs->cr = AMR_MUX_MCR4;
        info->regs->dr = AM_MUX_MCR4_ENABLE_INTS | AM_MUX_MCR4_REVERSE_Bb | AM_MUX_MCR4_REVERSE_Bc;

        restore_flags(flags);
        return 0;
}

static void amd7930_bclose(int dev, unsigned int chan)
{
        struct amd7930_info *info;
        register unsigned long flags;

        if (dev > num_drivers || chan<0 || chan>1) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;

        save_and_cli(flags);

        if (info->Bisdn[chan]) {
                info->Bisdn[chan]->channel_status = CHANNEL_AVAILABLE;
                info->regs->cr = AMR_MUX_MCR2 + chan;
                info->regs->dr = 0;
                info->Bisdn[chan] = NULL;

                /* Disable B channel transmit */
                info->regs->cr = AMR_LIU_LMR1;
                info->regs->dr &= ~(AM_LIU_LMR1_B1_ENABL + chan);

                if (info->Bb.channel_status == CHANNEL_AVAILABLE &&
                    info->Bc.channel_status == CHANNEL_AVAILABLE) {

                        /* Disable B channel interrupts */
                        info->regs->cr = AMR_MUX_MCR4;
                        info->regs->dr = 0;
                }
        }

        restore_flags(flags);
}

static void amd7930_bxmit(int dev, unsigned int chan,
                          __u8 * buffer, unsigned long count,
                          void (*callback)(void *, int), void *callback_arg)
{
        struct amd7930_info *info;
        struct amd7930_channel *Bchan;
        register unsigned long flags;

        if (dev > num_drivers) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;
        Bchan = info->Bisdn[chan];

        if (Bchan) {
                save_and_cli(flags);

                Bchan->output_ptr = buffer;
                Bchan->output_count = count;
                Bchan->output_format = AUDIO_ENCODING_ULAW;
                Bchan->output_callback = (void *) callback;
                Bchan->output_callback_arg = callback_arg;

                restore_flags(flags);
        }
}

static void amd7930_brecv(int dev, unsigned int chan, 
                          __u8 * buffer, unsigned long size,
                          void (*callback)(void *, int, unsigned int),
                          void *callback_arg)
{
        struct amd7930_info *info;
        struct amd7930_channel *Bchan;
        register unsigned long flags;

        if (dev > num_drivers) {
                return;
        }

        info = (struct amd7930_info *) drivers[dev].private;
        Bchan = info->Bisdn[chan];

        if (Bchan) {
                save_and_cli(flags);

                Bchan->input_ptr = buffer;
                Bchan->input_count = size;
                Bchan->input_format = AUDIO_ENCODING_ULAW;
                Bchan->input_callback = (void *) callback;
                Bchan->input_callback_arg = callback_arg;

                restore_flags(flags);
        }
}

struct foreign_interface amd7930_foreign_interface = {
        amd7930_get_irqnum,
        amd7930_get_liu_state,
        amd7930_liu_init,
        amd7930_liu_activate,
        amd7930_liu_deactivate,
        amd7930_dxmit,
        amd7930_drecv,
        amd7930_bopen,
        amd7930_bclose,
        amd7930_bxmit,
        amd7930_brecv
};
EXPORT_SYMBOL(amd7930_foreign_interface);
#endif


/*
 *      Device detection and initialization.
 */

static struct sparcaudio_operations amd7930_ops = {
        amd7930_open,
        amd7930_release,
        amd7930_ioctl,
        amd7930_start_output,
        amd7930_stop_output,
        amd7930_start_input,
        amd7930_stop_input,
        amd7930_sunaudio_getdev,
        amd7930_set_output_volume,
        amd7930_get_output_volume,
        amd7930_set_input_volume,
        amd7930_get_input_volume,
        amd7930_set_monitor_volume,
        amd7930_get_monitor_volume,
        NULL,                   /* amd7930_set_output_balance */
        amd7930_get_output_balance,
        NULL,                   /* amd7930_set_input_balance */
        amd7930_get_input_balance,
        amd7930_set_output_channels,
        amd7930_get_output_channels,
        amd7930_set_input_channels,
        amd7930_get_input_channels,
        amd7930_set_output_precision,
        amd7930_get_output_precision,
        amd7930_set_input_precision,
        amd7930_get_input_precision,
        amd7930_set_output_port,
        amd7930_get_output_port,
        NULL,                   /* amd7930_set_input_port */
        amd7930_get_input_port,
        amd7930_set_encoding,
        amd7930_get_encoding,
        amd7930_set_encoding,
        amd7930_get_encoding,
        amd7930_set_output_rate,
        amd7930_get_output_rate,
        amd7930_set_input_rate,
        amd7930_get_input_rate,
        amd7930_sunaudio_getdev_sunos,
        amd7930_get_output_ports,
        amd7930_get_input_ports,
        NULL,                    /* amd7930_set_output_muted */
        amd7930_get_output_muted,
        NULL,                   /* amd7930_set_output_pause */
        NULL,                   /* amd7930_get_output_pause */
        NULL,                   /* amd7930_set_input_pause */
        NULL,                   /* amd7930_get_input_pause */
        NULL,                   /* amd7930_set_output_samples */
        NULL,                   /* amd7930_get_output_samples */
        NULL,                   /* amd7930_set_input_samples */
        NULL,                   /* amd7930_get_input_samples */
        NULL,                   /* amd7930_set_output_error */
        NULL,                   /* amd7930_get_output_error */
        NULL,                   /* amd7930_set_input_error */
        NULL,                   /* amd7930_get_input_error */
        amd7930_get_formats,
};

/* Attach to an amd7930 chip given its PROM node. */
static int amd7930_attach(struct sparcaudio_driver *drv, int node,
                          struct linux_sbus *sbus, struct linux_sbus_device *sdev)
{
        struct linux_prom_registers regs;
        struct linux_prom_irqs irq;
        struct amd7930_info *info;
        int err;

        /* Allocate our private information structure. */
        drv->private = kmalloc(sizeof(struct amd7930_info), GFP_KERNEL);
        if (!drv->private)
                return -ENOMEM;

        /* Point at the information structure and initialize it. */
        drv->ops = &amd7930_ops;
        info = (struct amd7930_info *)drv->private;
        memset(info, 0, sizeof(*info));
        info->ints_on = 1; /* force disable below */

        drv->dev = sdev;

        /* Map the registers into memory. */
        prom_getproperty(node, "reg", (char *)&regs, sizeof(regs));
        if (sbus && sdev)
                prom_apply_sbus_ranges(sbus, &regs, 1, sdev);
        info->regs_size = regs.reg_size;
        info->regs = sparc_alloc_io(regs.phys_addr, 0, regs.reg_size,
                                           "amd7930", regs.which_io, 0);
        if (!info->regs) {
                printk(KERN_ERR "amd7930: could not allocate registers\n");
                kfree(drv->private);
                return -EIO;
        }

        /* Put amd7930 in idle mode (interrupts disabled) */
        amd7930_idle(info);

        /* Enable extended FIFO operation on D-channel */
        info->regs->cr = AMR_DLC_EFCR;
        info->regs->dr = AMR_DLC_EFCR_EXTEND_FIFO;
        info->regs->cr = AMR_DLC_DMR4;
        info->regs->dr = /* AMR_DLC_DMR4_RCV_30 | */ AMR_DLC_DMR4_XMT_14;

        /* Attach the interrupt handler to the audio interrupt. */
        prom_getproperty(node, "intr", (char *)&irq, sizeof(irq));
        info->irq = irq.pri;
        request_irq(info->irq, amd7930_interrupt,
                    SA_INTERRUPT, "amd7930", drv);
        enable_irq(info->irq);
        amd7930_enable_ints(info);

        /* Initalize the local copy of the MAP registers. */
        memset(&info->map, 0, sizeof(info->map));
        info->map.mmr1 = AM_MAP_MMR1_GX | AM_MAP_MMR1_GER
                         | AM_MAP_MMR1_GR | AM_MAP_MMR1_STG;
        /* Start out with speaker, microphone */
        info->map.mmr2 |= (AM_MAP_MMR2_LS | AM_MAP_MMR2_AINB);

        /* Set the default audio parameters. */
        info->rgain = 128;
        info->pgain = 200;
        info->mgain = 0;
        info->format_type = AUDIO_ENCODING_ULAW;
        info->Bb.input_format = AUDIO_ENCODING_ULAW;
        info->Bb.output_format = AUDIO_ENCODING_ULAW;
        info->Bc.input_format = AUDIO_ENCODING_ULAW;
        info->Bc.output_format = AUDIO_ENCODING_ULAW;
        amd7930_update_map(drv);

        /* Register the amd7930 with the midlevel audio driver. */
        err = register_sparcaudio_driver(drv, 1);
        if (err < 0) {
                printk(KERN_ERR "amd7930: unable to register\n");
                disable_irq(info->irq);
                free_irq(info->irq, drv);
                sparc_free_io(info->regs, info->regs_size);
                kfree(drv->private);
                return -EIO;
        }

        /* Announce the hardware to the user. */
        printk(KERN_INFO "amd7930 at 0x%lx irq %d\n",
                (unsigned long)info->regs, info->irq);

        /* Success! */
        return 0;
}

#ifdef MODULE
/* Detach from an amd7930 chip given the device structure. */
static void amd7930_detach(struct sparcaudio_driver *drv)
{
        struct amd7930_info *info = (struct amd7930_info *)drv->private;

        unregister_sparcaudio_driver(drv, 1);
        amd7930_idle(info);
        disable_irq(info->irq);
        free_irq(info->irq, drv);
        sparc_free_io(info->regs, info->regs_size);
        kfree(drv->private);
}
#endif

/* Probe for the amd7930 chip and then attach the driver. */
#ifdef MODULE
int init_module(void)
#else
int __init amd7930_init(void)
#endif
{
        struct linux_sbus *bus;
        struct linux_sbus_device *sdev;
        int node;

        /* Try to find the sun4c "audio" node first. */
        node = prom_getchild(prom_root_node);
        node = prom_searchsiblings(node, "audio");
        if (node && amd7930_attach(&drivers[0], node, NULL, NULL) == 0)
                num_drivers = 1;
        else
                num_drivers = 0;

        /* Probe each SBUS for amd7930 chips. */
        for_all_sbusdev(sdev,bus) {
                if (!strcmp(sdev->prom_name, "audio")) {
                        /* Don't go over the max number of drivers. */
                        if (num_drivers >= MAX_DRIVERS)
                                continue;

                        if (amd7930_attach(&drivers[num_drivers],
                                           sdev->prom_node, sdev->my_bus, sdev) == 0)
                                num_drivers++;
                }
        }

        /* Only return success if we found some amd7930 chips. */
        return (num_drivers > 0) ? 0 : -EIO;
}

#ifdef MODULE
void cleanup_module(void)
{
        register int i;

        for (i = 0; i < num_drivers; i++) {
                amd7930_detach(&drivers[i]);
                num_drivers--;
        }
}
#endif


/*************************************************************/
/*                 Audio format conversion                   */
/*************************************************************/

/* Translation tables */

static unsigned char ulaw[] = {
    3,   7,  11,  15,  19,  23,  27,  31, 
   35,  39,  43,  47,  51,  55,  59,  63, 
   66,  68,  70,  72,  74,  76,  78,  80, 
   82,  84,  86,  88,  90,  92,  94,  96, 
   98,  99, 100, 101, 102, 103, 104, 105, 
  106, 107, 108, 109, 110, 111, 112, 113, 
  113, 114, 114, 115, 115, 116, 116, 117, 
  117, 118, 118, 119, 119, 120, 120, 121, 
  121, 121, 122, 122, 122, 122, 123, 123, 
  123, 123, 124, 124, 124, 124, 125, 125, 
  125, 125, 125, 125, 126, 126, 126, 126, 
  126, 126, 126, 126, 127, 127, 127, 127, 
  127, 127, 127, 127, 127, 127, 127, 127, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  253, 249, 245, 241, 237, 233, 229, 225, 
  221, 217, 213, 209, 205, 201, 197, 193, 
  190, 188, 186, 184, 182, 180, 178, 176, 
  174, 172, 170, 168, 166, 164, 162, 160, 
  158, 157, 156, 155, 154, 153, 152, 151, 
  150, 149, 148, 147, 146, 145, 144, 143, 
  143, 142, 142, 141, 141, 140, 140, 139, 
  139, 138, 138, 137, 137, 136, 136, 135, 
  135, 135, 134, 134, 134, 134, 133, 133, 
  133, 133, 132, 132, 132, 132, 131, 131, 
  131, 131, 131, 131, 130, 130, 130, 130, 
  130, 130, 130, 130, 129, 129, 129, 129, 
  129, 129, 129, 129, 129, 129, 129, 129, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128, 
  128, 128, 128, 128, 128, 128, 128, 128
};

static __u8 mulaw2bilinear(__u8 data)
{
        return ulaw[data];
}


static unsigned char linear[] = {
     0,    0,    0,    0,    0,    0,    0,    1,
     0,    0,    0,    2,    0,    0,    0,    3,
     0,    0,    0,    4,    0,    0,    0,    5,
     0,    0,    0,    6,    0,    0,    0,    7,
     0,    0,    0,    8,    0,    0,    0,    9,
     0,    0,    0,   10,    0,    0,    0,   11,
     0,    0,    0,   12,    0,    0,    0,   13,
     0,    0,    0,   14,    0,    0,    0,   15,
     0,    0,   16,    0,   17,    0,   18,    0,
    19,    0,   20,    0,   21,    0,   22,    0,
    23,    0,   24,    0,   25,    0,   26,    0,
    27,    0,   28,    0,   29,    0,   30,    0,
    31,    0,   32,   33,   34,   35,   36,   37,
    38,   39,   40,   41,   42,   43,   44,   45,
    46,   48,   50,   52,   54,   56,   58,   60,
    62,   65,   69,   73,   77,   83,   91,  103,
   255,  231,  219,  211,  205,  201,  197,  193,
   190,  188,  186,  184,  182,  180,  178,  176,
   174,  173,  172,  171,  170,  169,  168,  167,
   166,  165,  164,  163,  162,  161,  160,    0,
   159,    0,  158,    0,  157,    0,  156,    0,
   155,    0,  154,    0,  153,    0,  152,    0,
   151,    0,  150,    0,  149,    0,  148,    0,
   147,    0,  146,    0,  145,    0,  144,    0,
     0,  143,    0,    0,    0,  142,    0,    0,
     0,  141,    0,    0,    0,  140,    0,    0,
     0,  139,    0,    0,    0,  138,    0,    0,
     0,  137,    0,    0,    0,  136,    0,    0,
     0,  135,    0,    0,    0,  134,    0,    0,
     0,  133,    0,    0,    0,  132,    0,    0,
     0,  131,    0,    0,    0,  130,    0,    0,
     0,  129,    0,    0,    0,  128,    0,    0
};

static __u8 bilinear2mulaw(__u8 data)
{
        return linear[data];
}

static int exp_lut[256] = {
        0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
        5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};

#define BIAS 0x84
#define CLIP 32635

#define SWAP_ENDIAN(x) ((x >> 8) | ((x & 0xff) << 8))

static __u8  linear2mulaw(__u16 data)
{
        static int sign, exponent, mantissa;

        /* not really sure, if swapping is ok - comment next line to disable it */
        data = SWAP_ENDIAN(data);
        
        sign = (data >> 8) & 0x80;
        if (sign != 0) data = -data;

        if (data > CLIP) data = CLIP;
        data += BIAS;
        exponent = exp_lut[(data >> 7) & 0xFF];
        mantissa = (data >> (exponent + 3)) & 0x0F;

        return (~(sign | (exponent << 4) | mantissa));
}

static __u16 mulaw2linear(__u8 data)
{
        /* this conversion is not working */
        return data;
}

#if 0
#define INOUT(x,y) (((x) << 16) | (y))
static int convert_audio(int in_format, int out_format, __u8* buffer, int count)
{
        static int i,sign,exponent;
        static __u16 data;

        if (in_format == out_format) return count;

        switch(INOUT(in_format, out_format)) {
        case INOUT(AUDIO_ENCODING_ULAW, AUDIO_ENCODING_LINEAR8):
                for (i = 0;i < count; i++) {
                        buffer[i] = ulaw[buffer[i]];
                };
                break;
        case INOUT(AUDIO_ENCODING_ULAW, AUDIO_ENCODING_LINEAR):
                break;
        case INOUT(AUDIO_ENCODING_LINEAR, AUDIO_ENCODING_ULAW):
                /* buffer is two-byte => convert to first */
                for (i = 0; i < count/2; i++) {
                        data = ((__u16*)buffer)[i];
                        sign = (data >> 8) & 0x80;
                        if (data > CLIP) data = CLIP;
                        data += BIAS;
                        exponent = exp_lut[(data >> 7) & 0xFF];
                        buffer[i] = ~(sign | (exponent << 4) | 
                                                  ((data >> (exponent + 3)) & 0x0F));
                };
                break;
        case INOUT(AUDIO_ENCODING_LINEAR8, AUDIO_ENCODING_ULAW):
                for (i = 0; i < count; i++) {
                        buffer[i] = linear[buffer[i]];
                };
                break;
        default:
                return 0;
        };

        return count;
}
#undef INOUT
#endif

#undef BIAS
#undef CLIP
#undef SWAP_ENDIAN