// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for DBRI sound chip found on Sparcs.
 * Copyright (C) 2004, 2005 Martin Habets (mhabets@users.sourceforge.net)
 *
 * Converted to ring buffered version by Krzysztof Helt (krzysztof.h1@wp.pl)
 *
 * Based entirely upon drivers/sbus/audio/dbri.c which is:
 * Copyright (C) 1997 Rudolf Koenig (rfkoenig@immd4.informatik.uni-erlangen.de)
 * Copyright (C) 1998, 1999 Brent Baccala (baccala@freesoft.org)
 *
 * This is the low level driver for the DBRI & MMCODEC duo used for ISDN & AUDIO
 * on Sun SPARCStation 10, 20, LX and Voyager models.
 *
 * - DBRI: AT&T T5900FX Dual Basic Rates ISDN Interface. It is a 32 channel
 *   data time multiplexer with ISDN support (aka T7259)
 *   Interfaces: SBus,ISDN NT & TE, CHI, 4 bits parallel.
 *   CHI: (spelled ki) Concentration Highway Interface (AT&T or Intel bus ?).
 *   Documentation:
 *   - "STP 4000SBus Dual Basic Rate ISDN (DBRI) Transceiver" from
 *     Sparc Technology Business (courtesy of Sun Support)
 *   - Data sheet of the T7903, a newer but very similar ISA bus equivalent
 *     available from the Lucent (formerly AT&T microelectronics) home
 *     page.
 *   - https://www.freesoft.org/Linux/DBRI/
 * - MMCODEC: Crystal Semiconductor CS4215 16 bit Multimedia Audio Codec
 *   Interfaces: CHI, Audio In & Out, 2 bits parallel
 *   Documentation: from the Crystal Semiconductor home page.
 *
 * The DBRI is a 32 pipe machine, each pipe can transfer some bits between
 * memory and a serial device (long pipes, no. 0-15) or between two serial
 * devices (short pipes, no. 16-31), or simply send a fixed data to a serial
 * device (short pipes).
 * A timeslot defines the bit-offset and no. of bits read from a serial device.
 * The timeslots are linked to 6 circular lists, one for each direction for
 * each serial device (NT,TE,CHI). A timeslot is associated to 1 or 2 pipes
 * (the second one is a monitor/tee pipe, valid only for serial input).
 *
 * The mmcodec is connected via the CHI bus and needs the data & some
 * parameters (volume, output selection) time multiplexed in 8 byte
 * chunks. It also has a control mode, which serves for audio format setting.
 *
 * Looking at the CS4215 data sheet it is easy to set up 2 or 4 codecs on
 * the same CHI bus, so I thought perhaps it is possible to use the on-board
 * & the speakerbox codec simultaneously, giving 2 (not very independent :-)
 * audio devices. But the SUN HW group decided against it, at least on my
 * LX the speakerbox connector has at least 1 pin missing and 1 wrongly
 * connected.
 *
 * I've tried to stick to the following function naming conventions:
 * snd_*        ALSA stuff
 * cs4215_*     CS4215 codec specific stuff
 * dbri_*       DBRI high-level stuff
 * other        DBRI low-level stuff
 */

#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/initval.h>

#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/atomic.h>
#include <linux/module.h>

MODULE_AUTHOR("Rudolf Koenig, Brent Baccala and Martin Habets");
MODULE_DESCRIPTION("Sun DBRI");
MODULE_LICENSE("GPL");

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
/* Enable this card */
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;

module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for Sun DBRI soundcard.");
module_param_array(id, charp, NULL, 0444);
MODULE_PARM_DESC(id, "ID string for Sun DBRI soundcard.");
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(enable, "Enable Sun DBRI soundcard.");

#undef DBRI_DEBUG

#define D_INT   (1<<0)
#define D_GEN   (1<<1)
#define D_CMD   (1<<2)
#define D_MM    (1<<3)
#define D_USR   (1<<4)
#define D_DESC  (1<<5)

static int dbri_debug;
module_param(dbri_debug, int, 0644);
MODULE_PARM_DESC(dbri_debug, "Debug value for Sun DBRI soundcard.");

#ifdef DBRI_DEBUG
static const char * const cmds[] = {
        "WAIT", "PAUSE", "JUMP", "IIQ", "REX", "SDP", "CDP", "DTS",
        "SSP", "CHI", "NT", "TE", "CDEC", "TEST", "CDM", "RESRV"
};

#define dprintk(a, x...) if (dbri_debug & a) printk(KERN_DEBUG x)

#else
#define dprintk(a, x...) do { } while (0)

#endif                          /* DBRI_DEBUG */

#define DBRI_CMD(cmd, intr, value) ((cmd << 28) |       \
                                    (intr << 27) |      \
                                    value)

/***************************************************************************
        CS4215 specific definitions and structures
****************************************************************************/

struct cs4215 {
        __u8 data[4];           /* Data mode: Time slots 5-8 */
        __u8 ctrl[4];           /* Ctrl mode: Time slots 1-4 */
        __u8 onboard;
        __u8 offset;            /* Bit offset from frame sync to time slot 1 */
        volatile __u32 status;
        volatile __u32 version;
        __u8 precision;         /* In bits, either 8 or 16 */
        __u8 channels;          /* 1 or 2 */
};

/*
 * Control mode first
 */

/* Time Slot 1, Status register */
#define CS4215_CLB      (1<<2)  /* Control Latch Bit */
#define CS4215_OLB      (1<<3)  /* 1: line: 2.0V, speaker 4V */
                                /* 0: line: 2.8V, speaker 8V */
#define CS4215_MLB      (1<<4)  /* 1: Microphone: 20dB gain disabled */
#define CS4215_RSRVD_1  (1<<5)

/* Time Slot 2, Data Format Register */
#define CS4215_DFR_LINEAR16     0
#define CS4215_DFR_ULAW         1
#define CS4215_DFR_ALAW         2
#define CS4215_DFR_LINEAR8      3
#define CS4215_DFR_STEREO       (1<<2)
static struct {
        unsigned short freq;
        unsigned char xtal;
        unsigned char csval;
} CS4215_FREQ[] = {
        {  8000, (1 << 4), (0 << 3) },
        { 16000, (1 << 4), (1 << 3) },
        { 27429, (1 << 4), (2 << 3) },  /* Actually 24428.57 */
        { 32000, (1 << 4), (3 << 3) },
     /* {    NA, (1 << 4), (4 << 3) }, */
     /* {    NA, (1 << 4), (5 << 3) }, */
        { 48000, (1 << 4), (6 << 3) },
        {  9600, (1 << 4), (7 << 3) },
        {  5512, (2 << 4), (0 << 3) },  /* Actually 5512.5 */
        { 11025, (2 << 4), (1 << 3) },
        { 18900, (2 << 4), (2 << 3) },
        { 22050, (2 << 4), (3 << 3) },
        { 37800, (2 << 4), (4 << 3) },
        { 44100, (2 << 4), (5 << 3) },
        { 33075, (2 << 4), (6 << 3) },
        {  6615, (2 << 4), (7 << 3) },
        { 0, 0, 0}
};

#define CS4215_HPF      (1<<7)  /* High Pass Filter, 1: Enabled */

#define CS4215_12_MASK  0xfcbf  /* Mask off reserved bits in slot 1 & 2 */

/* Time Slot 3, Serial Port Control register */
#define CS4215_XEN      (1<<0)  /* 0: Enable serial output */
#define CS4215_XCLK     (1<<1)  /* 1: Master mode: Generate SCLK */
#define CS4215_BSEL_64  (0<<2)  /* Bitrate: 64 bits per frame */
#define CS4215_BSEL_128 (1<<2)
#define CS4215_BSEL_256 (2<<2)
#define CS4215_MCK_MAST (0<<4)  /* Master clock */
#define CS4215_MCK_XTL1 (1<<4)  /* 24.576 MHz clock source */
#define CS4215_MCK_XTL2 (2<<4)  /* 16.9344 MHz clock source */
#define CS4215_MCK_CLK1 (3<<4)  /* Clockin, 256 x Fs */
#define CS4215_MCK_CLK2 (4<<4)  /* Clockin, see DFR */

/* Time Slot 4, Test Register */
#define CS4215_DAD      (1<<0)  /* 0:Digital-Dig loop, 1:Dig-Analog-Dig loop */
#define CS4215_ENL      (1<<1)  /* Enable Loopback Testing */

/* Time Slot 5, Parallel Port Register */
/* Read only here and the same as the in data mode */

/* Time Slot 6, Reserved  */

/* Time Slot 7, Version Register  */
#define CS4215_VERSION_MASK 0xf /* Known versions 0/C, 1/D, 2/E */

/* Time Slot 8, Reserved  */

/*
 * Data mode
 */
/* Time Slot 1-2: Left Channel Data, 2-3: Right Channel Data  */

/* Time Slot 5, Output Setting  */
#define CS4215_LO(v)    v       /* Left Output Attenuation 0x3f: -94.5 dB */
#define CS4215_LE       (1<<6)  /* Line Out Enable */
#define CS4215_HE       (1<<7)  /* Headphone Enable */

/* Time Slot 6, Output Setting  */
#define CS4215_RO(v)    v       /* Right Output Attenuation 0x3f: -94.5 dB */
#define CS4215_SE       (1<<6)  /* Speaker Enable */
#define CS4215_ADI      (1<<7)  /* A/D Data Invalid: Busy in calibration */

/* Time Slot 7, Input Setting */
#define CS4215_LG(v)    v       /* Left Gain Setting 0xf: 22.5 dB */
#define CS4215_IS       (1<<4)  /* Input Select: 1=Microphone, 0=Line */
#define CS4215_OVR      (1<<5)  /* 1: Over range condition occurred */
#define CS4215_PIO0     (1<<6)  /* Parallel I/O 0 */
#define CS4215_PIO1     (1<<7)

/* Time Slot 8, Input Setting */
#define CS4215_RG(v)    v       /* Right Gain Setting 0xf: 22.5 dB */
#define CS4215_MA(v)    (v<<4)  /* Monitor Path Attenuation 0xf: mute */

/***************************************************************************
                DBRI specific definitions and structures
****************************************************************************/

/* DBRI main registers */
#define REG0    0x00            /* Status and Control */
#define REG1    0x04            /* Mode and Interrupt */
#define REG2    0x08            /* Parallel IO */
#define REG3    0x0c            /* Test */
#define REG8    0x20            /* Command Queue Pointer */
#define REG9    0x24            /* Interrupt Queue Pointer */

#define DBRI_NO_CMDS    64
#define DBRI_INT_BLK    64
#define DBRI_NO_DESCS   64
#define DBRI_NO_PIPES   32
#define DBRI_MAX_PIPE   (DBRI_NO_PIPES - 1)

#define DBRI_REC        0
#define DBRI_PLAY       1
#define DBRI_NO_STREAMS 2

/* One transmit/receive descriptor */
/* When ba != 0 descriptor is used */
struct dbri_mem {
        volatile __u32 word1;
        __u32 ba;       /* Transmit/Receive Buffer Address */
        __u32 nda;      /* Next Descriptor Address */
        volatile __u32 word4;
};

/* This structure is in a DMA region where it can accessed by both
 * the CPU and the DBRI
 */
struct dbri_dma {
        s32 cmd[DBRI_NO_CMDS];                  /* Place for commands */
        volatile s32 intr[DBRI_INT_BLK];        /* Interrupt field  */
        struct dbri_mem desc[DBRI_NO_DESCS];    /* Xmit/receive descriptors */
};

#define dbri_dma_off(member, elem)      \
        ((u32)(unsigned long)           \
         (&(((struct dbri_dma *)0)->member[elem])))

enum in_or_out { PIPEinput, PIPEoutput };

struct dbri_pipe {
        u32 sdp;                /* SDP command word */
        int nextpipe;           /* Next pipe in linked list */
        int length;             /* Length of timeslot (bits) */
        int first_desc;         /* Index of first descriptor */
        int desc;               /* Index of active descriptor */
        volatile __u32 *recv_fixed_ptr; /* Ptr to receive fixed data */
};

/* Per stream (playback or record) information */
struct dbri_streaminfo {
        struct snd_pcm_substream *substream;
        u32 dvma_buffer;        /* Device view of ALSA DMA buffer */
        int size;               /* Size of DMA buffer             */
        size_t offset;          /* offset in user buffer          */
        int pipe;               /* Data pipe used                 */
        int left_gain;          /* mixer elements                 */
        int right_gain;
};

/* This structure holds the information for both chips (DBRI & CS4215) */
struct snd_dbri {
        int regs_size, irq;     /* Needed for unload */
        struct platform_device *op;     /* OF device info */
        spinlock_t lock;

        struct dbri_dma *dma;   /* Pointer to our DMA block */
        dma_addr_t dma_dvma;    /* DBRI visible DMA address */

        void __iomem *regs;     /* dbri HW regs */
        int dbri_irqp;          /* intr queue pointer */

        struct dbri_pipe pipes[DBRI_NO_PIPES];  /* DBRI's 32 data pipes */
        int next_desc[DBRI_NO_DESCS];           /* Index of next desc, or -1 */
        spinlock_t cmdlock;     /* Protects cmd queue accesses */
        s32 *cmdptr;            /* Pointer to the last queued cmd */

        int chi_bpf;

        struct cs4215 mm;       /* mmcodec special info */
                                /* per stream (playback/record) info */
        struct dbri_streaminfo stream_info[DBRI_NO_STREAMS];
};

#define DBRI_MAX_VOLUME         63      /* Output volume */
#define DBRI_MAX_GAIN           15      /* Input gain */

/* DBRI Reg0 - Status Control Register - defines. (Page 17) */
#define D_P             (1<<15) /* Program command & queue pointer valid */
#define D_G             (1<<14) /* Allow 4-Word SBus Burst */
#define D_S             (1<<13) /* Allow 16-Word SBus Burst */
#define D_E             (1<<12) /* Allow 8-Word SBus Burst */
#define D_X             (1<<7)  /* Sanity Timer Disable */
#define D_T             (1<<6)  /* Permit activation of the TE interface */
#define D_N             (1<<5)  /* Permit activation of the NT interface */
#define D_C             (1<<4)  /* Permit activation of the CHI interface */
#define D_F             (1<<3)  /* Force Sanity Timer Time-Out */
#define D_D             (1<<2)  /* Disable Master Mode */
#define D_H             (1<<1)  /* Halt for Analysis */
#define D_R             (1<<0)  /* Soft Reset */

/* DBRI Reg1 - Mode and Interrupt Register - defines. (Page 18) */
#define D_LITTLE_END    (1<<8)  /* Byte Order */
#define D_BIG_END       (0<<8)  /* Byte Order */
#define D_MRR           (1<<4)  /* Multiple Error Ack on SBus (read only) */
#define D_MLE           (1<<3)  /* Multiple Late Error on SBus (read only) */
#define D_LBG           (1<<2)  /* Lost Bus Grant on SBus (read only) */
#define D_MBE           (1<<1)  /* Burst Error on SBus (read only) */
#define D_IR            (1<<0)  /* Interrupt Indicator (read only) */

/* DBRI Reg2 - Parallel IO Register - defines. (Page 18) */
#define D_ENPIO3        (1<<7)  /* Enable Pin 3 */
#define D_ENPIO2        (1<<6)  /* Enable Pin 2 */
#define D_ENPIO1        (1<<5)  /* Enable Pin 1 */
#define D_ENPIO0        (1<<4)  /* Enable Pin 0 */
#define D_ENPIO         (0xf0)  /* Enable all the pins */
#define D_PIO3          (1<<3)  /* Pin 3: 1: Data mode, 0: Ctrl mode */
#define D_PIO2          (1<<2)  /* Pin 2: 1: Onboard PDN */
#define D_PIO1          (1<<1)  /* Pin 1: 0: Reset */
#define D_PIO0          (1<<0)  /* Pin 0: 1: Speakerbox PDN */

/* DBRI Commands (Page 20) */
#define D_WAIT          0x0     /* Stop execution */
#define D_PAUSE         0x1     /* Flush long pipes */
#define D_JUMP          0x2     /* New command queue */
#define D_IIQ           0x3     /* Initialize Interrupt Queue */
#define D_REX           0x4     /* Report command execution via interrupt */
#define D_SDP           0x5     /* Setup Data Pipe */
#define D_CDP           0x6     /* Continue Data Pipe (reread NULL Pointer) */
#define D_DTS           0x7     /* Define Time Slot */
#define D_SSP           0x8     /* Set short Data Pipe */
#define D_CHI           0x9     /* Set CHI Global Mode */
#define D_NT            0xa     /* NT Command */
#define D_TE            0xb     /* TE Command */
#define D_CDEC          0xc     /* Codec setup */
#define D_TEST          0xd     /* No comment */
#define D_CDM           0xe     /* CHI Data mode command */

/* Special bits for some commands */
#define D_PIPE(v)      ((v)<<0) /* Pipe No.: 0-15 long, 16-21 short */

/* Setup Data Pipe */
/* IRM */
#define D_SDP_2SAME     (1<<18) /* Report 2nd time in a row value received */
#define D_SDP_CHANGE    (2<<18) /* Report any changes */
#define D_SDP_EVERY     (3<<18) /* Report any changes */
#define D_SDP_EOL       (1<<17) /* EOL interrupt enable */
#define D_SDP_IDLE      (1<<16) /* HDLC idle interrupt enable */

/* Pipe data MODE */
#define D_SDP_MEM       (0<<13) /* To/from memory */
#define D_SDP_HDLC      (2<<13)
#define D_SDP_HDLC_D    (3<<13) /* D Channel (prio control) */
#define D_SDP_SER       (4<<13) /* Serial to serial */
#define D_SDP_FIXED     (6<<13) /* Short only */
#define D_SDP_MODE(v)   ((v)&(7<<13))

#define D_SDP_TO_SER    (1<<12) /* Direction */
#define D_SDP_FROM_SER  (0<<12) /* Direction */
#define D_SDP_MSB       (1<<11) /* Bit order within Byte */
#define D_SDP_LSB       (0<<11) /* Bit order within Byte */
#define D_SDP_P         (1<<10) /* Pointer Valid */
#define D_SDP_A         (1<<8)  /* Abort */
#define D_SDP_C         (1<<7)  /* Clear */

/* Define Time Slot */
#define D_DTS_VI        (1<<17) /* Valid Input Time-Slot Descriptor */
#define D_DTS_VO        (1<<16) /* Valid Output Time-Slot Descriptor */
#define D_DTS_INS       (1<<15) /* Insert Time Slot */
#define D_DTS_DEL       (0<<15) /* Delete Time Slot */
#define D_DTS_PRVIN(v) ((v)<<10)        /* Previous In Pipe */
#define D_DTS_PRVOUT(v)        ((v)<<5) /* Previous Out Pipe */

/* Time Slot defines */
#define D_TS_LEN(v)     ((v)<<24)       /* Number of bits in this time slot */
#define D_TS_CYCLE(v)   ((v)<<14)       /* Bit Count at start of TS */
#define D_TS_DI         (1<<13) /* Data Invert */
#define D_TS_1CHANNEL   (0<<10) /* Single Channel / Normal mode */
#define D_TS_MONITOR    (2<<10) /* Monitor pipe */
#define D_TS_NONCONTIG  (3<<10) /* Non contiguous mode */
#define D_TS_ANCHOR     (7<<10) /* Starting short pipes */
#define D_TS_MON(v)    ((v)<<5) /* Monitor Pipe */
#define D_TS_NEXT(v)   ((v)<<0) /* Pipe no.: 0-15 long, 16-21 short */

/* Concentration Highway Interface Modes */
#define D_CHI_CHICM(v)  ((v)<<16)       /* Clock mode */
#define D_CHI_IR        (1<<15) /* Immediate Interrupt Report */
#define D_CHI_EN        (1<<14) /* CHIL Interrupt enabled */
#define D_CHI_OD        (1<<13) /* Open Drain Enable */
#define D_CHI_FE        (1<<12) /* Sample CHIFS on Rising Frame Edge */
#define D_CHI_FD        (1<<11) /* Frame Drive */
#define D_CHI_BPF(v)    ((v)<<0)        /* Bits per Frame */

/* NT: These are here for completeness */
#define D_NT_FBIT       (1<<17) /* Frame Bit */
#define D_NT_NBF        (1<<16) /* Number of bad frames to loose framing */
#define D_NT_IRM_IMM    (1<<15) /* Interrupt Report & Mask: Immediate */
#define D_NT_IRM_EN     (1<<14) /* Interrupt Report & Mask: Enable */
#define D_NT_ISNT       (1<<13) /* Configure interface as NT */
#define D_NT_FT         (1<<12) /* Fixed Timing */
#define D_NT_EZ         (1<<11) /* Echo Channel is Zeros */
#define D_NT_IFA        (1<<10) /* Inhibit Final Activation */
#define D_NT_ACT        (1<<9)  /* Activate Interface */
#define D_NT_MFE        (1<<8)  /* Multiframe Enable */
#define D_NT_RLB(v)     ((v)<<5)        /* Remote Loopback */
#define D_NT_LLB(v)     ((v)<<2)        /* Local Loopback */
#define D_NT_FACT       (1<<1)  /* Force Activation */
#define D_NT_ABV        (1<<0)  /* Activate Bipolar Violation */

/* Codec Setup */
#define D_CDEC_CK(v)    ((v)<<24)       /* Clock Select */
#define D_CDEC_FED(v)   ((v)<<12)       /* FSCOD Falling Edge Delay */
#define D_CDEC_RED(v)   ((v)<<0)        /* FSCOD Rising Edge Delay */

/* Test */
#define D_TEST_RAM(v)   ((v)<<16)       /* RAM Pointer */
#define D_TEST_SIZE(v)  ((v)<<11)       /* */
#define D_TEST_ROMONOFF 0x5     /* Toggle ROM opcode monitor on/off */
#define D_TEST_PROC     0x6     /* Microprocessor test */
#define D_TEST_SER      0x7     /* Serial-Controller test */
#define D_TEST_RAMREAD  0x8     /* Copy from Ram to system memory */
#define D_TEST_RAMWRITE 0x9     /* Copy into Ram from system memory */
#define D_TEST_RAMBIST  0xa     /* RAM Built-In Self Test */
#define D_TEST_MCBIST   0xb     /* Microcontroller Built-In Self Test */
#define D_TEST_DUMP     0xe     /* ROM Dump */

/* CHI Data Mode */
#define D_CDM_THI       (1 << 8)        /* Transmit Data on CHIDR Pin */
#define D_CDM_RHI       (1 << 7)        /* Receive Data on CHIDX Pin */
#define D_CDM_RCE       (1 << 6)        /* Receive on Rising Edge of CHICK */
#define D_CDM_XCE       (1 << 2) /* Transmit Data on Rising Edge of CHICK */
#define D_CDM_XEN       (1 << 1)        /* Transmit Highway Enable */
#define D_CDM_REN       (1 << 0)        /* Receive Highway Enable */

/* The Interrupts */
#define D_INTR_BRDY     1       /* Buffer Ready for processing */
#define D_INTR_MINT     2       /* Marked Interrupt in RD/TD */
#define D_INTR_IBEG     3       /* Flag to idle transition detected (HDLC) */
#define D_INTR_IEND     4       /* Idle to flag transition detected (HDLC) */
#define D_INTR_EOL      5       /* End of List */
#define D_INTR_CMDI     6       /* Command has bean read */
#define D_INTR_XCMP     8       /* Transmission of frame complete */
#define D_INTR_SBRI     9       /* BRI status change info */
#define D_INTR_FXDT     10      /* Fixed data change */
#define D_INTR_CHIL     11      /* CHI lost frame sync (channel 36 only) */
#define D_INTR_COLL     11      /* Unrecoverable D-Channel collision */
#define D_INTR_DBYT     12      /* Dropped by frame slip */
#define D_INTR_RBYT     13      /* Repeated by frame slip */
#define D_INTR_LINT     14      /* Lost Interrupt */
#define D_INTR_UNDR     15      /* DMA underrun */

#define D_INTR_TE       32
#define D_INTR_NT       34
#define D_INTR_CHI      36
#define D_INTR_CMD      38

#define D_INTR_GETCHAN(v)       (((v) >> 24) & 0x3f)
#define D_INTR_GETCODE(v)       (((v) >> 20) & 0xf)
#define D_INTR_GETCMD(v)        (((v) >> 16) & 0xf)
#define D_INTR_GETVAL(v)        ((v) & 0xffff)
#define D_INTR_GETRVAL(v)       ((v) & 0xfffff)

#define D_P_0           0       /* TE receive anchor */
#define D_P_1           1       /* TE transmit anchor */
#define D_P_2           2       /* NT transmit anchor */
#define D_P_3           3       /* NT receive anchor */
#define D_P_4           4       /* CHI send data */
#define D_P_5           5       /* CHI receive data */
#define D_P_6           6       /* */
#define D_P_7           7       /* */
#define D_P_8           8       /* */
#define D_P_9           9       /* */
#define D_P_10          10      /* */
#define D_P_11          11      /* */
#define D_P_12          12      /* */
#define D_P_13          13      /* */
#define D_P_14          14      /* */
#define D_P_15          15      /* */
#define D_P_16          16      /* CHI anchor pipe */
#define D_P_17          17      /* CHI send */
#define D_P_18          18      /* CHI receive */
#define D_P_19          19      /* CHI receive */
#define D_P_20          20      /* CHI receive */
#define D_P_21          21      /* */
#define D_P_22          22      /* */
#define D_P_23          23      /* */
#define D_P_24          24      /* */
#define D_P_25          25      /* */
#define D_P_26          26      /* */
#define D_P_27          27      /* */
#define D_P_28          28      /* */
#define D_P_29          29      /* */
#define D_P_30          30      /* */
#define D_P_31          31      /* */

/* Transmit descriptor defines */
#define DBRI_TD_F       (1 << 31)       /* End of Frame */
#define DBRI_TD_D       (1 << 30)       /* Do not append CRC */
#define DBRI_TD_CNT(v)  ((v) << 16) /* Number of valid bytes in the buffer */
#define DBRI_TD_B       (1 << 15)       /* Final interrupt */
#define DBRI_TD_M       (1 << 14)       /* Marker interrupt */
#define DBRI_TD_I       (1 << 13)       /* Transmit Idle Characters */
#define DBRI_TD_FCNT(v) (v)             /* Flag Count */
#define DBRI_TD_UNR     (1 << 3) /* Underrun: transmitter is out of data */
#define DBRI_TD_ABT     (1 << 2)        /* Abort: frame aborted */
#define DBRI_TD_TBC     (1 << 0)        /* Transmit buffer Complete */
#define DBRI_TD_STATUS(v)       ((v) & 0xff)    /* Transmit status */
                        /* Maximum buffer size per TD: almost 8KB */
#define DBRI_TD_MAXCNT  ((1 << 13) - 4)

/* Receive descriptor defines */
#define DBRI_RD_F       (1 << 31)       /* End of Frame */
#define DBRI_RD_C       (1 << 30)       /* Completed buffer */
#define DBRI_RD_B       (1 << 15)       /* Final interrupt */
#define DBRI_RD_M       (1 << 14)       /* Marker interrupt */
#define DBRI_RD_BCNT(v) (v)             /* Buffer size */
#define DBRI_RD_CRC     (1 << 7)        /* 0: CRC is correct */
#define DBRI_RD_BBC     (1 << 6)        /* 1: Bad Byte received */
#define DBRI_RD_ABT     (1 << 5)        /* Abort: frame aborted */
#define DBRI_RD_OVRN    (1 << 3)        /* Overrun: data lost */
#define DBRI_RD_STATUS(v)      ((v) & 0xff)     /* Receive status */
#define DBRI_RD_CNT(v) (((v) >> 16) & 0x1fff)   /* Valid bytes in the buffer */

/* stream_info[] access */
/* Translate the ALSA direction into the array index */
#define DBRI_STREAMNO(substream)                                \
                (substream->stream ==                           \
                 SNDRV_PCM_STREAM_PLAYBACK ? DBRI_PLAY: DBRI_REC)

/* Return a pointer to dbri_streaminfo */
#define DBRI_STREAM(dbri, substream)    \
                &dbri->stream_info[DBRI_STREAMNO(substream)]

/*
 * Short data pipes transmit LSB first. The CS4215 receives MSB first. Grrr.
 * So we have to reverse the bits. Note: not all bit lengths are supported
 */
static __u32 reverse_bytes(__u32 b, int len)
{
        switch (len) {
        case 32:
                b = ((b & 0xffff0000) >> 16) | ((b & 0x0000ffff) << 16);
                fallthrough;
        case 16:
                b = ((b & 0xff00ff00) >> 8) | ((b & 0x00ff00ff) << 8);
                fallthrough;
        case 8:
                b = ((b & 0xf0f0f0f0) >> 4) | ((b & 0x0f0f0f0f) << 4);
                fallthrough;
        case 4:
                b = ((b & 0xcccccccc) >> 2) | ((b & 0x33333333) << 2);
                fallthrough;
        case 2:
                b = ((b & 0xaaaaaaaa) >> 1) | ((b & 0x55555555) << 1);
        case 1:
        case 0:
                break;
        default:
                printk(KERN_ERR "DBRI reverse_bytes: unsupported length\n");
        }

        return b;
}

/*
****************************************************************************
************** DBRI initialization and command synchronization *************
****************************************************************************

Commands are sent to the DBRI by building a list of them in memory,
then writing the address of the first list item to DBRI register 8.
The list is terminated with a WAIT command, which generates a
CPU interrupt to signal completion.

Since the DBRI can run in parallel with the CPU, several means of
synchronization present themselves. The method implemented here uses
the dbri_cmdwait() to wait for execution of batch of sent commands.

A circular command buffer is used here. A new command is being added
while another can be executed. The scheme works by adding two WAIT commands
after each sent batch of commands. When the next batch is prepared it is
added after the WAIT commands then the WAITs are replaced with single JUMP
command to the new batch. Then the DBRI is forced to reread the last WAIT
command (replaced by the JUMP by then). If the DBRI is still executing
previous commands the request to reread the WAIT command is ignored.

Every time a routine wants to write commands to the DBRI, it must
first call dbri_cmdlock() and get pointer to a free space in
dbri->dma->cmd buffer. After this, the commands can be written to
the buffer, and dbri_cmdsend() is called with the final pointer value
to send them to the DBRI.

*/

#define MAXLOOPS 20
/*
 * Wait for the current command string to execute
 */
static void dbri_cmdwait(struct snd_dbri *dbri)
{
        int maxloops = MAXLOOPS;
        unsigned long flags;

        /* Delay if previous commands are still being processed */
        spin_lock_irqsave(&dbri->lock, flags);
        while ((--maxloops) > 0 && (sbus_readl(dbri->regs + REG0) & D_P)) {
                spin_unlock_irqrestore(&dbri->lock, flags);
                msleep_interruptible(1);
                spin_lock_irqsave(&dbri->lock, flags);
        }
        spin_unlock_irqrestore(&dbri->lock, flags);

        if (maxloops == 0)
                printk(KERN_ERR "DBRI: Chip never completed command buffer\n");
        else
                dprintk(D_CMD, "Chip completed command buffer (%d)\n",
                        MAXLOOPS - maxloops - 1);
}
/*
 * Lock the command queue and return pointer to space for len cmd words
 * It locks the cmdlock spinlock.
 */
static s32 *dbri_cmdlock(struct snd_dbri *dbri, int len)
{
        u32 dvma_addr = (u32)dbri->dma_dvma;

        /* Space for 2 WAIT cmds (replaced later by 1 JUMP cmd) */
        len += 2;
        spin_lock(&dbri->cmdlock);
        if (dbri->cmdptr - dbri->dma->cmd + len < DBRI_NO_CMDS - 2)
                return dbri->cmdptr + 2;
        else if (len < sbus_readl(dbri->regs + REG8) - dvma_addr)
                return dbri->dma->cmd;
        else
                printk(KERN_ERR "DBRI: no space for commands.");

        return NULL;
}

/*
 * Send prepared cmd string. It works by writing a JUMP cmd into
 * the last WAIT cmd and force DBRI to reread the cmd.
 * The JUMP cmd points to the new cmd string.
 * It also releases the cmdlock spinlock.
 *
 * Lock must be held before calling this.
 */
static void dbri_cmdsend(struct snd_dbri *dbri, s32 *cmd, int len)
{
        u32 dvma_addr = (u32)dbri->dma_dvma;
        s32 tmp, addr;
        static int wait_id = 0;

        wait_id++;
        wait_id &= 0xffff;      /* restrict it to a 16 bit counter. */
        *(cmd) = DBRI_CMD(D_WAIT, 1, wait_id);
        *(cmd+1) = DBRI_CMD(D_WAIT, 1, wait_id);

        /* Replace the last command with JUMP */
        addr = dvma_addr + (cmd - len - dbri->dma->cmd) * sizeof(s32);
        *(dbri->cmdptr+1) = addr;
        *(dbri->cmdptr) = DBRI_CMD(D_JUMP, 0, 0);

#ifdef DBRI_DEBUG
        if (cmd > dbri->cmdptr) {
                s32 *ptr;

                for (ptr = dbri->cmdptr; ptr < cmd+2; ptr++)
                        dprintk(D_CMD, "cmd: %lx:%08x\n",
                                (unsigned long)ptr, *ptr);
        } else {
                s32 *ptr = dbri->cmdptr;

                dprintk(D_CMD, "cmd: %lx:%08x\n", (unsigned long)ptr, *ptr);
                ptr++;
                dprintk(D_CMD, "cmd: %lx:%08x\n", (unsigned long)ptr, *ptr);
                for (ptr = dbri->dma->cmd; ptr < cmd+2; ptr++)
                        dprintk(D_CMD, "cmd: %lx:%08x\n",
                                (unsigned long)ptr, *ptr);
        }
#endif

        /* Reread the last command */
        tmp = sbus_readl(dbri->regs + REG0);
        tmp |= D_P;
        sbus_writel(tmp, dbri->regs + REG0);

        dbri->cmdptr = cmd;
        spin_unlock(&dbri->cmdlock);
}

/* Lock must be held when calling this */
static void dbri_reset(struct snd_dbri *dbri)
{
        int i;
        u32 tmp;

        dprintk(D_GEN, "reset 0:%x 2:%x 8:%x 9:%x\n",
                sbus_readl(dbri->regs + REG0),
                sbus_readl(dbri->regs + REG2),
                sbus_readl(dbri->regs + REG8), sbus_readl(dbri->regs + REG9));

        sbus_writel(D_R, dbri->regs + REG0);    /* Soft Reset */
        for (i = 0; (sbus_readl(dbri->regs + REG0) & D_R) && i < 64; i++)
                udelay(10);

        /* A brute approach - DBRI falls back to working burst size by itself
         * On SS20 D_S does not work, so do not try so high. */
        tmp = sbus_readl(dbri->regs + REG0);
        tmp |= D_G | D_E;
        tmp &= ~D_S;
        sbus_writel(tmp, dbri->regs + REG0);
}

/* Lock must not be held before calling this */
static void dbri_initialize(struct snd_dbri *dbri)
{
        u32 dvma_addr = (u32)dbri->dma_dvma;
        s32 *cmd;
        u32 dma_addr;
        unsigned long flags;
        int n;

        spin_lock_irqsave(&dbri->lock, flags);

        dbri_reset(dbri);

        /* Initialize pipes */
        for (n = 0; n < DBRI_NO_PIPES; n++)
                dbri->pipes[n].desc = dbri->pipes[n].first_desc = -1;

        spin_lock_init(&dbri->cmdlock);
        /*
         * Initialize the interrupt ring buffer.
         */
        dma_addr = dvma_addr + dbri_dma_off(intr, 0);
        dbri->dma->intr[0] = dma_addr;
        dbri->dbri_irqp = 1;
        /*
         * Set up the interrupt queue
         */
        spin_lock(&dbri->cmdlock);
        cmd = dbri->cmdptr = dbri->dma->cmd;
        *(cmd++) = DBRI_CMD(D_IIQ, 0, 0);
        *(cmd++) = dma_addr;
        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);
        dbri->cmdptr = cmd;
        *(cmd++) = DBRI_CMD(D_WAIT, 1, 0);
        *(cmd++) = DBRI_CMD(D_WAIT, 1, 0);
        dma_addr = dvma_addr + dbri_dma_off(cmd, 0);
        sbus_writel(dma_addr, dbri->regs + REG8);
        spin_unlock(&dbri->cmdlock);

        spin_unlock_irqrestore(&dbri->lock, flags);
        dbri_cmdwait(dbri);
}

/*
****************************************************************************
************************** DBRI data pipe management ***********************
****************************************************************************

While DBRI control functions use the command and interrupt buffers, the
main data path takes the form of data pipes, which can be short (command
and interrupt driven), or long (attached to DMA buffers).  These functions
provide a rudimentary means of setting up and managing the DBRI's pipes,
but the calling functions have to make sure they respect the pipes' linked
list ordering, among other things.  The transmit and receive functions
here interface closely with the transmit and receive interrupt code.

*/
static inline int pipe_active(struct snd_dbri *dbri, int pipe)
{
        return ((pipe >= 0) && (dbri->pipes[pipe].desc != -1));
}

/* reset_pipe(dbri, pipe)
 *
 * Called on an in-use pipe to clear anything being transmitted or received
 * Lock must be held before calling this.
 */
static void reset_pipe(struct snd_dbri *dbri, int pipe)
{
        int sdp;
        int desc;
        s32 *cmd;

        if (pipe < 0 || pipe > DBRI_MAX_PIPE) {
                printk(KERN_ERR "DBRI: reset_pipe called with "
                        "illegal pipe number\n");
                return;
        }

        sdp = dbri->pipes[pipe].sdp;
        if (sdp == 0) {
                printk(KERN_ERR "DBRI: reset_pipe called "
                        "on uninitialized pipe\n");
                return;
        }

        cmd = dbri_cmdlock(dbri, 3);
        *(cmd++) = DBRI_CMD(D_SDP, 0, sdp | D_SDP_C | D_SDP_P);
        *(cmd++) = 0;
        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);
        dbri_cmdsend(dbri, cmd, 3);

        desc = dbri->pipes[pipe].first_desc;
        if (desc >= 0)
                do {
                        dbri->dma->desc[desc].ba = 0;
                        dbri->dma->desc[desc].nda = 0;
                        desc = dbri->next_desc[desc];
                } while (desc != -1 && desc != dbri->pipes[pipe].first_desc);

        dbri->pipes[pipe].desc = -1;
        dbri->pipes[pipe].first_desc = -1;
}

/*
 * Lock must be held before calling this.
 */
static void setup_pipe(struct snd_dbri *dbri, int pipe, int sdp)
{
        if (pipe < 0 || pipe > DBRI_MAX_PIPE) {
                printk(KERN_ERR "DBRI: setup_pipe called "
                        "with illegal pipe number\n");
                return;
        }

        if ((sdp & 0xf800) != sdp) {
                printk(KERN_ERR "DBRI: setup_pipe called "
                        "with strange SDP value\n");
                /* sdp &= 0xf800; */
        }

        /* If this is a fixed receive pipe, arrange for an interrupt
         * every time its data changes
         */
        if (D_SDP_MODE(sdp) == D_SDP_FIXED && !(sdp & D_SDP_TO_SER))
                sdp |= D_SDP_CHANGE;

        sdp |= D_PIPE(pipe);
        dbri->pipes[pipe].sdp = sdp;
        dbri->pipes[pipe].desc = -1;
        dbri->pipes[pipe].first_desc = -1;

        reset_pipe(dbri, pipe);
}

/*
 * Lock must be held before calling this.
 */
static void link_time_slot(struct snd_dbri *dbri, int pipe,
                           int prevpipe, int nextpipe,
                           int length, int cycle)
{
        s32 *cmd;
        int val;

        if (pipe < 0 || pipe > DBRI_MAX_PIPE
                        || prevpipe < 0 || prevpipe > DBRI_MAX_PIPE
                        || nextpipe < 0 || nextpipe > DBRI_MAX_PIPE) {
                printk(KERN_ERR
                    "DBRI: link_time_slot called with illegal pipe number\n");
                return;
        }

        if (dbri->pipes[pipe].sdp == 0
                        || dbri->pipes[prevpipe].sdp == 0
                        || dbri->pipes[nextpipe].sdp == 0) {
                printk(KERN_ERR "DBRI: link_time_slot called "
                        "on uninitialized pipe\n");
                return;
        }

        dbri->pipes[prevpipe].nextpipe = pipe;
        dbri->pipes[pipe].nextpipe = nextpipe;
        dbri->pipes[pipe].length = length;

        cmd = dbri_cmdlock(dbri, 4);

        if (dbri->pipes[pipe].sdp & D_SDP_TO_SER) {
                /* Deal with CHI special case:
                 * "If transmission on edges 0 or 1 is desired, then cycle n
                 *  (where n = # of bit times per frame...) must be used."
                 *                  - DBRI data sheet, page 11
                 */
                if (prevpipe == 16 && cycle == 0)
                        cycle = dbri->chi_bpf;

                val = D_DTS_VO | D_DTS_INS | D_DTS_PRVOUT(prevpipe) | pipe;
                *(cmd++) = DBRI_CMD(D_DTS, 0, val);
                *(cmd++) = 0;
                *(cmd++) =
                    D_TS_LEN(length) | D_TS_CYCLE(cycle) | D_TS_NEXT(nextpipe);
        } else {
                val = D_DTS_VI | D_DTS_INS | D_DTS_PRVIN(prevpipe) | pipe;
                *(cmd++) = DBRI_CMD(D_DTS, 0, val);
                *(cmd++) =
                    D_TS_LEN(length) | D_TS_CYCLE(cycle) | D_TS_NEXT(nextpipe);
                *(cmd++) = 0;
        }
        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);

        dbri_cmdsend(dbri, cmd, 4);
}

#if 0
/*
 * Lock must be held before calling this.
 */
static void unlink_time_slot(struct snd_dbri *dbri, int pipe,
                             enum in_or_out direction, int prevpipe,
                             int nextpipe)
{
        s32 *cmd;
        int val;

        if (pipe < 0 || pipe > DBRI_MAX_PIPE
                        || prevpipe < 0 || prevpipe > DBRI_MAX_PIPE
                        || nextpipe < 0 || nextpipe > DBRI_MAX_PIPE) {
                printk(KERN_ERR
                    "DBRI: unlink_time_slot called with illegal pipe number\n");
                return;
        }

        cmd = dbri_cmdlock(dbri, 4);

        if (direction == PIPEinput) {
                val = D_DTS_VI | D_DTS_DEL | D_DTS_PRVIN(prevpipe) | pipe;
                *(cmd++) = DBRI_CMD(D_DTS, 0, val);
                *(cmd++) = D_TS_NEXT(nextpipe);
                *(cmd++) = 0;
        } else {
                val = D_DTS_VO | D_DTS_DEL | D_DTS_PRVOUT(prevpipe) | pipe;
                *(cmd++) = DBRI_CMD(D_DTS, 0, val);
                *(cmd++) = 0;
                *(cmd++) = D_TS_NEXT(nextpipe);
        }
        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);

        dbri_cmdsend(dbri, cmd, 4);
}
#endif

/* xmit_fixed() / recv_fixed()
 *
 * Transmit/receive data on a "fixed" pipe - i.e, one whose contents are not
 * expected to change much, and which we don't need to buffer.
 * The DBRI only interrupts us when the data changes (receive pipes),
 * or only changes the data when this function is called (transmit pipes).
 * Only short pipes (numbers 16-31) can be used in fixed data mode.
 *
 * These function operate on a 32-bit field, no matter how large
 * the actual time slot is.  The interrupt handler takes care of bit
 * ordering and alignment.  An 8-bit time slot will always end up
 * in the low-order 8 bits, filled either MSB-first or LSB-first,
 * depending on the settings passed to setup_pipe().
 *
 * Lock must not be held before calling it.
 */

static void xmit_fixed(struct snd_dbri *dbri, int pipe, unsigned int data)
{
        s32 *cmd;
        unsigned long flags;

        if (pipe < 16 || pipe > DBRI_MAX_PIPE) {
                printk(KERN_ERR "DBRI: xmit_fixed: Illegal pipe number\n");
                return;
        }

        if (D_SDP_MODE(dbri->pipes[pipe].sdp) == 0) {
                printk(KERN_ERR "DBRI: xmit_fixed: "
                        "Uninitialized pipe %d\n", pipe);
                return;
        }

        if (D_SDP_MODE(dbri->pipes[pipe].sdp) != D_SDP_FIXED) {
                printk(KERN_ERR "DBRI: xmit_fixed: Non-fixed pipe %d\n", pipe);
                return;
        }

        if (!(dbri->pipes[pipe].sdp & D_SDP_TO_SER)) {
                printk(KERN_ERR "DBRI: xmit_fixed: Called on receive pipe %d\n",
                        pipe);
                return;
        }

        /* DBRI short pipes always transmit LSB first */

        if (dbri->pipes[pipe].sdp & D_SDP_MSB)
                data = reverse_bytes(data, dbri->pipes[pipe].length);

        cmd = dbri_cmdlock(dbri, 3);

        *(cmd++) = DBRI_CMD(D_SSP, 0, pipe);
        *(cmd++) = data;
        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);

        spin_lock_irqsave(&dbri->lock, flags);
        dbri_cmdsend(dbri, cmd, 3);
        spin_unlock_irqrestore(&dbri->lock, flags);
        dbri_cmdwait(dbri);

}

static void recv_fixed(struct snd_dbri *dbri, int pipe, volatile __u32 *ptr)
{
        if (pipe < 16 || pipe > DBRI_MAX_PIPE) {
                printk(KERN_ERR "DBRI: recv_fixed called with "
                        "illegal pipe number\n");
                return;
        }

        if (D_SDP_MODE(dbri->pipes[pipe].sdp) != D_SDP_FIXED) {
                printk(KERN_ERR "DBRI: recv_fixed called on "
                        "non-fixed pipe %d\n", pipe);
                return;
        }

        if (dbri->pipes[pipe].sdp & D_SDP_TO_SER) {
                printk(KERN_ERR "DBRI: recv_fixed called on "
                        "transmit pipe %d\n", pipe);
                return;
        }

        dbri->pipes[pipe].recv_fixed_ptr = ptr;
}

/* setup_descs()
 *
 * Setup transmit/receive data on a "long" pipe - i.e, one associated
 * with a DMA buffer.
 *
 * Only pipe numbers 0-15 can be used in this mode.
 *
 * This function takes a stream number pointing to a data buffer,
 * and work by building chains of descriptors which identify the
 * data buffers.  Buffers too large for a single descriptor will
 * be spread across multiple descriptors.
 *
 * All descriptors create a ring buffer.
 *
 * Lock must be held before calling this.
 */
static int setup_descs(struct snd_dbri *dbri, int streamno, unsigned int period)
{
        struct dbri_streaminfo *info = &dbri->stream_info[streamno];
        u32 dvma_addr = (u32)dbri->dma_dvma;
        __u32 dvma_buffer;
        int desc;
        int len;
        int first_desc = -1;
        int last_desc = -1;

        if (info->pipe < 0 || info->pipe > 15) {
                printk(KERN_ERR "DBRI: setup_descs: Illegal pipe number\n");
                return -2;
        }

        if (dbri->pipes[info->pipe].sdp == 0) {
                printk(KERN_ERR "DBRI: setup_descs: Uninitialized pipe %d\n",
                       info->pipe);
                return -2;
        }

        dvma_buffer = info->dvma_buffer;
        len = info->size;

        if (streamno == DBRI_PLAY) {
                if (!(dbri->pipes[info->pipe].sdp & D_SDP_TO_SER)) {
                        printk(KERN_ERR "DBRI: setup_descs: "
                                "Called on receive pipe %d\n", info->pipe);
                        return -2;
                }
        } else {
                if (dbri->pipes[info->pipe].sdp & D_SDP_TO_SER) {
                        printk(KERN_ERR
                            "DBRI: setup_descs: Called on transmit pipe %d\n",
                             info->pipe);
                        return -2;
                }
                /* Should be able to queue multiple buffers
                 * to receive on a pipe
                 */
                if (pipe_active(dbri, info->pipe)) {
                        printk(KERN_ERR "DBRI: recv_on_pipe: "
                                "Called on active pipe %d\n", info->pipe);
                        return -2;
                }

                /* Make sure buffer size is multiple of four */
                len &= ~3;
        }

        /* Free descriptors if pipe has any */
        desc = dbri->pipes[info->pipe].first_desc;
        if (desc >= 0)
                do {
                        dbri->dma->desc[desc].ba = 0;
                        dbri->dma->desc[desc].nda = 0;
                        desc = dbri->next_desc[desc];
                } while (desc != -1 &&
                         desc != dbri->pipes[info->pipe].first_desc);

        dbri->pipes[info->pipe].desc = -1;
        dbri->pipes[info->pipe].first_desc = -1;

        desc = 0;
        while (len > 0) {
                int mylen;

                for (; desc < DBRI_NO_DESCS; desc++) {
                        if (!dbri->dma->desc[desc].ba)
                                break;
                }

                if (desc == DBRI_NO_DESCS) {
                        printk(KERN_ERR "DBRI: setup_descs: No descriptors\n");
                        return -1;
                }

                if (len > DBRI_TD_MAXCNT)
                        mylen = DBRI_TD_MAXCNT; /* 8KB - 4 */
                else
                        mylen = len;

                if (mylen > period)
                        mylen = period;

                dbri->next_desc[desc] = -1;
                dbri->dma->desc[desc].ba = dvma_buffer;
                dbri->dma->desc[desc].nda = 0;

                if (streamno == DBRI_PLAY) {
                        dbri->dma->desc[desc].word1 = DBRI_TD_CNT(mylen);
                        dbri->dma->desc[desc].word4 = 0;
                        dbri->dma->desc[desc].word1 |= DBRI_TD_F | DBRI_TD_B;
                } else {
                        dbri->dma->desc[desc].word1 = 0;
                        dbri->dma->desc[desc].word4 =
                            DBRI_RD_B | DBRI_RD_BCNT(mylen);
                }

                if (first_desc == -1)
                        first_desc = desc;
                else {
                        dbri->next_desc[last_desc] = desc;
                        dbri->dma->desc[last_desc].nda =
                            dvma_addr + dbri_dma_off(desc, desc);
                }

                last_desc = desc;
                dvma_buffer += mylen;
                len -= mylen;
        }

        if (first_desc == -1 || last_desc == -1) {
                printk(KERN_ERR "DBRI: setup_descs: "
                        " Not enough descriptors available\n");
                return -1;
        }

        dbri->dma->desc[last_desc].nda =
            dvma_addr + dbri_dma_off(desc, first_desc);
        dbri->next_desc[last_desc] = first_desc;
        dbri->pipes[info->pipe].first_desc = first_desc;
        dbri->pipes[info->pipe].desc = first_desc;

#ifdef DBRI_DEBUG
        for (desc = first_desc; desc != -1;) {
                dprintk(D_DESC, "DESC %d: %08x %08x %08x %08x\n",
                        desc,
                        dbri->dma->desc[desc].word1,
                        dbri->dma->desc[desc].ba,
                        dbri->dma->desc[desc].nda, dbri->dma->desc[desc].word4);
                        desc = dbri->next_desc[desc];
                        if (desc == first_desc)
                                break;
        }
#endif
        return 0;
}

/*
****************************************************************************
************************** DBRI - CHI interface ****************************
****************************************************************************

The CHI is a four-wire (clock, frame sync, data in, data out) time-division
multiplexed serial interface which the DBRI can operate in either master
(give clock/frame sync) or slave (take clock/frame sync) mode.

*/

enum master_or_slave { CHImaster, CHIslave };

/*
 * Lock must not be held before calling it.
 */
static void reset_chi(struct snd_dbri *dbri,
                      enum master_or_slave master_or_slave,
                      int bits_per_frame)
{
        s32 *cmd;
        int val;

        /* Set CHI Anchor: Pipe 16 */

        cmd = dbri_cmdlock(dbri, 4);
        val = D_DTS_VO | D_DTS_VI | D_DTS_INS
                | D_DTS_PRVIN(16) | D_PIPE(16) | D_DTS_PRVOUT(16);
        *(cmd++) = DBRI_CMD(D_DTS, 0, val);
        *(cmd++) = D_TS_ANCHOR | D_TS_NEXT(16);
        *(cmd++) = D_TS_ANCHOR | D_TS_NEXT(16);
        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);
        dbri_cmdsend(dbri, cmd, 4);

        dbri->pipes[16].sdp = 1;
        dbri->pipes[16].nextpipe = 16;

        cmd = dbri_cmdlock(dbri, 4);

        if (master_or_slave == CHIslave) {
                /* Setup DBRI for CHI Slave - receive clock, frame sync (FS)
                 *
                 * CHICM  = 0 (slave mode, 8 kHz frame rate)
                 * IR     = give immediate CHI status interrupt
                 * EN     = give CHI status interrupt upon change
                 */
                *(cmd++) = DBRI_CMD(D_CHI, 0, D_CHI_CHICM(0));
        } else {
                /* Setup DBRI for CHI Master - generate clock, FS
                 *
                 * BPF                          =  bits per 8 kHz frame
                 * 12.288 MHz / CHICM_divisor   = clock rate
                 * FD = 1 - drive CHIFS on rising edge of CHICK
                 */
                int clockrate = bits_per_frame * 8;
                int divisor = 12288 / clockrate;

                if (divisor > 255 || divisor * clockrate != 12288)
                        printk(KERN_ERR "DBRI: illegal bits_per_frame "
                                "in setup_chi\n");

                *(cmd++) = DBRI_CMD(D_CHI, 0, D_CHI_CHICM(divisor) | D_CHI_FD
                                    | D_CHI_BPF(bits_per_frame));
        }

        dbri->chi_bpf = bits_per_frame;

        /* CHI Data Mode
         *
         * RCE   =  0 - receive on falling edge of CHICK
         * XCE   =  1 - transmit on rising edge of CHICK
         * XEN   =  1 - enable transmitter
         * REN   =  1 - enable receiver
         */

        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);
        *(cmd++) = DBRI_CMD(D_CDM, 0, D_CDM_XCE | D_CDM_XEN | D_CDM_REN);
        *(cmd++) = DBRI_CMD(D_PAUSE, 0, 0);

        dbri_cmdsend(dbri, cmd, 4);
}

/*
****************************************************************************
*********************** CS4215 audio codec management **********************
****************************************************************************

In the standard SPARC audio configuration, the CS4215 codec is attached
to the DBRI via the CHI interface and few of the DBRI's PIO pins.

 * Lock must not be held before calling it.

*/
static void cs4215_setup_pipes(struct snd_dbri *dbri)
{
        unsigned long flags;

        spin_lock_irqsave(&dbri->lock, flags);
        /*
         * Data mode:
         * Pipe  4: Send timeslots 1-4 (audio data)
         * Pipe 20: Send timeslots 5-8 (part of ctrl data)
         * Pipe  6: Receive timeslots 1-4 (audio data)
         * Pipe 21: Receive timeslots 6-7. We can only receive 20 bits via
         *          interrupt, and the rest of the data (slot 5 and 8) is
         *          not relevant for us (only for doublechecking).
         *
         * Control mode:
         * Pipe 17: Send timeslots 1-4 (slots 5-8 are read only)
         * Pipe 18: Receive timeslot 1 (clb).
         * Pipe 19: Receive timeslot 7 (version).
         */

        setup_pipe(dbri, 4, D_SDP_MEM | D_SDP_TO_SER | D_SDP_MSB);
        setup_pipe(dbri, 20, D_SDP_FIXED | D_SDP_TO_SER | D_SDP_MSB);
        setup_pipe(dbri, 6, D_SDP_MEM | D_SDP_FROM_SER | D_SDP_MSB);
        setup_pipe(dbri, 21, D_SDP_FIXED | D_SDP_FROM_SER | D_SDP_MSB);

        setup_pipe(dbri, 17, D_SDP_FIXED | D_SDP_TO_SER | D_SDP_MSB);
        setup_pipe(dbri, 18, D_SDP_FIXED | D_SDP_FROM_SER | D_SDP_MSB);
        setup_pipe(dbri, 19, D_SDP_FIXED | D_SDP_FROM_SER | D_SDP_MSB);
        spin_unlock_irqrestore(&dbri->lock, flags);

        dbri_cmdwait(dbri);
}

static int cs4215_init_data(struct cs4215 *mm)
{
        /*
         * No action, memory resetting only.
         *
         * Data Time Slot 5-8
         * Speaker,Line and Headphone enable. Gain set to the half.
         * Input is mike.
         */
        mm->data[0] = CS4215_LO(0x20) | CS4215_HE | CS4215_LE;
        mm->data[1] = CS4215_RO(0x20) | CS4215_SE;
        mm->data[2] = CS4215_LG(0x8) | CS4215_IS | CS4215_PIO0 | CS4215_PIO1;
        mm->data[3] = CS4215_RG(0x8) | CS4215_MA(0xf);

        /*
         * Control Time Slot 1-4
         * 0: Default I/O voltage scale
         * 1: 8 bit ulaw, 8kHz, mono, high pass filter disabled
         * 2: Serial enable, CHI master, 128 bits per frame, clock 1
         * 3: Tests disabled
         */
        mm->ctrl[0] = CS4215_RSRVD_1 | CS4215_MLB;
        mm->ctrl[1] = CS4215_DFR_ULAW | CS4215_FREQ[0].csval;
        mm->ctrl[2] = CS4215_XCLK | CS4215_BSEL_128 | CS4215_FREQ[0].xtal;
        mm->ctrl[3] = 0;

        mm->status = 0;
        mm->version = 0xff;
        mm->precision = 8;      /* For ULAW */
        mm->channels = 1;

        return 0;
}

static void cs4215_setdata(struct snd_dbri *dbri, int muted)
{
        if (muted) {
                dbri->mm.data[0] |= 63;
                dbri->mm.data[1] |= 63;
                dbri->mm.data[2] &= ~15;
                dbri->mm.data[3] &= ~15;
        } else {
                /* Start by setting the playback attenuation. */
                struct dbri_streaminfo *info = &dbri->stream_info[DBRI_PLAY];
                int left_gain = info->left_gain & 0x3f;
                int right_gain = info->right_gain & 0x3f;

                dbri->mm.data[0] &= ~0x3f;      /* Reset the volume bits */
                dbri->mm.data[1] &= ~0x3f;
                dbri->mm.data[0] |= (DBRI_MAX_VOLUME - left_gain);
                dbri->mm.data[1] |= (DBRI_MAX_VOLUME - right_gain);

                /* Now set the recording gain. */
                info = &dbri->stream_info[DBRI_REC];
                left_gain = info->left_gain & 0xf;
                right_gain = info->right_gain & 0xf;
                dbri->mm.data[2] |= CS4215_LG(left_gain);
                dbri->mm.data[3] |= CS4215_RG(right_gain);
        }

        xmit_fixed(dbri, 20, *(int *)dbri->mm.data);
}

/*
 * Set the CS4215 to data mode.
 */
static void cs4215_open(struct snd_dbri *dbri)
{
        int data_width;
        u32 tmp;
        unsigned long flags;

        dprintk(D_MM, "cs4215_open: %d channels, %d bits\n",
                dbri->mm.channels, dbri->mm.precision);

        /* Temporarily mute outputs, and wait 1/8000 sec (125 us)
         * to make sure this takes.  This avoids clicking noises.
         */

        cs4215_setdata(dbri, 1);
        udelay(125);

        /*
         * Data mode:
         * Pipe  4: Send timeslots 1-4 (audio data)
         * Pipe 20: Send timeslots 5-8 (part of ctrl data)
         * Pipe  6: Receive timeslots 1-4 (audio data)
         * Pipe 21: Receive timeslots 6-7. We can only receive 20 bits via
         *          interrupt, and the rest of the data (slot 5 and 8) is
         *          not relevant for us (only for doublechecking).
         *
         * Just like in control mode, the time slots are all offset by eight
         * bits.  The CS4215, it seems, observes TSIN (the delayed signal)
         * even if it's the CHI master.  Don't ask me...
         */
        spin_lock_irqsave(&dbri->lock, flags);
        tmp = sbus_readl(dbri->regs + REG0);
        tmp &= ~(D_C);          /* Disable CHI */
        sbus_writel(tmp, dbri->regs + REG0);

        /* Switch CS4215 to data mode - set PIO3 to 1 */
        sbus_writel(D_ENPIO | D_PIO1 | D_PIO3 |
                    (dbri->mm.onboard ? D_PIO0 : D_PIO2), dbri->regs + REG2);

        reset_chi(dbri, CHIslave, 128);

        /* Note: this next doesn't work for 8-bit stereo, because the two
         * channels would be on timeslots 1 and 3, with 2 and 4 idle.
         * (See CS4215 datasheet Fig 15)
         *
         * DBRI non-contiguous mode would be required to make this work.
         */
        data_width = dbri->mm.channels * dbri->mm.precision;

        link_time_slot(dbri, 4, 16, 16, data_width, dbri->mm.offset);
        link_time_slot(dbri, 20, 4, 16, 32, dbri->mm.offset + 32);
        link_time_slot(dbri, 6, 16, 16, data_width, dbri->mm.offset);
        link_time_slot(dbri, 21, 6, 16, 16, dbri->mm.offset + 40);

        /* FIXME: enable CHI after _setdata? */
        tmp = sbus_readl(dbri->regs + REG0);
        tmp |= D_C;             /* Enable CHI */
        sbus_writel(tmp, dbri->regs + REG0);
        spin_unlock_irqrestore(&dbri->lock, flags);

        cs4215_setdata(dbri, 0);
}

/*
 * Send the control information (i.e. audio format)
 */
static int cs4215_setctrl(struct snd_dbri *dbri)
{
        int i, val;
        u32 tmp;
        unsigned long flags;

        /* FIXME - let the CPU do something useful during these delays */

        /* Temporarily mute outputs, and wait 1/8000 sec (125 us)
         * to make sure this takes.  This avoids clicking noises.
         */
        cs4215_setdata(dbri, 1);
        udelay(125);

        /*
         * Enable Control mode: Set DBRI's PIO3 (4215's D/~C) to 0, then wait
         * 12 cycles <= 12/(5512.5*64) sec = 34.01 usec
         */
        val = D_ENPIO | D_PIO1 | (dbri->mm.onboard ? D_PIO0 : D_PIO2);
        sbus_writel(val, dbri->regs + REG2);
        dprintk(D_MM, "cs4215_setctrl: reg2=0x%x\n", val);
        udelay(34);

        /* In Control mode, the CS4215 is a slave device, so the DBRI must
         * operate as CHI master, supplying clocking and frame synchronization.
         *
         * In Data mode, however, the CS4215 must be CHI master to insure
         * that its data stream is synchronous with its codec.
         *
         * The upshot of all this?  We start by putting the DBRI into master
         * mode, program the CS4215 in Control mode, then switch the CS4215
         * into Data mode and put the DBRI into slave mode.  Various timing
         * requirements must be observed along the way.
         *
         * Oh, and one more thing, on a SPARCStation 20 (and maybe
         * others?), the addressing of the CS4215's time slots is
         * offset by eight bits, so we add eight to all the "cycle"
         * values in the Define Time Slot (DTS) commands.  This is
         * done in hardware by a TI 248 that delays the DBRI->4215
         * frame sync signal by eight clock cycles.  Anybody know why?
         */
        spin_lock_irqsave(&dbri->lock, flags);
        tmp = sbus_readl(dbri->regs + REG0);
        tmp &= ~D_C;            /* Disable CHI */
        sbus_writel(tmp, dbri->regs + REG0);

        reset_chi(dbri, CHImaster, 128);

        /*
         * Control mode:
         * Pipe 17: Send timeslots 1-4 (slots 5-8 are read only)
         * Pipe 18: Receive timeslot 1 (clb).
         * Pipe 19: Receive timeslot 7 (version).
         */

        link_time_slot(dbri, 17, 16, 16, 32, dbri->mm.offset);
        link_time_slot(dbri, 18, 16, 16, 8, dbri->mm.offset);
        link_time_slot(dbri, 19, 18, 16, 8, dbri->mm.offset + 48);
        spin_unlock_irqrestore(&dbri->lock, flags);

        /* Wait for the chip to echo back CLB (Control Latch Bit) as zero */
        dbri->mm.ctrl[0] &= ~CS4215_CLB;
        xmit_fixed(dbri, 17, *(int *)dbri->mm.ctrl);

        spin_lock_irqsave(&dbri->lock, flags);
        tmp = sbus_readl(dbri->regs + REG0);
        tmp |= D_C;             /* Enable CHI */
        sbus_writel(tmp, dbri->regs + REG0);
        spin_unlock_irqrestore(&dbri->lock, flags);

        for (i = 10; ((dbri->mm.status & 0xe4) != 0x20); --i)
                msleep_interruptible(1);

        if (i == 0) {
                dprintk(D_MM, "CS4215 didn't respond to CLB (0x%02x)\n",
                        dbri->mm.status);
                return -1;
        }

        /* Disable changes to our copy of the version number, as we are about
         * to leave control mode.
         */
        recv_fixed(dbri, 19, NULL);

        /* Terminate CS4215 control mode - data sheet says
         * "Set CLB=1 and send two more frames of valid control info"
         */
        dbri->mm.ctrl[0] |= CS4215_CLB;
        xmit_fixed(dbri, 17, *(int *)dbri->mm.ctrl);

        /* Two frames of control info @ 8kHz frame rate = 250 us delay */
        udelay(250);

        cs4215_setdata(dbri, 0);

        return 0;
}

/*
 * Setup the codec with the sampling rate, audio format and number of
 * channels.
 * As part of the process we resend the settings for the data
 * timeslots as well.
 */
static int cs4215_prepare(struct snd_dbri *dbri, unsigned int rate,
                          snd_pcm_format_t format, unsigned int channels)
{
        int freq_idx;
        int ret = 0;

        /* Lookup index for this rate */
        for (freq_idx = 0; CS4215_FREQ[freq_idx].freq != 0; freq_idx++) {
                if (CS4215_FREQ[freq_idx].freq == rate)
                        break;
        }
        if (CS4215_FREQ[freq_idx].freq != rate) {
                printk(KERN_WARNING "DBRI: Unsupported rate %d Hz\n", rate);
                return -1;
        }

        switch (format) {
        case SNDRV_PCM_FORMAT_MU_LAW:
                dbri->mm.ctrl[1] = CS4215_DFR_ULAW;
                dbri->mm.precision = 8;
                break;
        case SNDRV_PCM_FORMAT_A_LAW:
                dbri->mm.ctrl[1] = CS4215_DFR_ALAW;
                dbri->mm.precision = 8;
                break;
        case SNDRV_PCM_FORMAT_U8:
                dbri->mm.ctrl[1] = CS4215_DFR_LINEAR8;
                dbri->mm.precision = 8;
                break;
        case SNDRV_PCM_FORMAT_S16_BE:
                dbri->mm.ctrl[1] = CS4215_DFR_LINEAR16;
                dbri->mm.precision = 16;
                break;
        default:
                printk(KERN_WARNING "DBRI: Unsupported format %d\n", format);
                return -1;
        }

        /* Add rate parameters */
        dbri->mm.ctrl[1] |= CS4215_FREQ[freq_idx].csval;
        dbri->mm.ctrl[2] = CS4215_XCLK |
            CS4215_BSEL_128 | CS4215_FREQ[freq_idx].xtal;

        dbri->mm.channels = channels;
        if (channels == 2)
                dbri->mm.ctrl[1] |= CS4215_DFR_STEREO;

        ret = cs4215_setctrl(dbri);
        if (ret == 0)
                cs4215_open(dbri);      /* set codec to data mode */

        return ret;
}

/*
 *
 */
static int cs4215_init(struct snd_dbri *dbri)
{
        u32 reg2 = sbus_readl(dbri->regs + REG2);
        dprintk(D_MM, "cs4215_init: reg2=0x%x\n", reg2);

        /* Look for the cs4215 chips */
        if (reg2 & D_PIO2) {
                dprintk(D_MM, "Onboard CS4215 detected\n");
                dbri->mm.onboard = 1;
        }
        if (reg2 & D_PIO0) {
                dprintk(D_MM, "Speakerbox detected\n");
                dbri->mm.onboard = 0;

                if (reg2 & D_PIO2) {
                        printk(KERN_INFO "DBRI: Using speakerbox / "
                               "ignoring onboard mmcodec.\n");
                        sbus_writel(D_ENPIO2, dbri->regs + REG2);
                }
        }

        if (!(reg2 & (D_PIO0 | D_PIO2))) {
                printk(KERN_ERR "DBRI: no mmcodec found.\n");
                return -EIO;
        }

        cs4215_setup_pipes(dbri);
        cs4215_init_data(&dbri->mm);

        /* Enable capture of the status & version timeslots. */
        recv_fixed(dbri, 18, &dbri->mm.status);
        recv_fixed(dbri, 19, &dbri->mm.version);

        dbri->mm.offset = dbri->mm.onboard ? 0 : 8;
        if (cs4215_setctrl(dbri) == -1 || dbri->mm.version == 0xff) {
                dprintk(D_MM, "CS4215 failed probe at offset %d\n",
                        dbri->mm.offset);
                return -EIO;
        }
        dprintk(D_MM, "Found CS4215 at offset %d\n", dbri->mm.offset);

        return 0;
}

/*
****************************************************************************
*************************** DBRI interrupt handler *************************
****************************************************************************

The DBRI communicates with the CPU mainly via a circular interrupt
buffer.  When an interrupt is signaled, the CPU walks through the
buffer and calls dbri_process_one_interrupt() for each interrupt word.
Complicated interrupts are handled by dedicated functions (which
appear first in this file).  Any pending interrupts can be serviced by
calling dbri_process_interrupt_buffer(), which works even if the CPU's
interrupts are disabled.

*/

/* xmit_descs()
 *
 * Starts transmitting the current TD's for recording/playing.
 * For playback, ALSA has filled the DMA memory with new data (we hope).
 */
static void xmit_descs(struct snd_dbri *dbri)
{
        struct dbri_streaminfo *info;
        u32 dvma_addr;
        s32 *cmd;
        unsigned long flags;
        int first_td;

        if (dbri == NULL)
                return;         /* Disabled */

        dvma_addr = (u32)dbri->dma_dvma;
        info = &dbri->stream_info[DBRI_REC];
        spin_lock_irqsave(&dbri->lock, flags);

        if (info->pipe >= 0) {
                first_td = dbri->pipes[info->pipe].first_desc;

                dprintk(D_DESC, "xmit_descs rec @ TD %d\n", first_td);

                /* Stream could be closed by the time we run. */
                if (first_td >= 0) {
                        cmd = dbri_cmdlock(dbri, 2);
                        *(cmd++) = DBRI_CMD(D_SDP, 0,
                                            dbri->pipes[info->pipe].sdp
                                            | D_SDP_P | D_SDP_EVERY | D_SDP_C);
                        *(cmd++) = dvma_addr +
                                   dbri_dma_off(desc, first_td);
                        dbri_cmdsend(dbri, cmd, 2);

                        /* Reset our admin of the pipe. */
                        dbri->pipes[info->pipe].desc = first_td;
                }
        }

        info = &dbri->stream_info[DBRI_PLAY];

        if (info->pipe >= 0) {
                first_td = dbri->pipes[info->pipe].first_desc;

                dprintk(D_DESC, "xmit_descs play @ TD %d\n", first_td);

                /* Stream could be closed by the time we run. */
                if (first_td >= 0) {
                        cmd = dbri_cmdlock(dbri, 2);
                        *(cmd++) = DBRI_CMD(D_SDP, 0,
                                            dbri->pipes[info->pipe].sdp
                                            | D_SDP_P | D_SDP_EVERY | D_SDP_C);
                        *(cmd++) = dvma_addr +
                                   dbri_dma_off(desc, first_td);
                        dbri_cmdsend(dbri, cmd, 2);

                        /* Reset our admin of the pipe. */
                        dbri->pipes[info->pipe].desc = first_td;
                }
        }

        spin_unlock_irqrestore(&dbri->lock, flags);
}

/* transmission_complete_intr()
 *
 * Called by main interrupt handler when DBRI signals transmission complete
 * on a pipe (interrupt triggered by the B bit in a transmit descriptor).
 *
 * Walks through the pipe's list of transmit buffer descriptors and marks
 * them as available. Stops when the first descriptor is found without
 * TBC (Transmit Buffer Complete) set, or we've run through them all.
 *
 * The DMA buffers are not released. They form a ring buffer and
 * they are filled by ALSA while others are transmitted by DMA.
 *
 */

static void transmission_complete_intr(struct snd_dbri *dbri, int pipe)
{
        struct dbri_streaminfo *info = &dbri->stream_info[DBRI_PLAY];
        int td = dbri->pipes[pipe].desc;
        int status;

        while (td >= 0) {
                if (td >= DBRI_NO_DESCS) {
                        printk(KERN_ERR "DBRI: invalid td on pipe %d\n", pipe);
                        return;
                }

                status = DBRI_TD_STATUS(dbri->dma->desc[td].word4);
                if (!(status & DBRI_TD_TBC))
                        break;

                dprintk(D_INT, "TD %d, status 0x%02x\n", td, status);

                dbri->dma->desc[td].word4 = 0;  /* Reset it for next time. */
                info->offset += DBRI_RD_CNT(dbri->dma->desc[td].word1);

                td = dbri->next_desc[td];
                dbri->pipes[pipe].desc = td;
        }

        /* Notify ALSA */
        spin_unlock(&dbri->lock);
        snd_pcm_period_elapsed(info->substream);
        spin_lock(&dbri->lock);
}

static void reception_complete_intr(struct snd_dbri *dbri, int pipe)
{
        struct dbri_streaminfo *info;
        int rd = dbri->pipes[pipe].desc;
        s32 status;

        if (rd < 0 || rd >= DBRI_NO_DESCS) {
                printk(KERN_ERR "DBRI: invalid rd on pipe %d\n", pipe);
                return;
        }

        dbri->pipes[pipe].desc = dbri->next_desc[rd];
        status = dbri->dma->desc[rd].word1;
        dbri->dma->desc[rd].word1 = 0;  /* Reset it for next time. */

        info = &dbri->stream_info[DBRI_REC];
        info->offset += DBRI_RD_CNT(status);

        /* FIXME: Check status */

        dprintk(D_INT, "Recv RD %d, status 0x%02x, len %d\n",
                rd, DBRI_RD_STATUS(status), DBRI_RD_CNT(status));

        /* Notify ALSA */
        spin_unlock(&dbri->lock);
        snd_pcm_period_elapsed(info->substream);
        spin_lock(&dbri->lock);
}

static void dbri_process_one_interrupt(struct snd_dbri *dbri, int x)
{
        int val = D_INTR_GETVAL(x);
        int channel = D_INTR_GETCHAN(x);
        int command = D_INTR_GETCMD(x);
        int code = D_INTR_GETCODE(x);
#ifdef DBRI_DEBUG
        int rval = D_INTR_GETRVAL(x);
#endif

        if (channel == D_INTR_CMD) {
                dprintk(D_CMD, "INTR: Command: %-5s  Value:%d\n",
                        cmds[command], val);
        } else {
                dprintk(D_INT, "INTR: Chan:%d Code:%d Val:%#x\n",
                        channel, code, rval);
        }

        switch (code) {
        case D_INTR_CMDI:
                if (command != D_WAIT)
                        printk(KERN_ERR "DBRI: Command read interrupt\n");
                break;
        case D_INTR_BRDY:
                reception_complete_intr(dbri, channel);
                break;
        case D_INTR_XCMP:
        case D_INTR_MINT:
                transmission_complete_intr(dbri, channel);
                break;
        case D_INTR_UNDR:
                /* UNDR - Transmission underrun
                 * resend SDP command with clear pipe bit (C) set
                 */
                {
        /* FIXME: do something useful in case of underrun */
                        printk(KERN_ERR "DBRI: Underrun error\n");
#if 0
                        s32 *cmd;
                        int pipe = channel;
                        int td = dbri->pipes[pipe].desc;

                        dbri->dma->desc[td].word4 = 0;
                        cmd = dbri_cmdlock(dbri, NoGetLock);
                        *(cmd++) = DBRI_CMD(D_SDP, 0,
                                            dbri->pipes[pipe].sdp
                                            | D_SDP_P | D_SDP_C | D_SDP_2SAME);
                        *(cmd++) = dbri->dma_dvma + dbri_dma_off(desc, td);
                        dbri_cmdsend(dbri, cmd);
#endif
                }
                break;
        case D_INTR_FXDT:
                /* FXDT - Fixed data change */
                if (dbri->pipes[channel].sdp & D_SDP_MSB)
                        val = reverse_bytes(val, dbri->pipes[channel].length);

                if (dbri->pipes[channel].recv_fixed_ptr)
                        *(dbri->pipes[channel].recv_fixed_ptr) = val;
                break;
        default:
                if (channel != D_INTR_CMD)
                        printk(KERN_WARNING
                               "DBRI: Ignored Interrupt: %d (0x%x)\n", code, x);
        }
}

/* dbri_process_interrupt_buffer advances through the DBRI's interrupt
 * buffer until it finds a zero word (indicating nothing more to do
 * right now).  Non-zero words require processing and are handed off
 * to dbri_process_one_interrupt AFTER advancing the pointer.
 */
static void dbri_process_interrupt_buffer(struct snd_dbri *dbri)
{
        s32 x;

        while ((x = dbri->dma->intr[dbri->dbri_irqp]) != 0) {
                dbri->dma->intr[dbri->dbri_irqp] = 0;
                dbri->dbri_irqp++;
                if (dbri->dbri_irqp == DBRI_INT_BLK)
                        dbri->dbri_irqp = 1;

                dbri_process_one_interrupt(dbri, x);
        }
}

static irqreturn_t snd_dbri_interrupt(int irq, void *dev_id)
{
        struct snd_dbri *dbri = dev_id;
        static int errcnt = 0;
        int x;

        if (dbri == NULL)
                return IRQ_NONE;
        spin_lock(&dbri->lock);

        /*
         * Read it, so the interrupt goes away.
         */
        x = sbus_readl(dbri->regs + REG1);

        if (x & (D_MRR | D_MLE | D_LBG | D_MBE)) {
                u32 tmp;

                if (x & D_MRR)
                        printk(KERN_ERR
                               "DBRI: Multiple Error Ack on SBus reg1=0x%x\n",
                               x);
                if (x & D_MLE)
                        printk(KERN_ERR
                               "DBRI: Multiple Late Error on SBus reg1=0x%x\n",
                               x);
                if (x & D_LBG)
                        printk(KERN_ERR
                               "DBRI: Lost Bus Grant on SBus reg1=0x%x\n", x);
                if (x & D_MBE)
                        printk(KERN_ERR
                               "DBRI: Burst Error on SBus reg1=0x%x\n", x);

                /* Some of these SBus errors cause the chip's SBus circuitry
                 * to be disabled, so just re-enable and try to keep going.
                 *
                 * The only one I've seen is MRR, which will be triggered
                 * if you let a transmit pipe underrun, then try to CDP it.
                 *
                 * If these things persist, we reset the chip.
                 */
                if ((++errcnt) % 10 == 0) {
                        dprintk(D_INT, "Interrupt errors exceeded.\n");
                        dbri_reset(dbri);
                } else {
                        tmp = sbus_readl(dbri->regs + REG0);
                        tmp &= ~(D_D);
                        sbus_writel(tmp, dbri->regs + REG0);
                }
        }

        dbri_process_interrupt_buffer(dbri);

        spin_unlock(&dbri->lock);

        return IRQ_HANDLED;
}

/****************************************************************************
                PCM Interface
****************************************************************************/
static const struct snd_pcm_hardware snd_dbri_pcm_hw = {
        .info           = SNDRV_PCM_INFO_MMAP |
                          SNDRV_PCM_INFO_INTERLEAVED |
                          SNDRV_PCM_INFO_BLOCK_TRANSFER |
                          SNDRV_PCM_INFO_MMAP_VALID |
                          SNDRV_PCM_INFO_BATCH,
        .formats        = SNDRV_PCM_FMTBIT_MU_LAW |
                          SNDRV_PCM_FMTBIT_A_LAW |
                          SNDRV_PCM_FMTBIT_U8 |
                          SNDRV_PCM_FMTBIT_S16_BE,
        .rates          = SNDRV_PCM_RATE_8000_48000 | SNDRV_PCM_RATE_5512,
        .rate_min               = 5512,
        .rate_max               = 48000,
        .channels_min           = 1,