interface.h

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/*
 * i2sbus driver -- interface register definitions
 *
 * Copyright 2006 Johannes Berg <[email protected]>
 *
 * GPL v2, can be found in COPYING.
 */
#ifndef __I2SBUS_INTERFACE_H
#define __I2SBUS_INTERFACE_H

/* i2s bus control registers, at least what we know about them */

#define __PAD(m,n) u8 __pad##m[n]
#define _PAD(line, n) __PAD(line, n)
#define PAD(n) _PAD(__LINE__, (n))
struct i2s_interface_regs {
    __le32 intr_ctl;    /* 0x00 */
    PAD(12);
    __le32 serial_format;   /* 0x10 */
    PAD(12);
    __le32 codec_msg_out;   /* 0x20 */
    PAD(12);
    __le32 codec_msg_in;    /* 0x30 */
    PAD(12);
    __le32 frame_count; /* 0x40 */
    PAD(12);
    __le32 frame_match; /* 0x50 */
    PAD(12);
    __le32 data_word_sizes; /* 0x60 */
    PAD(12);
    __le32 peak_level_sel;  /* 0x70 */
    PAD(12);
    __le32 peak_level_in0;  /* 0x80 */
    PAD(12);
    __le32 peak_level_in1;  /* 0x90 */
    PAD(12);
    /* total size: 0x100 bytes */
}  __attribute__((__packed__));

/* interrupt register is just a bitfield with
 * interrupt enable and pending bits */
#define I2S_REG_INTR_CTL        0x00
#   define I2S_INT_FRAME_COUNT      (1<<31)
#   define I2S_PENDING_FRAME_COUNT      (1<<30)
#   define I2S_INT_MESSAGE_FLAG     (1<<29)
#   define I2S_PENDING_MESSAGE_FLAG     (1<<28)
#   define I2S_INT_NEW_PEAK         (1<<27)
#   define I2S_PENDING_NEW_PEAK     (1<<26)
#   define I2S_INT_CLOCKS_STOPPED       (1<<25)
#   define I2S_PENDING_CLOCKS_STOPPED   (1<<24)
#   define I2S_INT_EXTERNAL_SYNC_ERROR  (1<<23)
#   define I2S_PENDING_EXTERNAL_SYNC_ERROR  (1<<22)
#   define I2S_INT_EXTERNAL_SYNC_OK     (1<<21)
#   define I2S_PENDING_EXTERNAL_SYNC_OK (1<<20)
#   define I2S_INT_NEW_SAMPLE_RATE      (1<<19)
#   define I2S_PENDING_NEW_SAMPLE_RATE  (1<<18)
#   define I2S_INT_STATUS_FLAG      (1<<17)
#   define I2S_PENDING_STATUS_FLAG      (1<<16)

/* serial format register is more interesting :)
 * It contains:
 *  - clock source
 *  - MClk divisor
 *  - SClk divisor
 *  - SClk master flag
 *  - serial format (sony, i2s 64x, i2s 32x, dav, silabs)
 *  - external sample frequency interrupt (don't understand)
 *  - external sample frequency
 */
#define I2S_REG_SERIAL_FORMAT       0x10
/* clock source. You get either 18.432, 45.1584 or 49.1520 MHz */
#   define I2S_SF_CLOCK_SOURCE_SHIFT    30
#   define I2S_SF_CLOCK_SOURCE_MASK     (3<<I2S_SF_CLOCK_SOURCE_SHIFT)
#   define I2S_SF_CLOCK_SOURCE_18MHz    (0<<I2S_SF_CLOCK_SOURCE_SHIFT)
#   define I2S_SF_CLOCK_SOURCE_45MHz    (1<<I2S_SF_CLOCK_SOURCE_SHIFT)
#   define I2S_SF_CLOCK_SOURCE_49MHz    (2<<I2S_SF_CLOCK_SOURCE_SHIFT)
/* also, let's define the exact clock speeds here, in Hz */
#define I2S_CLOCK_SPEED_18MHz   18432000
#define I2S_CLOCK_SPEED_45MHz   45158400
#define I2S_CLOCK_SPEED_49MHz   49152000
/* MClk is the clock that drives the codec, usually called its 'system clock'.
 * It is derived by taking only every 'divisor' tick of the clock.
 */
#   define I2S_SF_MCLKDIV_SHIFT     24
#   define I2S_SF_MCLKDIV_MASK      (0x1F<<I2S_SF_MCLKDIV_SHIFT)
#   define I2S_SF_MCLKDIV_1         (0x14<<I2S_SF_MCLKDIV_SHIFT)
#   define I2S_SF_MCLKDIV_3         (0x13<<I2S_SF_MCLKDIV_SHIFT)
#   define I2S_SF_MCLKDIV_5         (0x12<<I2S_SF_MCLKDIV_SHIFT)
#   define I2S_SF_MCLKDIV_14        (0x0E<<I2S_SF_MCLKDIV_SHIFT)
#   define I2S_SF_MCLKDIV_OTHER(div)    (((div/2-1)<<I2S_SF_MCLKDIV_SHIFT)&I2S_SF_MCLKDIV_MASK)
static inline int i2s_sf_mclkdiv(int div, int *out)
{
    int d;

    switch(div) {
    case 1: *out |= I2S_SF_MCLKDIV_1; return 0;
    case 3: *out |= I2S_SF_MCLKDIV_3; return 0;
    case 5: *out |= I2S_SF_MCLKDIV_5; return 0;
    case 14: *out |= I2S_SF_MCLKDIV_14; return 0;
    default:
        if (div%2) return -1;
        d = div/2-1;
        if (d == 0x14 || d == 0x13 || d == 0x12 || d == 0x0E)
            return -1;
        *out |= I2S_SF_MCLKDIV_OTHER(div);
        return 0;
    }
}
/* SClk is the clock that drives the i2s wire bus. Note that it is
 * derived from the MClk above by taking only every 'divisor' tick
 * of MClk.
 */
#   define I2S_SF_SCLKDIV_SHIFT     20
#   define I2S_SF_SCLKDIV_MASK      (0xF<<I2S_SF_SCLKDIV_SHIFT)
#   define I2S_SF_SCLKDIV_1         (8<<I2S_SF_SCLKDIV_SHIFT)
#   define I2S_SF_SCLKDIV_3         (9<<I2S_SF_SCLKDIV_SHIFT)
#   define I2S_SF_SCLKDIV_OTHER(div)    (((div/2-1)<<I2S_SF_SCLKDIV_SHIFT)&I2S_SF_SCLKDIV_MASK)
static inline int i2s_sf_sclkdiv(int div, int *out)
{
    int d;

    switch(div) {
    case 1: *out |= I2S_SF_SCLKDIV_1; return 0;
    case 3: *out |= I2S_SF_SCLKDIV_3; return 0;
    default:
        if (div%2) return -1;
        d = div/2-1;
        if (d == 8 || d == 9) return -1;
        *out |= I2S_SF_SCLKDIV_OTHER(div);
        return 0;
    }
}
#   define I2S_SF_SCLK_MASTER       (1<<19)
/* serial format is the way the data is put to the i2s wire bus */
#   define I2S_SF_SERIAL_FORMAT_SHIFT   16
#   define I2S_SF_SERIAL_FORMAT_MASK    (7<<I2S_SF_SERIAL_FORMAT_SHIFT)
#   define I2S_SF_SERIAL_FORMAT_SONY    (0<<I2S_SF_SERIAL_FORMAT_SHIFT)
#   define I2S_SF_SERIAL_FORMAT_I2S_64X (1<<I2S_SF_SERIAL_FORMAT_SHIFT)
#   define I2S_SF_SERIAL_FORMAT_I2S_32X (2<<I2S_SF_SERIAL_FORMAT_SHIFT)
#   define I2S_SF_SERIAL_FORMAT_I2S_DAV (4<<I2S_SF_SERIAL_FORMAT_SHIFT)
#   define I2S_SF_SERIAL_FORMAT_I2S_SILABS  (5<<I2S_SF_SERIAL_FORMAT_SHIFT)
/* unknown */
#   define I2S_SF_EXT_SAMPLE_FREQ_INT_SHIFT 12
#   define I2S_SF_EXT_SAMPLE_FREQ_INT_MASK  (0xF<<I2S_SF_SAMPLE_FREQ_INT_SHIFT)
/* probably gives external frequency? */
#   define I2S_SF_EXT_SAMPLE_FREQ_MASK  0xFFF

/* used to send codec messages, but how isn't clear */
#define I2S_REG_CODEC_MSG_OUT       0x20

/* used to receive codec messages, but how isn't clear */
#define I2S_REG_CODEC_MSG_IN        0x30

/* frame count reg isn't clear to me yet, but probably useful */
#define I2S_REG_FRAME_COUNT     0x40

/* program to some value, and get interrupt if frame count reaches it */
#define I2S_REG_FRAME_MATCH     0x50

/* this register describes how the bus transfers data */
#define I2S_REG_DATA_WORD_SIZES     0x60
/* number of interleaved input channels */
#   define I2S_DWS_NUM_CHANNELS_IN_SHIFT    24
#   define I2S_DWS_NUM_CHANNELS_IN_MASK (0x1F<<I2S_DWS_NUM_CHANNELS_IN_SHIFT)
/* word size of input data */
#   define I2S_DWS_DATA_IN_SIZE_SHIFT   16
#   define I2S_DWS_DATA_IN_16BIT        (0<<I2S_DWS_DATA_IN_SIZE_SHIFT)
#   define I2S_DWS_DATA_IN_24BIT        (3<<I2S_DWS_DATA_IN_SIZE_SHIFT)
/* number of interleaved output channels */
#   define I2S_DWS_NUM_CHANNELS_OUT_SHIFT   8
#   define I2S_DWS_NUM_CHANNELS_OUT_MASK    (0x1F<<I2S_DWS_NUM_CHANNELS_OUT_SHIFT)
/* word size of output data */
#   define I2S_DWS_DATA_OUT_SIZE_SHIFT  0
#   define I2S_DWS_DATA_OUT_16BIT       (0<<I2S_DWS_DATA_OUT_SIZE_SHIFT)
#   define I2S_DWS_DATA_OUT_24BIT       (3<<I2S_DWS_DATA_OUT_SIZE_SHIFT)


/* unknown */
#define I2S_REG_PEAK_LEVEL_SEL      0x70

/* unknown */
#define I2S_REG_PEAK_LEVEL_IN0      0x80

/* unknown */
#define I2S_REG_PEAK_LEVEL_IN1      0x90

#endif /* __I2SBUS_INTERFACE_H */