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as3525: use a table for mclk dividers, get rid of a division

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25981 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Rafaël Carré 2010-05-13 05:58:52 +00:00
parent d556f26820
commit bc0434d63a
1 changed files with 29 additions and 14 deletions
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43
firmware/target/arm/as3525/pcm-as3525.c
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@ -134,20 +134,35 @@ void pcm_postinit(void)
audiohw_postinit();
}
static unsigned mclk_divider(void)
/* divider is 9 bits but the highest one (for 8kHz) fit in 8 bits */
static const unsigned char divider[SAMPR_NUM_FREQ] = {
[HW_FREQ_96] = ((AS3525_MCLK_FREQ/128 + SAMPR_96/2) / SAMPR_96) - 1,
[HW_FREQ_88] = ((AS3525_MCLK_FREQ/128 + SAMPR_88/2) / SAMPR_88) - 1,
[HW_FREQ_64] = ((AS3525_MCLK_FREQ/128 + SAMPR_64/2) / SAMPR_64) - 1,
[HW_FREQ_48] = ((AS3525_MCLK_FREQ/128 + SAMPR_48/2) / SAMPR_48) - 1,
[HW_FREQ_44] = ((AS3525_MCLK_FREQ/128 + SAMPR_44/2) / SAMPR_44) - 1,
[HW_FREQ_32] = ((AS3525_MCLK_FREQ/128 + SAMPR_32/2) / SAMPR_32) - 1,
[HW_FREQ_24] = ((AS3525_MCLK_FREQ/128 + SAMPR_24/2) / SAMPR_24) - 1,
[HW_FREQ_22] = ((AS3525_MCLK_FREQ/128 + SAMPR_22/2) / SAMPR_22) - 1,
[HW_FREQ_16] = ((AS3525_MCLK_FREQ/128 + SAMPR_16/2) / SAMPR_16) - 1,
[HW_FREQ_12] = ((AS3525_MCLK_FREQ/128 + SAMPR_12/2) / SAMPR_12) - 1,
[HW_FREQ_11] = ((AS3525_MCLK_FREQ/128 + SAMPR_11/2) / SAMPR_11) - 1,
[HW_FREQ_8 ] = ((AS3525_MCLK_FREQ/128 + SAMPR_8 /2) / SAMPR_8 ) - 1,
};
static inline unsigned char mclk_divider(void)
{
/* TODO : use a table ? */
return (((AS3525_MCLK_FREQ/128) + (pcm_sampr/2)) / pcm_sampr) - 1;
return divider[pcm_fsel];
}
void pcm_dma_apply_settings(void)
{
int cgu_audio = CGU_AUDIO; /* read register */
cgu_audio &= ~(3 << 0); /* clear i2sout MCLK_SEL */
cgu_audio |= (AS3525_MCLK_SEL << 0); /* set i2sout MCLK_SEL */
cgu_audio &= ~(511 << 2); /* clear i2sout divider */
cgu_audio |= mclk_divider() << 2; /* set new i2sout divider */
CGU_AUDIO = cgu_audio; /* write back register */
int cgu_audio = CGU_AUDIO; /* read register */
cgu_audio &= ~(3 << 0); /* clear i2sout MCLK_SEL */
cgu_audio |= (AS3525_MCLK_SEL << 0); /* set i2sout MCLK_SEL */
cgu_audio &= ~(0x1ff << 2); /* clear i2sout divider */
cgu_audio |= mclk_divider() << 2; /* set new i2sout divider */
CGU_AUDIO = cgu_audio; /* write back register */
}
size_t pcm_get_bytes_waiting(void)
@ -281,12 +296,12 @@ void pcm_rec_dma_close(void)
void pcm_rec_dma_init(void)
{
int cgu_audio = CGU_AUDIO; /* read register */
cgu_audio &= ~(3 << 12); /* clear i2sin MCLK_SEL */
int cgu_audio = CGU_AUDIO; /* read register */
cgu_audio &= ~(3 << 12); /* clear i2sin MCLK_SEL */
cgu_audio |= (AS3525_MCLK_SEL << 12); /* set i2sin MCLK_SEL */
cgu_audio &= ~(511 << 14); /* clear i2sin divider */
cgu_audio |= mclk_divider() << 14; /* set new i2sin divider */
CGU_AUDIO = cgu_audio; /* write back register */
cgu_audio &= ~(0x1ff << 14); /* clear i2sin divider */
cgu_audio |= mclk_divider() << 14; /* set new i2sin divider */
CGU_AUDIO = cgu_audio; /* write back register */
/* i2c clk src = I2SOUTIF, sdata src = AFE,
* data valid at positive edge of SCLK */