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ASoC: optimize init sequence of Freescale MPC8610 sound drivers
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In the Freescale MPC8610 sound drivers, relocate all code from the _prepare
functions into the corresponding _hw_params functions.  These drivers assumed
that the sample size is known in the _prepare function and not in the
_hw_params function, but this is not true.

Move the code in fsl_dma_prepare() into fsl_dma_hw_param().  Create
fsl_ssi_hw_params() and move the code from fsl_ssi_prepare() into it.

Turn off snooping for DMA operations to/from I/O registers, since that's not
necessary.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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Timur Tabi authored and Mark Brown committed Feb 6, 2009
1 parent 8836c27 commit 85ef237
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Showing 2 changed files with 94 additions and 103 deletions.
178 changes: 85 additions & 93 deletions sound/soc/fsl/fsl_dma.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -464,11 +464,7 @@ static int fsl_dma_open(struct snd_pcm_substream *substream)
sizeof(struct fsl_dma_link_descriptor);

for (i = 0; i < NUM_DMA_LINKS; i++) {
struct fsl_dma_link_descriptor *link = &dma_private->link[i];

link->source_attr = cpu_to_be32(CCSR_DMA_ATR_SNOOP);
link->dest_attr = cpu_to_be32(CCSR_DMA_ATR_SNOOP);
link->next = cpu_to_be64(temp_link);
dma_private->link[i].next = cpu_to_be64(temp_link);

temp_link += sizeof(struct fsl_dma_link_descriptor);
}
Expand Down Expand Up @@ -525,79 +521,9 @@ static int fsl_dma_open(struct snd_pcm_substream *substream)
* This function obtains hardware parameters about the opened stream and
* programs the DMA controller accordingly.
*
* Note that due to a quirk of the SSI's STX register, the target address
* for the DMA operations depends on the sample size. So we don't program
* the dest_addr (for playback -- source_addr for capture) fields in the
* link descriptors here. We do that in fsl_dma_prepare()
*/
static int fsl_dma_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct fsl_dma_private *dma_private = runtime->private_data;

dma_addr_t temp_addr; /* Pointer to next period */

unsigned int i;

/* Get all the parameters we need */
size_t buffer_size = params_buffer_bytes(hw_params);
size_t period_size = params_period_bytes(hw_params);

/* Initialize our DMA tracking variables */
dma_private->period_size = period_size;
dma_private->num_periods = params_periods(hw_params);
dma_private->dma_buf_end = dma_private->dma_buf_phys + buffer_size;
dma_private->dma_buf_next = dma_private->dma_buf_phys +
(NUM_DMA_LINKS * period_size);
if (dma_private->dma_buf_next >= dma_private->dma_buf_end)
dma_private->dma_buf_next = dma_private->dma_buf_phys;

/*
* The actual address in STX0 (destination for playback, source for
* capture) is based on the sample size, but we don't know the sample
* size in this function, so we'll have to adjust that later. See
* comments in fsl_dma_prepare().
*
* The DMA controller does not have a cache, so the CPU does not
* need to tell it to flush its cache. However, the DMA
* controller does need to tell the CPU to flush its cache.
* That's what the SNOOP bit does.
*
* Also, even though the DMA controller supports 36-bit addressing, for
* simplicity we currently support only 32-bit addresses for the audio
* buffer itself.
*/
temp_addr = substream->dma_buffer.addr;

for (i = 0; i < NUM_DMA_LINKS; i++) {
struct fsl_dma_link_descriptor *link = &dma_private->link[i];

link->count = cpu_to_be32(period_size);

if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
link->source_addr = cpu_to_be32(temp_addr);
else
link->dest_addr = cpu_to_be32(temp_addr);

temp_addr += period_size;
}

return 0;
}

/**
* fsl_dma_prepare - prepare the DMA registers for playback.
*
* This function is called after the specifics of the audio data are known,
* i.e. snd_pcm_runtime is initialized.
*
* In this function, we finish programming the registers of the DMA
* controller that are dependent on the sample size.
*
* One of the drawbacks with big-endian is that when copying integers of
* different sizes to a fixed-sized register, the address to which the
* integer must be copied is dependent on the size of the integer.
* One drawback of big-endian is that when copying integers of different
* sizes to a fixed-sized register, the address to which the integer must be
* copied is dependent on the size of the integer.
*
* For example, if P is the address of a 32-bit register, and X is a 32-bit
* integer, then X should be copied to address P. However, if X is a 16-bit
Expand All @@ -613,22 +539,58 @@ static int fsl_dma_hw_params(struct snd_pcm_substream *substream,
* and 8 bytes at a time). So we do not support packed 24-bit samples.
* 24-bit data must be padded to 32 bits.
*/
static int fsl_dma_prepare(struct snd_pcm_substream *substream)
static int fsl_dma_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct fsl_dma_private *dma_private = runtime->private_data;

/* Number of bits per sample */
unsigned int sample_size =
snd_pcm_format_physical_width(params_format(hw_params));

/* Number of bytes per frame */
unsigned int frame_size = 2 * (sample_size / 8);

/* Bus address of SSI STX register */
dma_addr_t ssi_sxx_phys = dma_private->ssi_sxx_phys;

/* Size of the DMA buffer, in bytes */
size_t buffer_size = params_buffer_bytes(hw_params);

/* Number of bytes per period */
size_t period_size = params_period_bytes(hw_params);

/* Pointer to next period */
dma_addr_t temp_addr = substream->dma_buffer.addr;

/* Pointer to DMA controller */
struct ccsr_dma_channel __iomem *dma_channel = dma_private->dma_channel;
u32 mr;

u32 mr; /* DMA Mode Register */

unsigned int i;
dma_addr_t ssi_sxx_phys; /* Bus address of SSI STX register */
unsigned int frame_size; /* Number of bytes per frame */

ssi_sxx_phys = dma_private->ssi_sxx_phys;
/* Initialize our DMA tracking variables */
dma_private->period_size = period_size;
dma_private->num_periods = params_periods(hw_params);
dma_private->dma_buf_end = dma_private->dma_buf_phys + buffer_size;
dma_private->dma_buf_next = dma_private->dma_buf_phys +
(NUM_DMA_LINKS * period_size);

if (dma_private->dma_buf_next >= dma_private->dma_buf_end)
/* This happens if the number of periods == NUM_DMA_LINKS */
dma_private->dma_buf_next = dma_private->dma_buf_phys;

mr = in_be32(&dma_channel->mr) & ~(CCSR_DMA_MR_BWC_MASK |
CCSR_DMA_MR_SAHTS_MASK | CCSR_DMA_MR_DAHTS_MASK);

switch (runtime->sample_bits) {
/* Due to a quirk of the SSI's STX register, the target address
* for the DMA operations depends on the sample size. So we calculate
* that offset here. While we're at it, also tell the DMA controller
* how much data to transfer per sample.
*/
switch (sample_size) {
case 8:
mr |= CCSR_DMA_MR_DAHTS_1 | CCSR_DMA_MR_SAHTS_1;
ssi_sxx_phys += 3;
Expand All @@ -641,12 +603,12 @@ static int fsl_dma_prepare(struct snd_pcm_substream *substream)
mr |= CCSR_DMA_MR_DAHTS_4 | CCSR_DMA_MR_SAHTS_4;
break;
default:
/* We should never get here */
dev_err(substream->pcm->card->dev,
"unsupported sample size %u\n", runtime->sample_bits);
"unsupported sample size %u\n", sample_size);
return -EINVAL;
}

frame_size = runtime->frame_bits / 8;
/*
* BWC should always be a multiple of the frame size. BWC determines
* how many bytes are sent/received before the DMA controller checks the
Expand All @@ -655,24 +617,55 @@ static int fsl_dma_prepare(struct snd_pcm_substream *substream)
* capture, the receive FIFO is triggered when it contains one frame, so
* we want to receive one frame at a time.
*/

if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
mr |= CCSR_DMA_MR_BWC(2 * frame_size);
else
mr |= CCSR_DMA_MR_BWC(frame_size);

out_be32(&dma_channel->mr, mr);

/*
* Program the address of the DMA transfer to/from the SSI.
*/
for (i = 0; i < NUM_DMA_LINKS; i++) {
struct fsl_dma_link_descriptor *link = &dma_private->link[i];

if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
link->count = cpu_to_be32(period_size);

/* Even though the DMA controller supports 36-bit addressing,
* for simplicity we allow only 32-bit addresses for the audio
* buffer itself. This was enforced in fsl_dma_new() with the
* DMA mask.
*
* The snoop bit tells the DMA controller whether it should tell
* the ECM to snoop during a read or write to an address. For
* audio, we use DMA to transfer data between memory and an I/O
* device (the SSI's STX0 or SRX0 register). Snooping is only
* needed if there is a cache, so we need to snoop memory
* addresses only. For playback, that means we snoop the source
* but not the destination. For capture, we snoop the
* destination but not the source.
*
* Note that failing to snoop properly is unlikely to cause
* cache incoherency if the period size is larger than the
* size of L1 cache. This is because filling in one period will
* flush out the data for the previous period. So if you
* increased period_bytes_min to a large enough size, you might
* get more performance by not snooping, and you'll still be
* okay.
*/
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
link->source_addr = cpu_to_be32(temp_addr);
link->source_attr = cpu_to_be32(CCSR_DMA_ATR_SNOOP);

link->dest_addr = cpu_to_be32(ssi_sxx_phys);
else
link->dest_attr = cpu_to_be32(CCSR_DMA_ATR_NOSNOOP);
} else {
link->source_addr = cpu_to_be32(ssi_sxx_phys);
link->source_attr = cpu_to_be32(CCSR_DMA_ATR_NOSNOOP);

link->dest_addr = cpu_to_be32(temp_addr);
link->dest_attr = cpu_to_be32(CCSR_DMA_ATR_SNOOP);
}

temp_addr += period_size;
}

return 0;
Expand Down Expand Up @@ -808,7 +801,6 @@ static struct snd_pcm_ops fsl_dma_ops = {
.ioctl = snd_pcm_lib_ioctl,
.hw_params = fsl_dma_hw_params,
.hw_free = fsl_dma_hw_free,
.prepare = fsl_dma_prepare,
.pointer = fsl_dma_pointer,
};

Expand Down
19 changes: 9 additions & 10 deletions sound/soc/fsl/fsl_ssi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -400,7 +400,7 @@ static int fsl_ssi_startup(struct snd_pcm_substream *substream,
}

/**
* fsl_ssi_prepare: prepare the SSI.
* fsl_ssi_hw_params - program the sample size
*
* Most of the SSI registers have been programmed in the startup function,
* but the word length must be programmed here. Unfortunately, programming
Expand All @@ -412,20 +412,19 @@ static int fsl_ssi_startup(struct snd_pcm_substream *substream,
* Note: The SxCCR.DC and SxCCR.PM bits are only used if the SSI is the
* clock master.
*/
static int fsl_ssi_prepare(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *hw_params, struct snd_soc_dai *cpu_dai)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct fsl_ssi_private *ssi_private = rtd->dai->cpu_dai->private_data;

struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
struct fsl_ssi_private *ssi_private = cpu_dai->private_data;

if (substream == ssi_private->first_stream) {
struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
unsigned int sample_size =
snd_pcm_format_width(params_format(hw_params));
u32 wl;

/* The SSI should always be disabled at this points (SSIEN=0) */
wl = CCSR_SSI_SxCCR_WL(snd_pcm_format_width(runtime->format));
wl = CCSR_SSI_SxCCR_WL(sample_size);

/* In synchronous mode, the SSI uses STCCR for capture */
clrsetbits_be32(&ssi->stccr, CCSR_SSI_SxCCR_WL_MASK, wl);
Expand Down Expand Up @@ -579,7 +578,7 @@ static struct snd_soc_dai fsl_ssi_dai_template = {
},
.ops = {
.startup = fsl_ssi_startup,
.prepare = fsl_ssi_prepare,
.hw_params = fsl_ssi_hw_params,
.shutdown = fsl_ssi_shutdown,
.trigger = fsl_ssi_trigger,
.set_sysclk = fsl_ssi_set_sysclk,
Expand Down

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