OrgACRN
/
sof
mirror of https://github.com/thesofproject/sof.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

ssp: add helpers to handle runtime ssp configuration 

Create ssp_pre_start/stop() helpers to do kinds of runtime
configuration, and do the bclk request/release there to make sure the
bclk source is hold only when the DAI is active, this will help for
power saving at SSP idle.

Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
This commit is contained in:
Keyon Jie 2020-11-19 17:35:54 +08:00 committed by Liam Girdwood
parent b6c2d6a833
commit d19573e429
1 changed files with 87 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

87
src/drivers/intel/ssp/ssp.c
View File

@ -659,6 +659,93 @@ out:
return ret;
}
/*
* Portion of the SSP configuration should be applied just before the
* SSP dai is activated, for either power saving or params runtime
* configurable flexibility.
*/
static int ssp_pre_start(struct dai *dai)
{
struct ssp_pdata *ssp = dai_get_drvdata(dai);
struct sof_ipc_dai_config *config = &ssp->config;
uint32_t sscr0;
uint32_t mdiv;
bool need_ecs = false;
int ret = 0;
dai_info(dai, "ssp_pre_start()");
/* SSP active means bclk already configured. */
if (ssp->state[SOF_IPC_STREAM_PLAYBACK] == COMP_STATE_ACTIVE ||
ssp->state[SOF_IPC_STREAM_CAPTURE] == COMP_STATE_ACTIVE)
return 0;
sscr0 = ssp_read(dai, SSCR0);
#if CONFIG_INTEL_MN
/* BCLK config */
ret = mn_set_bclk(config->dai_index, config->ssp.bclk_rate,
&mdiv, &need_ecs);
if (ret < 0) {
dai_err(dai, "invalid bclk_rate = %d for dai_index = %d",
config->ssp.bclk_rate, config->dai_index);
goto out;
}
#else
if (ssp_freq[SSP_DEFAULT_IDX].freq % config->ssp.bclk_rate != 0) {
dai_err(dai, "invalid bclk_rate = %d for dai_index = %d",
config->ssp.bclk_rate, config->dai_index);
goto out;
}
mdiv = ssp_freq[SSP_DEFAULT_IDX].freq / config->ssp.bclk_rate;
#endif
if (need_ecs)
sscr0 |= SSCR0_ECS;
/* clock divisor is SCR + 1 */
mdiv -= 1;
/* divisor must be within SCR range */
if (mdiv > (SSCR0_SCR_MASK >> 8)) {
dai_err(dai, "ssp_pre_start(): divisor %d is not within SCR range",
mdiv);
ret = -EINVAL;
goto out;
}
/* set the SCR divisor */
sscr0 &= ~SSCR0_SCR_MASK;
sscr0 |= SSCR0_SCR(mdiv);
ssp_write(dai, SSCR0, sscr0);
dai_info(dai, "ssp_set_config(), sscr0 = 0x%08x", sscr0);
out:
platform_shared_commit(ssp, sizeof(*ssp));
return ret;
}
/*
* For power saving, we should do kinds of power release when the SSP
* dai is changed to inactive, though the runtime param configuration
* don't have to be reset.
*/
static void ssp_post_stop(struct dai *dai)
{
#if CONFIG_INTEL_MN
struct ssp_pdata *ssp = dai_get_drvdata(dai);
/* release bclk if SSP is inactive */
if (ssp->state[SOF_IPC_STREAM_PLAYBACK] != COMP_STATE_ACTIVE &&
ssp->state[SOF_IPC_STREAM_CAPTURE] != COMP_STATE_ACTIVE)
mn_release_bclk(dai->index);
#endif
}
/* get SSP hw params */
static int ssp_get_hw_params(struct dai *dai,
struct sof_ipc_stream_params *params, int dir)