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ASoC: sti: Add clock adjustement control
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Add capability to adjust player clock, for clocks drift management.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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Arnaud Pouliquen authored and Mark Brown committed Jul 16, 2015
1 parent 1e6babb commit fa05079
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Showing 2 changed files with 150 additions and 1 deletion.
2 changes: 2 additions & 0 deletions sound/soc/sti/uniperif.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1175,6 +1175,7 @@ struct uniperif {
/* Clocks */
struct clk *clk;
int mclk;
int clk_adj;

/* Runtime data */
enum uniperif_state state;
Expand All @@ -1183,6 +1184,7 @@ struct uniperif {

/* Specific to IEC958 player */
struct uniperif_iec958_settings stream_settings;
struct mutex ctrl_lock; /* For resource updated by stream and controls*/

/*alsa ctrl*/
struct snd_kcontrol_new *snd_ctrls;
Expand Down
149 changes: 148 additions & 1 deletion sound/soc/sti/uniperif_player.c
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,9 @@
(UNIPERIF_PLAYER_TYPE_IS_HDMI(p) || \
UNIPERIF_PLAYER_TYPE_IS_SPDIF(p))

#define UNIPERIF_PLAYER_CLK_ADJ_MIN -999999
#define UNIPERIF_PLAYER_CLK_ADJ_MAX 1000000

/*
* Note: snd_pcm_hardware is linked to DMA controller but is declared here to
* integrate DAI_CPU capability in term of rate and supported channels
Expand Down Expand Up @@ -172,6 +175,70 @@ static irqreturn_t uni_player_irq_handler(int irq, void *dev_id)
return ret;
}

int uni_player_clk_set_rate(struct uniperif *player, unsigned long rate)
{
int rate_adjusted, rate_achieved, delta, ret;
int adjustment = player->clk_adj;

/*
* a
* F = f + --------- * f = f + d
* 1000000
*
* a
* d = --------- * f
* 1000000
*
* where:
* f - nominal rate
* a - adjustment in ppm (parts per milion)
* F - rate to be set in synthesizer
* d - delta (difference) between f and F
*/
if (adjustment < 0) {
/* div64_64 operates on unsigned values... */
delta = -1;
adjustment = -adjustment;
} else {
delta = 1;
}
/* 500000 ppm is 0.5, which is used to round up values */
delta *= (int)div64_u64((uint64_t)rate *
(uint64_t)adjustment + 500000, 1000000);
rate_adjusted = rate + delta;

/* Adjusted rate should never be == 0 */
if (!rate_adjusted)
return -EINVAL;

ret = clk_set_rate(player->clk, rate_adjusted);
if (ret < 0)
return ret;

rate_achieved = clk_get_rate(player->clk);
if (!rate_achieved)
/* If value is 0 means that clock or parent not valid */
return -EINVAL;

/*
* Using ALSA's adjustment control, we can modify the rate to be up
* to twice as much as requested, but no more
*/
delta = rate_achieved - rate;
if (delta < 0) {
/* div64_64 operates on unsigned values... */
delta = -delta;
adjustment = -1;
} else {
adjustment = 1;
}
/* Frequency/2 is added to round up result */
adjustment *= (int)div64_u64((uint64_t)delta * 1000000 + rate / 2,
rate);
player->clk_adj = adjustment;
return 0;
}

static void uni_player_set_channel_status(struct uniperif *player,
struct snd_pcm_runtime *runtime)
{
Expand Down Expand Up @@ -470,6 +537,78 @@ static int uni_player_prepare_pcm(struct uniperif *player,
return 0;
}

/*
* uniperif rate adjustement control
*/
static int snd_sti_clk_adjustment_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = 1;
uinfo->value.integer.min = UNIPERIF_PLAYER_CLK_ADJ_MIN;
uinfo->value.integer.max = UNIPERIF_PLAYER_CLK_ADJ_MAX;
uinfo->value.integer.step = 1;

return 0;
}

static int snd_sti_clk_adjustment_get(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_soc_dai *dai = snd_kcontrol_chip(kcontrol);
struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
struct uniperif *player = priv->dai_data.uni;

ucontrol->value.integer.value[0] = player->clk_adj;

return 0;
}

static int snd_sti_clk_adjustment_put(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_value *ucontrol)
{
struct snd_soc_dai *dai = snd_kcontrol_chip(kcontrol);
struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
struct uniperif *player = priv->dai_data.uni;
int ret = 0;

if ((ucontrol->value.integer.value[0] < UNIPERIF_PLAYER_CLK_ADJ_MIN) ||
(ucontrol->value.integer.value[0] > UNIPERIF_PLAYER_CLK_ADJ_MAX))
return -EINVAL;

mutex_lock(&player->ctrl_lock);
player->clk_adj = ucontrol->value.integer.value[0];

if (player->mclk)
ret = uni_player_clk_set_rate(player, player->mclk);
mutex_unlock(&player->ctrl_lock);

return ret;
}

static struct snd_kcontrol_new uni_player_clk_adj_ctl = {
.iface = SNDRV_CTL_ELEM_IFACE_PCM,
.name = "PCM Playback Oversampling Freq. Adjustment",
.info = snd_sti_clk_adjustment_info,
.get = snd_sti_clk_adjustment_get,
.put = snd_sti_clk_adjustment_put,
};

static struct snd_kcontrol_new *snd_sti_ctl[] = {
&uni_player_clk_adj_ctl,
};

static int uni_player_startup(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
struct uniperif *player = priv->dai_data.uni;

player->clk_adj = 0;

return 0;
}

static int uni_player_set_sysclk(struct snd_soc_dai *dai, int clk_id,
unsigned int freq, int dir)
{
Expand All @@ -483,9 +622,11 @@ static int uni_player_set_sysclk(struct snd_soc_dai *dai, int clk_id,
if (clk_id != 0)
return -EINVAL;

ret = clk_set_rate(player->clk, freq);
mutex_lock(&player->ctrl_lock);
ret = uni_player_clk_set_rate(player, freq);
if (!ret)
player->mclk = freq;
mutex_unlock(&player->ctrl_lock);

return ret;
}
Expand Down Expand Up @@ -816,6 +957,7 @@ static int uni_player_parse_dt(struct platform_device *pdev,
}

const struct snd_soc_dai_ops uni_player_dai_ops = {
.startup = uni_player_startup,
.shutdown = uni_player_shutdown,
.prepare = uni_player_prepare,
.trigger = uni_player_trigger,
Expand Down Expand Up @@ -863,6 +1005,8 @@ int uni_player_init(struct platform_device *pdev,
if (ret < 0)
return ret;

mutex_init(&player->ctrl_lock);

/* Ensure that disabled by default */
SET_UNIPERIF_CONFIG_BACK_STALL_REQ_DISABLE(player);
SET_UNIPERIF_CTRL_ROUNDING_OFF(player);
Expand All @@ -889,6 +1033,9 @@ int uni_player_init(struct platform_device *pdev,
IEC958_AES4_CON_WORDLEN_24_20;
}

player->num_ctrls = ARRAY_SIZE(snd_sti_ctl);
player->snd_ctrls = snd_sti_ctl[0];

return 0;
}
EXPORT_SYMBOL_GPL(uni_player_init);

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