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Diffstat (limited to 'sound/soc/atmel/atmel_ssc_dai.c')
-rw-r--r--sound/soc/atmel/atmel_ssc_dai.c111
1 files changed, 107 insertions, 4 deletions
diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
index fb0b7e8b08ff..841d05946b88 100644
--- a/sound/soc/atmel/atmel_ssc_dai.c
+++ b/sound/soc/atmel/atmel_ssc_dai.c
@@ -187,6 +187,94 @@ static irqreturn_t atmel_ssc_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
+/*
+ * When the bit clock is input, limit the maximum rate according to the
+ * Serial Clock Ratio Considerations section from the SSC documentation:
+ *
+ * The Transmitter and the Receiver can be programmed to operate
+ * with the clock signals provided on either the TK or RK pins.
+ * This allows the SSC to support many slave-mode data transfers.
+ * In this case, the maximum clock speed allowed on the RK pin is:
+ * - Peripheral clock divided by 2 if Receiver Frame Synchro is input
+ * - Peripheral clock divided by 3 if Receiver Frame Synchro is output
+ * In addition, the maximum clock speed allowed on the TK pin is:
+ * - Peripheral clock divided by 6 if Transmit Frame Synchro is input
+ * - Peripheral clock divided by 2 if Transmit Frame Synchro is output
+ *
+ * When the bit clock is output, limit the rate according to the
+ * SSC divider restrictions.
+ */
+static int atmel_ssc_hw_rule_rate(struct snd_pcm_hw_params *params,
+ struct snd_pcm_hw_rule *rule)
+{
+ struct atmel_ssc_info *ssc_p = rule->private;
+ struct ssc_device *ssc = ssc_p->ssc;
+ struct snd_interval *i = hw_param_interval(params, rule->var);
+ struct snd_interval t;
+ struct snd_ratnum r = {
+ .den_min = 1,
+ .den_max = 4095,
+ .den_step = 1,
+ };
+ unsigned int num = 0, den = 0;
+ int frame_size;
+ int mck_div = 2;
+ int ret;
+
+ frame_size = snd_soc_params_to_frame_size(params);
+ if (frame_size < 0)
+ return frame_size;
+
+ switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
+ case SND_SOC_DAIFMT_CBM_CFS:
+ if ((ssc_p->dir_mask & SSC_DIR_MASK_CAPTURE)
+ && ssc->clk_from_rk_pin)
+ /* Receiver Frame Synchro (i.e. capture)
+ * is output (format is _CFS) and the RK pin
+ * is used for input (format is _CBM_).
+ */
+ mck_div = 3;
+ break;
+
+ case SND_SOC_DAIFMT_CBM_CFM:
+ if ((ssc_p->dir_mask & SSC_DIR_MASK_PLAYBACK)
+ && !ssc->clk_from_rk_pin)
+ /* Transmit Frame Synchro (i.e. playback)
+ * is input (format is _CFM) and the TK pin
+ * is used for input (format _CBM_ but not
+ * using the RK pin).
+ */
+ mck_div = 6;
+ break;
+ }
+
+ switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ r.num = ssc_p->mck_rate / mck_div / frame_size;
+
+ ret = snd_interval_ratnum(i, 1, &r, &num, &den);
+ if (ret >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
+ params->rate_num = num;
+ params->rate_den = den;
+ }
+ break;
+
+ case SND_SOC_DAIFMT_CBM_CFS:
+ case SND_SOC_DAIFMT_CBM_CFM:
+ t.min = 8000;
+ t.max = ssc_p->mck_rate / mck_div / frame_size;
+ t.openmin = t.openmax = 0;
+ t.integer = 0;
+ ret = snd_interval_refine(i, &t);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
/*-------------------------------------------------------------------------*\
* DAI functions
@@ -200,6 +288,7 @@ static int atmel_ssc_startup(struct snd_pcm_substream *substream,
struct atmel_ssc_info *ssc_p = &ssc_info[dai->id];
struct atmel_pcm_dma_params *dma_params;
int dir, dir_mask;
+ int ret;
pr_debug("atmel_ssc_startup: SSC_SR=0x%u\n",
ssc_readl(ssc_p->ssc->regs, SR));
@@ -207,6 +296,7 @@ static int atmel_ssc_startup(struct snd_pcm_substream *substream,
/* Enable PMC peripheral clock for this SSC */
pr_debug("atmel_ssc_dai: Starting clock\n");
clk_enable(ssc_p->ssc->clk);
+ ssc_p->mck_rate = clk_get_rate(ssc_p->ssc->clk);
/* Reset the SSC to keep it at a clean status */
ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
@@ -219,6 +309,17 @@ static int atmel_ssc_startup(struct snd_pcm_substream *substream,
dir_mask = SSC_DIR_MASK_CAPTURE;
}
+ ret = snd_pcm_hw_rule_add(substream->runtime, 0,
+ SNDRV_PCM_HW_PARAM_RATE,
+ atmel_ssc_hw_rule_rate,
+ ssc_p,
+ SNDRV_PCM_HW_PARAM_FRAME_BITS,
+ SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+ if (ret < 0) {
+ dev_err(dai->dev, "Failed to specify rate rule: %d\n", ret);
+ return ret;
+ }
+
dma_params = &ssc_dma_params[dai->id][dir];
dma_params->ssc = ssc_p->ssc;
dma_params->substream = substream;
@@ -783,8 +884,6 @@ static int atmel_ssc_resume(struct snd_soc_dai *cpu_dai)
# define atmel_ssc_resume NULL
#endif /* CONFIG_PM */
-#define ATMEL_SSC_RATES (SNDRV_PCM_RATE_8000_96000)
-
#define ATMEL_SSC_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE |\
SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
@@ -804,12 +903,16 @@ static struct snd_soc_dai_driver atmel_ssc_dai = {
.playback = {
.channels_min = 1,
.channels_max = 2,
- .rates = ATMEL_SSC_RATES,
+ .rates = SNDRV_PCM_RATE_CONTINUOUS,
+ .rate_min = 8000,
+ .rate_max = 384000,
.formats = ATMEL_SSC_FORMATS,},
.capture = {
.channels_min = 1,
.channels_max = 2,
- .rates = ATMEL_SSC_RATES,
+ .rates = SNDRV_PCM_RATE_CONTINUOUS,
+ .rate_min = 8000,
+ .rate_max = 384000,
.formats = ATMEL_SSC_FORMATS,},
.ops = &atmel_ssc_dai_ops,
};