linux-kernel - [PATCH 2/3] ASoC: atmel_ssc_dai: refactor the startup and shutdown

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Date:	Fri, 30 Jan 2015 17:38:43 +0800
From:	Bo Shen <voice.shen@...el.com>
To:	Mark Brown <broonie@...nel.org>
CC:	<nicolas.ferre@...el.com>, <Songjun.Wu@...el.com>,
	<linux-sound@...r.kernel.org>, <alsa-devel@...a-project.org>,
	<linux-kernel@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	Bo Shen <voice.shen@...el.com>
Subject: [PATCH 2/3] ASoC: atmel_ssc_dai: refactor the startup and shutdown

In startup function, enable ssc clock and in shutdown function,
disable clock. And also remove disable ssc in shutdown function,
as ssc is disabled in prepare function.

Signed-off-by: Bo Shen <voice.shen@...el.com>
---

 sound/soc/atmel/atmel_ssc_dai.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
index c1d93b8..0ed5ac3 100644
--- a/sound/soc/atmel/atmel_ssc_dai.c
+++ b/sound/soc/atmel/atmel_ssc_dai.c
@@ -204,6 +204,13 @@ static int atmel_ssc_startup(struct snd_pcm_substream *substream,
 	pr_debug("atmel_ssc_startup: SSC_SR=0x%u\n",
 		ssc_readl(ssc_p->ssc->regs, SR));
 
+	/* Enable PMC peripheral clock for this SSC */
+	pr_debug("atmel_ssc_dai: Starting clock\n");
+	clk_enable(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));
+
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		dir = 0;
 		dir_mask = SSC_DIR_MASK_PLAYBACK;
@@ -250,11 +257,6 @@ static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
 	dma_params = ssc_p->dma_params[dir];
 
 	if (dma_params != NULL) {
-		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
-		pr_debug("atmel_ssc_shutdown: %s disabled SSC_SR=0x%08x\n",
-			(dir ? "receive" : "transmit"),
-			ssc_readl(ssc_p->ssc->regs, SR));
-
 		dma_params->ssc = NULL;
 		dma_params->substream = NULL;
 		ssc_p->dma_params[dir] = NULL;
@@ -266,10 +268,6 @@ static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
 	ssc_p->dir_mask &= ~dir_mask;
 	if (!ssc_p->dir_mask) {
 		if (ssc_p->initialized) {
-			/* Shutdown the SSC clock. */
-			pr_debug("atmel_ssc_dai: Stopping clock\n");
-			clk_disable(ssc_p->ssc->clk);
-
 			free_irq(ssc_p->ssc->irq, ssc_p);
 			ssc_p->initialized = 0;
 		}
@@ -280,6 +278,10 @@ static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
 		ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
 	}
 	spin_unlock_irq(&ssc_p->lock);
+
+	/* Shutdown the SSC clock. */
+	pr_debug("atmel_ssc_dai: Stopping clock\n");
+	clk_disable(ssc_p->ssc->clk);
 }
 
 
@@ -597,14 +599,6 @@ static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
 			rcmr, rfmr, tcmr, tfmr);
 
 	if (!ssc_p->initialized) {
-
-		/* Enable PMC peripheral clock for this SSC */
-		pr_debug("atmel_ssc_dai: Starting clock\n");
-		clk_enable(ssc_p->ssc->clk);
-
-		/* Reset the SSC and its PDC registers */
-		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
-
 		ssc_writel(ssc_p->ssc->regs, PDC_RPR, 0);
 		ssc_writel(ssc_p->ssc->regs, PDC_RCR, 0);
 		ssc_writel(ssc_p->ssc->regs, PDC_RNPR, 0);
-- 
2.3.0.rc0

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