[RFC PATCH 10/13] sound: atmel_ssc_dai: PM: actually stopping clock on suspend/resume

[Richard Genoud]

From: Nicolas Ferre <nicolas.fe...@atmel.com>

Stop SSC clock on suspend/resume cycle checking if the controller is actually
initialized. This will save power while sleeping.

Signed-off-by: Nicolas Ferre <nicolas.fe...@atmel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koe...@pengutronix.de>
---
 sound/soc/atmel/atmel_ssc_dai.c |   20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
index f3fdfa0..14da27a 100644
--- a/sound/soc/atmel/atmel_ssc_dai.c
+++ b/sound/soc/atmel/atmel_ssc_dai.c
@@ -659,12 +659,10 @@ static int atmel_ssc_prepare(struct snd_pcm_substream 
*substream,
 #ifdef CONFIG_PM
 static int atmel_ssc_suspend(struct snd_soc_dai *cpu_dai)
 {
-       struct atmel_ssc_info *ssc_p;
+       struct atmel_ssc_info *ssc_p = &ssc_info[cpu_dai->id];
 
        if (!cpu_dai->active)
-               return 0;
-
-       ssc_p = &ssc_info[cpu_dai->id];
+               goto out;
 
        /* Save the status register before disabling transmit and receive */
        ssc_p->ssc_state.ssc_sr = ssc_readl(ssc_p->ssc->regs, SR);
@@ -680,6 +678,11 @@ static int atmel_ssc_suspend(struct snd_soc_dai *cpu_dai)
        ssc_p->ssc_state.ssc_tcmr = ssc_readl(ssc_p->ssc->regs, TCMR);
        ssc_p->ssc_state.ssc_tfmr = ssc_readl(ssc_p->ssc->regs, TFMR);
 
+out:
+       if (ssc_p->initialized) {
+               pr_debug("atmel_ssc_dai: suspend - stop clock\n");
+               clk_disable(ssc_p->ssc->clk);
+       }
        return 0;
 }
 
@@ -687,14 +690,17 @@ static int atmel_ssc_suspend(struct snd_soc_dai *cpu_dai)
 
 static int atmel_ssc_resume(struct snd_soc_dai *cpu_dai)
 {
-       struct atmel_ssc_info *ssc_p;
+       struct atmel_ssc_info *ssc_p = &ssc_info[cpu_dai->id];
        u32 cr;
 
+       if (ssc_p->initialized) {
+               pr_debug("atmel_ssc_dai: resume - restart clock\n");
+               clk_enable(ssc_p->ssc->clk);
+       }
+
        if (!cpu_dai->active)
                return 0;
 
-       ssc_p = &ssc_info[cpu_dai->id];
-
        /* restore SSC register settings */
        ssc_writel(ssc_p->ssc->regs, TFMR, ssc_p->ssc_state.ssc_tfmr);
        ssc_writel(ssc_p->ssc->regs, TCMR, ssc_p->ssc_state.ssc_tcmr);
-- 
1.7.10.4

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