[alsa-devel] [PATCH v2] ASoC: ti: omap-mcpdm: Add support for pdmclk clock handling

[Peter Ujfalusi]

McPDM module receives it's functional clock from external source. This
clock is the pdmclk provided by the twl6040 audio IC. If the clock is not
available all register accesses to McPDM fails and the module is not
operational.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
Acked-by: Jarkko Nikula <jarkko.nikula at bitmer.com>
---
Hi,

this has been lurking in my next-wip branch for some time...
It might not needed anymore as I have not heard about issues with McPDM for a
while.

It was dropped back then because some core parts were not picked in time and
this caused some issues, but can not find the exact reason

Regards,
Peter

 sound/soc/ti/omap-mcpdm.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/sound/soc/ti/omap-mcpdm.c b/sound/soc/ti/omap-mcpdm.c
index b8c8290265c7..2c536947b69f 100644
--- a/sound/soc/ti/omap-mcpdm.c
+++ b/sound/soc/ti/omap-mcpdm.c
@@ -17,6 +17,7 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/irq.h>
+#include <linux/clk.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
 #include <linux/of_device.h>
@@ -42,6 +43,7 @@ struct omap_mcpdm {
 	int irq;
 	struct pm_qos_request pm_qos_req;
 	int latency[2];
+	struct clk *pdmclk;
 
 	struct mutex mutex;
 
@@ -416,6 +418,10 @@ static int omap_mcpdm_probe(struct snd_soc_dai *dai)
 	struct omap_mcpdm *mcpdm = snd_soc_dai_get_drvdata(dai);
 	int ret;
 
+	ret = clk_prepare_enable(mcpdm->pdmclk);
+	if (ret)
+		return ret;
+
 	pm_runtime_enable(mcpdm->dev);
 
 	/* Disable lines while request is ongoing */
@@ -454,6 +460,7 @@ static int omap_mcpdm_remove(struct snd_soc_dai *dai)
 	if (pm_qos_request_active(&mcpdm->pm_qos_req))
 		pm_qos_remove_request(&mcpdm->pm_qos_req);
 
+	clk_disable_unprepare(mcpdm->pdmclk);
 	return 0;
 }
 
@@ -473,12 +480,19 @@ static int omap_mcpdm_suspend(struct snd_soc_dai *dai)
 		mcpdm->pm_active_count++;
 	}
 
+	clk_disable_unprepare(mcpdm->pdmclk);
+
 	return 0;
 }
 
 static int omap_mcpdm_resume(struct snd_soc_dai *dai)
 {
 	struct omap_mcpdm *mcpdm = snd_soc_dai_get_drvdata(dai);
+	int ret;
+
+	ret = clk_prepare_enable(mcpdm->pdmclk);
+	if (ret)
+		return ret;
 
 	if (mcpdm->pm_active_count) {
 		while (mcpdm->pm_active_count--)
@@ -573,6 +587,15 @@ static int asoc_mcpdm_probe(struct platform_device *pdev)
 
 	mcpdm->dev = &pdev->dev;
 
+	mcpdm->pdmclk = devm_clk_get(&pdev->dev, "pdmclk");
+	if (IS_ERR(mcpdm->pdmclk)) {
+		if (PTR_ERR(mcpdm->pdmclk) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		dev_warn(&pdev->dev, "Error getting pdmclk (%ld)!\n",
+			 PTR_ERR(mcpdm->pdmclk));
+		mcpdm->pdmclk = NULL;
+	}
+
 	ret =  devm_snd_soc_register_component(&pdev->dev,
 					       &omap_mcpdm_component,
 					       &omap_mcpdm_dai, 1);
-- 
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki