Re: SoC pxa2xx-ac97 + wm9705 + touchscreen suspend/resume

[Mark Brown <broonie@sirena.org.uk>]

On Thu, Apr 02, 2009 at 03:40:17PM +0100, Russell King - ARM Linux wrote:

> It's actually worse though - using my devmem2 hack no longer restores
> things to a functional state.  devmem2 says the control register is
> now set as:

Gah, I see one problem with the patch I sent.  The one below *might* do
better if you have time to test it.  In any case, thanks a lot for your
help here - I'm fairly confident that the remaining problems you're
seeing are due to the lack of suspend and resume operations in the
WM9705 driver.

>From eeec4f57eb9d8f5f45d9536319e0eb130cc3ba28 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
Date: Thu, 2 Apr 2009 15:49:41 +0100
Subject: [PATCH] ASoC: Implement suspend and resume operations for WM9705

Compile tested only.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
---
 sound/soc/codecs/wm9705.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/sound/soc/codecs/wm9705.c b/sound/soc/codecs/wm9705.c
index 3265817..2109b50 100644
--- a/sound/soc/codecs/wm9705.c
+++ b/sound/soc/codecs/wm9705.c
@@ -317,6 +317,41 @@ static int wm9705_reset(struct snd_soc_codec *codec)
 	return -EIO;
 }
 
+#ifdef CONFIG_PM
+static int wm9705_soc_suspend(struct platform_device *pdev)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct snd_soc_codec *codec = socdev->card->codec;
+
+	soc_ac97_ops.write(codec->ac97, AC97_POWERDONW, 0xffff);
+
+	return 0;
+}
+
+static int wm9705_soc_resume(struct platform_device *pdev)
+{
+	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
+	struct snd_soc_codec *codec = socdev->card->codec;
+	int i, ret;
+	u16 *cache = codec->reg_cache;
+
+	ret = wm9705_reset(codec);
+	if (ret < 0) {
+		printk(KERN_ERR "could not reset AC97 codec\n");
+		return ret;
+	}
+
+	for (i = 2; i < ARRAY_SIZE(wm9705_reg) << 1; i += 2) {
+		soc_ac97_ops.write(codec->ac97, i, cache[i>>1]);
+	}
+
+	return 0;
+}
+#else
+#define wm9705_soc_suspend NULL
+#define wm9705_soc_resume NULL
+#endif
+
 static int wm9705_soc_probe(struct platform_device *pdev)
 {
 	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
@@ -407,6 +442,8 @@ static int wm9705_soc_remove(struct platform_device *pdev)
 struct snd_soc_codec_device soc_codec_dev_wm9705 = {
 	.probe = 	wm9705_soc_probe,
 	.remove = 	wm9705_soc_remove,
+	.suspend =	wm9705_soc_suspend,
+	.resume =	wm9705_soc_resume,
 };
 EXPORT_SYMBOL_GPL(soc_codec_dev_wm9705);
 
-- 
1.6.2.1