On Tue, May 05, 2009 at 12:55:21PM -0500, Timur Tabi wrote:
> You forgot to add "v2" to the subject line. And you'll need a v3 on the
> next version of the patch, because ...
Ok, next round ...
Daniel
>From fff7cf8e74d1529060abe5207ad9b7d39c578026 Mon Sep 17 00:00:00 2001
From: Daniel Mack <daniel@xxxxxxxx>
Date: Thu, 2 Apr 2009 15:43:44 +0200
Subject: [PATCH v3] ASoC: cs4270: add power management support
Signed-off-by: Daniel Mack <daniel@xxxxxxxx>
Cc: Timur Tabi <timur@xxxxxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxxxxx>
---
sound/soc/codecs/cs4270.c | 58 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 57 insertions(+), 1 deletions(-)
diff --git a/sound/soc/codecs/cs4270.c b/sound/soc/codecs/cs4270.c
index bc338df..4d4a45e 100644
--- a/sound/soc/codecs/cs4270.c
+++ b/sound/soc/codecs/cs4270.c
@@ -18,7 +18,7 @@
* - The machine driver's 'startup' function must call
* cs4270_set_dai_sysclk() with the value of MCLK.
* - Only I2S and left-justified modes are supported
- * - Power management is not supported
+ * - Power management is supported
*/
#include <linux/module.h>
@@ -27,6 +27,7 @@
#include <sound/soc.h>
#include <sound/initval.h>
#include <linux/i2c.h>
+#include <linux/delay.h>
#include "cs4270.h"
@@ -65,6 +66,8 @@
#define CS4270_PWRCTL_PDN_ADC 0x20
#define CS4270_PWRCTL_PDN_DAC 0x02
#define CS4270_PWRCTL_PDN 0x01
+#define CS4270_PWRCTL_PDN_ALL \
+ (CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
#define CS4270_MODE_SPEED_MASK 0x30
#define CS4270_MODE_1X 0x00
#define CS4270_MODE_2X 0x10
@@ -788,6 +791,57 @@ static struct i2c_device_id cs4270_id[] = {
};
MODULE_DEVICE_TABLE(i2c, cs4270_id);
+#ifdef CONFIG_PM
+
+/* This suspend/resume implementation can handle both - a simple standby
+ * where the codec remains powered, and a full suspend, where the voltage
+ * domain the codec is connected to is teared down and/or any other hardware
+ * reset condition is asserted.
+ *
+ * The codec's own power saving features are enabled in the suspend callback,
+ * and all registers are written back to the hardware when resuming.
+ */
+
+static int cs4270_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+ struct cs4270_private *cs4270 = i2c_get_clientdata(client);
+ struct snd_soc_codec *codec = &cs4270->codec;
+ int reg = snd_soc_read(codec, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
+
+ return snd_soc_write(codec, CS4270_PWRCTL, reg);
+}
+
+static int cs4270_i2c_resume(struct i2c_client *client)
+{
+ struct cs4270_private *cs4270 = i2c_get_clientdata(client);
+ struct snd_soc_codec *codec = &cs4270->codec;
+ int reg;
+
+ /* In case the device was put to hard reset during sleep, we need to
+ * wait 500ns here before any I2C communication. */
+ ndelay(500);
+
+ /* first restore the entire register cache ... */
+ for (reg = CS4270_FIRSTREG; reg <= CS4270_LASTREG; reg++) {
+ u8 val = snd_soc_read(codec, reg);
+
+ if (i2c_smbus_write_byte_data(client, reg, val)) {
+ dev_err(codec->dev, "i2c write failed\n");
+ return -EIO;
+ }
+ }
+
+ /* ... then disable the power-down bits */
+ reg = snd_soc_read(codec, CS4270_PWRCTL);
+ reg &= ~CS4270_PWRCTL_PDN_ALL;
+
+ return snd_soc_write(codec, CS4270_PWRCTL, reg);
+}
+#else
+#define cs4270_i2c_suspend NULL
+#define cs4270_i2c_resume NULL
+#endif /* CONFIG_PM */
+
/*
* cs4270_i2c_driver - I2C device identification
*
@@ -802,6 +856,8 @@ static struct i2c_driver cs4270_i2c_driver = {
.id_table = cs4270_id,
.probe = cs4270_i2c_probe,
.remove = cs4270_i2c_remove,
+ .suspend = cs4270_i2c_suspend,
+ .resume = cs4270_i2c_resume,
};
/*
--
1.6.2.1
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