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Commit 5e7c0344 authored by Daniel Mack's avatar Daniel Mack Committed by Mark Brown
Browse files

ASoC: cs4270: add power management support 



Signed-off-by: default avatarDaniel Mack <daniel@caiaq.de>
Acked-by: default avatarTimur Tabi <timur@freescale.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 80ab8817

sound/soc/codecs/cs4270.c

+57 −1
Original line number Diff line number Diff line
@@ -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,

};



/*