ASoC: ssm2602: Split SPI and I2C code into different modules

There are a few known (minor) problems with having the support code for both I2C
and SPI in the same module:
    * We need to be extra careful to make sure to not build the driver into the
      kernel if one of the subsystems is build as a module (Currently only I2C
      can be build as a module).
    * The module init path error handling is rather ugly. E.g. what should be
      done if either the SPI or the I2C driver fails to register? Most drivers
      that implement SPI and I2C in the same module currently fallback to
      undefined behavior in that case. Splitting the the driver into two
      modules, one for each bus allows the registration of the other bus driver
      to continue without problems if one of them fails.

This patch splits the ssm2602 driver into 3 modules. One core module that
implements the device logic, but is independent of the bus method used. And one
module for SPI and I2C each that registers the drivers and sets up the regmap
struct for the bus.

While we are at it also cleanup the include section of the ssm2602 driver and
remove unneeded includes.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 20 insertions, 138 deletions

diff --git a/sound/soc/codecs/ssm2602.c b/sound/soc/codecs/ssm2602.c
index f444d585b916..49d28eaa6d73 100644
--- a/sound/soc/codecs/ssm2602.c
+++ b/sound/soc/codecs/ssm2602.c
@@ -27,28 +27,16 @@
  */
 
 #include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/pm.h>
-#include <linux/i2c.h>
-#include <linux/spi/spi.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
-#include <sound/core.h>
+
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
-#include <sound/initval.h>
 #include <sound/tlv.h>
 
 #include "ssm2602.h"
 
-enum ssm2602_type {
-	SSM2602,
-	SSM2604,
-};
-
 /* codec private data */
 struct ssm2602_priv {
 	unsigned int sysclk;
@@ -529,7 +517,7 @@ static int ssm2602_resume(struct snd_soc_codec *codec)
 	return 0;
 }
 
-static int ssm2602_probe(struct snd_soc_codec *codec)
+static int ssm2602_codec_probe(struct snd_soc_codec *codec)
 {
 	struct ssm2602_priv *ssm2602 = snd_soc_codec_get_drvdata(codec);
 	struct snd_soc_dapm_context *dapm = &codec->dapm;
@@ -554,7 +542,7 @@ static int ssm2602_probe(struct snd_soc_codec *codec)
 			ARRAY_SIZE(ssm2602_routes));
 }
 
-static int ssm2604_probe(struct snd_soc_codec *codec)
+static int ssm2604_codec_probe(struct snd_soc_codec *codec)
 {
 	struct snd_soc_dapm_context *dapm = &codec->dapm;
 	int ret;
@@ -568,7 +556,7 @@ static int ssm2604_probe(struct snd_soc_codec *codec)
 			ARRAY_SIZE(ssm2604_routes));
 }
 
-static int ssm260x_probe(struct snd_soc_codec *codec)
+static int ssm260x_codec_probe(struct snd_soc_codec *codec)
 {
 	struct ssm2602_priv *ssm2602 = snd_soc_codec_get_drvdata(codec);
 	int ret;
@@ -597,10 +585,10 @@ static int ssm260x_probe(struct snd_soc_codec *codec)
 
 	switch (ssm2602->type) {
 	case SSM2602:
-		ret = ssm2602_probe(codec);
+		ret = ssm2602_codec_probe(codec);
 		break;
 	case SSM2604:
-		ret = ssm2604_probe(codec);
+		ret = ssm2604_codec_probe(codec);
 		break;
 	}
 
@@ -620,7 +608,7 @@ static int ssm2602_remove(struct snd_soc_codec *codec)
 }
 
 static struct snd_soc_codec_driver soc_codec_dev_ssm2602 = {
-	.probe =	ssm260x_probe,
+	.probe =	ssm260x_codec_probe,
 	.remove =	ssm2602_remove,
 	.suspend =	ssm2602_suspend,
 	.resume =	ssm2602_resume,
@@ -639,7 +627,7 @@ static bool ssm2602_register_volatile(struct device *dev, unsigned int reg)
 	return reg == SSM2602_RESET;
 }
 
-static const struct regmap_config ssm2602_regmap_config = {
+const struct regmap_config ssm2602_regmap_config = {
 	.val_bits = 9,
 	.reg_bits = 7,
 
@@ -650,134 +638,28 @@ static const struct regmap_config ssm2602_regmap_config = {
 	.reg_defaults_raw = ssm2602_reg,
 	.num_reg_defaults_raw = ARRAY_SIZE(ssm2602_reg),
 };
+EXPORT_SYMBOL_GPL(ssm2602_regmap_config);
 
-#if defined(CONFIG_SPI_MASTER)
-static int ssm2602_spi_probe(struct spi_device *spi)
+int ssm2602_probe(struct device *dev, enum ssm2602_type type,
+	struct regmap *regmap)
 {
 	struct ssm2602_priv *ssm2602;
-	int ret;
-
-	ssm2602 = devm_kzalloc(&spi->dev, sizeof(struct ssm2602_priv),
-			       GFP_KERNEL);
-	if (ssm2602 == NULL)
-		return -ENOMEM;
-
-	spi_set_drvdata(spi, ssm2602);
-	ssm2602->type = SSM2602;
-
-	ssm2602->regmap = devm_regmap_init_spi(spi, &ssm2602_regmap_config);
-	if (IS_ERR(ssm2602->regmap))
-		return PTR_ERR(ssm2602->regmap);
-
-	ret = snd_soc_register_codec(&spi->dev,
-			&soc_codec_dev_ssm2602, &ssm2602_dai, 1);
-	return ret;
-}
 
-static int ssm2602_spi_remove(struct spi_device *spi)
-{
-	snd_soc_unregister_codec(&spi->dev);
-	return 0;
-}
-
-static struct spi_driver ssm2602_spi_driver = {
-	.driver = {
-		.name	= "ssm2602",
-		.owner	= THIS_MODULE,
-	},
-	.probe		= ssm2602_spi_probe,
-	.remove		= ssm2602_spi_remove,
-};
-#endif
-
-#if IS_ENABLED(CONFIG_I2C)
-/*
- * ssm2602 2 wire address is determined by GPIO5
- * state during powerup.
- *    low  = 0x1a
- *    high = 0x1b
- */
-static int ssm2602_i2c_probe(struct i2c_client *i2c,
-			     const struct i2c_device_id *id)
-{
-	struct ssm2602_priv *ssm2602;
-	int ret;
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
 
-	ssm2602 = devm_kzalloc(&i2c->dev, sizeof(struct ssm2602_priv),
-			       GFP_KERNEL);
+	ssm2602 = devm_kzalloc(dev, sizeof(*ssm2602), GFP_KERNEL);
 	if (ssm2602 == NULL)
 		return -ENOMEM;
 
-	i2c_set_clientdata(i2c, ssm2602);
-	ssm2602->type = id->driver_data;
-
-	ssm2602->regmap = devm_regmap_init_i2c(i2c, &ssm2602_regmap_config);
-	if (IS_ERR(ssm2602->regmap))
-		return PTR_ERR(ssm2602->regmap);
-
-	ret = snd_soc_register_codec(&i2c->dev,
-			&soc_codec_dev_ssm2602, &ssm2602_dai, 1);
-	return ret;
-}
-
-static int ssm2602_i2c_remove(struct i2c_client *client)
-{
-	snd_soc_unregister_codec(&client->dev);
-	return 0;
-}
-
-static const struct i2c_device_id ssm2602_i2c_id[] = {
-	{ "ssm2602", SSM2602 },
-	{ "ssm2603", SSM2602 },
-	{ "ssm2604", SSM2604 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, ssm2602_i2c_id);
-
-/* corgi i2c codec control layer */
-static struct i2c_driver ssm2602_i2c_driver = {
-	.driver = {
-		.name = "ssm2602",
-		.owner = THIS_MODULE,
-	},
-	.probe = ssm2602_i2c_probe,
-	.remove = ssm2602_i2c_remove,
-	.id_table = ssm2602_i2c_id,
-};
-#endif
-
-
-static int __init ssm2602_modinit(void)
-{
-	int ret = 0;
-
-#if defined(CONFIG_SPI_MASTER)
-	ret = spi_register_driver(&ssm2602_spi_driver);
-	if (ret)
-		return ret;
-#endif
-
-#if IS_ENABLED(CONFIG_I2C)
-	ret = i2c_add_driver(&ssm2602_i2c_driver);
-	if (ret)
-		return ret;
-#endif
-
-	return ret;
-}
-module_init(ssm2602_modinit);
-
-static void __exit ssm2602_exit(void)
-{
-#if defined(CONFIG_SPI_MASTER)
-	spi_unregister_driver(&ssm2602_spi_driver);
-#endif
+	dev_set_drvdata(dev, ssm2602);
+	ssm2602->type = SSM2602;
+	ssm2602->regmap = regmap;
 
-#if IS_ENABLED(CONFIG_I2C)
-	i2c_del_driver(&ssm2602_i2c_driver);
-#endif
+	return snd_soc_register_codec(dev, &soc_codec_dev_ssm2602,
+		&ssm2602_dai, 1);
 }
-module_exit(ssm2602_exit);
+EXPORT_SYMBOL_GPL(ssm2602_probe);
 
 MODULE_DESCRIPTION("ASoC SSM2602/SSM2603/SSM2604 driver");
 MODULE_AUTHOR("Cliff Cai");