text: /*
   * Driver for DJBL codec
   *
   * Copyright 2016 Analog Devices Inc.
   *  Author: Lars-Peter Clausen <lars@metafoo.de>
   *
   * Licensed under the GPL-2.
   */
  
  #include <linux/mod_devicetable.h>
  #include <linux/module.h>
  #include <linux/regmap.h>
  #include <linux/spi/spi.h>
  #include <sound/soc.h>
  
  #include "djbl.h"
  
  static void djbl_spi_switch_mode(struct device *dev)
  {
  	struct spi_device *spi = to_spi_device(dev);
  
  	/*
  	 * To get the device into SPI mode CLATCH has to be pulled low three
  	 * times.  Do this by issuing three dummy reads.
  	 */
  	spi_w8r8(spi, 0x00);
  	spi_w8r8(spi, 0x00);
  	spi_w8r8(spi, 0x00);
  }
  
  static int djbl_spi_probe(struct spi_device *spi)
  {
  	struct regmap_config config;
  
  	config = djbl_regmap_config;
  	config.read_flag_mask = 0x1;
  
  	return djbl_probe(&spi->dev,
  		devm_regmap_init_spi(spi, &config), djbl_spi_switch_mode);
  }
  
  static int djbl_spi_remove(struct spi_device *spi)
  {
  	snd_soc_unregister_codec(&spi->dev);
  	return 0;
  }
  
  static const struct spi_device_id djbl_spi_id[] = {
  	{ "djbl", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(spi, djbl_spi_id);
  
  static struct spi_driver djbl_spi_driver = {
  	.driver = {
  		.name = "djbl",
  	},
  	.probe = djbl_spi_probe,
  	.remove = djbl_spi_remove,
  	.id_table = djbl_spi_id,
  };
  module_spi_driver(djbl_spi_driver);
  
  MODULE_DESCRIPTION("ASoC DJBL CODEC SPI driver");
  MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
  MODULE_LICENSE("GPL v2");
  