sound/soc/codecs/adau1977-spi.c

   1 /*
   2  * ADAU1977/ADAU1978/ADAU1979 driver
   3  *
   4  * Copyright 2014 Analog Devices Inc.
   5  *  Author: Lars-Peter Clausen <lars@metafoo.de>
   6  *
   7  * Licensed under the GPL-2.
   8  */
   9
  10 #include <linux/mod_devicetable.h>
  11 #include <linux/module.h>
  12 #include <linux/regmap.h>
  13 #include <linux/spi/spi.h>
  14 #include <sound/soc.h>
  15
  16 #include "adau1977.h"
  17
  18 static void adau1977_spi_switch_mode(struct device *dev)
  19 {
  20         struct spi_device *spi = to_spi_device(dev);
  21
  22         /*
  23          * To get the device into SPI mode CLATCH has to be pulled low three
  24          * times.  Do this by issuing three dummy reads.
  25          */
  26         spi_w8r8(spi, 0x00);
  27         spi_w8r8(spi, 0x00);
  28         spi_w8r8(spi, 0x00);
  29 }
  30
  31 static int adau1977_spi_probe(struct spi_device *spi)
  32 {
  33         const struct spi_device_id *id = spi_get_device_id(spi);
  34         struct regmap_config config;
  35
  36         if (!id)
  37                 return -EINVAL;
  38
  39         config = adau1977_regmap_config;
  40         config.val_bits = 8;
  41         config.reg_bits = 16;
  42         config.read_flag_mask = 0x1;
  43
  44         return adau1977_probe(&spi->dev,
  45                 devm_regmap_init_spi(spi, &config),
  46                 id->driver_data, adau1977_spi_switch_mode);
  47 }
  48
  49 static const struct spi_device_id adau1977_spi_ids[] = {
  50         { "adau1977", ADAU1977 },
  51         { "adau1978", ADAU1978 },
  52         { "adau1979", ADAU1978 },
  53         { }
  54 };
  55 MODULE_DEVICE_TABLE(spi, adau1977_spi_ids);
  56
  57 static struct spi_driver adau1977_spi_driver = {
  58         .driver = {
  59                 .name = "adau1977",
  60         },
  61         .probe = adau1977_spi_probe,
  62         .id_table = adau1977_spi_ids,
  63 };
  64 module_spi_driver(adau1977_spi_driver);
  65
  66 MODULE_DESCRIPTION("ASoC ADAU1977/ADAU1978/ADAU1979 driver");
  67 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
  68 MODULE_LICENSE("GPL");