sound/soc/codecs/adau1977-spi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ADAU1977/ADAU1978/ADAU1979 driver
   4  *
   5  * Copyright 2014 Analog Devices Inc.
   6  *  Author: Lars-Peter Clausen <lars@metafoo.de>
   7  */
   8
   9 #include <linux/mod_devicetable.h>
  10 #include <linux/module.h>
  11 #include <linux/regmap.h>
  12 #include <linux/of.h>
  13 #include <linux/of_device.h>
  14 #include <linux/spi/spi.h>
  15 #include <sound/soc.h>
  16
  17 #include "adau1977.h"
  18
  19 static void adau1977_spi_switch_mode(struct device *dev)
  20 {
  21         struct spi_device *spi = to_spi_device(dev);
  22
  23         /*
  24          * To get the device into SPI mode CLATCH has to be pulled low three
  25          * times.  Do this by issuing three dummy reads.
  26          */
  27         spi_w8r8(spi, 0x00);
  28         spi_w8r8(spi, 0x00);
  29         spi_w8r8(spi, 0x00);
  30 }
  31
  32 static int adau1977_spi_probe(struct spi_device *spi)
  33 {
  34         const struct spi_device_id *id = spi_get_device_id(spi);
  35         struct regmap_config config;
  36
  37         if (!id)
  38                 return -EINVAL;
  39
  40         config = adau1977_regmap_config;
  41         config.val_bits = 8;
  42         config.reg_bits = 16;
  43         config.read_flag_mask = 0x1;
  44
  45         return adau1977_probe(&spi->dev,
  46                 devm_regmap_init_spi(spi, &config),
  47                 id->driver_data, adau1977_spi_switch_mode);
  48 }
  49
  50 static const struct spi_device_id adau1977_spi_ids[] = {
  51         { "adau1977", ADAU1977 },
  52         { "adau1978", ADAU1978 },
  53         { "adau1979", ADAU1978 },
  54         { }
  55 };
  56 MODULE_DEVICE_TABLE(spi, adau1977_spi_ids);
  57
  58 static const struct of_device_id adau1977_spi_of_match[] = {
  59         { .compatible = "adi,adau1977" },
  60         { .compatible = "adi,adau1978" },
  61         { .compatible = "adi,adau1979" },
  62         { },
  63 };
  64 MODULE_DEVICE_TABLE(of, adau1977_spi_of_match);
  65
  66 static struct spi_driver adau1977_spi_driver = {
  67         .driver = {
  68                 .name = "adau1977",
  69                 .of_match_table = of_match_ptr(adau1977_spi_of_match),
  70         },
  71         .probe = adau1977_spi_probe,
  72         .id_table = adau1977_spi_ids,
  73 };
  74 module_spi_driver(adau1977_spi_driver);
  75
  76 MODULE_DESCRIPTION("ASoC ADAU1977/ADAU1978/ADAU1979 driver");
  77 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
  78 MODULE_LICENSE("GPL");