xref: /openbmc/linux/sound/soc/codecs/adau1977-spi.c (revision 6d99a79c)
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");
69