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// SPDX-License-Identifier: GPL-2.0
/*
* Cirrus Logic CS42448/CS42888 Audio CODEC DAI SPI driver
*
* Copyright 2026 NXP
*
*/
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include <sound/soc.h>
#include "cs42xx8.h"
/*
* CS42448/CS42888 SPI register access (from datasheet Figure 23):
*
* The SPI frame is 3 bytes:
* Byte 0: chip address [7:1] = 1001111, bit[0] = R/W (0=write, 1=read)
* Write: 0x9E, Read: 0x9F
* Byte 1: MAP - Memory Address Pointer
* bit[7] = INCR (auto-increment for burst), bits[6:0] = address
* Byte 2: data byte
*
* We configure reg_bits=16 so that regmap treats the address field as 2 bytes
* (big-endian). The chip address byte (0x9E/0x9F) is placed in the high byte
* via write_flag_mask / read_flag_mask, and the MAP register address occupies
* the low byte. Currently INCR (MAP bit[7]) is not set and use_single_read/write
* are enabled. This produces the correct 3-byte on-wire frame without any
* custom bus implementation:
*
* write: [0x9E, MAP_addr, data]
* read: [0x9F, MAP_addr] -> [data]
*/
static int cs42xx8_spi_probe(struct spi_device *spi)
{
struct cs42xx8_driver_data *drvdata;
struct regmap_config config;
int ret;
drvdata = (struct cs42xx8_driver_data *)spi_get_device_match_data(spi);
if (!drvdata)
return dev_err_probe(&spi->dev, -EINVAL,
"failed to find driver data\n");
config = cs42xx8_regmap_config;
/*
* reg_bits=16 makes regmap send a 2-byte address field (big-endian).
* write_flag_mask/read_flag_mask are OR'd into that address field:
*/
config.reg_bits = 16;
config.write_flag_mask = 0x9E;
config.read_flag_mask = 0x9F;
ret = cs42xx8_probe(&spi->dev,
devm_regmap_init_spi(spi, &config), drvdata);
if (ret)
return ret;
pm_runtime_enable(&spi->dev);
pm_request_idle(&spi->dev);
return 0;
}
static void cs42xx8_spi_remove(struct spi_device *spi)
{
pm_runtime_disable(&spi->dev);
}
static const struct of_device_id cs42xx8_of_match[] = {
{ .compatible = "cirrus,cs42448", .data = &cs42448_data, },
{ .compatible = "cirrus,cs42888", .data = &cs42888_data, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, cs42xx8_of_match);
static const struct spi_device_id cs42xx8_spi_id[] = {
{ .name = "cs42448", .driver_data = (kernel_ulong_t)&cs42448_data },
{ .name = "cs42888", .driver_data = (kernel_ulong_t)&cs42888_data },
{ }
};
MODULE_DEVICE_TABLE(spi, cs42xx8_spi_id);
static struct spi_driver cs42xx8_spi_driver = {
.driver = {
.name = "cs42xx8",
.pm = pm_ptr(&cs42xx8_pm),
.of_match_table = cs42xx8_of_match,
},
.probe = cs42xx8_spi_probe,
.remove = cs42xx8_spi_remove,
.id_table = cs42xx8_spi_id,
};
module_spi_driver(cs42xx8_spi_driver);
MODULE_DESCRIPTION("Cirrus Logic CS42448/CS42888 ALSA SoC Codec SPI Driver");
MODULE_AUTHOR("Chancel Liu <chancel.liu@nxp.com>");
MODULE_LICENSE("GPL");
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