huawei-mrd-kernel/drivers/iio/pressure/zpa2326_spi.c

103 lines
2.8 KiB
C

/*
* Murata ZPA2326 SPI pressure and temperature sensor driver
*
* Copyright (c) 2016 Parrot S.A.
*
* Author: Gregor Boirie <gregor.boirie@parrot.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include <linux/of_device.h>
#include "zpa2326.h"
/*
* read_flag_mask:
* - address bit 7 must be set to request a register read operation
* - address bit 6 must be set to request register address auto increment
*/
static const struct regmap_config zpa2326_regmap_spi_config = {
.reg_bits = 8,
.val_bits = 8,
.writeable_reg = zpa2326_isreg_writeable,
.readable_reg = zpa2326_isreg_readable,
.precious_reg = zpa2326_isreg_precious,
.max_register = ZPA2326_TEMP_OUT_H_REG,
.read_flag_mask = BIT(7) | BIT(6),
.cache_type = REGCACHE_NONE,
};
static int zpa2326_probe_spi(struct spi_device *spi)
{
struct regmap *regmap;
int err;
regmap = devm_regmap_init_spi(spi, &zpa2326_regmap_spi_config);
if (IS_ERR(regmap)) {
dev_err(&spi->dev, "failed to init registers map");
return PTR_ERR(regmap);
}
/*
* Enforce SPI slave settings to prevent from DT misconfiguration.
*
* Clock is idle high. Sampling happens on trailing edge, i.e., rising
* edge. Maximum bus frequency is 1 MHz. Registers are 8 bits wide.
*/
spi->mode = SPI_MODE_3;
spi->max_speed_hz = min(spi->max_speed_hz, 1000000U);
spi->bits_per_word = 8;
err = spi_setup(spi);
if (err < 0)
return err;
return zpa2326_probe(&spi->dev, spi_get_device_id(spi)->name,
spi->irq, ZPA2326_DEVICE_ID, regmap);
}
static int zpa2326_remove_spi(struct spi_device *spi)
{
zpa2326_remove(&spi->dev);
return 0;
}
static const struct spi_device_id zpa2326_spi_ids[] = {
{ "zpa2326", 0 },
{ },
};
MODULE_DEVICE_TABLE(spi, zpa2326_spi_ids);
#if defined(CONFIG_OF)
static const struct of_device_id zpa2326_spi_matches[] = {
{ .compatible = "murata,zpa2326" },
{ }
};
MODULE_DEVICE_TABLE(of, zpa2326_spi_matches);
#endif
static struct spi_driver zpa2326_spi_driver = {
.driver = {
.name = "zpa2326-spi",
.of_match_table = of_match_ptr(zpa2326_spi_matches),
.pm = ZPA2326_PM_OPS,
},
.probe = zpa2326_probe_spi,
.remove = zpa2326_remove_spi,
.id_table = zpa2326_spi_ids,
};
module_spi_driver(zpa2326_spi_driver);
MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
MODULE_DESCRIPTION("SPI driver for Murata ZPA2326 pressure sensor");
MODULE_LICENSE("GPL v2");