cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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zpa2326_spi.c (2496B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Murata ZPA2326 SPI pressure and temperature sensor driver
      4 *
      5 * Copyright (c) 2016 Parrot S.A.
      6 *
      7 * Author: Gregor Boirie <gregor.boirie@parrot.com>
      8 */
      9
     10#include <linux/module.h>
     11#include <linux/regmap.h>
     12#include <linux/spi/spi.h>
     13#include <linux/mod_devicetable.h>
     14#include "zpa2326.h"
     15
     16/*
     17 * read_flag_mask:
     18 *   - address bit 7 must be set to request a register read operation
     19 *   - address bit 6 must be set to request register address auto increment
     20 */
     21static const struct regmap_config zpa2326_regmap_spi_config = {
     22	.reg_bits       = 8,
     23	.val_bits       = 8,
     24	.writeable_reg  = zpa2326_isreg_writeable,
     25	.readable_reg   = zpa2326_isreg_readable,
     26	.precious_reg   = zpa2326_isreg_precious,
     27	.max_register   = ZPA2326_TEMP_OUT_H_REG,
     28	.read_flag_mask = BIT(7) | BIT(6),
     29	.cache_type     = REGCACHE_NONE,
     30};
     31
     32static int zpa2326_probe_spi(struct spi_device *spi)
     33{
     34	struct regmap *regmap;
     35	int            err;
     36
     37	regmap = devm_regmap_init_spi(spi, &zpa2326_regmap_spi_config);
     38	if (IS_ERR(regmap)) {
     39		dev_err(&spi->dev, "failed to init registers map");
     40		return PTR_ERR(regmap);
     41	}
     42
     43	/*
     44	 * Enforce SPI slave settings to prevent from DT misconfiguration.
     45	 *
     46	 * Clock is idle high. Sampling happens on trailing edge, i.e., rising
     47	 * edge. Maximum bus frequency is 1 MHz. Registers are 8 bits wide.
     48	 */
     49	spi->mode = SPI_MODE_3;
     50	spi->max_speed_hz = min(spi->max_speed_hz, 1000000U);
     51	spi->bits_per_word = 8;
     52	err = spi_setup(spi);
     53	if (err < 0)
     54		return err;
     55
     56	return zpa2326_probe(&spi->dev, spi_get_device_id(spi)->name,
     57			     spi->irq, ZPA2326_DEVICE_ID, regmap);
     58}
     59
     60static void zpa2326_remove_spi(struct spi_device *spi)
     61{
     62	zpa2326_remove(&spi->dev);
     63}
     64
     65static const struct spi_device_id zpa2326_spi_ids[] = {
     66	{ "zpa2326", 0 },
     67	{ },
     68};
     69MODULE_DEVICE_TABLE(spi, zpa2326_spi_ids);
     70
     71static const struct of_device_id zpa2326_spi_matches[] = {
     72	{ .compatible = "murata,zpa2326" },
     73	{ }
     74};
     75MODULE_DEVICE_TABLE(of, zpa2326_spi_matches);
     76
     77static struct spi_driver zpa2326_spi_driver = {
     78	.driver = {
     79		.name           = "zpa2326-spi",
     80		.of_match_table = zpa2326_spi_matches,
     81		.pm             = ZPA2326_PM_OPS,
     82	},
     83	.probe    = zpa2326_probe_spi,
     84	.remove   = zpa2326_remove_spi,
     85	.id_table = zpa2326_spi_ids,
     86};
     87module_spi_driver(zpa2326_spi_driver);
     88
     89MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
     90MODULE_DESCRIPTION("SPI driver for Murata ZPA2326 pressure sensor");
     91MODULE_LICENSE("GPL v2");
     92MODULE_IMPORT_NS(IIO_ZPA2326);