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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adgs1408.c (3016B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * ADGS1408/ADGS1409 SPI MUX driver
      4 *
      5 * Copyright 2018 Analog Devices Inc.
      6 */
      7
      8#include <linux/err.h>
      9#include <linux/mod_devicetable.h>
     10#include <linux/module.h>
     11#include <linux/mux/driver.h>
     12#include <linux/property.h>
     13#include <linux/spi/spi.h>
     14
     15#define ADGS1408_SW_DATA       (0x01)
     16#define ADGS1408_REG_READ(reg) ((reg) | 0x80)
     17#define ADGS1408_DISABLE       (0x00)
     18#define ADGS1408_MUX(state)    (((state) << 1) | 1)
     19
     20enum adgs1408_chip_id {
     21	ADGS1408 = 1,
     22	ADGS1409,
     23};
     24
     25static int adgs1408_spi_reg_write(struct spi_device *spi,
     26				  u8 reg_addr, u8 reg_data)
     27{
     28	u8 tx_buf[2];
     29
     30	tx_buf[0] = reg_addr;
     31	tx_buf[1] = reg_data;
     32
     33	return spi_write_then_read(spi, tx_buf, sizeof(tx_buf), NULL, 0);
     34}
     35
     36static int adgs1408_set(struct mux_control *mux, int state)
     37{
     38	struct spi_device *spi = to_spi_device(mux->chip->dev.parent);
     39	u8 reg;
     40
     41	if (state == MUX_IDLE_DISCONNECT)
     42		reg = ADGS1408_DISABLE;
     43	else
     44		reg = ADGS1408_MUX(state);
     45
     46	return adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, reg);
     47}
     48
     49static const struct mux_control_ops adgs1408_ops = {
     50	.set = adgs1408_set,
     51};
     52
     53static int adgs1408_probe(struct spi_device *spi)
     54{
     55	struct device *dev = &spi->dev;
     56	enum adgs1408_chip_id chip_id;
     57	struct mux_chip *mux_chip;
     58	struct mux_control *mux;
     59	s32 idle_state;
     60	int ret;
     61
     62	chip_id = (enum adgs1408_chip_id)device_get_match_data(dev);
     63	if (!chip_id)
     64		chip_id = spi_get_device_id(spi)->driver_data;
     65
     66	mux_chip = devm_mux_chip_alloc(dev, 1, 0);
     67	if (IS_ERR(mux_chip))
     68		return PTR_ERR(mux_chip);
     69
     70	mux_chip->ops = &adgs1408_ops;
     71
     72	ret = adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, ADGS1408_DISABLE);
     73	if (ret < 0)
     74		return ret;
     75
     76	ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state);
     77	if (ret < 0)
     78		idle_state = MUX_IDLE_AS_IS;
     79
     80	mux = mux_chip->mux;
     81
     82	if (chip_id == ADGS1408)
     83		mux->states = 8;
     84	else
     85		mux->states = 4;
     86
     87	switch (idle_state) {
     88	case MUX_IDLE_DISCONNECT:
     89	case MUX_IDLE_AS_IS:
     90	case 0 ... 7:
     91		/* adgs1409 supports only 4 states */
     92		if (idle_state < mux->states) {
     93			mux->idle_state = idle_state;
     94			break;
     95		}
     96		fallthrough;
     97	default:
     98		dev_err(dev, "invalid idle-state %d\n", idle_state);
     99		return -EINVAL;
    100	}
    101
    102	return devm_mux_chip_register(dev, mux_chip);
    103}
    104
    105static const struct spi_device_id adgs1408_spi_id[] = {
    106	{ "adgs1408", ADGS1408 },
    107	{ "adgs1409", ADGS1409 },
    108	{ }
    109};
    110MODULE_DEVICE_TABLE(spi, adgs1408_spi_id);
    111
    112static const struct of_device_id adgs1408_of_match[] = {
    113	{ .compatible = "adi,adgs1408", .data = (void *)ADGS1408, },
    114	{ .compatible = "adi,adgs1409", .data = (void *)ADGS1409, },
    115	{ }
    116};
    117MODULE_DEVICE_TABLE(of, adgs1408_of_match);
    118
    119static struct spi_driver adgs1408_driver = {
    120	.driver = {
    121		.name = "adgs1408",
    122		.of_match_table = adgs1408_of_match,
    123	},
    124	.probe = adgs1408_probe,
    125	.id_table = adgs1408_spi_id,
    126};
    127module_spi_driver(adgs1408_driver);
    128
    129MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
    130MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver");
    131MODULE_LICENSE("GPL");