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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xrs700x_i2c.c (3713B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 2020 NovaTech LLC
      4 * George McCollister <george.mccollister@gmail.com>
      5 */
      6
      7#include <linux/bits.h>
      8#include <linux/i2c.h>
      9#include <linux/module.h>
     10#include "xrs700x.h"
     11#include "xrs700x_reg.h"
     12
     13struct xrs700x_i2c_cmd {
     14	__be32 reg;
     15	__be16 val;
     16} __packed;
     17
     18static int xrs700x_i2c_reg_read(void *context, unsigned int reg,
     19				unsigned int *val)
     20{
     21	struct device *dev = context;
     22	struct i2c_client *i2c = to_i2c_client(dev);
     23	struct xrs700x_i2c_cmd cmd;
     24	int ret;
     25
     26	cmd.reg = cpu_to_be32(reg | 1);
     27
     28	ret = i2c_master_send(i2c, (char *)&cmd.reg, sizeof(cmd.reg));
     29	if (ret < 0) {
     30		dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
     31		return ret;
     32	}
     33
     34	ret = i2c_master_recv(i2c, (char *)&cmd.val, sizeof(cmd.val));
     35	if (ret < 0) {
     36		dev_err(dev, "xrs i2c_master_recv returned %d\n", ret);
     37		return ret;
     38	}
     39
     40	*val = be16_to_cpu(cmd.val);
     41	return 0;
     42}
     43
     44static int xrs700x_i2c_reg_write(void *context, unsigned int reg,
     45				 unsigned int val)
     46{
     47	struct device *dev = context;
     48	struct i2c_client *i2c = to_i2c_client(dev);
     49	struct xrs700x_i2c_cmd cmd;
     50	int ret;
     51
     52	cmd.reg = cpu_to_be32(reg);
     53	cmd.val = cpu_to_be16(val);
     54
     55	ret = i2c_master_send(i2c, (char *)&cmd, sizeof(cmd));
     56	if (ret < 0) {
     57		dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
     58		return ret;
     59	}
     60
     61	return 0;
     62}
     63
     64static const struct regmap_config xrs700x_i2c_regmap_config = {
     65	.val_bits = 16,
     66	.reg_stride = 2,
     67	.reg_bits = 32,
     68	.pad_bits = 0,
     69	.write_flag_mask = 0,
     70	.read_flag_mask = 0,
     71	.reg_read = xrs700x_i2c_reg_read,
     72	.reg_write = xrs700x_i2c_reg_write,
     73	.max_register = 0,
     74	.cache_type = REGCACHE_NONE,
     75	.reg_format_endian = REGMAP_ENDIAN_BIG,
     76	.val_format_endian = REGMAP_ENDIAN_BIG
     77};
     78
     79static int xrs700x_i2c_probe(struct i2c_client *i2c,
     80			     const struct i2c_device_id *i2c_id)
     81{
     82	struct xrs700x *priv;
     83	int ret;
     84
     85	priv = xrs700x_switch_alloc(&i2c->dev, i2c);
     86	if (!priv)
     87		return -ENOMEM;
     88
     89	priv->regmap = devm_regmap_init(&i2c->dev, NULL, &i2c->dev,
     90					&xrs700x_i2c_regmap_config);
     91	if (IS_ERR(priv->regmap)) {
     92		ret = PTR_ERR(priv->regmap);
     93		dev_err(&i2c->dev, "Failed to initialize regmap: %d\n", ret);
     94		return ret;
     95	}
     96
     97	i2c_set_clientdata(i2c, priv);
     98
     99	ret = xrs700x_switch_register(priv);
    100
    101	/* Main DSA driver may not be started yet. */
    102	if (ret)
    103		return ret;
    104
    105	return 0;
    106}
    107
    108static int xrs700x_i2c_remove(struct i2c_client *i2c)
    109{
    110	struct xrs700x *priv = i2c_get_clientdata(i2c);
    111
    112	if (!priv)
    113		return 0;
    114
    115	xrs700x_switch_remove(priv);
    116
    117	i2c_set_clientdata(i2c, NULL);
    118
    119	return 0;
    120}
    121
    122static void xrs700x_i2c_shutdown(struct i2c_client *i2c)
    123{
    124	struct xrs700x *priv = i2c_get_clientdata(i2c);
    125
    126	if (!priv)
    127		return;
    128
    129	xrs700x_switch_shutdown(priv);
    130
    131	i2c_set_clientdata(i2c, NULL);
    132}
    133
    134static const struct i2c_device_id xrs700x_i2c_id[] = {
    135	{ "xrs700x-switch", 0 },
    136	{},
    137};
    138
    139MODULE_DEVICE_TABLE(i2c, xrs700x_i2c_id);
    140
    141static const struct of_device_id __maybe_unused xrs700x_i2c_dt_ids[] = {
    142	{ .compatible = "arrow,xrs7003e", .data = &xrs7003e_info },
    143	{ .compatible = "arrow,xrs7003f", .data = &xrs7003f_info },
    144	{ .compatible = "arrow,xrs7004e", .data = &xrs7004e_info },
    145	{ .compatible = "arrow,xrs7004f", .data = &xrs7004f_info },
    146	{},
    147};
    148MODULE_DEVICE_TABLE(of, xrs700x_i2c_dt_ids);
    149
    150static struct i2c_driver xrs700x_i2c_driver = {
    151	.driver = {
    152		.name	= "xrs700x-i2c",
    153		.of_match_table = of_match_ptr(xrs700x_i2c_dt_ids),
    154	},
    155	.probe	= xrs700x_i2c_probe,
    156	.remove	= xrs700x_i2c_remove,
    157	.shutdown = xrs700x_i2c_shutdown,
    158	.id_table = xrs700x_i2c_id,
    159};
    160
    161module_i2c_driver(xrs700x_i2c_driver);
    162
    163MODULE_AUTHOR("George McCollister <george.mccollister@gmail.com>");
    164MODULE_DESCRIPTION("Arrow SpeedChips XRS700x DSA I2C driver");
    165MODULE_LICENSE("GPL v2");