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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tps65911-comparator.c (4296B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * tps65910.c  --  TI TPS6591x
      4 *
      5 * Copyright 2010 Texas Instruments Inc.
      6 *
      7 * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
      8 */
      9
     10#include <linux/kernel.h>
     11#include <linux/module.h>
     12#include <linux/init.h>
     13#include <linux/slab.h>
     14#include <linux/err.h>
     15#include <linux/platform_device.h>
     16#include <linux/debugfs.h>
     17#include <linux/gpio.h>
     18#include <linux/mfd/tps65910.h>
     19
     20#define COMP1					0
     21#define COMP2					1
     22
     23/* Comparator 1 voltage selection table in millivolts */
     24static const u16 COMP_VSEL_TABLE[] = {
     25	0, 2500, 2500, 2500, 2500, 2550, 2600, 2650,
     26	2700, 2750, 2800, 2850, 2900, 2950, 3000, 3050,
     27	3100, 3150, 3200, 3250, 3300, 3350, 3400, 3450,
     28	3500,
     29};
     30
     31struct comparator {
     32	const char *name;
     33	int reg;
     34	int uV_max;
     35	const u16 *vsel_table;
     36};
     37
     38static struct comparator tps_comparators[] = {
     39	{
     40		.name = "COMP1",
     41		.reg = TPS65911_VMBCH,
     42		.uV_max = 3500,
     43		.vsel_table = COMP_VSEL_TABLE,
     44	},
     45	{
     46		.name = "COMP2",
     47		.reg = TPS65911_VMBCH2,
     48		.uV_max = 3500,
     49		.vsel_table = COMP_VSEL_TABLE,
     50	},
     51};
     52
     53static int comp_threshold_set(struct tps65910 *tps65910, int id, int voltage)
     54{
     55	struct comparator tps_comp = tps_comparators[id];
     56	int curr_voltage = 0;
     57	int ret;
     58	u8 index = 0, val;
     59
     60	while (curr_voltage < tps_comp.uV_max) {
     61		curr_voltage = tps_comp.vsel_table[index];
     62		if (curr_voltage >= voltage)
     63			break;
     64		else if (curr_voltage < voltage)
     65			index ++;
     66	}
     67
     68	if (curr_voltage > tps_comp.uV_max)
     69		return -EINVAL;
     70
     71	val = index << 1;
     72	ret = regmap_write(tps65910->regmap, tps_comp.reg, val);
     73
     74	return ret;
     75}
     76
     77static int comp_threshold_get(struct tps65910 *tps65910, int id)
     78{
     79	struct comparator tps_comp = tps_comparators[id];
     80	unsigned int val;
     81	int ret;
     82
     83	ret = regmap_read(tps65910->regmap, tps_comp.reg, &val);
     84	if (ret < 0)
     85		return ret;
     86
     87	val >>= 1;
     88	return tps_comp.vsel_table[val];
     89}
     90
     91static ssize_t comp_threshold_show(struct device *dev,
     92				struct device_attribute *attr, char *buf)
     93{
     94	struct tps65910 *tps65910 = dev_get_drvdata(dev->parent);
     95	struct attribute comp_attr = attr->attr;
     96	int id, uVolt;
     97
     98	if (!strcmp(comp_attr.name, "comp1_threshold"))
     99		id = COMP1;
    100	else if (!strcmp(comp_attr.name, "comp2_threshold"))
    101		id = COMP2;
    102	else
    103		return -EINVAL;
    104
    105	uVolt = comp_threshold_get(tps65910, id);
    106
    107	return sprintf(buf, "%d\n", uVolt);
    108}
    109
    110static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL);
    111static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL);
    112
    113static int tps65911_comparator_probe(struct platform_device *pdev)
    114{
    115	struct tps65910 *tps65910 = dev_get_drvdata(pdev->dev.parent);
    116	struct tps65910_board *pdata = dev_get_platdata(tps65910->dev);
    117	int ret;
    118
    119	ret = comp_threshold_set(tps65910, COMP1,  pdata->vmbch_threshold);
    120	if (ret < 0) {
    121		dev_err(&pdev->dev, "cannot set COMP1 threshold\n");
    122		return ret;
    123	}
    124
    125	ret = comp_threshold_set(tps65910, COMP2, pdata->vmbch2_threshold);
    126	if (ret < 0) {
    127		dev_err(&pdev->dev, "cannot set COMP2 threshold\n");
    128		return ret;
    129	}
    130
    131	/* Create sysfs entry */
    132	ret = device_create_file(&pdev->dev, &dev_attr_comp1_threshold);
    133	if (ret < 0)
    134		dev_err(&pdev->dev, "failed to add COMP1 sysfs file\n");
    135
    136	ret = device_create_file(&pdev->dev, &dev_attr_comp2_threshold);
    137	if (ret < 0)
    138		dev_err(&pdev->dev, "failed to add COMP2 sysfs file\n");
    139
    140	return ret;
    141}
    142
    143static int tps65911_comparator_remove(struct platform_device *pdev)
    144{
    145	struct tps65910 *tps65910;
    146
    147	tps65910 = dev_get_drvdata(pdev->dev.parent);
    148	device_remove_file(&pdev->dev, &dev_attr_comp2_threshold);
    149	device_remove_file(&pdev->dev, &dev_attr_comp1_threshold);
    150
    151	return 0;
    152}
    153
    154static struct platform_driver tps65911_comparator_driver = {
    155	.driver = {
    156		.name = "tps65911-comparator",
    157	},
    158	.probe = tps65911_comparator_probe,
    159	.remove = tps65911_comparator_remove,
    160};
    161
    162static int __init tps65911_comparator_init(void)
    163{
    164	return platform_driver_register(&tps65911_comparator_driver);
    165}
    166subsys_initcall(tps65911_comparator_init);
    167
    168static void __exit tps65911_comparator_exit(void)
    169{
    170	platform_driver_unregister(&tps65911_comparator_driver);
    171}
    172module_exit(tps65911_comparator_exit);
    173
    174MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
    175MODULE_DESCRIPTION("TPS65911 comparator driver");
    176MODULE_LICENSE("GPL v2");
    177MODULE_ALIAS("platform:tps65911-comparator");