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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max1600.c (2911B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * MAX1600 PCMCIA power switch library
      4 *
      5 * Copyright (C) 2016 Russell King
      6 */
      7#include <linux/device.h>
      8#include <linux/module.h>
      9#include <linux/gpio/consumer.h>
     10#include <linux/slab.h>
     11#include "max1600.h"
     12
     13static const char *max1600_gpio_name[2][MAX1600_GPIO_MAX] = {
     14	{ "a0vcc", "a1vcc", "a0vpp", "a1vpp" },
     15	{ "b0vcc", "b1vcc", "b0vpp", "b1vpp" },
     16};
     17
     18int max1600_init(struct device *dev, struct max1600 **ptr,
     19	unsigned int channel, unsigned int code)
     20{
     21	struct max1600 *m;
     22	int chan;
     23	int i;
     24
     25	switch (channel) {
     26	case MAX1600_CHAN_A:
     27		chan = 0;
     28		break;
     29	case MAX1600_CHAN_B:
     30		chan = 1;
     31		break;
     32	default:
     33		return -EINVAL;
     34	}
     35
     36	if (code != MAX1600_CODE_LOW && code != MAX1600_CODE_HIGH)
     37		return -EINVAL;
     38
     39	m = devm_kzalloc(dev, sizeof(*m), GFP_KERNEL);
     40	if (!m)
     41		return -ENOMEM;
     42
     43	m->dev = dev;
     44	m->code = code;
     45
     46	for (i = 0; i < MAX1600_GPIO_MAX; i++) {
     47		const char *name;
     48
     49		name = max1600_gpio_name[chan][i];
     50		if (i != MAX1600_GPIO_0VPP) {
     51			m->gpio[i] = devm_gpiod_get(dev, name, GPIOD_OUT_LOW);
     52		} else {
     53			m->gpio[i] = devm_gpiod_get_optional(dev, name,
     54							     GPIOD_OUT_LOW);
     55			if (!m->gpio[i])
     56				break;
     57		}
     58		if (IS_ERR(m->gpio[i]))
     59			return PTR_ERR(m->gpio[i]);
     60	}
     61
     62	*ptr = m;
     63
     64	return 0;
     65}
     66EXPORT_SYMBOL_GPL(max1600_init);
     67
     68int max1600_configure(struct max1600 *m, unsigned int vcc, unsigned int vpp)
     69{
     70	DECLARE_BITMAP(values, MAX1600_GPIO_MAX) = { 0, };
     71	int n = MAX1600_GPIO_0VPP;
     72
     73	if (m->gpio[MAX1600_GPIO_0VPP]) {
     74		if (vpp == 0) {
     75			__assign_bit(MAX1600_GPIO_0VPP, values, 0);
     76			__assign_bit(MAX1600_GPIO_1VPP, values, 0);
     77		} else if (vpp == 120) {
     78			__assign_bit(MAX1600_GPIO_0VPP, values, 0);
     79			__assign_bit(MAX1600_GPIO_1VPP, values, 1);
     80		} else if (vpp == vcc) {
     81			__assign_bit(MAX1600_GPIO_0VPP, values, 1);
     82			__assign_bit(MAX1600_GPIO_1VPP, values, 0);
     83		} else {
     84			dev_err(m->dev, "unrecognised Vpp %u.%uV\n",
     85				vpp / 10, vpp % 10);
     86			return -EINVAL;
     87		}
     88		n = MAX1600_GPIO_MAX;
     89	} else if (vpp != vcc && vpp != 0) {
     90		dev_err(m->dev, "no VPP control\n");
     91		return -EINVAL;
     92	}
     93
     94	if (vcc == 0) {
     95		__assign_bit(MAX1600_GPIO_0VCC, values, 0);
     96		__assign_bit(MAX1600_GPIO_1VCC, values, 0);
     97	} else if (vcc == 33) { /* VY */
     98		__assign_bit(MAX1600_GPIO_0VCC, values, 1);
     99		__assign_bit(MAX1600_GPIO_1VCC, values, 0);
    100	} else if (vcc == 50) { /* VX */
    101		__assign_bit(MAX1600_GPIO_0VCC, values, 0);
    102		__assign_bit(MAX1600_GPIO_1VCC, values, 1);
    103	} else {
    104		dev_err(m->dev, "unrecognised Vcc %u.%uV\n",
    105			vcc / 10, vcc % 10);
    106		return -EINVAL;
    107	}
    108
    109	if (m->code == MAX1600_CODE_HIGH) {
    110		/*
    111		 * Cirrus mode appears to be the same as Intel mode,
    112		 * except the VCC pins are inverted.
    113		 */
    114		__change_bit(MAX1600_GPIO_0VCC, values);
    115		__change_bit(MAX1600_GPIO_1VCC, values);
    116	}
    117
    118	return gpiod_set_array_value_cansleep(n, m->gpio, NULL, values);
    119}
    120EXPORT_SYMBOL_GPL(max1600_configure);
    121
    122MODULE_LICENSE("GPL v2");