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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bpa-rs600.c (4895B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Hardware monitoring driver for BluTek BPA-RS600 Power Supplies
      4 *
      5 * Copyright 2021 Allied Telesis Labs
      6 */
      7
      8#include <linux/i2c.h>
      9#include <linux/init.h>
     10#include <linux/kernel.h>
     11#include <linux/module.h>
     12#include <linux/pmbus.h>
     13#include "pmbus.h"
     14
     15enum chips { bpa_rs600, bpd_rs600 };
     16
     17static int bpa_rs600_read_byte_data(struct i2c_client *client, int page, int reg)
     18{
     19	int ret;
     20
     21	if (page > 0)
     22		return -ENXIO;
     23
     24	switch (reg) {
     25	case PMBUS_FAN_CONFIG_12:
     26		/*
     27		 * Two fans are reported in PMBUS_FAN_CONFIG_12 but there is
     28		 * only one fan in the module. Mask out the FAN2 bits.
     29		 */
     30		ret = pmbus_read_byte_data(client, 0, PMBUS_FAN_CONFIG_12);
     31		if (ret >= 0)
     32			ret &= ~(PB_FAN_2_INSTALLED | PB_FAN_2_PULSE_MASK);
     33		break;
     34	default:
     35		ret = -ENODATA;
     36		break;
     37	}
     38
     39	return ret;
     40}
     41
     42/*
     43 * The BPA-RS600 violates the PMBus spec. Specifically it treats the
     44 * mantissa as unsigned. Deal with this here to allow the PMBus core
     45 * to work with correctly encoded data.
     46 */
     47static int bpa_rs600_read_vin(struct i2c_client *client)
     48{
     49	int ret, exponent, mantissa;
     50
     51	ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_READ_VIN);
     52	if (ret < 0)
     53		return ret;
     54
     55	if (ret & BIT(10)) {
     56		exponent = ret >> 11;
     57		mantissa = ret & 0x7ff;
     58
     59		exponent++;
     60		mantissa >>= 1;
     61
     62		ret = (exponent << 11) | mantissa;
     63	}
     64
     65	return ret;
     66}
     67
     68/*
     69 * Firmware V5.70 incorrectly reports 1640W for MFR_PIN_MAX.
     70 * Deal with this by returning a sensible value.
     71 */
     72static int bpa_rs600_read_pin_max(struct i2c_client *client)
     73{
     74	int ret;
     75
     76	ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_PIN_MAX);
     77	if (ret < 0)
     78		return ret;
     79
     80	/* Detect invalid 1640W (linear encoding) */
     81	if (ret == 0x0b34)
     82		/* Report 700W (linear encoding) */
     83		return 0x095e;
     84
     85	return ret;
     86}
     87
     88static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int phase, int reg)
     89{
     90	int ret;
     91
     92	if (page > 0)
     93		return -ENXIO;
     94
     95	switch (reg) {
     96	case PMBUS_VIN_UV_WARN_LIMIT:
     97	case PMBUS_VIN_OV_WARN_LIMIT:
     98	case PMBUS_VOUT_UV_WARN_LIMIT:
     99	case PMBUS_VOUT_OV_WARN_LIMIT:
    100	case PMBUS_IIN_OC_WARN_LIMIT:
    101	case PMBUS_IOUT_OC_WARN_LIMIT:
    102	case PMBUS_PIN_OP_WARN_LIMIT:
    103	case PMBUS_POUT_OP_WARN_LIMIT:
    104	case PMBUS_VIN_UV_FAULT_LIMIT:
    105	case PMBUS_VIN_OV_FAULT_LIMIT:
    106	case PMBUS_VOUT_UV_FAULT_LIMIT:
    107	case PMBUS_VOUT_OV_FAULT_LIMIT:
    108		/* These commands return data but it is invalid/un-documented */
    109		ret = -ENXIO;
    110		break;
    111	case PMBUS_READ_VIN:
    112		ret = bpa_rs600_read_vin(client);
    113		break;
    114	case PMBUS_MFR_PIN_MAX:
    115		ret = bpa_rs600_read_pin_max(client);
    116		break;
    117	default:
    118		if (reg >= PMBUS_VIRT_BASE)
    119			ret = -ENXIO;
    120		else
    121			ret = -ENODATA;
    122		break;
    123	}
    124
    125	return ret;
    126}
    127
    128static struct pmbus_driver_info bpa_rs600_info = {
    129	.pages = 1,
    130	.format[PSC_VOLTAGE_IN] = linear,
    131	.format[PSC_VOLTAGE_OUT] = linear,
    132	.format[PSC_CURRENT_IN] = linear,
    133	.format[PSC_CURRENT_OUT] = linear,
    134	.format[PSC_POWER] = linear,
    135	.format[PSC_TEMPERATURE] = linear,
    136	.format[PSC_FAN] = linear,
    137	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
    138		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT |
    139		PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
    140		PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
    141		PMBUS_HAVE_FAN12 |
    142		PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
    143		PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
    144		PMBUS_HAVE_STATUS_FAN12,
    145	.read_byte_data = bpa_rs600_read_byte_data,
    146	.read_word_data = bpa_rs600_read_word_data,
    147};
    148
    149static const struct i2c_device_id bpa_rs600_id[] = {
    150	{ "bpa-rs600", bpa_rs600 },
    151	{ "bpd-rs600", bpd_rs600 },
    152	{},
    153};
    154MODULE_DEVICE_TABLE(i2c, bpa_rs600_id);
    155
    156static int bpa_rs600_probe(struct i2c_client *client)
    157{
    158	struct device *dev = &client->dev;
    159	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
    160	int ret;
    161	const struct i2c_device_id *mid;
    162
    163	if (!i2c_check_functionality(client->adapter,
    164				     I2C_FUNC_SMBUS_READ_BYTE_DATA
    165				     | I2C_FUNC_SMBUS_READ_WORD_DATA
    166				     | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
    167		return -ENODEV;
    168
    169	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
    170	if (ret < 0) {
    171		dev_err(dev, "Failed to read Manufacturer Model\n");
    172		return ret;
    173	}
    174
    175	for (mid = bpa_rs600_id; mid->name[0]; mid++) {
    176		if (!strncasecmp(buf, mid->name, strlen(mid->name)))
    177			break;
    178	}
    179	if (!mid->name[0]) {
    180		buf[ret] = '\0';
    181		dev_err(dev, "Unsupported Manufacturer Model '%s'\n", buf);
    182		return -ENODEV;
    183	}
    184
    185	return pmbus_do_probe(client, &bpa_rs600_info);
    186}
    187
    188static const struct of_device_id __maybe_unused bpa_rs600_of_match[] = {
    189	{ .compatible = "blutek,bpa-rs600" },
    190	{},
    191};
    192MODULE_DEVICE_TABLE(of, bpa_rs600_of_match);
    193
    194static struct i2c_driver bpa_rs600_driver = {
    195	.driver = {
    196		.name = "bpa-rs600",
    197		.of_match_table = of_match_ptr(bpa_rs600_of_match),
    198	},
    199	.probe_new = bpa_rs600_probe,
    200	.id_table = bpa_rs600_id,
    201};
    202
    203module_i2c_driver(bpa_rs600_driver);
    204
    205MODULE_AUTHOR("Chris Packham");
    206MODULE_DESCRIPTION("PMBus driver for BluTek BPA-RS600");
    207MODULE_LICENSE("GPL");
    208MODULE_IMPORT_NS(PMBUS);