linux/drivers/hwmon/pt5161l.c
Cosmo Chou 7bbc079531 hwmon: (pt5161l) Fix invalid temperature reading
The temperature reading function was using a signed long for the ADC
code, which could lead to mishandling of invalid codes on 32-bit
platforms. This allowed out-of-range ADC codes to be incorrectly
interpreted as valid values and used in temperature calculations.

Change adc_code to u32 to ensure that invalid ADC codes are correctly
identified on all platforms.

Fixes: 1b2ca93cd0 ("hwmon: Add driver for Astera Labs PT5161L retimer")
Signed-off-by: Cosmo Chou <chou.cosmo@gmail.com>
Message-ID: <20240819104630.2375441-1-chou.cosmo@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2024-08-26 20:58:05 -07:00

668 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/mutex.h>
/* Aries current average temp ADC code CSR */
#define ARIES_CURRENT_AVG_TEMP_ADC_CSR 0x42c
/* Device Load check register */
#define ARIES_CODE_LOAD_REG 0x605
/* Value indicating FW was loaded properly, [3:1] = 3'b111 */
#define ARIES_LOAD_CODE 0xe
/* Main Micro Heartbeat register */
#define ARIES_MM_HEARTBEAT_ADDR 0x923
/* Reg offset to specify Address for MM assisted accesses */
#define ARIES_MM_ASSIST_REG_ADDR_OFFSET 0xd99
/* Reg offset to specify Command for MM assisted accesses */
#define ARIES_MM_ASSIST_CMD_OFFSET 0xd9d
/* Reg offset to MM SPARE 0 used specify Address[7:0] */
#define ARIES_MM_ASSIST_SPARE_0_OFFSET 0xd9f
/* Reg offset to MM SPARE 3 used specify Data Byte 0 */
#define ARIES_MM_ASSIST_SPARE_3_OFFSET 0xda2
/* Wide register reads */
#define ARIES_MM_RD_WIDE_REG_2B 0x1d
#define ARIES_MM_RD_WIDE_REG_3B 0x1e
#define ARIES_MM_RD_WIDE_REG_4B 0x1f
#define ARIES_MM_RD_WIDE_REG_5B 0x20
/* Time delay between checking MM status of EEPROM write (microseconds) */
#define ARIES_MM_STATUS_TIME 5000
/* AL Main SRAM DMEM offset (A0) */
#define AL_MAIN_SRAM_DMEM_OFFSET (64 * 1024)
/* SRAM read command */
#define AL_TG_RD_LOC_IND_SRAM 0x16
/* Offset for main micro FW info */
#define ARIES_MAIN_MICRO_FW_INFO (96 * 1024 - 128)
/* FW Info (Major) offset location in struct */
#define ARIES_MM_FW_VERSION_MAJOR 0
/* FW Info (Minor) offset location in struct */
#define ARIES_MM_FW_VERSION_MINOR 1
/* FW Info (Build no.) offset location in struct */
#define ARIES_MM_FW_VERSION_BUILD 2
#define ARIES_TEMP_CAL_CODE_DEFAULT 84
/* Struct defining FW version loaded on an Aries device */
struct pt5161l_fw_ver {
u8 major;
u8 minor;
u16 build;
};
/* Each client has this additional data */
struct pt5161l_data {
struct i2c_client *client;
struct dentry *debugfs;
struct pt5161l_fw_ver fw_ver;
struct mutex lock; /* for atomic I2C transactions */
bool init_done;
bool code_load_okay; /* indicate if code load reg value is expected */
bool mm_heartbeat_okay; /* indicate if Main Micro heartbeat is good */
bool mm_wide_reg_access; /* MM assisted wide register access */
};
static struct dentry *pt5161l_debugfs_dir;
/*
* Write multiple data bytes to Aries over I2C
*/
static int pt5161l_write_block_data(struct pt5161l_data *data, u32 address,
u8 len, u8 *val)
{
struct i2c_client *client = data->client;
int ret;
u8 remain_len = len;
u8 xfer_len, curr_len;
u8 buf[16];
u8 cmd = 0x0F; /* [7]:pec_en, [4:2]:func, [1]:start, [0]:end */
u8 config = 0x40; /* [6]:cfg_type, [4:1]:burst_len, [0]:address bit16 */
while (remain_len > 0) {
if (remain_len > 4) {
curr_len = 4;
remain_len -= 4;
} else {
curr_len = remain_len;
remain_len = 0;
}
buf[0] = config | (curr_len - 1) << 1 | ((address >> 16) & 0x1);
buf[1] = (address >> 8) & 0xff;
buf[2] = address & 0xff;
memcpy(&buf[3], val, curr_len);
xfer_len = 3 + curr_len;
ret = i2c_smbus_write_block_data(client, cmd, xfer_len, buf);
if (ret)
return ret;
val += curr_len;
address += curr_len;
}
return 0;
}
/*
* Read multiple data bytes from Aries over I2C
*/
static int pt5161l_read_block_data(struct pt5161l_data *data, u32 address,
u8 len, u8 *val)
{
struct i2c_client *client = data->client;
int ret, tries;
u8 remain_len = len;
u8 curr_len;
u8 wbuf[16], rbuf[24];
u8 cmd = 0x08; /* [7]:pec_en, [4:2]:func, [1]:start, [0]:end */
u8 config = 0x00; /* [6]:cfg_type, [4:1]:burst_len, [0]:address bit16 */
while (remain_len > 0) {
if (remain_len > 16) {
curr_len = 16;
remain_len -= 16;
} else {
curr_len = remain_len;
remain_len = 0;
}
wbuf[0] = config | (curr_len - 1) << 1 |
((address >> 16) & 0x1);
wbuf[1] = (address >> 8) & 0xff;
wbuf[2] = address & 0xff;
for (tries = 0; tries < 3; tries++) {
ret = i2c_smbus_write_block_data(client, (cmd | 0x2), 3,
wbuf);
if (ret)
return ret;
ret = i2c_smbus_read_block_data(client, (cmd | 0x1),
rbuf);
if (ret == curr_len)
break;
}
if (tries >= 3)
return ret;
memcpy(val, rbuf, curr_len);
val += curr_len;
address += curr_len;
}
return 0;
}
static int pt5161l_read_wide_reg(struct pt5161l_data *data, u32 address,
u8 width, u8 *val)
{
int ret, tries;
u8 buf[8];
u8 status;
/*
* Safely access wide registers using mailbox method to prevent
* risking conflict with Aries firmware; otherwise fallback to
* legacy, less secure method.
*/
if (data->mm_wide_reg_access) {
buf[0] = address & 0xff;
buf[1] = (address >> 8) & 0xff;
buf[2] = (address >> 16) & 0x1;
ret = pt5161l_write_block_data(data,
ARIES_MM_ASSIST_SPARE_0_OFFSET,
3, buf);
if (ret)
return ret;
/* Set command based on width */
switch (width) {
case 2:
buf[0] = ARIES_MM_RD_WIDE_REG_2B;
break;
case 3:
buf[0] = ARIES_MM_RD_WIDE_REG_3B;
break;
case 4:
buf[0] = ARIES_MM_RD_WIDE_REG_4B;
break;
case 5:
buf[0] = ARIES_MM_RD_WIDE_REG_5B;
break;
default:
return -EINVAL;
}
ret = pt5161l_write_block_data(data, ARIES_MM_ASSIST_CMD_OFFSET,
1, buf);
if (ret)
return ret;
status = 0xff;
for (tries = 0; tries < 100; tries++) {
ret = pt5161l_read_block_data(data,
ARIES_MM_ASSIST_CMD_OFFSET,
1, &status);
if (ret)
return ret;
if (status == 0)
break;
usleep_range(ARIES_MM_STATUS_TIME,
ARIES_MM_STATUS_TIME + 1000);
}
if (status != 0)
return -ETIMEDOUT;
ret = pt5161l_read_block_data(data,
ARIES_MM_ASSIST_SPARE_3_OFFSET,
width, val);
if (ret)
return ret;
} else {
return pt5161l_read_block_data(data, address, width, val);
}
return 0;
}
/*
* Read multiple (up to eight) data bytes from micro SRAM over I2C
*/
static int
pt5161l_read_block_data_main_micro_indirect(struct pt5161l_data *data,
u32 address, u8 len, u8 *val)
{
int ret, tries;
u8 buf[8];
u8 i, status;
u32 uind_offs = ARIES_MM_ASSIST_REG_ADDR_OFFSET;
u32 eeprom_base, eeprom_addr;
/* No multi-byte indirect support here. Hence read a byte at a time */
eeprom_base = address - AL_MAIN_SRAM_DMEM_OFFSET;
for (i = 0; i < len; i++) {
eeprom_addr = eeprom_base + i;
buf[0] = eeprom_addr & 0xff;
buf[1] = (eeprom_addr >> 8) & 0xff;
buf[2] = (eeprom_addr >> 16) & 0xff;
ret = pt5161l_write_block_data(data, uind_offs, 3, buf);
if (ret)
return ret;
buf[0] = AL_TG_RD_LOC_IND_SRAM;
ret = pt5161l_write_block_data(data, uind_offs + 4, 1, buf);
if (ret)
return ret;
status = 0xff;
for (tries = 0; tries < 255; tries++) {
ret = pt5161l_read_block_data(data, uind_offs + 4, 1,
&status);
if (ret)
return ret;
if (status == 0)
break;
}
if (status != 0)
return -ETIMEDOUT;
ret = pt5161l_read_block_data(data, uind_offs + 3, 1, buf);
if (ret)
return ret;
val[i] = buf[0];
}
return 0;
}
/*
* Check firmware load status
*/
static int pt5161l_fw_load_check(struct pt5161l_data *data)
{
int ret;
u8 buf[8];
ret = pt5161l_read_block_data(data, ARIES_CODE_LOAD_REG, 1, buf);
if (ret)
return ret;
if (buf[0] < ARIES_LOAD_CODE) {
dev_dbg(&data->client->dev,
"Code Load reg unexpected. Not all modules are loaded %x\n",
buf[0]);
data->code_load_okay = false;
} else {
data->code_load_okay = true;
}
return 0;
}
/*
* Check main micro heartbeat
*/
static int pt5161l_heartbeat_check(struct pt5161l_data *data)
{
int ret, tries;
u8 buf[8];
u8 heartbeat;
bool hb_changed = false;
ret = pt5161l_read_block_data(data, ARIES_MM_HEARTBEAT_ADDR, 1, buf);
if (ret)
return ret;
heartbeat = buf[0];
for (tries = 0; tries < 100; tries++) {
ret = pt5161l_read_block_data(data, ARIES_MM_HEARTBEAT_ADDR, 1,
buf);
if (ret)
return ret;
if (buf[0] != heartbeat) {
hb_changed = true;
break;
}
}
data->mm_heartbeat_okay = hb_changed;
return 0;
}
/*
* Check the status of firmware
*/
static int pt5161l_fwsts_check(struct pt5161l_data *data)
{
int ret;
u8 buf[8];
u8 major = 0, minor = 0;
u16 build = 0;
ret = pt5161l_fw_load_check(data);
if (ret)
return ret;
ret = pt5161l_heartbeat_check(data);
if (ret)
return ret;
if (data->code_load_okay && data->mm_heartbeat_okay) {
ret = pt5161l_read_block_data_main_micro_indirect(data, ARIES_MAIN_MICRO_FW_INFO +
ARIES_MM_FW_VERSION_MAJOR,
1, &major);
if (ret)
return ret;
ret = pt5161l_read_block_data_main_micro_indirect(data, ARIES_MAIN_MICRO_FW_INFO +
ARIES_MM_FW_VERSION_MINOR,
1, &minor);
if (ret)
return ret;
ret = pt5161l_read_block_data_main_micro_indirect(data, ARIES_MAIN_MICRO_FW_INFO +
ARIES_MM_FW_VERSION_BUILD,
2, buf);
if (ret)
return ret;
build = buf[1] << 8 | buf[0];
}
data->fw_ver.major = major;
data->fw_ver.minor = minor;
data->fw_ver.build = build;
return 0;
}
static int pt5161l_fw_is_at_least(struct pt5161l_data *data, u8 major, u8 minor,
u16 build)
{
u32 ver = major << 24 | minor << 16 | build;
u32 curr_ver = data->fw_ver.major << 24 | data->fw_ver.minor << 16 |
data->fw_ver.build;
if (curr_ver >= ver)
return true;
return false;
}
static int pt5161l_init_dev(struct pt5161l_data *data)
{
int ret;
mutex_lock(&data->lock);
ret = pt5161l_fwsts_check(data);
mutex_unlock(&data->lock);
if (ret)
return ret;
/* Firmware 2.2.0 enables safe access to wide registers */
if (pt5161l_fw_is_at_least(data, 2, 2, 0))
data->mm_wide_reg_access = true;
data->init_done = true;
return 0;
}
static int pt5161l_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct pt5161l_data *data = dev_get_drvdata(dev);
int ret;
u8 buf[8];
u32 adc_code;
switch (attr) {
case hwmon_temp_input:
if (!data->init_done) {
ret = pt5161l_init_dev(data);
if (ret)
return ret;
}
mutex_lock(&data->lock);
ret = pt5161l_read_wide_reg(data,
ARIES_CURRENT_AVG_TEMP_ADC_CSR, 4,
buf);
mutex_unlock(&data->lock);
if (ret) {
dev_dbg(dev, "Read adc_code failed %d\n", ret);
return ret;
}
adc_code = buf[3] << 24 | buf[2] << 16 | buf[1] << 8 | buf[0];
if (adc_code == 0 || adc_code >= 0x3ff) {
dev_dbg(dev, "Invalid adc_code %x\n", adc_code);
return -EIO;
}
*val = 110000 +
((adc_code - (ARIES_TEMP_CAL_CODE_DEFAULT + 250)) *
-320);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static umode_t pt5161l_is_visible(const void *data,
enum hwmon_sensor_types type, u32 attr,
int channel)
{
switch (attr) {
case hwmon_temp_input:
return 0444;
default:
break;
}
return 0;
}
static const struct hwmon_channel_info *pt5161l_info[] = {
HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
NULL
};
static const struct hwmon_ops pt5161l_hwmon_ops = {
.is_visible = pt5161l_is_visible,
.read = pt5161l_read,
};
static const struct hwmon_chip_info pt5161l_chip_info = {
.ops = &pt5161l_hwmon_ops,
.info = pt5161l_info,
};
static ssize_t pt5161l_debugfs_read_fw_ver(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct pt5161l_data *data = file->private_data;
int ret;
char ver[32];
mutex_lock(&data->lock);
ret = pt5161l_fwsts_check(data);
mutex_unlock(&data->lock);
if (ret)
return ret;
ret = snprintf(ver, sizeof(ver), "%u.%u.%u\n", data->fw_ver.major,
data->fw_ver.minor, data->fw_ver.build);
return simple_read_from_buffer(buf, count, ppos, ver, ret);
}
static const struct file_operations pt5161l_debugfs_ops_fw_ver = {
.read = pt5161l_debugfs_read_fw_ver,
.open = simple_open,
};
static ssize_t pt5161l_debugfs_read_fw_load_sts(struct file *file,
char __user *buf, size_t count,
loff_t *ppos)
{
struct pt5161l_data *data = file->private_data;
int ret;
bool status = false;
char health[16];
mutex_lock(&data->lock);
ret = pt5161l_fw_load_check(data);
mutex_unlock(&data->lock);
if (ret == 0)
status = data->code_load_okay;
ret = snprintf(health, sizeof(health), "%s\n",
status ? "normal" : "abnormal");
return simple_read_from_buffer(buf, count, ppos, health, ret);
}
static const struct file_operations pt5161l_debugfs_ops_fw_load_sts = {
.read = pt5161l_debugfs_read_fw_load_sts,
.open = simple_open,
};
static ssize_t pt5161l_debugfs_read_hb_sts(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct pt5161l_data *data = file->private_data;
int ret;
bool status = false;
char health[16];
mutex_lock(&data->lock);
ret = pt5161l_heartbeat_check(data);
mutex_unlock(&data->lock);
if (ret == 0)
status = data->mm_heartbeat_okay;
ret = snprintf(health, sizeof(health), "%s\n",
status ? "normal" : "abnormal");
return simple_read_from_buffer(buf, count, ppos, health, ret);
}
static const struct file_operations pt5161l_debugfs_ops_hb_sts = {
.read = pt5161l_debugfs_read_hb_sts,
.open = simple_open,
};
static int pt5161l_init_debugfs(struct pt5161l_data *data)
{
data->debugfs = debugfs_create_dir(dev_name(&data->client->dev),
pt5161l_debugfs_dir);
debugfs_create_file("fw_ver", 0444, data->debugfs, data,
&pt5161l_debugfs_ops_fw_ver);
debugfs_create_file("fw_load_status", 0444, data->debugfs, data,
&pt5161l_debugfs_ops_fw_load_sts);
debugfs_create_file("heartbeat_status", 0444, data->debugfs, data,
&pt5161l_debugfs_ops_hb_sts);
return 0;
}
static int pt5161l_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct pt5161l_data *data;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
mutex_init(&data->lock);
pt5161l_init_dev(data);
dev_set_drvdata(dev, data);
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data,
&pt5161l_chip_info,
NULL);
pt5161l_init_debugfs(data);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static void pt5161l_remove(struct i2c_client *client)
{
struct pt5161l_data *data = i2c_get_clientdata(client);
debugfs_remove_recursive(data->debugfs);
}
static const struct of_device_id __maybe_unused pt5161l_of_match[] = {
{ .compatible = "asteralabs,pt5161l" },
{},
};
MODULE_DEVICE_TABLE(of, pt5161l_of_match);
static const struct acpi_device_id __maybe_unused pt5161l_acpi_match[] = {
{ "PT5161L", 0 },
{},
};
MODULE_DEVICE_TABLE(acpi, pt5161l_acpi_match);
static const struct i2c_device_id pt5161l_id[] = {
{ "pt5161l" },
{}
};
MODULE_DEVICE_TABLE(i2c, pt5161l_id);
static struct i2c_driver pt5161l_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "pt5161l",
.of_match_table = of_match_ptr(pt5161l_of_match),
.acpi_match_table = ACPI_PTR(pt5161l_acpi_match),
},
.probe = pt5161l_probe,
.remove = pt5161l_remove,
.id_table = pt5161l_id,
};
static int __init pt5161l_init(void)
{
pt5161l_debugfs_dir = debugfs_create_dir("pt5161l", NULL);
return i2c_add_driver(&pt5161l_driver);
}
static void __exit pt5161l_exit(void)
{
i2c_del_driver(&pt5161l_driver);
debugfs_remove_recursive(pt5161l_debugfs_dir);
}
module_init(pt5161l_init);
module_exit(pt5161l_exit);
MODULE_AUTHOR("Cosmo Chou <cosmo.chou@quantatw.com>");
MODULE_DESCRIPTION("Hwmon driver for Astera Labs Aries PCIe retimer");
MODULE_LICENSE("GPL");