hwmon: (pmbus) Add pmbus driver for MAX15301

Add pmbus driver support for Maxim MAX15301 InTune Automatically
Compensated Digital PoL Controller with Driver and PMBus Telemetry

Even though the specification does not specifically mention it,
extensive empirical testing has revealed that auto-detection of
limit-registers will fail in a random fashion unless the delay
parameter is set to above about 80us. The default delay is set
to 100us to include some safety margin.

This patch is tested on a Flex BMR461 converter module.

Signed-off-by: Erik Rosen <erik.rosen@metormote.com>
Link: https://lore.kernel.org/r/20210419101251.24840-1-erik.rosen@metormote.com
[groeck: Added rationale for delay to driver header]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Erik Rosen 2021-04-19 12:12:51 +02:00 committed by Guenter Roeck
parent bab10bf90a
commit 1e4063329f
6 changed files with 294 additions and 0 deletions

View File

@ -115,6 +115,7 @@ Hardware Monitoring Kernel Drivers
ltc4260 ltc4260
ltc4261 ltc4261
max127 max127
max15301
max16064 max16064
max16065 max16065
max1619 max1619

View File

@ -0,0 +1,87 @@
.. SPDX-License-Identifier: GPL-2.0
Kernel driver max15301
======================
Supported chips:
* Maxim MAX15301
Prefix: 'max15301', 'bmr461'
Addresses scanned: -
Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX15301.pdf
Author: Erik Rosen <erik.rosen@metormote.com>
Description
-----------
This driver supports hardware monitoring for Maxim MAX15301 controller chip and
compatible modules.
The driver is a client driver to the core PMBus driver. Please see
Documentation/hwmon/pmbus.rst and Documentation.hwmon/pmbus-core for details
on PMBus client drivers.
Usage Notes
-----------
This driver does not auto-detect devices. You will have to instantiate the
devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
details.
Platform data support
---------------------
The driver supports standard PMBus driver platform data.
Module parameters
-----------------
delay
-----
The controller requires a minimum interval between I2C bus accesses.
The default interval is set to 100 us. For manual override, the driver
provides a writeable module parameter, 'delay', which can be used to
set the interval to a value between 0 and 65,535 microseconds.
Sysfs entries
-------------
The following attributes are supported. Limits are read-write; all other
attributes are read-only.
======================= ========================================================
in1_label "vin"
in1_input Measured input voltage.
in1_lcrit Critical minimum input voltage.
in1_crit Critical maximum input voltage.
in1_lcrit_alarm Input voltage critical low alarm.
in1_crit_alarm Input voltage critical high alarm.
in2_label "vout1"
in2_input Measured output voltage.
in2_lcrit Critical minimum output Voltage.
in2_crit Critical maximum output voltage.
in2_lcrit_alarm Critical output voltage critical low alarm.
in2_crit_alarm Critical output voltage critical high alarm.
curr1_label "iout1"
curr1_input Measured output current.
curr1_crit Critical maximum output current.
curr1_crit_alarm Output current critical high alarm.
temp1_input Measured maximum temperature of all phases.
temp1_max Maximum temperature limit.
temp1_max_alarm High temperature alarm.
temp1_crit Critical maximum temperature limit.
temp1_crit_alarm Critical maximum temperature alarm.
======================= ========================================================

View File

@ -10791,6 +10791,13 @@ S: Orphan
F: drivers/video/fbdev/matrox/matroxfb_* F: drivers/video/fbdev/matrox/matroxfb_*
F: include/uapi/linux/matroxfb.h F: include/uapi/linux/matroxfb.h
MAX15301 DRIVER
M: Daniel Nilsson <daniel.nilsson@flex.com>
L: linux-hwmon@vger.kernel.org
S: Maintained
F: Documentation/hwmon/max15301.rst
F: drivers/hwmon/pmbus/max15301.c
MAX16065 HARDWARE MONITOR DRIVER MAX16065 HARDWARE MONITOR DRIVER
M: Guenter Roeck <linux@roeck-us.net> M: Guenter Roeck <linux@roeck-us.net>
L: linux-hwmon@vger.kernel.org L: linux-hwmon@vger.kernel.org

View File

@ -176,6 +176,15 @@ config SENSORS_LTC3815
This driver can also be built as a module. If so, the module will This driver can also be built as a module. If so, the module will
be called ltc3815. be called ltc3815.
config SENSORS_MAX15301
tristate "Maxim MAX15301"
help
If you say yes here you get hardware monitoring support for Maxim
MAX15301, as well as for Flex BMR461.
This driver can also be built as a module. If so, the module will
be called max15301.
config SENSORS_MAX16064 config SENSORS_MAX16064
tristate "Maxim MAX16064" tristate "Maxim MAX16064"
help help

View File

@ -20,6 +20,7 @@ obj-$(CONFIG_SENSORS_ISL68137) += isl68137.o
obj-$(CONFIG_SENSORS_LM25066) += lm25066.o obj-$(CONFIG_SENSORS_LM25066) += lm25066.o
obj-$(CONFIG_SENSORS_LTC2978) += ltc2978.o obj-$(CONFIG_SENSORS_LTC2978) += ltc2978.o
obj-$(CONFIG_SENSORS_LTC3815) += ltc3815.o obj-$(CONFIG_SENSORS_LTC3815) += ltc3815.o
obj-$(CONFIG_SENSORS_MAX15301) += max15301.o
obj-$(CONFIG_SENSORS_MAX16064) += max16064.o obj-$(CONFIG_SENSORS_MAX16064) += max16064.o
obj-$(CONFIG_SENSORS_MAX16601) += max16601.o obj-$(CONFIG_SENSORS_MAX16601) += max16601.o
obj-$(CONFIG_SENSORS_MAX20730) += max20730.o obj-$(CONFIG_SENSORS_MAX20730) += max20730.o

View File

@ -0,0 +1,189 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Hardware monitoring driver for Maxim MAX15301
*
* Copyright (c) 2021 Flextronics International Sweden AB
*
* Even though the specification does not specifically mention it,
* extensive empirical testing has revealed that auto-detection of
* limit-registers will fail in a random fashion unless the delay
* parameter is set to above about 80us. The default delay is set
* to 100us to include some safety margin.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/ktime.h>
#include <linux/delay.h>
#include <linux/pmbus.h>
#include "pmbus.h"
static const struct i2c_device_id max15301_id[] = {
{"bmr461", 0},
{"max15301", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, max15301_id);
struct max15301_data {
int id;
ktime_t access; /* Chip access time */
int delay; /* Delay between chip accesses in us */
struct pmbus_driver_info info;
};
#define to_max15301_data(x) container_of(x, struct max15301_data, info)
#define MAX15301_WAIT_TIME 100 /* us */
static ushort delay = MAX15301_WAIT_TIME;
module_param(delay, ushort, 0644);
MODULE_PARM_DESC(delay, "Delay between chip accesses in us");
static struct max15301_data max15301_data = {
.info = {
.pages = 1,
.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
| PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
| PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
| PMBUS_HAVE_STATUS_TEMP
| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT,
}
};
/* This chip needs a delay between accesses */
static inline void max15301_wait(const struct max15301_data *data)
{
if (data->delay) {
s64 delta = ktime_us_delta(ktime_get(), data->access);
if (delta < data->delay)
udelay(data->delay - delta);
}
}
static int max15301_read_word_data(struct i2c_client *client, int page,
int phase, int reg)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct max15301_data *data = to_max15301_data(info);
int ret;
if (page > 0)
return -ENXIO;
if (reg >= PMBUS_VIRT_BASE)
return -ENXIO;
max15301_wait(data);
ret = pmbus_read_word_data(client, page, phase, reg);
data->access = ktime_get();
return ret;
}
static int max15301_read_byte_data(struct i2c_client *client, int page, int reg)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct max15301_data *data = to_max15301_data(info);
int ret;
if (page > 0)
return -ENXIO;
max15301_wait(data);
ret = pmbus_read_byte_data(client, page, reg);
data->access = ktime_get();
return ret;
}
static int max15301_write_word_data(struct i2c_client *client, int page, int reg,
u16 word)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct max15301_data *data = to_max15301_data(info);
int ret;
if (page > 0)
return -ENXIO;
if (reg >= PMBUS_VIRT_BASE)
return -ENXIO;
max15301_wait(data);
ret = pmbus_write_word_data(client, page, reg, word);
data->access = ktime_get();
return ret;
}
static int max15301_write_byte(struct i2c_client *client, int page, u8 value)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct max15301_data *data = to_max15301_data(info);
int ret;
if (page > 0)
return -ENXIO;
max15301_wait(data);
ret = pmbus_write_byte(client, page, value);
data->access = ktime_get();
return ret;
}
static int max15301_probe(struct i2c_client *client)
{
int status;
u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
const struct i2c_device_id *mid;
struct pmbus_driver_info *info = &max15301_data.info;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_BYTE_DATA
| I2C_FUNC_SMBUS_BLOCK_DATA))
return -ENODEV;
status = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, device_id);
if (status < 0) {
dev_err(&client->dev, "Failed to read Device Id\n");
return status;
}
for (mid = max15301_id; mid->name[0]; mid++) {
if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
break;
}
if (!mid->name[0]) {
dev_err(&client->dev, "Unsupported device\n");
return -ENODEV;
}
max15301_data.delay = delay;
info->read_byte_data = max15301_read_byte_data;
info->read_word_data = max15301_read_word_data;
info->write_byte = max15301_write_byte;
info->write_word_data = max15301_write_word_data;
return pmbus_do_probe(client, info);
}
static struct i2c_driver max15301_driver = {
.driver = {
.name = "max15301",
},
.probe_new = max15301_probe,
.id_table = max15301_id,
};
module_i2c_driver(max15301_driver);
MODULE_AUTHOR("Erik Rosen <erik.rosen@metormote.com>");
MODULE_DESCRIPTION("PMBus driver for Maxim MAX15301");
MODULE_LICENSE("GPL");