hwmon: (pmbus) Add ltc4286 driver

Add a driver to support ltc4286 chip

Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com>
Link: https://lore.kernel.org/r/20231123015440.199822-3-Delphine_CC_Chiu@Wiwynn.com
[groeck: Fixed formatting]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Delphine CC Chiu 2023-11-23 09:54:37 +08:00 committed by Guenter Roeck
parent 7707cf82e1
commit 0c459759ca
5 changed files with 282 additions and 0 deletions

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@ -128,6 +128,7 @@ Hardware Monitoring Kernel Drivers
ltc4245
ltc4260
ltc4261
ltc4286
max127
max15301
max16064

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@ -0,0 +1,95 @@
.. SPDX-License-Identifier: GPL-2.0-or-later
Kernel driver ltc4286
=====================
Supported chips:
* Analog Devices LTC4286
Prefix: 'ltc4286'
Addresses scanned: -
Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4286.pdf
* Analog Devices LTC4287
Prefix: 'ltc4287'
Addresses scanned: -
Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4287.pdf
Author: Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com>
Description
-----------
This driver supports hardware monitoring for Analog Devices LTC4286
and LTC4287 Hot-Swap Controller and Digital Power Monitors.
LTC4286 and LTC4287 are hot-swap controllers that allow a circuit board
to be removed from or inserted into a live backplane. They also feature
current and voltage readback via an integrated 12 bit analog-to-digital
converter (ADC), accessed using a PMBus interface.
The driver is a client driver to the core PMBus driver. Please see
Documentation/hwmon/pmbus.rst 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.
The shunt value in micro-ohms can be set via device tree at compile-time. Please
refer to the Documentation/devicetree/bindings/hwmon/lltc,ltc4286.yaml for bindings
if the device tree is used.
Platform data support
---------------------
The driver supports standard PMBus driver platform data. Please see
Documentation/hwmon/pmbus.rst for details.
Sysfs entries
-------------
The following attributes are supported. Limits are read-write, history reset
attributes are write-only, all other attributes are read-only.
======================= =======================================================
in1_label "vin"
in1_input Measured voltage.
in1_alarm Input voltage alarm.
in1_min Minimum input voltage.
in1_max Maximum input voltage.
in2_label "vout1"
in2_input Measured voltage.
in2_alarm Output voltage alarm.
in2_min Minimum output voltage.
in2_max Maximum output voltage.
curr1_label "iout1"
curr1_input Measured current.
curr1_alarm Output current alarm.
curr1_max Maximum current.
power1_label "pin"
power1_input Input power.
power1_alarm Input power alarm.
power1_max Maximum poewr.
temp1_input Chip temperature.
temp1_min Minimum chip temperature.
temp1_max Maximum chip temperature.
temp1_crit Critical chip temperature.
temp1_alarm Chip temperature alarm.
======================= =======================================================

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@ -227,6 +227,16 @@ config SENSORS_LTC3815
This driver can also be built as a module. If so, the module will
be called ltc3815.
config SENSORS_LTC4286
bool "Analog Devices LTC4286"
help
LTC4286 is an integrated solution for hot swap applications that
allows a board to be safely inserted and removed from a live
backplane.
This chip could be used to monitor voltage, current, ...etc.
If you say yes here you get hardware monitoring support for Analog
Devices LTC4286.
config SENSORS_MAX15301
tristate "Maxim MAX15301"
help

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@ -24,6 +24,7 @@ obj-$(CONFIG_SENSORS_LM25066) += lm25066.o
obj-$(CONFIG_SENSORS_LT7182S) += lt7182s.o
obj-$(CONFIG_SENSORS_LTC2978) += ltc2978.o
obj-$(CONFIG_SENSORS_LTC3815) += ltc3815.o
obj-$(CONFIG_SENSORS_LTC4286) += ltc4286.o
obj-$(CONFIG_SENSORS_MAX15301) += max15301.o
obj-$(CONFIG_SENSORS_MAX16064) += max16064.o
obj-$(CONFIG_SENSORS_MAX16601) += max16601.o

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@ -0,0 +1,175 @@
// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pmbus.h>
#include "pmbus.h"
/* LTC4286 register */
#define LTC4286_MFR_CONFIG1 0xF2
/* LTC4286 configuration */
#define VRANGE_SELECT_BIT BIT(1)
#define LTC4286_MFR_ID_SIZE 3
/*
* Initialize the MBR as default settings which is referred to LTC4286 datasheet
* (March 22, 2022 version) table 3 page 16
*/
static struct pmbus_driver_info ltc4286_info = {
.pages = 1,
.format[PSC_VOLTAGE_IN] = direct,
.format[PSC_VOLTAGE_OUT] = direct,
.format[PSC_CURRENT_OUT] = direct,
.format[PSC_POWER] = direct,
.format[PSC_TEMPERATURE] = direct,
.m[PSC_VOLTAGE_IN] = 32,
.b[PSC_VOLTAGE_IN] = 0,
.R[PSC_VOLTAGE_IN] = 1,
.m[PSC_VOLTAGE_OUT] = 32,
.b[PSC_VOLTAGE_OUT] = 0,
.R[PSC_VOLTAGE_OUT] = 1,
.m[PSC_CURRENT_OUT] = 1024,
.b[PSC_CURRENT_OUT] = 0,
/*
* The rsense value used in MBR formula in LTC4286 datasheet should be ohm unit.
* However, the rsense value that user input is micro ohm.
* Thus, the MBR setting which involves rsense should be shifted by 6 digits.
*/
.R[PSC_CURRENT_OUT] = 3 - 6,
.m[PSC_POWER] = 1,
.b[PSC_POWER] = 0,
/*
* The rsense value used in MBR formula in LTC4286 datasheet should be ohm unit.
* However, the rsense value that user input is micro ohm.
* Thus, the MBR setting which involves rsense should be shifted by 6 digits.
*/
.R[PSC_POWER] = 4 - 6,
.m[PSC_TEMPERATURE] = 1,
.b[PSC_TEMPERATURE] = 273,
.R[PSC_TEMPERATURE] = 0,
.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
PMBUS_HAVE_PIN | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT |
PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_TEMP,
};
static const struct i2c_device_id ltc4286_id[] = {
{ "ltc4286", 0 },
{ "ltc4287", 1 },
{}
};
MODULE_DEVICE_TABLE(i2c, ltc4286_id);
static int ltc4286_probe(struct i2c_client *client)
{
int ret;
const struct i2c_device_id *mid;
u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
struct pmbus_driver_info *info;
u32 rsense;
int vrange_nval, vrange_oval;
ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, block_buffer);
if (ret < 0) {
return dev_err_probe(&client->dev, ret,
"Failed to read manufacturer id\n");
}
/*
* Refer to ltc4286 datasheet page 20
* the manufacturer id is LTC
*/
if (ret != LTC4286_MFR_ID_SIZE ||
strncmp(block_buffer, "LTC", LTC4286_MFR_ID_SIZE)) {
return dev_err_probe(&client->dev, -ENODEV,
"Manufacturer id mismatch\n");
}
ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, block_buffer);
if (ret < 0) {
return dev_err_probe(&client->dev, ret,
"Failed to read manufacturer model\n");
}
for (mid = ltc4286_id; mid->name[0]; mid++) {
if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
break;
}
if (!mid->name[0])
return dev_err_probe(&client->dev, -ENODEV,
"Unsupported device\n");
if (of_property_read_u32(client->dev.of_node,
"shunt-resistor-micro-ohms", &rsense))
rsense = 300; /* 0.3 mOhm if not set via DT */
if (rsense == 0)
return -EINVAL;
/* Check for the latter MBR value won't overflow */
if (rsense > (INT_MAX / 1024))
return -EINVAL;
info = devm_kmemdup(&client->dev, &ltc4286_info, sizeof(*info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
/* Check MFR1 CONFIG register bit 1 VRANGE_SELECT before driver loading */
vrange_oval = i2c_smbus_read_word_data(client, LTC4286_MFR_CONFIG1);
if (vrange_oval < 0)
return dev_err_probe(&client->dev, vrange_oval,
"Failed to read manufacturer configuration one\n");
vrange_nval = vrange_oval;
if (device_property_read_bool(&client->dev, "adi,vrange-low-enable")) {
vrange_nval &=
~VRANGE_SELECT_BIT; /* VRANGE_SELECT = 0, 25.6 volts */
info->m[PSC_VOLTAGE_IN] = 128;
info->m[PSC_VOLTAGE_OUT] = 128;
info->m[PSC_POWER] = 4 * rsense;
} else {
vrange_nval |=
VRANGE_SELECT_BIT; /* VRANGE_SELECT = 1, 102.4 volts */
info->m[PSC_POWER] = rsense;
}
if (vrange_nval != vrange_oval) {
/* Set MFR1 CONFIG register bit 1 VRANGE_SELECT */
ret = i2c_smbus_write_word_data(client, LTC4286_MFR_CONFIG1,
vrange_nval);
if (ret < 0)
return dev_err_probe(&client->dev, ret,
"Failed to set vrange\n");
}
info->m[PSC_CURRENT_OUT] = 1024 * rsense;
return pmbus_do_probe(client, info);
}
static const struct of_device_id ltc4286_of_match[] = {
{ .compatible = "lltc,ltc4286" },
{ .compatible = "lltc,ltc4287" },
{}
};
static struct i2c_driver ltc4286_driver = {
.driver = {
.name = "ltc4286",
.of_match_table = ltc4286_of_match,
},
.probe = ltc4286_probe,
.id_table = ltc4286_id,
};
module_i2c_driver(ltc4286_driver);
MODULE_AUTHOR("Delphine CC Chiu <Delphine_CC_Chiu@wiwynn.com>");
MODULE_DESCRIPTION("PMBUS driver for LTC4286 and compatibles");
MODULE_LICENSE("GPL");