Add a driver to support ltc4286 chip Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@xxxxxxxxxx> Changelog: v4 - Add empty line before "config SENSORS_LTC4286" in Kconfig - Add ltc4286 to Documentation/hwmon/index.rst - Revise comment typo - Use devm_kmemdup instead of memcpy - Check MBR value before writting into v3 - Use dev_err_probe() instead of dev_err() - The VRANGE_SELECT bit only be written if it actually changed - Avoid the info pointer being overwritten - Check the MBR value range to avoid overflow - Revise ltc4286.rst to corrcet description v2 - Revise Linear Technologies LTC4286 to Analog Devices LTC4286 in Kconfig - Add more description for this driver in Kconfig - Add some comments for MBR setting in ltc4286.c - Add ltc4286.rst --- Documentation/hwmon/index.rst | 1 + Documentation/hwmon/ltc4286.rst | 95 +++++++++++++++++ drivers/hwmon/pmbus/Kconfig | 10 ++ drivers/hwmon/pmbus/Makefile | 1 + drivers/hwmon/pmbus/ltc4286.c | 177 ++++++++++++++++++++++++++++++++ 5 files changed, 284 insertions(+) create mode 100644 Documentation/hwmon/ltc4286.rst create mode 100644 drivers/hwmon/pmbus/ltc4286.c diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 72f4e6065bae..080827cc4c34 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -128,6 +128,7 @@ Hardware Monitoring Kernel Drivers ltc4245 ltc4260 ltc4261 + ltc4286 max127 max15301 max16064 diff --git a/Documentation/hwmon/ltc4286.rst b/Documentation/hwmon/ltc4286.rst new file mode 100644 index 000000000000..2cd149676d86 --- /dev/null +++ b/Documentation/hwmon/ltc4286.rst @@ -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@xxxxxxxxxx> + + +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. +======================= ======================================================= diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig index b4e93bd5835e..2d4f972e5a65 100644 --- a/drivers/hwmon/pmbus/Kconfig +++ b/drivers/hwmon/pmbus/Kconfig @@ -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 diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile index 84ee960a6c2d..94e28f6d6a61 100644 --- a/drivers/hwmon/pmbus/Makefile +++ b/drivers/hwmon/pmbus/Makefile @@ -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 diff --git a/drivers/hwmon/pmbus/ltc4286.c b/drivers/hwmon/pmbus/ltc4286.c new file mode 100644 index 000000000000..e6690b38349a --- /dev/null +++ b/drivers/hwmon/pmbus/ltc4286.c @@ -0,0 +1,177 @@ +// 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 +#define VRANGE_25P6 0 + +/* + * 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; + int temp_setting; + const struct i2c_device_id *mid; + u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1]; + struct pmbus_driver_info *info; + u32 rsense; + + 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, ret, + "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"); + + ret = of_property_read_u32(client->dev.of_node, + "shunt-resistor-micro-ohms", &rsense); + if (ret < 0) + return ret; + + if (rsense == 0) + return -EINVAL; + + if (rsense > INT_MAX) + return -ERANGE; + + info = devm_kmemdup(&client->dev, <c4286_info, sizeof(*info), + GFP_KERNEL); + if (!info) + return -ENOMEM; + + /* Default of VRANGE_SELECT = 1, 102.4V */ + if (device_property_read_bool(&client->dev, "adi,vrange-low-enable")) { + /* Setup MFR1 CONFIG register bit 1 VRANGE_SELECT */ + ret = i2c_smbus_read_word_data(client, LTC4286_MFR_CONFIG1); + if (ret < 0) + return dev_err_probe( + &client->dev, ret, + "Failed to read manufacturer configuration one\n"); + + ret &= ~VRANGE_SELECT_BIT; /* VRANGE_SELECT = 0, 25.6V */ + ret = i2c_smbus_write_word_data(client, LTC4286_MFR_CONFIG1, + ret); + if (ret < 0) + return dev_err_probe(&client->dev, ret, + "Failed to set vrange\n"); + + info->m[PSC_VOLTAGE_IN] = 128; + info->m[PSC_VOLTAGE_OUT] = 128; + + temp_setting = 4 * rsense; + if (temp_setting > INT_MAX) + return dev_err_probe(&client->dev, -ERANGE, + "Power coefficient overflow\n"); + info->m[PSC_POWER] = temp_setting; + } else { + info->m[PSC_POWER] = rsense; + } + + temp_setting = 1024 * rsense; + if (temp_setting > INT_MAX) + return dev_err_probe(&client->dev, -ERANGE, + "Current coefficient overflow\n"); + info->m[PSC_CURRENT_OUT] = temp_setting; + + 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@xxxxxxxxxx>"); +MODULE_DESCRIPTION("PMBUS driver for LTC4286 and compatibles"); +MODULE_LICENSE("GPL"); -- 2.25.1