--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver lt7182s
+=====================
+
+Supported chips:
+
+ * ADI LT7182S
+
+ Prefix: 'lt7182s'
+
+ Addresses scanned: -
+
+ Datasheet: https://www.analog.com/en/products/lt7182s.html
+
+Author: Guenter Roeck <linux@roeck-us.net>
+
+
+Description
+-----------
+
+LT7182S is a Dual Channel 6A, 20V PolyPhase Step-Down Silent Switcher with
+Digital Power System Management support.
+
+
+Usage Notes
+-----------
+
+This driver does not probe for PMBus devices. You will have to instantiate
+devices explicitly.
+
+Example: the following commands will load the driver for a LT7182S
+at address 0x4f on I2C bus #4::
+
+ # modprobe lt7182s
+ # echo lt7182s 0x4f > /sys/bus/i2c/devices/i2c-4/new_device
+
+It can also be instantiated by declaring an entry in device tree.
+
+
+Sysfs attributes
+----------------
+
+======================= ====================================
+curr[1-2]_label "iin[12]"
+curr[1-2]_input Measured input current
+curr[1-2]_max Maximum input current
+curr[1-2]_max_alarm Current high alarm
+
+curr[3-4]_label "iout[1-2]"
+curr[3-4]_input Measured output current
+curr[3-4]_highest Highest measured output current
+curr[3-4]_max Maximum output current
+curr[3-4]_max_alarm Output current high alarm
+
+in[1-2]_label "vin[12]"
+in[1-2]_input Measured input voltage
+in[1-2]_highest Highest measured input voltage
+in[1-2]_crit Critical maximum input voltage
+in[1-2]_crit_alarm Input voltage critical high alarm
+in[1-2]_min Minimum input voltage
+in[1-2]_min_alarm Input voltage low alarm
+in[1-2]_rated_min Rated minimum input voltage
+in[1-2]_rated_max Rated maximum input voltage
+in1_reset_history Write to reset history for all attributes
+
+in[3-5]_label "vmon[1-3]"
+in[3-5]_input Measured voltage on ITH1/ITH2/EXTVCC pins
+ Only available if enabled with MFR_ADC_CONTROL_LT7182S
+ command.
+
+in[3-4|6-7]_label "vout[1-2]"
+in[3-4|6-7]_input Measured output voltage
+in[3-4|6-7]_highest Highest measured output voltage
+in[3-4|6-7]_lcrit Critical minimum output voltage
+in[3-4|6-7]_lcrit_alarm Output voltage critical low alarm
+in[3-4|6-7]_min Minimum output voltage
+in[3-4|6-7]_max_alarm Output voltage low alarm
+in[3-4|6-7]_max Maximum output voltage
+in[3-4|6-7]_max_alarm Output voltage high alarm
+in[3-4|6-7]_crit Critical maximum output voltage
+in[3-4|6-7]_crit_alarm Output voltage critical high alarm
+
+power[1-2]_label "pout[1-2]"
+power[1-2]_input Measured output power
+
+temp1_input Measured temperature
+temp1_crit Critical high temperature
+temp1_crit_alarm Chip temperature critical high alarm
+temp1_max Maximum temperature
+temp1_max_alarm Chip temperature high alarm
+======================= ====================================
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hardware monitoring driver for Analog Devices LT7182S
+ *
+ * Copyright (c) 2022 Guenter Roeck
+ *
+ */
+
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include "pmbus.h"
+
+#define LT7182S_NUM_PAGES 2
+
+#define MFR_READ_EXTVCC 0xcd
+#define MFR_READ_ITH 0xce
+#define MFR_CONFIG_ALL_LT7182S 0xd1
+#define MFR_IOUT_PEAK 0xd7
+#define MFR_ADC_CONTROL_LT7182S 0xd8
+
+#define MFR_DEBUG_TELEMETRY BIT(0)
+
+#define MFR_VOUT_PEAK 0xdd
+#define MFR_VIN_PEAK 0xde
+#define MFR_TEMPERATURE_1_PEAK 0xdf
+#define MFR_CLEAR_PEAKS 0xe3
+
+#define MFR_CONFIG_IEEE BIT(8)
+
+static int lt7182s_read_word_data(struct i2c_client *client, int page, int phase, int reg)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_VIRT_READ_VMON:
+ if (page == 0 || page == 1)
+ ret = pmbus_read_word_data(client, page, phase, MFR_READ_ITH);
+ else
+ ret = pmbus_read_word_data(client, 0, phase, MFR_READ_EXTVCC);
+ break;
+ case PMBUS_VIRT_READ_IOUT_MAX:
+ ret = pmbus_read_word_data(client, page, phase, MFR_IOUT_PEAK);
+ break;
+ case PMBUS_VIRT_READ_VOUT_MAX:
+ ret = pmbus_read_word_data(client, page, phase, MFR_VOUT_PEAK);
+ break;
+ case PMBUS_VIRT_READ_VIN_MAX:
+ ret = pmbus_read_word_data(client, page, phase, MFR_VIN_PEAK);
+ break;
+ case PMBUS_VIRT_READ_TEMP_MAX:
+ ret = pmbus_read_word_data(client, page, phase, MFR_TEMPERATURE_1_PEAK);
+ break;
+ case PMBUS_VIRT_RESET_VIN_HISTORY:
+ ret = (page == 0) ? 0 : -ENODATA;
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
+static int lt7182s_write_word_data(struct i2c_client *client, int page, int reg, u16 word)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_VIRT_RESET_VIN_HISTORY:
+ ret = pmbus_write_byte(client, 0, MFR_CLEAR_PEAKS);
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
+static struct pmbus_driver_info lt7182s_info = {
+ .pages = LT7182S_NUM_PAGES,
+ .format[PSC_VOLTAGE_IN] = linear,
+ .format[PSC_VOLTAGE_OUT] = linear,
+ .format[PSC_CURRENT_IN] = linear,
+ .format[PSC_CURRENT_OUT] = linear,
+ .format[PSC_TEMPERATURE] = linear,
+ .format[PSC_POWER] = linear,
+ .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
+ PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
+ PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
+ PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+ .func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
+ PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
+ PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
+ PMBUS_HAVE_STATUS_INPUT,
+ .read_word_data = lt7182s_read_word_data,
+ .write_word_data = lt7182s_write_word_data,
+};
+
+static int lt7182s_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct pmbus_driver_info *info;
+ u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_BYTE_DATA |
+ I2C_FUNC_SMBUS_READ_WORD_DATA |
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA))
+ return -ENODEV;
+
+ ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
+ if (ret < 0) {
+ dev_err(dev, "Failed to read PMBUS_MFR_ID\n");
+ return ret;
+ }
+ if (ret != 3 || strncmp(buf, "ADI", 3)) {
+ buf[ret] = '\0';
+ dev_err(dev, "Manufacturer '%s' not supported\n", buf);
+ return -ENODEV;
+ }
+
+ ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+ if (ret < 0) {
+ dev_err(dev, "Failed to read PMBUS_MFR_MODEL\n");
+ return ret;
+ }
+ if (ret != 7 || strncmp(buf, "LT7182S", 7)) {
+ buf[ret] = '\0';
+ dev_err(dev, "Model '%s' not supported\n", buf);
+ return -ENODEV;
+ }
+
+ info = devm_kmemdup(dev, <7182s_info,
+ sizeof(struct pmbus_driver_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ /* Set data format to IEEE754 if configured */
+ ret = i2c_smbus_read_word_data(client, MFR_CONFIG_ALL_LT7182S);
+ if (ret < 0)
+ return ret;
+ if (ret & MFR_CONFIG_IEEE) {
+ info->format[PSC_VOLTAGE_IN] = ieee754;
+ info->format[PSC_VOLTAGE_OUT] = ieee754;
+ info->format[PSC_CURRENT_IN] = ieee754;
+ info->format[PSC_CURRENT_OUT] = ieee754;
+ info->format[PSC_TEMPERATURE] = ieee754;
+ info->format[PSC_POWER] = ieee754;
+ }
+
+ /* Enable VMON output if configured */
+ ret = i2c_smbus_read_byte_data(client, MFR_ADC_CONTROL_LT7182S);
+ if (ret < 0)
+ return ret;
+ if (ret & MFR_DEBUG_TELEMETRY) {
+ info->pages = 3;
+ info->func[0] |= PMBUS_HAVE_VMON;
+ info->func[1] |= PMBUS_HAVE_VMON;
+ info->func[2] = PMBUS_HAVE_VMON;
+ }
+
+ return pmbus_do_probe(client, info);
+}
+
+static const struct i2c_device_id lt7182s_id[] = {
+ { "lt7182s", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, lt7182s_id);
+
+static const struct of_device_id __maybe_unused lt7182s_of_match[] = {
+ { .compatible = "adi,lt7182s" },
+ {}
+};
+
+static struct i2c_driver lt7182s_driver = {
+ .driver = {
+ .name = "lt7182s",
+ .of_match_table = of_match_ptr(lt7182s_of_match),
+ },
+ .probe_new = lt7182s_probe,
+ .id_table = lt7182s_id,
+};
+
+module_i2c_driver(lt7182s_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("PMBus driver for Analog Devices LT7182S");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);
projects / people / ms / linux.git / commitdiff
