--- /dev/null
+Kernel driver ltc3815
+=====================
+
+Supported chips:
+ * Linear Technology LTC3815
+ Prefix: 'ltc3815'
+ Addresses scanned: -
+ Datasheet: http://www.linear.com/product/ltc3815
+
+Author: Guenter Roeck <linux@roeck-us.net>
+
+
+Description
+-----------
+
+LTC3815 is a Monolithic Synchronous DC/DC Step-Down Converter.
+
+
+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 an LTC3815
+at address 0x20 on I2C bus #1:
+
+# modprobe ltc3815
+# echo ltc3815 0x20 > /sys/bus/i2c/devices/i2c-1/new_device
+
+
+Sysfs attributes
+----------------
+
+in1_label "vin"
+in1_input Measured input voltage.
+in1_alarm Input voltage alarm.
+in1_highest Highest input voltage.
+in1_reset_history Reset input voltage history.
+
+in2_label "vout1".
+in2_input Measured output voltage.
+in2_alarm Output voltage alarm.
+in2_highest Highest output voltage.
+in2_reset_history Reset output voltage history.
+
+temp1_input Measured chip temperature.
+temp1_alarm Temperature alarm.
+temp1_highest Highest measured temperature.
+temp1_reset_history Reset temperature history.
+
+curr1_label "iin".
+curr1_input Measured input current.
+curr1_highest Highest input current.
+curr1_reset_history Reset input current history.
+
+curr2_label "iout1".
+curr2_input Measured output current.
+curr2_alarm Output current alarm.
+curr2_highest Highest output current.
+curr2_reset_history Reset output current history.
--- /dev/null
+/*
+ * Hardware monitoring driver for LTC3815
+ *
+ * Copyright (c) 2015 Linear Technology
+ * Copyright (c) 2015 Guenter Roeck
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include "pmbus.h"
+
+#define LTC3815_MFR_IOUT_PEAK 0xd7
+#define LTC3815_MFR_VOUT_PEAK 0xdd
+#define LTC3815_MFR_VIN_PEAK 0xde
+#define LTC3815_MFR_TEMP_PEAK 0xdf
+#define LTC3815_MFR_IIN_PEAK 0xe1
+#define LTC3815_MFR_SPECIAL_ID 0xe7
+
+#define LTC3815_ID 0x8000
+#define LTC3815_ID_MASK 0xff00
+
+static int ltc3815_read_byte_data(struct i2c_client *client, int page, int reg)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_VOUT_MODE:
+ /*
+ * The chip returns 0x3e, suggesting VID mode with manufacturer
+ * specific VID codes. Since the output voltage is reported
+ * with a LSB of 0.5mV, override and report direct mode with
+ * appropriate coefficients.
+ */
+ ret = 0x40;
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
+static int ltc3815_write_byte(struct i2c_client *client, int page, u8 reg)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_CLEAR_FAULTS:
+ /*
+ * LTC3815 does not support the CLEAR_FAULTS command.
+ * Emulate it by clearing the status register.
+ */
+ ret = pmbus_read_word_data(client, 0, PMBUS_STATUS_WORD);
+ if (ret > 0) {
+ pmbus_write_word_data(client, 0, PMBUS_STATUS_WORD,
+ ret);
+ ret = 0;
+ }
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
+static int ltc3815_read_word_data(struct i2c_client *client, int page, int reg)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_VIRT_READ_VIN_MAX:
+ ret = pmbus_read_word_data(client, page, LTC3815_MFR_VIN_PEAK);
+ break;
+ case PMBUS_VIRT_READ_VOUT_MAX:
+ ret = pmbus_read_word_data(client, page, LTC3815_MFR_VOUT_PEAK);
+ break;
+ case PMBUS_VIRT_READ_TEMP_MAX:
+ ret = pmbus_read_word_data(client, page, LTC3815_MFR_TEMP_PEAK);
+ break;
+ case PMBUS_VIRT_READ_IOUT_MAX:
+ ret = pmbus_read_word_data(client, page, LTC3815_MFR_IOUT_PEAK);
+ break;
+ case PMBUS_VIRT_READ_IIN_MAX:
+ ret = pmbus_read_word_data(client, page, LTC3815_MFR_IIN_PEAK);
+ break;
+ case PMBUS_VIRT_RESET_VOUT_HISTORY:
+ case PMBUS_VIRT_RESET_VIN_HISTORY:
+ case PMBUS_VIRT_RESET_TEMP_HISTORY:
+ case PMBUS_VIRT_RESET_IOUT_HISTORY:
+ case PMBUS_VIRT_RESET_IIN_HISTORY:
+ ret = 0;
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
+static int ltc3815_write_word_data(struct i2c_client *client, int page,
+ int reg, u16 word)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_VIRT_RESET_IIN_HISTORY:
+ ret = pmbus_write_word_data(client, page,
+ LTC3815_MFR_IIN_PEAK, 0);
+ break;
+ case PMBUS_VIRT_RESET_IOUT_HISTORY:
+ ret = pmbus_write_word_data(client, page,
+ LTC3815_MFR_IOUT_PEAK, 0);
+ break;
+ case PMBUS_VIRT_RESET_VOUT_HISTORY:
+ ret = pmbus_write_word_data(client, page,
+ LTC3815_MFR_VOUT_PEAK, 0);
+ break;
+ case PMBUS_VIRT_RESET_VIN_HISTORY:
+ ret = pmbus_write_word_data(client, page,
+ LTC3815_MFR_VIN_PEAK, 0);
+ break;
+ case PMBUS_VIRT_RESET_TEMP_HISTORY:
+ ret = pmbus_write_word_data(client, page,
+ LTC3815_MFR_TEMP_PEAK, 0);
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
+static const struct i2c_device_id ltc3815_id[] = {
+ {"ltc3815", 0},
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ltc3815_id);
+
+static struct pmbus_driver_info ltc3815_info = {
+ .pages = 1,
+ .format[PSC_VOLTAGE_IN] = direct,
+ .format[PSC_VOLTAGE_OUT] = direct,
+ .format[PSC_CURRENT_IN] = direct,
+ .format[PSC_CURRENT_OUT] = direct,
+ .format[PSC_TEMPERATURE] = direct,
+ .m[PSC_VOLTAGE_IN] = 250,
+ .b[PSC_VOLTAGE_IN] = 0,
+ .R[PSC_VOLTAGE_IN] = 0,
+ .m[PSC_VOLTAGE_OUT] = 2,
+ .b[PSC_VOLTAGE_OUT] = 0,
+ .R[PSC_VOLTAGE_OUT] = 3,
+ .m[PSC_CURRENT_IN] = 1,
+ .b[PSC_CURRENT_IN] = 0,
+ .R[PSC_CURRENT_IN] = 2,
+ .m[PSC_CURRENT_OUT] = 1,
+ .b[PSC_CURRENT_OUT] = 0,
+ .R[PSC_CURRENT_OUT] = 2,
+ .m[PSC_TEMPERATURE] = 1,
+ .b[PSC_TEMPERATURE] = 0,
+ .R[PSC_TEMPERATURE] = 0,
+ .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_VOUT |
+ PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
+ .read_byte_data = ltc3815_read_byte_data,
+ .read_word_data = ltc3815_read_word_data,
+ .write_byte = ltc3815_write_byte,
+ .write_word_data = ltc3815_write_word_data,
+};
+
+static int ltc3815_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int chip_id;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_WORD_DATA))
+ return -ENODEV;
+
+ chip_id = i2c_smbus_read_word_data(client, LTC3815_MFR_SPECIAL_ID);
+ if (chip_id < 0)
+ return chip_id;
+ if ((chip_id & LTC3815_ID_MASK) != LTC3815_ID)
+ return -ENODEV;
+
+ return pmbus_do_probe(client, id, <c3815_info);
+}
+
+static struct i2c_driver ltc3815_driver = {
+ .driver = {
+ .name = "ltc3815",
+ },
+ .probe = ltc3815_probe,
+ .remove = pmbus_do_remove,
+ .id_table = ltc3815_id,
+};
+
+module_i2c_driver(ltc3815_driver);
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("PMBus driver for LTC3815");
+MODULE_LICENSE("GPL");
projects / linux-beck.git / commitdiff