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path: root/drivers/hwmon/pmbus/ltc3815.c
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-rw-r--r--drivers/hwmon/pmbus/ltc3815.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/ltc3815.c b/drivers/hwmon/pmbus/ltc3815.c
new file mode 100644
index 0000000000..f2023b17aa
--- /dev/null
+++ b/drivers/hwmon/pmbus/ltc3815.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for LTC3815
+ *
+ * Copyright (c) 2015 Linear Technology
+ * Copyright (c) 2015 Guenter Roeck
+ */
+
+#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, 0xff, 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 phase, int reg)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_VIRT_READ_VIN_MAX:
+ ret = pmbus_read_word_data(client, page, phase,
+ LTC3815_MFR_VIN_PEAK);
+ break;
+ case PMBUS_VIRT_READ_VOUT_MAX:
+ ret = pmbus_read_word_data(client, page, phase,
+ LTC3815_MFR_VOUT_PEAK);
+ break;
+ case PMBUS_VIRT_READ_TEMP_MAX:
+ ret = pmbus_read_word_data(client, page, phase,
+ LTC3815_MFR_TEMP_PEAK);
+ break;
+ case PMBUS_VIRT_READ_IOUT_MAX:
+ ret = pmbus_read_word_data(client, page, phase,
+ LTC3815_MFR_IOUT_PEAK);
+ break;
+ case PMBUS_VIRT_READ_IIN_MAX:
+ ret = pmbus_read_word_data(client, page, phase,
+ 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)
+{
+ 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, &ltc3815_info);
+}
+
+static struct i2c_driver ltc3815_driver = {
+ .driver = {
+ .name = "ltc3815",
+ },
+ .probe = ltc3815_probe,
+ .id_table = ltc3815_id,
+};
+
+module_i2c_driver(ltc3815_driver);
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("PMBus driver for LTC3815");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);