summaryrefslogtreecommitdiff
path: root/drivers/hwmon/pmbus/max16601.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/hwmon/pmbus/max16601.c')
-rw-r--r--drivers/hwmon/pmbus/max16601.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/max16601.c b/drivers/hwmon/pmbus/max16601.c
new file mode 100644
index 000000000000..51cdfaf9023c
--- /dev/null
+++ b/drivers/hwmon/pmbus/max16601.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hardware monitoring driver for Maxim MAX16601
+ *
+ * Implementation notes:
+ *
+ * Ths chip supports two rails, VCORE and VSA. Telemetry information for the
+ * two rails is reported in two subsequent I2C addresses. The driver
+ * instantiates a dummy I2C client at the second I2C address to report
+ * information for the VSA rail in a single instance of the driver.
+ * Telemetry for the VSA rail is reported to the PMBus core in PMBus page 2.
+ *
+ * The chip reports input current using two separate methods. The input current
+ * reported with the standard READ_IIN command is derived from the output
+ * current. The first method is reported to the PMBus core with PMBus page 0,
+ * the second method is reported with PMBus page 1.
+ *
+ * The chip supports reading per-phase temperatures and per-phase input/output
+ * currents for VCORE. Telemetry is reported in vendor specific registers.
+ * The driver translates the vendor specific register values to PMBus standard
+ * register values and reports per-phase information in PMBus page 0.
+ *
+ * Copyright 2019, 2020 Google LLC.
+ */
+
+#include <linux/bits.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "pmbus.h"
+
+#define REG_SETPT_DVID 0xd1
+#define DAC_10MV_MODE BIT(4)
+#define REG_IOUT_AVG_PK 0xee
+#define REG_IIN_SENSOR 0xf1
+#define REG_TOTAL_INPUT_POWER 0xf2
+#define REG_PHASE_ID 0xf3
+#define CORE_RAIL_INDICATOR BIT(7)
+#define REG_PHASE_REPORTING 0xf4
+
+struct max16601_data {
+ struct pmbus_driver_info info;
+ struct i2c_client *vsa;
+ int iout_avg_pkg;
+};
+
+#define to_max16601_data(x) container_of(x, struct max16601_data, info)
+
+static int max16601_read_byte(struct i2c_client *client, int page, int reg)
+{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ struct max16601_data *data = to_max16601_data(info);
+
+ if (page > 0) {
+ if (page == 2) /* VSA */
+ return i2c_smbus_read_byte_data(data->vsa, reg);
+ return -EOPNOTSUPP;
+ }
+ return -ENODATA;
+}
+
+static int max16601_read_word(struct i2c_client *client, int page, int phase,
+ int reg)
+{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ struct max16601_data *data = to_max16601_data(info);
+ u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
+ int ret;
+
+ switch (page) {
+ case 0: /* VCORE */
+ if (phase == 0xff)
+ return -ENODATA;
+ switch (reg) {
+ case PMBUS_READ_IIN:
+ case PMBUS_READ_IOUT:
+ case PMBUS_READ_TEMPERATURE_1:
+ ret = i2c_smbus_write_byte_data(client, REG_PHASE_ID,
+ phase);
+ if (ret)
+ return ret;
+ ret = i2c_smbus_read_block_data(client,
+ REG_PHASE_REPORTING,
+ buf);
+ if (ret < 0)
+ return ret;
+ if (ret < 6)
+ return -EIO;
+ switch (reg) {
+ case PMBUS_READ_TEMPERATURE_1:
+ return buf[1] << 8 | buf[0];
+ case PMBUS_READ_IOUT:
+ return buf[3] << 8 | buf[2];
+ case PMBUS_READ_IIN:
+ return buf[5] << 8 | buf[4];
+ default:
+ break;
+ }
+ }
+ return -EOPNOTSUPP;
+ case 1: /* VCORE, read IIN/PIN from sensor element */
+ switch (reg) {
+ case PMBUS_READ_IIN:
+ return i2c_smbus_read_word_data(client, REG_IIN_SENSOR);
+ case PMBUS_READ_PIN:
+ return i2c_smbus_read_word_data(client,
+ REG_TOTAL_INPUT_POWER);
+ default:
+ break;
+ }
+ return -EOPNOTSUPP;
+ case 2: /* VSA */
+ switch (reg) {
+ case PMBUS_VIRT_READ_IOUT_MAX:
+ ret = i2c_smbus_read_word_data(data->vsa,
+ REG_IOUT_AVG_PK);
+ if (ret < 0)
+ return ret;
+ if (sign_extend32(ret, 10) >
+ sign_extend32(data->iout_avg_pkg, 10))
+ data->iout_avg_pkg = ret;
+ return data->iout_avg_pkg;
+ case PMBUS_VIRT_RESET_IOUT_HISTORY:
+ return 0;
+ case PMBUS_IOUT_OC_FAULT_LIMIT:
+ case PMBUS_IOUT_OC_WARN_LIMIT:
+ case PMBUS_OT_FAULT_LIMIT:
+ case PMBUS_OT_WARN_LIMIT:
+ case PMBUS_READ_IIN:
+ case PMBUS_READ_IOUT:
+ case PMBUS_READ_TEMPERATURE_1:
+ case PMBUS_STATUS_WORD:
+ return i2c_smbus_read_word_data(data->vsa, reg);
+ default:
+ return -EOPNOTSUPP;
+ }
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int max16601_write_byte(struct i2c_client *client, int page, u8 reg)
+{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ struct max16601_data *data = to_max16601_data(info);
+
+ if (page == 2) {
+ if (reg == PMBUS_CLEAR_FAULTS)
+ return i2c_smbus_write_byte(data->vsa, reg);
+ return -EOPNOTSUPP;
+ }
+ return -ENODATA;
+}
+
+static int max16601_write_word(struct i2c_client *client, int page, int reg,
+ u16 value)
+{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ struct max16601_data *data = to_max16601_data(info);
+
+ switch (page) {
+ case 0: /* VCORE */
+ return -ENODATA;
+ case 1: /* VCORE IIN/PIN from sensor element */
+ default:
+ return -EOPNOTSUPP;
+ case 2: /* VSA */
+ switch (reg) {
+ case PMBUS_VIRT_RESET_IOUT_HISTORY:
+ data->iout_avg_pkg = 0xfc00;
+ return 0;
+ case PMBUS_IOUT_OC_FAULT_LIMIT:
+ case PMBUS_IOUT_OC_WARN_LIMIT:
+ case PMBUS_OT_FAULT_LIMIT:
+ case PMBUS_OT_WARN_LIMIT:
+ return i2c_smbus_write_word_data(data->vsa, reg, value);
+ default:
+ return -EOPNOTSUPP;
+ }
+ }
+}
+
+static int max16601_identify(struct i2c_client *client,
+ struct pmbus_driver_info *info)
+{
+ int reg;
+
+ reg = i2c_smbus_read_byte_data(client, REG_SETPT_DVID);
+ if (reg < 0)
+ return reg;
+ if (reg & DAC_10MV_MODE)
+ info->vrm_version[0] = vr13;
+ else
+ info->vrm_version[0] = vr12;
+
+ return 0;
+}
+
+static struct pmbus_driver_info max16601_info = {
+ .pages = 3,
+ .format[PSC_VOLTAGE_IN] = linear,
+ .format[PSC_VOLTAGE_OUT] = vid,
+ .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_IIN | PMBUS_HAVE_PIN |
+ PMBUS_HAVE_STATUS_INPUT |
+ PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+ PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+ PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
+ PMBUS_HAVE_POUT | PMBUS_PAGE_VIRTUAL | PMBUS_PHASE_VIRTUAL,
+ .func[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_PAGE_VIRTUAL,
+ .func[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT |
+ PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+ PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_PAGE_VIRTUAL,
+ .phases[0] = 8,
+ .pfunc[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
+ .pfunc[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
+ .pfunc[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
+ .pfunc[3] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
+ .pfunc[4] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
+ .pfunc[5] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
+ .pfunc[6] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP,
+ .pfunc[7] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT,
+ .identify = max16601_identify,
+ .read_byte_data = max16601_read_byte,
+ .read_word_data = max16601_read_word,
+ .write_byte = max16601_write_byte,
+ .write_word_data = max16601_write_word,
+};
+
+static void max16601_remove(void *_data)
+{
+ struct max16601_data *data = _data;
+
+ i2c_unregister_device(data->vsa);
+}
+
+static int max16601_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
+ struct max16601_data *data;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_BYTE_DATA |
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA))
+ return -ENODEV;
+
+ ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);
+ if (ret < 0)
+ return -ENODEV;
+
+ /* PMBUS_IC_DEVICE_ID is expected to return "MAX16601y.xx" */
+ if (ret < 11 || strncmp(buf, "MAX16601", 8)) {
+ buf[ret] = '\0';
+ dev_err(dev, "Unsupported chip '%s'\n", buf);
+ return -ENODEV;
+ }
+
+ ret = i2c_smbus_read_byte_data(client, REG_PHASE_ID);
+ if (ret < 0)
+ return ret;
+ if (!(ret & CORE_RAIL_INDICATOR)) {
+ dev_err(dev,
+ "Driver must be instantiated on CORE rail I2C address\n");
+ return -ENODEV;
+ }
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->iout_avg_pkg = 0xfc00;
+ data->vsa = i2c_new_dummy_device(client->adapter, client->addr + 1);
+ if (IS_ERR(data->vsa)) {
+ dev_err(dev, "Failed to register VSA client\n");
+ return PTR_ERR(data->vsa);
+ }
+ ret = devm_add_action_or_reset(dev, max16601_remove, data);
+ if (ret)
+ return ret;
+
+ data->info = max16601_info;
+
+ return pmbus_do_probe(client, id, &data->info);
+}
+
+static const struct i2c_device_id max16601_id[] = {
+ {"max16601", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, max16601_id);
+
+static struct i2c_driver max16601_driver = {
+ .driver = {
+ .name = "max16601",
+ },
+ .probe = max16601_probe,
+ .remove = pmbus_do_remove,
+ .id_table = max16601_id,
+};
+
+module_i2c_driver(max16601_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("PMBus driver for Maxim MAX16601");
+MODULE_LICENSE("GPL v2");