[PATCH v4 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU

From: Robert Marko
Date: Mon Jun 07 2021 - 06:34:58 EST

This adds support for the Delta DPS-920AB PSU.

Only missing feature is fan control which the PSU supports.

Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
---
Changes in v4:
* Alphabetically order documentation in index.rst
* Null terminate manufacturer and mode ID-s
* Drop debugfs directory and I2C clients from the
global structure, use local variables

Changes in v3:
* Use generic pmbus_read/write_word_data()
* Correct word data return code
* Cache PMBUS_MFR_ID and PMBUS_MFR_MODEL instead
of reading them everytime that debugfs is read

Changes in v2:
* Check for Manufacturer and Model
* Restrict word read/write to supported only
* Update documentation to reflect driver changes
* Add basic debugfs entries

Documentation/hwmon/dps920ab.rst | 73 +++++++++++
Documentation/hwmon/index.rst | 1 +
drivers/hwmon/pmbus/Kconfig | 9 ++
drivers/hwmon/pmbus/Makefile | 1 +
drivers/hwmon/pmbus/dps920ab.c | 207 +++++++++++++++++++++++++++++++
5 files changed, 291 insertions(+)
create mode 100644 Documentation/hwmon/dps920ab.rst
create mode 100644 drivers/hwmon/pmbus/dps920ab.c

diff --git a/Documentation/hwmon/dps920ab.rst b/Documentation/hwmon/dps920ab.rst
new file mode 100644
index 000000000000..c33b4cdc0a60
--- /dev/null
+++ b/Documentation/hwmon/dps920ab.rst
@@ -0,0 +1,73 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver dps920ab
+========================
+
+Supported chips:
+
+ * Delta DPS920AB
+
+ Prefix: 'dps920ab'
+
+ Addresses scanned: -
+
+Authors:
+ Robert Marko <robert.marko@xxxxxxxxxx>
+
+
+Description
+-----------
+
+This driver implements support for Delta DPS920AB 920W 54V DC single output
+power supply with PMBus support.
+
+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.
+
+
+Sysfs entries
+-------------
+
+======================= ======================================================
+curr1_label "iin"
+curr1_input Measured input current
+curr1_alarm Input current high alarm
+
+curr2_label "iout1"
+curr2_input Measured output current
+curr2_max Maximum output current
+curr2_rated_max Maximum rated output current
+
+in1_label "vin"
+in1_input Measured input voltage
+in1_alarm Input voltage alarm
+
+in2_label "vout1"
+in2_input Measured output voltage
+in2_rated_min Minimum rated output voltage
+in2_rated_max Maximum rated output voltage
+in2_alarm Output voltage alarm
+
+power1_label "pin"
+power1_input Measured input power
+power1_alarm Input power high alarm
+
+power2_label "pout1"
+power2_input Measured output power
+power2_rated_max Maximum rated output power
+
+temp[1-3]_input Measured temperature
+temp[1-3]_alarm Temperature alarm
+
+fan1_alarm Fan 1 warning.
+fan1_fault Fan 1 fault.
+fan1_input Fan 1 speed in RPM.
+======================= ======================================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 8d5a2df1ecb6..8abdaf440a3c 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -53,6 +53,7 @@ Hardware Monitoring Kernel Drivers
da9055
dell-smm-hwmon
dme1737
+ dps920ab
drivetemp
ds1621
ds620
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 32d2fc850621..865ade0aa205 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -66,6 +66,15 @@ config SENSORS_IBM_CFFPS
This driver can also be built as a module. If so, the module will
be called ibm-cffps.

+config SENSORS_DPS920AB
+ tristate "Delta DPS920AB Power Supply"
+ help
+ If you say yes here you get hardware monitoring support for Delta
+ DPS920AB Power Supplies.
+
+ This driver can also be built as a module. If so, the module will
+ be called dps920ab.
+
config SENSORS_INSPUR_IPSPS
tristate "INSPUR Power System Power Supply"
help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 6a4ba0fdc1db..f59ba0123d68 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_SENSORS_ADM1266) += adm1266.o
obj-$(CONFIG_SENSORS_ADM1275) += adm1275.o
obj-$(CONFIG_SENSORS_BEL_PFE) += bel-pfe.o
obj-$(CONFIG_SENSORS_IBM_CFFPS) += ibm-cffps.o
+obj-$(CONFIG_SENSORS_DPS920AB) += dps920ab.o
obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
obj-$(CONFIG_SENSORS_IR35221) += ir35221.o
obj-$(CONFIG_SENSORS_IR38064) += ir38064.o
diff --git a/drivers/hwmon/pmbus/dps920ab.c b/drivers/hwmon/pmbus/dps920ab.c
new file mode 100644
index 000000000000..692a86cdfb6d
--- /dev/null
+++ b/drivers/hwmon/pmbus/dps920ab.c
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Delta DPS920AB PSU
+ *
+ * Copyright (C) 2021 Delta Networks, Inc.
+ * Copyright (C) 2021 Sartura Ltd.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include "pmbus.h"
+
+struct dps920ab_data {
+ char *mfr_model;
+ char *mfr_id;
+};
+
+static int dps920ab_read_word_data(struct i2c_client *client, int page, int phase, int reg)
+{
+ /*
+ * This masks commands which are not supported.
+ * PSU advertises that all features are supported,
+ * in reality that unfortunately is not true.
+ * So enable only those that the datasheet confirms.
+ */
+ switch (reg) {
+ case PMBUS_FAN_COMMAND_1:
+ case PMBUS_IOUT_OC_WARN_LIMIT:
+ case PMBUS_STATUS_WORD:
+ case PMBUS_READ_VIN:
+ case PMBUS_READ_IIN:
+ case PMBUS_READ_VOUT:
+ case PMBUS_READ_IOUT:
+ case PMBUS_READ_TEMPERATURE_1:
+ case PMBUS_READ_TEMPERATURE_2:
+ case PMBUS_READ_TEMPERATURE_3:
+ case PMBUS_READ_FAN_SPEED_1:
+ case PMBUS_READ_POUT:
+ case PMBUS_READ_PIN:
+ case PMBUS_MFR_VOUT_MIN:
+ case PMBUS_MFR_VOUT_MAX:
+ case PMBUS_MFR_IOUT_MAX:
+ case PMBUS_MFR_POUT_MAX:
+ return pmbus_read_word_data(client, page, phase, reg);
+ default:
+ return -ENXIO;
+ }
+}
+
+static int dps920ab_write_word_data(struct i2c_client *client, int page, int reg,
+ u16 word)
+{
+ /*
+ * This masks commands which are not supported.
+ * PSU only has one R/W register and that is
+ * for the fan.
+ */
+ switch (reg) {
+ case PMBUS_FAN_COMMAND_1:
+ return pmbus_write_word_data(client, page, reg, word);
+ default:
+ return -EACCES;
+ }
+}
+
+static struct pmbus_driver_info dps920ab_info = {
+ .pages = 1,
+
+ .format[PSC_VOLTAGE_IN] = linear,
+ .format[PSC_VOLTAGE_OUT] = linear,
+ .format[PSC_CURRENT_IN] = linear,
+ .format[PSC_CURRENT_OUT] = linear,
+ .format[PSC_POWER] = linear,
+ .format[PSC_FAN] = linear,
+ .format[PSC_TEMPERATURE] = linear,
+
+ .func[0] =
+ PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
+ PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
+ PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
+ PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12 |
+ PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
+ PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+ .read_word_data = dps920ab_read_word_data,
+ .write_word_data = dps920ab_write_word_data,
+};
+
+static int dps920ab_mfr_id_show(struct seq_file *s, void *data)
+{
+ struct dps920ab_data *priv = s->private;
+
+ seq_printf(s, "%s\n", priv->mfr_id);
+
+ return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_id);
+
+static int dps920ab_mfr_model_show(struct seq_file *s, void *data)
+{
+ struct dps920ab_data *priv = s->private;
+
+ seq_printf(s, "%s\n", priv->mfr_model);
+
+ return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_model);
+
+static void dps920ab_init_debugfs(struct dps920ab_data *data, struct i2c_client *client)
+{
+ struct dentry *debugfs_dir;
+ struct dentry *root;
+
+ root = pmbus_get_debugfs_dir(client);
+ if (!root)
+ return;
+
+ debugfs_dir = debugfs_create_dir(client->name, root);
+ if (!debugfs_dir)
+ return;
+
+ debugfs_create_file("mfr_id",
+ 0400,
+ debugfs_dir,
+ data,
+ &dps920ab_mfr_id_fops);
+
+ debugfs_create_file("mfr_model",
+ 0400,
+ debugfs_dir,
+ data,
+ &dps920ab_mfr_model_fops);
+}
+
+static int dps920ab_probe(struct i2c_client *client)
+{
+ u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
+ struct dps920ab_data *data;
+ int ret;
+
+ data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
+ if (ret < 0) {
+ dev_err(&client->dev, "Failed to read Manufacturer ID\n");
+ return ret;
+ }
+
+ buf[ret] = '\0';
+ if (ret != 5 || strncmp(buf, "DELTA", 5)) {
+ buf[ret] = '\0';
+ dev_err(&client->dev, "Unsupported Manufacturer ID '%s'\n", buf);
+ return -ENODEV;
+ }
+ data->mfr_id = devm_kstrdup(&client->dev, buf, GFP_KERNEL);
+ if (!data->mfr_id)
+ return -ENOMEM;
+
+ ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+ if (ret < 0) {
+ dev_err(&client->dev, "Failed to read Manufacturer Model\n");
+ return ret;
+ }
+
+ buf[ret] = '\0';
+ if (ret != 11 || strncmp(buf, "DPS-920AB", 9)) {
+ dev_err(&client->dev, "Unsupported Manufacturer Model '%s'\n", buf);
+ return -ENODEV;
+ }
+ data->mfr_model = devm_kstrdup(&client->dev, buf, GFP_KERNEL);
+ if (!data->mfr_model)
+ return -ENOMEM;
+
+ ret = pmbus_do_probe(client, &dps920ab_info);
+ if (ret)
+ return ret;
+
+ dps920ab_init_debugfs(data, client);
+
+ return 0;
+}
+
+static const struct of_device_id __maybe_unused dps920ab_of_match[] = {
+ { .compatible = "delta,dps920ab", },
+ {}
+};
+
+MODULE_DEVICE_TABLE(of, dps920ab_of_match);
+
+static struct i2c_driver dps920ab_driver = {
+ .driver = {
+ .name = "dps920ab",
+ .of_match_table = of_match_ptr(dps920ab_of_match),
+ },
+ .probe_new = dps920ab_probe,
+};
+
+module_i2c_driver(dps920ab_driver);
+
+MODULE_AUTHOR("Robert Marko <robert.marko@xxxxxxxxxx>");
+MODULE_DESCRIPTION("PMBus driver for Delta DPS920AB PSU");
+MODULE_LICENSE("GPL");
--
2.31.1