[PATCH v3 3/3] hwmon: (pmbus): Add driver for BluTek BPA-RS600

[Chris Packham <chris.packham@alliedtelesis.co.nz>]

The BPA-RS600 is a compact 600W AC to DC removable power supply module.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---

Notes:
    Changes in v3:
    - Fix typo BPD -> BPA
    - Allow for NUL terminator in buf
    Changes in v2:
    - Whitespace and line length cleanup
    - Add comments about commands that return data but shouldn't be used

 Documentation/hwmon/bpa-rs600.rst |  74 +++++++++++++
 drivers/hwmon/pmbus/Kconfig       |   9 ++
 drivers/hwmon/pmbus/Makefile      |   1 +
 drivers/hwmon/pmbus/bpa-rs600.c   | 172 ++++++++++++++++++++++++++++++
 4 files changed, 256 insertions(+)
 create mode 100644 Documentation/hwmon/bpa-rs600.rst
 create mode 100644 drivers/hwmon/pmbus/bpa-rs600.c

diff --git a/Documentation/hwmon/bpa-rs600.rst b/Documentation/hwmon/bpa-rs600.rst
new file mode 100644
index 000000000000..28313995d4ae
--- /dev/null
+++ b/Documentation/hwmon/bpa-rs600.rst
@@ -0,0 +1,74 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver bpa-rs600
+=======================
+
+Supported chips:
+
+  * BPA-RS600-120
+
+    Datasheet: Publicly available at the BluTek website
+       http://blutekpower.com/wp-content/uploads/2019/01/BPA-RS600-120-07-19-2018.pdf
+
+Authors:
+      - Chris Packham <chris.packham@alliedtelesis.co.nz>
+
+Description
+-----------
+
+The BPA-RS600 is a compact 600W removable power supply module.
+
+Usage Notes
+-----------
+
+This driver does not probe for PMBus devices. You will have to instantiate
+devices explicitly.
+
+Sysfs attributes
+----------------
+
+======================= ============================================
+curr1_label             "iin"
+curr1_input		Measured input current
+curr1_max		Maximum input current
+curr1_max_alarm		Input current high alarm
+
+curr2_label		"iout1"
+curr2_input		Measured output current
+curr2_max		Maximum output current
+curr2_max_alarm		Output current high alarm
+
+fan1_input		Measured fan speed
+fan1_alarm		Fan warning
+fan1_fault		Fan fault
+
+in1_label		"vin"
+in1_input		Measured input voltage
+in1_max			Maximum input voltage
+in1_max_alarm		Input voltage high alarm
+in1_min			Minimum input voltage
+in1_min_alarm		Input voltage low alarm
+
+in2_label		"vout1"
+in2_input		Measured output voltage
+in2_max			Maximum output voltage
+in2_max_alarm		Output voltage high alarm
+in2_min			Maximum output voltage
+in2_min_alarm		Output voltage low alarm
+
+power1_label		"pin"
+power1_input		Measured input power
+power1_alarm		Input power alarm
+power1_max		Maximum input power
+
+power2_label		"pout1"
+power2_input		Measured output power
+power2_max		Maximum output power
+power2_max_alarm	Output power high alarm
+
+temp1_input		Measured temperature around input connector
+temp1_alarm		Temperature alarm
+
+temp2_input		Measured temperature around output connector
+temp2_alarm		Temperature alarm
+======================= ============================================
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 32d2fc850621..512d6f656dca 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -56,6 +56,15 @@ config SENSORS_BEL_PFE
 	  This driver can also be built as a module. If so, the module will
 	  be called bel-pfe.
 
+config SENSORS_BPA_RS600
+	tristate "BluTek BPA-RS600 Power Supplies"
+	help
+	  If you say yes here you get hardware monitoring support for BluTek
+	  BPA-RS600 Power Supplies.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called bpa-rs600.
+
 config SENSORS_IBM_CFFPS
 	tristate "IBM Common Form Factor Power Supply"
 	depends on LEDS_CLASS
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 6a4ba0fdc1db..80a437060dc4 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_SENSORS_PMBUS)	+= pmbus.o
 obj-$(CONFIG_SENSORS_ADM1266)	+= adm1266.o
 obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o
 obj-$(CONFIG_SENSORS_BEL_PFE)	+= bel-pfe.o
+obj-$(CONFIG_SENSORS_BPA_RS600)	+= bpa-rs600.o
 obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
 obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
 obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
diff --git a/drivers/hwmon/pmbus/bpa-rs600.c b/drivers/hwmon/pmbus/bpa-rs600.c
new file mode 100644
index 000000000000..c4ede68b3e26
--- /dev/null
+++ b/drivers/hwmon/pmbus/bpa-rs600.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for BluTek BPA-RS600 Power Supplies
+ *
+ * Copyright 2021 Allied Telesis Labs
+ */
+
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pmbus.h>
+#include "pmbus.h"
+
+#define BPARS600_MFR_VIN_MIN	0xa0
+#define BPARS600_MFR_VIN_MAX	0xa1
+#define BPARS600_MFR_IIN_MAX	0xa2
+#define BPARS600_MFR_PIN_MAX	0xa3
+#define BPARS600_MFR_VOUT_MIN	0xa4
+#define BPARS600_MFR_VOUT_MAX	0xa5
+#define BPARS600_MFR_IOUT_MAX	0xa6
+#define BPARS600_MFR_POUT_MAX	0xa7
+
+static int bpa_rs600_read_byte_data(struct i2c_client *client, int page, int reg)
+{
+	int ret;
+
+	if (page > 0)
+		return -ENXIO;
+
+	switch (reg) {
+	case PMBUS_FAN_CONFIG_12:
+		/*
+		 * Two fans are reported in PMBUS_FAN_CONFIG_12 but there is
+		 * only one fan in the module. Mask out the FAN2 bits.
+		 */
+		ret = pmbus_read_byte_data(client, 0, PMBUS_FAN_CONFIG_12);
+		if (ret >= 0)
+			ret &= ~(PB_FAN_2_INSTALLED | PB_FAN_2_PULSE_MASK);
+		break;
+	default:
+		ret = -ENODATA;
+		break;
+	}
+
+	return ret;
+}
+
+static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int phase, int reg)
+{
+	int ret;
+
+	if (page > 0)
+		return -ENXIO;
+
+	switch (reg) {
+	case PMBUS_VIN_UV_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_VIN_MIN);
+		break;
+	case PMBUS_VIN_OV_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_VIN_MAX);
+		break;
+	case PMBUS_VOUT_UV_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_VOUT_MIN);
+		break;
+	case PMBUS_VOUT_OV_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_VOUT_MAX);
+		break;
+	case PMBUS_IIN_OC_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_IIN_MAX);
+		break;
+	case PMBUS_IOUT_OC_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_IOUT_MAX);
+		break;
+	case PMBUS_PIN_OP_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_PIN_MAX);
+		break;
+	case PMBUS_POUT_OP_WARN_LIMIT:
+		ret = pmbus_read_word_data(client, 0, 0xff, BPARS600_MFR_POUT_MAX);
+		break;
+	case PMBUS_VIN_UV_FAULT_LIMIT:
+	case PMBUS_VIN_OV_FAULT_LIMIT:
+	case PMBUS_VOUT_UV_FAULT_LIMIT:
+	case PMBUS_VOUT_OV_FAULT_LIMIT:
+		/* These commands return data but it is invalid/un-documented */
+		ret = -ENXIO;
+		break;
+	default:
+		if (reg >= PMBUS_VIRT_BASE)
+			ret = -ENXIO;
+		else
+			ret = -ENODATA;
+		break;
+	}
+
+	return ret;
+}
+
+static struct pmbus_driver_info bpa_rs600_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_TEMPERATURE] = linear,
+	.format[PSC_FAN] = linear,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
+		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT |
+		PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
+		PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
+		PMBUS_HAVE_FAN12 |
+		PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
+		PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP |
+		PMBUS_HAVE_STATUS_FAN12,
+	.read_byte_data = bpa_rs600_read_byte_data,
+	.read_word_data = bpa_rs600_read_word_data,
+};
+
+static int bpa_rs600_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	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_MODEL, buf);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read Manufacturer Model\n");
+		return ret;
+	}
+
+	if (strncmp(buf, "BPA-RS600", 8)) {
+		buf[ret] = '\0';
+		dev_err(dev, "Unsupported Manufacturer Model '%s'\n", buf);
+		return -ENODEV;
+	}
+
+	return pmbus_do_probe(client, &bpa_rs600_info);
+}
+
+static const struct i2c_device_id bpa_rs600_id[] = {
+	{ "bpars600", 0 },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, bpa_rs600_id);
+
+static const struct of_device_id __maybe_unused bpa_rs600_of_match[] = {
+	{ .compatible = "blutek,bpa-rs600" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bpa_rs600_of_match);
+
+static struct i2c_driver bpa_rs600_driver = {
+	.driver = {
+		.name = "bpa-rs600",
+		.of_match_table = of_match_ptr(bpa_rs600_of_match),
+	},
+	.probe_new = bpa_rs600_probe,
+	.id_table = bpa_rs600_id,
+};
+
+module_i2c_driver(bpa_rs600_driver);
+
+MODULE_AUTHOR("Chris Packham");
+MODULE_DESCRIPTION("PMBus driver for BluTek BPA-RS600");
+MODULE_LICENSE("GPL");
-- 
2.30.2