hwmon: (pmbus) Add IBM Common Form Factor (CFF) power supply driver

Add the driver to monitor IBM CFF power supplies with hwmon over
pmbus.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
[groeck: drop 'default n'; include bitops.h instead of jiffies.h]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/Kconfig

@@ -37,6 +37,15 @@ config SENSORS_ADM1275
 	  This driver can also be built as a module. If so, the module will
 	  be called adm1275.
 
+config SENSORS_IBM_CFFPS
+	tristate "IBM Common Form Factor Power Supply"
+	help
+	  If you say yes here you get hardware monitoring support for the IBM
+	  Common Form Factor power supply.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called ibm-cffps.
+
 config SENSORS_IR35221
 	tristate "Infineon IR35221"
 	default n

drivers/hwmon/pmbus/Makefile

@@ -5,6 +5,7 @@
 obj-$(CONFIG_PMBUS)		+= pmbus_core.o
 obj-$(CONFIG_SENSORS_PMBUS)	+= pmbus.o
 obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o
+obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
 obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
 obj-$(CONFIG_SENSORS_LM25066)	+= lm25066.o
 obj-$(CONFIG_SENSORS_LTC2978)	+= ltc2978.o

drivers/hwmon/pmbus/ibm-cffps.c

@@ -0,0 +1,151 @@
+/*
+ * Copyright 2017 IBM Corp.
+ *
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include "pmbus.h"
+
+/* STATUS_MFR_SPECIFIC bits */
+#define CFFPS_MFR_FAN_FAULT			BIT(0)
+#define CFFPS_MFR_THERMAL_FAULT			BIT(1)
+#define CFFPS_MFR_OV_FAULT			BIT(2)
+#define CFFPS_MFR_UV_FAULT			BIT(3)
+#define CFFPS_MFR_PS_KILL			BIT(4)
+#define CFFPS_MFR_OC_FAULT			BIT(5)
+#define CFFPS_MFR_VAUX_FAULT			BIT(6)
+#define CFFPS_MFR_CURRENT_SHARE_WARNING		BIT(7)
+
+static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
+				    int reg)
+{
+	int rc, mfr;
+
+	switch (reg) {
+	case PMBUS_STATUS_VOUT:
+	case PMBUS_STATUS_IOUT:
+	case PMBUS_STATUS_TEMPERATURE:
+	case PMBUS_STATUS_FAN_12:
+		rc = pmbus_read_byte_data(client, page, reg);
+		if (rc < 0)
+			return rc;
+
+		mfr = pmbus_read_byte_data(client, page,
+					   PMBUS_STATUS_MFR_SPECIFIC);
+		if (mfr < 0)
+			/*
+			 * Return the status register instead of an error,
+			 * since we successfully read status.
+			 */
+			return rc;
+
+		/* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
+		if (reg == PMBUS_STATUS_FAN_12) {
+			if (mfr & CFFPS_MFR_FAN_FAULT)
+				rc |= PB_FAN_FAN1_FAULT;
+		} else if (reg == PMBUS_STATUS_TEMPERATURE) {
+			if (mfr & CFFPS_MFR_THERMAL_FAULT)
+				rc |= PB_TEMP_OT_FAULT;
+		} else if (reg == PMBUS_STATUS_VOUT) {
+			if (mfr & (CFFPS_MFR_OV_FAULT | CFFPS_MFR_VAUX_FAULT))
+				rc |= PB_VOLTAGE_OV_FAULT;
+			if (mfr & CFFPS_MFR_UV_FAULT)
+				rc |= PB_VOLTAGE_UV_FAULT;
+		} else if (reg == PMBUS_STATUS_IOUT) {
+			if (mfr & CFFPS_MFR_OC_FAULT)
+				rc |= PB_IOUT_OC_FAULT;
+			if (mfr & CFFPS_MFR_CURRENT_SHARE_WARNING)
+				rc |= PB_CURRENT_SHARE_FAULT;
+		}
+		break;
+	default:
+		rc = -ENODATA;
+		break;
+	}
+
+	return rc;
+}
+
+static int ibm_cffps_read_word_data(struct i2c_client *client, int page,
+				    int reg)
+{
+	int rc, mfr;
+
+	switch (reg) {
+	case PMBUS_STATUS_WORD:
+		rc = pmbus_read_word_data(client, page, reg);
+		if (rc < 0)
+			return rc;
+
+		mfr = pmbus_read_byte_data(client, page,
+					   PMBUS_STATUS_MFR_SPECIFIC);
+		if (mfr < 0)
+			/*
+			 * Return the status register instead of an error,
+			 * since we successfully read status.
+			 */
+			return rc;
+
+		if (mfr & CFFPS_MFR_PS_KILL)
+			rc |= PB_STATUS_OFF;
+		break;
+	default:
+		rc = -ENODATA;
+		break;
+	}
+
+	return rc;
+}
+
+static struct pmbus_driver_info ibm_cffps_info = {
+	.pages = 1,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
+		PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
+		PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
+		PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
+		PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_FAN12,
+	.read_byte_data = ibm_cffps_read_byte_data,
+	.read_word_data = ibm_cffps_read_word_data,
+};
+
+static int ibm_cffps_probe(struct i2c_client *client,
+			   const struct i2c_device_id *id)
+{
+	return pmbus_do_probe(client, id, &ibm_cffps_info);
+}
+
+static const struct i2c_device_id ibm_cffps_id[] = {
+	{ "ibm_cffps1", 1 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ibm_cffps_id);
+
+static const struct of_device_id ibm_cffps_of_match[] = {
+	{ .compatible = "ibm,cffps1" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, ibm_cffps_of_match);
+
+static struct i2c_driver ibm_cffps_driver = {
+	.driver = {
+		.name = "ibm-cffps",
+		.of_match_table = ibm_cffps_of_match,
+	},
+	.probe = ibm_cffps_probe,
+	.remove = pmbus_do_remove,
+	.id_table = ibm_cffps_id,
+};
+
+module_i2c_driver(ibm_cffps_driver);
+
+MODULE_AUTHOR("Eddie James");
+MODULE_DESCRIPTION("PMBus driver for IBM Common Form Factor power supplies");
+MODULE_LICENSE("GPL");