[PATCH v2 2/3] hwmon: (pmbus): Add POWER system power supply driver

[Eddie James <eajames-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>]

From: "Edward A. James" <eajames-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>

Add the driver to monitor POWER system power supplies with hwmon over
pmbus.

Signed-off-by: Edward A. James <eajames-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---
 drivers/hwmon/pmbus/Kconfig   |  10 +++
 drivers/hwmon/pmbus/Makefile  |   1 +
 drivers/hwmon/pmbus/powerps.c | 144 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 155 insertions(+)
 create mode 100644 drivers/hwmon/pmbus/powerps.c

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 68d717a..8925c1a 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -125,6 +125,16 @@ config SENSORS_MAX8688
 	  This driver can also be built as a module. If so, the module will
 	  be called max8688.
 
+config SENSORS_POWERPS
+	tristate "IBM POWER System Power Supply"
+	default n
+	help
+	  If you say yes here you get hardware monitoring support for the IBM
+	  POWER system power supply.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called powerps.
+
 config SENSORS_TPS40422
 	tristate "TI TPS40422"
 	default n
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 75bb7ca..3303af5 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_SENSORS_MAX16064)	+= max16064.o
 obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
 obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
 obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
+obj-$(CONFIG_SENSORS_POWERPS)	+= powerps.o
 obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
 obj-$(CONFIG_SENSORS_UCD9000)	+= ucd9000.o
 obj-$(CONFIG_SENSORS_UCD9200)	+= ucd9200.o
diff --git a/drivers/hwmon/pmbus/powerps.c b/drivers/hwmon/pmbus/powerps.c
new file mode 100644
index 0000000..21d28f2
--- /dev/null
+++ b/drivers/hwmon/pmbus/powerps.c
@@ -0,0 +1,144 @@
+/*
+ * 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/device.h>
+#include <linux/i2c.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+
+#include "pmbus.h"
+
+/* STATUS_MFR_SPECIFIC bits */
+#define POWERPS_MFR_FAN_FAULT			BIT(0)
+#define POWERPS_MFR_THERMAL_FAULT		BIT(1)
+#define POWERPS_MFR_OV_FAULT			BIT(2)
+#define POWERPS_MFR_UV_FAULT			BIT(3)
+#define POWERPS_MFR_PS_KILL			BIT(4)
+#define POWERPS_MFR_OC_FAULT			BIT(5)
+#define POWERPS_MFR_VAUX_FAULT			BIT(6)
+#define POWERPS_MFR_CURRENT_SHARE_WARNING	BIT(7)
+
+static int powerps_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 rc;
+
+		/* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
+		if (reg == PMBUS_STATUS_FAN_12) {
+			if (mfr & POWERPS_MFR_FAN_FAULT)
+				rc |= PB_FAN_FAN1_FAULT;
+		} else if (reg == PMBUS_STATUS_TEMPERATURE) {
+			if (mfr & POWERPS_MFR_THERMAL_FAULT)
+				rc |= PB_TEMP_OT_FAULT;
+		} else if (reg == PMBUS_STATUS_VOUT) {
+			if (mfr &
+			    (POWERPS_MFR_OV_FAULT | POWERPS_MFR_VAUX_FAULT))
+				rc |= PB_VOLTAGE_OV_FAULT;
+			if (mfr & POWERPS_MFR_UV_FAULT)
+				rc |= PB_VOLTAGE_UV_FAULT;
+		} else if (reg == PMBUS_STATUS_IOUT) {
+			if (mfr & POWERPS_MFR_OC_FAULT)
+				rc |= PB_IOUT_OC_FAULT;
+			if (mfr & POWERPS_MFR_CURRENT_SHARE_WARNING)
+				rc |= PB_CURRENT_SHARE_FAULT;
+		}
+		break;
+	default:
+		rc = -ENODATA;
+		break;
+	}
+
+	return rc;
+}
+
+static int powerps_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 rc;
+
+		if (mfr & POWERPS_MFR_PS_KILL)
+			rc |= PB_STATUS_OFF;
+		break;
+	default:
+		rc = -ENODATA;
+		break;
+	}
+
+	return rc;
+}
+
+static struct pmbus_driver_info powerps_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 = powerps_read_byte_data,
+	.read_word_data = powerps_read_word_data,
+	.debugfs = true,
+};
+
+static int powerps_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	return pmbus_do_probe(client, id, &powerps_info);
+}
+
+static const struct i2c_device_id powerps_id[] = {
+	{ "power_ps", 1 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, powerps_id);
+
+/* IBM provides many compatible power supplies; use a generic name. */
+static const struct of_device_id powerps_of_match[] = {
+	{ .compatible = "ibm,power-ps" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, powerps_of_match);
+
+static struct i2c_driver powerps_driver = {
+	.driver = {
+		.name = "powerps",
+		.of_match_table = powerps_of_match,
+	},
+	.probe = powerps_probe,
+	.remove = pmbus_do_remove,
+	.id_table = powerps_id,
+};
+
+module_i2c_driver(powerps_driver);
+
+MODULE_AUTHOR("Eddie James");
+MODULE_DESCRIPTION("PMBus driver for POWER system power supplies");
+MODULE_LICENSE("GPL");
-- 
1.8.3.1

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