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>

3 files changed, 161 insertions, 0 deletions

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 68d717a3fd59..522ac37d8a69 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/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
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 75bb7ca619d9..737fa4efb3cc 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/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
diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c
new file mode 100644
index 000000000000..cb56da6834e5
--- /dev/null
+++ b/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");