hwmon: (pmbus/ir38064) Add driver for Infineon IR38064 Voltage Regulator

Add the pmbus driver for the Infineon ir38064 voltage regulator.

VOUT_MODE is not supported by the device.  The driver fakes linear16
mode with exponent value -8.

The device supports VOUT_PEAK, IOUT_PEAK, and TEMPERATURE_PEAK, however
this driver does not enable them.

Signed-off-by: Maxim Sloyko <maxims@google.com>
Signed-off-by: Patrick Venture <venture@google.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

4 files changed, 139 insertions, 0 deletions

diff --git a/Documentation/hwmon/ir38064 b/Documentation/hwmon/ir38064
new file mode 100644
index 000000000000..c3697d7aaaa4
--- /dev/null
+++ b/Documentation/hwmon/ir38064
@@ -0,0 +1,64 @@
+Kernel driver ir38064
+=====================
+
+Supported chips:
+  * Infineon IR38064
+    Prefix: 'ir38064'
+    Addresses scanned: -
+    Datasheet: Publicly available at the Infineon webiste
+      https://www.infineon.com/dgdl/Infineon-IR38064MTRPBF-DS-v03_07-EN.pdf?fileId=5546d462584d1d4a0158db0d9efb67ca
+
+Datasheet is not publicly available.
+
+
+Authors:
+        Maxim Sloyko <maxims@google.com>
+        Patrick Venture <venture@google.com>
+
+Description
+-----------
+
+IR38064 is a Single-input Voltage, Synchronous Buck Regulator, DC-DC Converter.
+
+Usage Notes
+-----------
+
+This driver does not probe for PMBus devices. You will have to instantiate
+devices explicitly.
+
+Sysfs attributes
+----------------
+
+curr1_label             "iout1"
+curr1_input             Measured output current
+curr1_crit              Critical maximum current
+curr1_crit_alarm        Current critical high alarm
+curr1_max               Maximum current
+curr1_max_alarm Current high alarm
+
+in1_label               "vin"
+in1_input               Measured input voltage
+in1_crit                Critical maximum input voltage
+in1_crit_alarm          Input voltage critical high alarm
+in1_min         Minimum input voltage
+in1_min_alarm           Input voltage low alarm
+
+in2_label               "vout1"
+in2_input               Measured output voltage
+in2_lcrit               Critical minimum output voltage
+in2_lcrit_alarm Output voltage critical low alarm
+in2_crit                Critical maximum output voltage
+in2_crit_alarm          Output voltage critical high alarm
+in2_max         Maximum output voltage
+in2_max_alarm           Output voltage high alarm
+in2_min         Minimum output voltage
+in2_min_alarm           Output voltage low alarm
+
+power1_label            "pout1"
+power1_input            Measured output power
+
+temp1_input             Measured temperature
+temp1_crit              Critical high temperature
+temp1_crit_alarm        Chip temperature critical high alarm
+temp1_max               Maximum temperature
+temp1_max_alarm Chip temperature high alarm
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 629cb45f8557..de87abab990e 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -54,6 +54,15 @@ config SENSORS_IR35221
           This driver can also be built as a module. If so, the module will
           be called ir35521.
 
+config SENSORS_IR38064
+        tristate "Infineon IR38064"
+        help
+          If you say yes here you get hardware monitoring support for Infineon
+          IR38064.
+
+          This driver can also be built as a module. If so, the module will
+          be called ir38064.
+
 config SENSORS_LM25066
         tristate "National Semiconductor LM25066 and compatibles"
         help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index ea0e39518c21..7d1fa6b3c8c9 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -8,6 +8,7 @@ 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-$(CONFIG_SENSORS_IR38064)   += ir38064.o
 obj-$(CONFIG_SENSORS_LM25066)   += lm25066.o
 obj-$(CONFIG_SENSORS_LTC2978)   += ltc2978.o
 obj-$(CONFIG_SENSORS_LTC3815)   += ltc3815.o
diff --git a/drivers/hwmon/pmbus/ir38064.c b/drivers/hwmon/pmbus/ir38064.c
new file mode 100644
index 000000000000..1820f5077f66
--- /dev/null
+++ b/drivers/hwmon/pmbus/ir38064.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hardware monitoring driver for Infineon IR38064
+ *
+ * Copyright (c) 2017 Google Inc
+ *
+ * VOUT_MODE is not supported by the device. The driver fakes VOUT linear16
+ * mode with exponent value -8 as direct mode with m=256/b=0/R=0.
+ *          
+ * The device supports VOUT_PEAK, IOUT_PEAK, and TEMPERATURE_PEAK, however
+ * this driver does not currently support them.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include "pmbus.h"
+
+static struct pmbus_driver_info ir38064_info = {
+        .pages = 1,
+        .format[PSC_VOLTAGE_IN] = linear,
+        .format[PSC_VOLTAGE_OUT] = direct,
+        .format[PSC_CURRENT_OUT] = linear,
+        .format[PSC_POWER] = linear,
+        .format[PSC_TEMPERATURE] = linear,
+        .m[PSC_VOLTAGE_OUT] = 256,
+        .b[PSC_VOLTAGE_OUT] = 0,
+        .R[PSC_VOLTAGE_OUT] = 0,
+        .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+            | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
+            | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+            | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+            | PMBUS_HAVE_POUT,
+};
+
+static int ir38064_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+        return pmbus_do_probe(client, id, &ir38064_info);
+}
+
+static const struct i2c_device_id ir38064_id[] = {
+        {"ir38064", 0},
+        {}
+};
+
+MODULE_DEVICE_TABLE(i2c, ir38064_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver ir38064_driver = {
+        .driver = {
+                   .name = "ir38064",
+                   },
+        .probe = ir38064_probe,
+        .remove = pmbus_do_remove,
+        .id_table = ir38064_id,
+};
+
+module_i2c_driver(ir38064_driver);
+
+MODULE_AUTHOR("Maxim Sloyko <maxims@google.com>");
+MODULE_DESCRIPTION("PMBus driver for Infineon IR38064");
+MODULE_LICENSE("GPL");