hwmon: (pmbus) Add tps40422 front-end driver

For TI power management chip TPS40422, READ_TEMPERATURE_2 command is supported on
page 1 of the chip, but the original driver(pmbus.c) only tried to detect this command
on page 0, this will lead to a result that the temperature sensor in page 1 couldn't
be detected. This change is to isolate the tps40422 driver from pmbus.c into a solo
front-end driver.

Signed-off-by: Zhu Laiwen <richard.zhu@nsn.com>
[Guenter Roeck: Dropped unnecessary license text (fixes checkpatch warning)]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

6 files changed, 142 insertions, 6 deletions

diff --git a/Documentation/hwmon/pmbus b/Documentation/hwmon/pmbus
index cf756ed48ff9..a3557da8f5b4 100644
--- a/Documentation/hwmon/pmbus
+++ b/Documentation/hwmon/pmbus
@@ -23,12 +23,11 @@ Supported chips:
         http://www.lineagepower.com/oem/pdf/PDT012A0X.pdf
         http://www.lineagepower.com/oem/pdf/UDT020A0X.pdf
         http://www.lineagepower.com/oem/pdf/MDT040A0X.pdf
-  * Texas Instruments TPS40400, TPS40422
-    Prefixes: 'tps40400', 'tps40422'
+  * Texas Instruments TPS40400
+    Prefixes: 'tps40400'
     Addresses scanned: -
     Datasheets:
         http://www.ti.com/lit/gpn/tps40400
-        http://www.ti.com/lit/gpn/tps40422
   * Generic PMBus devices
     Prefix: 'pmbus'
     Addresses scanned: -
diff --git a/Documentation/hwmon/tps40422 b/Documentation/hwmon/tps40422
new file mode 100644
index 000000000000..24bb0688d515
--- /dev/null
+++ b/Documentation/hwmon/tps40422
@@ -0,0 +1,64 @@
+Kernel driver tps40422
+======================
+
+Supported chips:
+  * TI TPS40422
+    Prefix: 'tps40422'
+    Addresses scanned: -
+    Datasheet: http://www.ti.com/lit/gpn/tps40422
+
+Author: Zhu Laiwen <richard.zhu@nsn.com>
+
+
+Description
+-----------
+
+This driver supports TI TPS40422 Dual-Output or Two-Phase Synchronous Buck
+Controller with PMBus
+
+The driver is a client driver to the core PMBus driver.
+Please see Documentation/hwmon/pmbus for details on PMBus client drivers.
+
+
+Usage Notes
+-----------
+
+This driver does not auto-detect devices. You will have to instantiate the
+devices explicitly. Please see Documentation/i2c/instantiating-devices for
+details.
+
+
+Platform data support
+---------------------
+
+The driver supports standard PMBus driver platform data.
+
+
+Sysfs entries
+-------------
+
+The following attributes are supported.
+
+in[1-2]_label           "vout[1-2]"
+in[1-2]_input           Measured voltage. From READ_VOUT register.
+in[1-2]_alarm           voltage alarm.
+
+curr[1-2]_input         Measured current. From READ_IOUT register.
+curr[1-2]_label         "iout[1-2]"
+curr1_max               Maximum current. From IOUT_OC_WARN_LIMIT register.
+curr1_crit              Critical maximum current. From IOUT_OC_FAULT_LIMIT register.
+curr1_max_alarm         Current high alarm. From IOUT_OC_WARN_LIMIT status.
+curr1_crit_alarm        Current critical high alarm. From IOUT_OC_FAULT status.
+curr2_alarm             Current high alarm. From IOUT_OC_WARNING status.
+
+temp1_input             Measured temperature. From READ_TEMPERATURE_2 register on page 0.
+temp1_max               Maximum temperature. From OT_WARN_LIMIT register.
+temp1_crit              Critical high temperature. From OT_FAULT_LIMIT register.
+temp1_max_alarm         Chip temperature high alarm. Set by comparing
+                        READ_TEMPERATURE_2 on page 0 with OT_WARN_LIMIT if TEMP_OT_WARNING
+                        status is set.
+temp1_crit_alarm        Chip temperature critical high alarm. Set by comparing
+                        READ_TEMPERATURE_2 on page 0 with OT_FAULT_LIMIT if TEMP_OT_FAULT
+                        status is set.
+temp2_input             Measured temperature. From READ_TEMPERATURE_2 register on page 1.
+temp2_alarm             Chip temperature alarm on page 1.
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 39cc63edfbb0..6e1e4935fc62 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -20,8 +20,7 @@ config SENSORS_PMBUS
         help
           If you say yes here you get hardware monitoring support for generic
           PMBus devices, including but not limited to ADP4000, BMR453, BMR454,
-          MDT040, NCP4200, NCP4208, PDT003, PDT006, PDT012, UDT020, TPS40400,
-          and TPS40422.
+          MDT040, NCP4200, NCP4208, PDT003, PDT006, PDT012, UDT020, and TPS40400.
 
           This driver can also be built as a module. If so, the module will
           be called pmbus.
@@ -87,6 +86,16 @@ config SENSORS_MAX8688
           This driver can also be built as a module. If so, the module will
           be called max8688.
 
+config SENSORS_TPS40422
+        tristate "TI TPS40422"
+        default n
+        help
+          If you say yes here you get hardware monitoring support for TI
+          TPS40422.
+
+          This driver can also be built as a module. If so, the module will
+          be called tps40422.
+
 config SENSORS_UCD9000
         tristate "TI UCD90120, UCD90124, UCD9090, UCD90910"
         default n
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 789376c85dbb..1454293e985c 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_SENSORS_LTC2978)	+= ltc2978.o
 obj-$(CONFIG_SENSORS_MAX16064)  += max16064.o
 obj-$(CONFIG_SENSORS_MAX34440)  += max34440.o
 obj-$(CONFIG_SENSORS_MAX8688)   += max8688.o
+obj-$(CONFIG_SENSORS_TPS40422)  += tps40422.o
 obj-$(CONFIG_SENSORS_UCD9000)   += ucd9000.o
 obj-$(CONFIG_SENSORS_UCD9200)   += ucd9200.o
 obj-$(CONFIG_SENSORS_ZL6100)    += zl6100.o
diff --git a/drivers/hwmon/pmbus/pmbus.c b/drivers/hwmon/pmbus/pmbus.c
index 7e91700131a7..554d0249dcde 100644
--- a/drivers/hwmon/pmbus/pmbus.c
+++ b/drivers/hwmon/pmbus/pmbus.c
@@ -193,7 +193,6 @@ static const struct i2c_device_id pmbus_id[] = {
         {"pdt012", 1},
         {"pmbus", 0},
         {"tps40400", 1},
-        {"tps40422", 2},
         {"udt020", 1},
         {}
 };
diff --git a/drivers/hwmon/pmbus/tps40422.c b/drivers/hwmon/pmbus/tps40422.c
new file mode 100644
index 000000000000..32803825d47e
--- /dev/null
+++ b/drivers/hwmon/pmbus/tps40422.c
@@ -0,0 +1,64 @@
+/*
+ * Hardware monitoring driver for TI TPS40422
+ *
+ * Copyright (c) 2014 Nokia Solutions and Networks.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include "pmbus.h"
+
+static struct pmbus_driver_info tps40422_info = {
+        .pages = 2,
+        .format[PSC_VOLTAGE_IN] = linear,
+        .format[PSC_VOLTAGE_OUT] = linear,
+        .format[PSC_TEMPERATURE] = linear,
+        .func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_TEMP2
+                | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_TEMP
+                | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT,
+        .func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_TEMP2
+                | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_TEMP
+                | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT,
+};
+
+static int tps40422_probe(struct i2c_client *client,
+                          const struct i2c_device_id *id)
+{
+        return pmbus_do_probe(client, id, &tps40422_info);
+}
+
+static const struct i2c_device_id tps40422_id[] = {
+        {"tps40422", 0},
+        {}
+};
+
+MODULE_DEVICE_TABLE(i2c, tps40422_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver tps40422_driver = {
+        .driver = {
+                   .name = "tps40422",
+                   },
+        .probe = tps40422_probe,
+        .remove = pmbus_do_remove,
+        .id_table = tps40422_id,
+};
+
+module_i2c_driver(tps40422_driver);
+
+MODULE_AUTHOR("Zhu Laiwen <richard.zhu@nsn.com>");
+MODULE_DESCRIPTION("PMBus driver for TI TPS40422");
+MODULE_LICENSE("GPL");