hwmon: Driver for Maxim MAX6639

2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

Documentation/hwmon/max6639

+Kernel driver max6639
+=====================
+
+Supported chips:
+  * Maxim MAX6639
+    Prefix: 'max6639'
+    Addresses scanned: I2C 0x2c, 0x2e, 0x2f
+    Datasheet: http://pdfserv.maxim-ic.com/en/ds/MAX6639.pdf
+
+Authors:
+    He Changqing <hechangqing@semptian.com>
+    Roland Stigge <stigge@antcom.de>
+
+Description
+-----------
+
+This driver implements support for the Maxim MAX6639. This chip is a 2-channel
+temperature monitor with dual PWM fan speed controller. It can monitor its own
+temperature and one external diode-connected transistor or two external
+diode-connected transistors.
+
+The following device attributes are implemented via sysfs:
+
+Attribute              R/W  Contents
+----------------------------------------------------------------------------
+temp1_input            R    Temperature channel 1 input (0..150 C)
+temp2_input            R    Temperature channel 2 input (0..150 C)
+temp1_fault            R    Temperature channel 1 diode fault
+temp2_fault            R    Temperature channel 2 diode fault
+temp1_max              RW   Set THERM temperature for input 1
+                            (in C, see datasheet)
+temp2_max              RW   Set THERM temperature for input 2
+temp1_crit             RW   Set ALERT temperature for input 1
+temp2_crit             RW   Set ALERT temperature for input 2
+temp1_emergency        RW   Set OT temperature for input 1
+                            (in C, see datasheet)
+temp2_emergency        RW   Set OT temperature for input 2
+pwm1                   RW   Fan 1 target duty cycle (0..255)
+pwm2                   RW   Fan 2 target duty cycle (0..255)
+fan1_input             R    TACH1 fan tachometer input (in RPM)
+fan2_input             R    TACH2 fan tachometer input (in RPM)
+fan1_fault             R    Fan 1 fault
+fan2_fault             R    Fan 2 fault
+temp1_max_alarm        R    Alarm on THERM temperature on channel 1
+temp2_max_alarm        R    Alarm on THERM temperature on channel 2
+temp1_crit_alarm       R    Alarm on ALERT temperature on channel 1
+temp2_crit_alarm       R    Alarm on ALERT temperature on channel 2
+temp1_emergency_alarm  R    Alarm on OT temperature on channel 1
+temp2_emergency_alarm  R    Alarm on OT temperature on channel 2

drivers/hwmon/Kconfig

@@ -685,6 +685,16 @@ config SENSORS_MAX1619
 	  This driver can also be built as a module.  If so, the module
 	  will be called max1619.
 
+config SENSORS_MAX6639
+	tristate "Maxim MAX6639 sensor chip"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the MAX6639
+	  sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called max6639.
+
 config SENSORS_MAX6650
 	tristate "Maxim MAX6650 sensor chip"
 	depends on I2C && EXPERIMENTAL

drivers/hwmon/Makefile

@@ -84,6 +84,7 @@ obj-$(CONFIG_SENSORS_LTC4245)	+= ltc4245.o
 obj-$(CONFIG_SENSORS_LTC4261)	+= ltc4261.o
 obj-$(CONFIG_SENSORS_MAX1111)	+= max1111.o
 obj-$(CONFIG_SENSORS_MAX1619)	+= max1619.o
+obj-$(CONFIG_SENSORS_MAX6639)	+= max6639.o
 obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o

include/linux/i2c/max6639.h

+#ifndef _LINUX_MAX6639_H
+#define _LINUX_MAX6639_H
+
+#include <linux/types.h>
+
+/* platform data for the MAX6639 temperature sensor and fan control */
+
+struct max6639_platform_data {
+	bool pwm_polarity;	/* Polarity low (0) or high (1, default) */
+	int ppr;		/* Pulses per rotation 1..4 (default == 2) */
+	int rpm_range;		/* 2000, 4000 (default), 8000 or 16000 */
+};
+
+#endif /* _LINUX_MAX6639_H */