hwmon: add Corsair Commander Pro driver

This is v7 of a driver for the Corsair Commander Pro.
It provides sysfs attributes for:
- Reading fan speed
- Reading temp sensors
- Reading voltage values
- Writing pwm and reading last written pwm
- Reading fan and temp connection status

It is an usb driver, so it needs to be ignored by usbhid.
The Corsair Commander Pro is a fan controller and provides
no means for user interaction.
The two device numbers are there, because there is a slightly
different version of the same device. (Only difference
seem to be in some presets.)

Squashed:
 hwmon: (corsair-cpro) add fan_target

 This adds fan_target entries to the corsair-cpro driver.
 Reading the attribute from the device does not seem possible, so
 it returns the last set value (same as pwm).

 send_usb_cmd now has one more argument, which is needed for the
 fan_target command.

 hwmon: corsair-cpro: Change to HID driver

 This changes corsair-cpro to a hid driver using hid reports.

Signed-off-by: Marius Zachmann <mail@mariuszachmann.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200626055936.4441-1-mail@mariuszachmann.de
Link: https://lore.kernel.org/r/20200709141413.30790-1-mail@mariuszachmann.de
[groeck: Squashed follow-up patches to avoid changes in HID code]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index d53db30d1365..06607125b793 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4401,6 +4401,12 @@ S:	Maintained
 F:	Documentation/hwmon/coretemp.rst
 F:	drivers/hwmon/coretemp.c
 
+CORSAIR-CPRO HARDWARE MONITOR DRIVER
+M:	Marius  <mail@mariuszachmann.de>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	drivers/hwmon/corsair-cpro.c
+
 COSA/SRP SYNC SERIAL DRIVER
 M:	Jan "Yenya" Kasprzak <kas@fi.muni.cz>
 S:	Maintained