gpio: Add gpio-charger to the documentation

The GPIO-based charger is another of the helpful devices built
on top of GPIO.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20200620201248.28843-1-linus.walleij@linaro.org

diff --git a/Documentation/driver-api/gpio/drivers-on-gpio.rst b/Documentation/driver-api/gpio/drivers-on-gpio.rst
index 820b403..41ec3cc 100644 (file)
--- a/Documentation/driver-api/gpio/drivers-on-gpio.rst
+++ b/Documentation/driver-api/gpio/drivers-on-gpio.rst
@@ -89,6 +89,13 @@ hardware descriptions such as device tree or ACPI:
   Consumer Electronics Control bus using only GPIO. It is used to communicate
   with devices on the HDMI bus.
 
   Consumer Electronics Control bus using only GPIO. It is used to communicate
   with devices on the HDMI bus.
 

+- gpio-charger: drivers/power/supply/gpio-charger.c is used if you need to do
+  battery charging and all you have to go by to check the presence of the
+  AC charger or more complex tasks such as indicating charging status using
+  nothing but GPIO lines, this driver provides that and also a clearly defined
+  way to pass the charging parameters from hardware descriptions such as the
+  device tree.
+

 Apart from this there are special GPIO drivers in subsystems like MMC/SD to
 read card detect and write protect GPIO lines, and in the TTY serial subsystem
 to emulate MCTRL (modem control) signals CTS/RTS by using two GPIO lines. The
 Apart from this there are special GPIO drivers in subsystems like MMC/SD to
 read card detect and write protect GPIO lines, and in the TTY serial subsystem
 to emulate MCTRL (modem control) signals CTS/RTS by using two GPIO lines. The