linux/drivers/pinctrl/bcm
Stefan Wahren b83bd893f3 pinctrl: bcm2835: reduce GPPUD set-up time
Since the BCM2835 datasheet doesn't exactly specify the set-up time for
the GPIO Pull-up/down Clock Registers there was an assumption of 150 cycles
at a clock rate of 1 MHz. During a discussion [1] in the Raspberry Pi forum
it turns out that clock rate refers to the VPU which has a rate of 250 MHz.
So we can reduce the delay to a sensible value and update the comment above.

I tested this optimization with a Raspberry Pi B and a multimeter.

[1] - https://www.raspberrypi.org/forums/viewtopic.php?f=72&t=163352

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-11-04 16:28:28 +01:00
..
Kconfig pinctrl: bcm: add OF dependencies 2016-07-22 16:43:32 +02:00
Makefile pinctrl: nsp: add pinmux driver support for Broadcom NSP SoC 2016-06-29 10:06:00 +02:00
pinctrl-bcm281xx.c pinctrl: bcm281xx: constify pinctrl_ops and pinmux_ops structures 2016-09-07 22:41:30 +02:00
pinctrl-bcm2835.c pinctrl: bcm2835: reduce GPPUD set-up time 2016-11-04 16:28:28 +01:00
pinctrl-cygnus-mux.c pinctrl: cygnus-mux: Use devm_pinctrl_register() for pinctrl registration 2016-04-21 00:02:00 +02:00
pinctrl-iproc-gpio.c pinctrl: iproc: Add NSP and Stingray GPIO support 2016-07-22 16:47:51 +02:00
pinctrl-ns2-mux.c pinctrl: ns2: constify pinctrl_ops and pinmux_ops structures 2016-09-07 22:39:44 +02:00
pinctrl-nsp-gpio.c pinctrl: nsp-gpio: fix non-static functions 2016-06-08 14:09:49 +02:00
pinctrl-nsp-mux.c pinctrl: nsp: constify pinctrl_ops and pinmux_ops structures 2016-09-07 22:40:40 +02:00