diff options
| author | Simon Glass <sjg@chromium.org> | 2021-02-04 21:22:09 -0700 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2021-03-03 15:40:47 -0500 |
| commit | 8a45b2205749252f61d26508d5de9dcce020b2ef (patch) | |
| tree | fac56f635fb7a10236dd41868a0b1629184ab39c /arch/sandbox | |
| parent | be04f1ab4291c724a65d86a743b8b7938f15a54c (diff) | |
| download | u-boot-8a45b2205749252f61d26508d5de9dcce020b2ef.zip u-boot-8a45b2205749252f61d26508d5de9dcce020b2ef.tar.gz u-boot-8a45b2205749252f61d26508d5de9dcce020b2ef.tar.bz2 | |
gpio: Add a way to read 3-way strapping pinsWIP/2021-03-03-gpio-improvements
Using the internal vs. external pull resistors it is possible to get
27 different combinations from 3 strapping pins. Add an implementation
of this.
This involves updating the sandbox GPIO driver to model external and
(weaker) internal pull resistors. The get_value() method now takes account
of what is driving a pin:
sandbox: GPIOD_EXT_DRIVEN - in which case GPIO_EXT_HIGH provides the
value
outside source - in which case GPIO_EXT_PULL_UP/DOWN indicates the
external state and we work the final state using those flags and
the internal GPIOD_PULL_UP/DOWN flags
Of course the outside source does not really exist in sandbox. We are just
modelling it for test purpose.
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/sandbox')
| -rw-r--r-- | arch/sandbox/include/asm/gpio.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/sandbox/include/asm/gpio.h b/arch/sandbox/include/asm/gpio.h index 33b83ea..9e10052 100644 --- a/arch/sandbox/include/asm/gpio.h +++ b/arch/sandbox/include/asm/gpio.h @@ -26,8 +26,11 @@ /* Our own private GPIO flags, which musn't conflict with GPIOD_... */ #define GPIOD_EXT_HIGH BIT(31) /* external source is high (else low) */ #define GPIOD_EXT_DRIVEN BIT(30) /* external source is driven */ +#define GPIOD_EXT_PULL_UP BIT(29) /* GPIO has external pull-up */ +#define GPIOD_EXT_PULL_DOWN BIT(28) /* GPIO has external pull-down */ -#define GPIOD_SANDBOX_MASK GENMASK(31, 30) +#define GPIOD_EXT_PULL (BIT(28) | BIT(29)) +#define GPIOD_SANDBOX_MASK GENMASK(31, 28) /** * Return the simulated value of a GPIO (used only in sandbox test code) |