On Saturday 05 November 2016 03:50 AM, Linus Walleij wrote:
On Wed, Nov 2, 2016 at 1:17 PM, Laxman Dewangan <ldewangan@xxxxxxxxxx> wrote:
Many of devices/SoCs supports the GPIO and special IO function
from their pins. On such cases, there is always configuration
bits to select the mode of pin as GPIO or as the special IO mode.
The functional modes are selected by pinmux option.
When device booted and reach to kernel, it is not possible to get
the current configuration of pin whether it is in GPIO mode or
in special IO mode without configurations.
Add APIs to return the current mode of pins without requesting it
as GPIO to find out the current mode.
This helps on dumping the pin configuration from debug/test utility
to get the current mode GPIO or functional mode.
The typical utility looks as:
pin_dump(pin)
{
if(gpio_is_enabled(pin)) {
dump direction using get_direction()
} else {
dump pinmux option and its configurations.
}
}
Yeah but since pinctrl and pinmux has its own debugfs files why is this
necessary? I understand it is convenient but only for debugging
right? They the inconvenience of using pinctrls debugfs files should
be bearable.
Yes, it is debugging and capturing all the info at single place.
Currently, gpio debugFs shows the gpio related stuff and the pinctrl on
pinconfig but there is not any dump which shows the complete pin mapping.
The effort is to compile all the data in single place with proper
message to avoid any manual work for decoding multiple outputs.
Also it is possible for any GPIO chip to implement its own
debug print if they like, check what we do in
->dbg_show in drivers/pinctrl/nomadik/pinctrl-nomadik.c
for example.
If the use is for debug prints, keep it driver-local.
(...)
This callback can print the stuff for GPIO related stuff as there is not
much info about the pinmux related configuration to gpio driver. For
GPIO or functional mode, it can only display gpio or functional mode.
Is there something we can link from gpio driver to pinctrl driver like
pinctrl_debug_show()?
Like in gpio_request(), we say that pinctrl_request(), similary on the
GPIO dbg_show(), we can say pinctrl_dbg_show() and get all the info for
prints.
This will also serve the purpose.
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