On Monday 23 September 2013 02:56 PM, Linus Walleij wrote:
On Mon, Sep 23, 2013 at 10:55 AM, Laxman Dewangan <ldewangan@xxxxxxxxxx> wrote:
On Monday 23 September 2013 01:36 PM, Linus Walleij wrote:
This is pin control. Do not try to shoehorn pin control drivers into
the GPIO subsystem. Take a good day off, read through
Documentation/pinctrl.txt and come back with a thoroughly rewritten
driver in drivers/pinctrl/pinctrl-as3722.c.
(...)
Yes, the appropriate location is pin control for pull up/down etc
configuration but with this device, the actual issue is with the way it is
require to configure the pull up/down and input/output of the pin. There is
no separate bits for pull up/down and direction and it is clubbed together.
The register's bits are defined as:
Selects the GPIO mode (I, I/O, Tri, Pulls) (BIT 2:0)
0 : Input
1 : Output (push and pull) VSUP_GPIO
2 : Output/Input (open drain, only NMOS is active)
3 : ADC input (Tristate)
4 : Input with pull-up to VDD_GPIO_lv
5 : Input with pull-down
6 : Output/Input open drain (nmos) with pull-up to VDD_GPIO_lv,
7 : Output (push and pull) VDD_GPIO_lv
So I can not actually configure the pull up/down, open drain and direction
independently until every thing is known.
Direction come from gpio driver but pull up/down and open drain
configuration come from the pin control.
And this is only the reason to make all configuration in single driver.
This is nothing special. Create a single combined GPIO and
pin control driver using the pin control framework and device
tree bindings.
Ok, I was thinking that we should not call gpiochip_add() from the pin
control driver in any new driver and that's why I developed gpio driver
but it seems it is allowed. I saw some of driver in pinctrl are doing
pin control and gpio functionality in single driver i.e.
pincntrl-nomadik, pinctrl-samsung, pincntrl-st etc.
So this gpio driver can be moved now to the pincntrl folder and can use
pincontrol and gpio framework.
I will respin the change.
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