On 11/06/2013 12:08 PM, Prabhakar Lad wrote:
Hi Grygorii,

On Tue, Nov 5, 2013 at 10:29 PM, Grygorii Strashko
<grygorii.stras...@ti.com> wrote:
On 11/05/2013 10:53 AM, Prabhakar Lad wrote:> Hi Grygorii,


Thanks for the review.

On Mon, Nov 4, 2013 at 11:58 PM, Grygorii Strashko
<grygorii.stras...@ti.com> wrote:
Hi Prabhakar Lad,


On 11/02/2013 05:39 PM, Lad, Prabhakar wrote:

From: KV Sujith <sujit...@ti.com>

This patch adds OF parser support for davinci gpio
driver and also appropriate documentation in gpio-davinci.txt
located at Documentation/devicetree/bindings/gpio/.


I worry, do we need to have gpio_chip.of_xlate() callback implemented?

I looked for the other OF GPIO implementations with same "ngpio"
property (marvel, msm) but I don’t see of_xlate() callback implemented.

The question: will below definitions in DT work or not after this series?
  Will of_get_gpio()/of_get_named_gpio() work?

Example1 - leds:
         leds {
                 compatible = "gpio-leds";
                 debug0 {
                         label = "green:debug0";
                         gpios = <&gpio 29 GPIO_ACTIVE_HIGH>;
                 };
         };

Example2 - any dev:
devA {
         compatible = "devA";
         gpios = <&gpio 120 GPIO_ACTIVE_LOW>;

}


Agreed of_get_gpio()/of_get_named_gpio() wont work without
xlate callback implemented, but I think this can be added as a
incremental patch later.


- From one side, Davinci GPIO controller in DT described by one entry
which defines number of supported GPIOs as "ti,ngpio = <144>;"

- From other side, on Linux level more than one gpio_chip objects are
instantiated (one per each 32 GPIO).

How the standard GPIO biding will work in this case? .. And will they?

Linus, I'd very appreciate if you will be able to clarify this point.



Signed-off-by: KV Sujith <sujit...@ti.com>
Signed-off-by: Philip Avinash <avinashphi...@ti.com>
[prabhakar.cse...@gmail.com: simplified the OF code, removed
                  unnecessary DT property and also simplified
                  the commit message]
Signed-off-by: Lad, Prabhakar <prabhakar.cse...@gmail.com>
---
    .../devicetree/bindings/gpio/gpio-davinci.txt      |   32
++++++++++++
    drivers/gpio/gpio-davinci.c                        |   54
++++++++++++++++++--
    2 files changed, 83 insertions(+), 3 deletions(-)
    create mode 100644
Documentation/devicetree/bindings/gpio/gpio-davinci.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
new file mode 100644
index 0000000..55aae1c
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
@@ -0,0 +1,32 @@
+Davinci GPIO controller bindings29

+
+Required Properties:
+- compatible: should be "ti,dm6441-gpio"
+
+- reg: Physical base address of the controller and the size of memory
mapped
+       registers.
+
+- gpio-controller : Marks the device node as a gpio controller.
+
+- interrupts: Array of GPIO interrupt number.


May be meaning of <interrupts> property need to be extended, because,
as of now, only banked or unbanked IRQs are supported - and not both.


OK

+
+- ti,ngpio: The number of GPIO pins supported.
+
+- ti,davinci-gpio-unbanked: The number of GPIOs that have an individual
interrupt
+                            line to processor.


Should interrupt-controller; specifier be added here?

No

So, it would be impossible to map GPIO IRQ to device through DT. Right?
Like:
         devX@0 {
                 compatible = "devX";
                 interrupt-parent = <&gpio>;
                 interrupts = <50 IRQ_TYPE_EDGE_FALLING>; /* gpio line 50 */


         };


may be I took you wrong here, the interrupt-controller is inherited
property taken from its parent, so didn’t mention that in the documentation

The GPIO controller uses interrupts form parent controller INTC/GIC
from one side, but from other side it can provide interrupts to its
users.
And as result can be interrupt-controller.

INTC/GIC -> GPIO -> user

It could work for banked IRQs only now :)



Regards,
--Prabhakar Lad


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to