Re: [PATCH v2 0/3] gpio: syscon: reuse for keystone 2 socs

[Alexander Shiyan]

Thu, 21 Aug 2014 19:23:20 +0300 от Grygorii Strashko <grygorii.strashko at ti.com>:
> Hi All,
> 
> Alexander,
> 
> I've updated gpio-syscon as requested in [3].
> I still don't like it, but any way I did it :(
> 
> Linus,
> 
> I'd very appreciated if you can comment on these series.
> Personally, I like v1 [3], because this v2 is not elegant and will
> require constant code patching in case of adding new SoCs or new SoC's versions.
> 
> This series intended to integrate Keystone 2 DSP GPIO controller functionality
> into gpio-syscon driver (drivers/gpio/gpio-syscon.c) as requested
> by Linus Walleij in [1].
> 
> On Keystone SOCs, ARM host can send interrupts to DSP cores using the
> DSP GPIO controller IP. Each DSP GPIO controller provides 28 IRQ signals for
> each DSP core. This is one of the component used by the IPC mechanism used
> on Keystone SOCs.
> 
> Keystone 2 DSP GPIO controller has specific features:
> - each GPIO can be configured only as output pin;
> - setting GPIO value to 1 causes IRQ generation on target DSP core;
> - reading pin value returns 0 - if IRQ was handled or 1 - IRQ is still
>   pending.
> 
> The gpio-syscon driver was need to be updated to satisfy Keystone 2 SoC
> requirements:
> - special sequence of operations need to be used to assign output GPIO value.
>    As result, first patch introduces SoC specific callback .set() to configure
>    output GPIO value.
> 
> Also, patch 3 was added to illustrate DSP GPIO configuration in DT used by Keystone 2.
> 
> Related sicussions:
>  [1] https://lkml.org/lkml/2014/7/16/170
>  [2] https://lkml.org/lkml/2014/7/23/352
>  [3] https://www.mail-archive.com/devicetree@vger.kernel.org/msg37863.html
> 
> Grygorii Strashko (3):
>   gpio: syscon: add soc specific callback to assign output value
>   gpio: syscon: reuse for keystone 2 socs
>   ARM: dts: keystone-k2hk: add dsp gpio controllers nodes
> 
>  .../bindings/gpio/gpio-mctrl-keystone.txt          |   42 ++++++
>  arch/arm/boot/dts/k2hk.dtsi                        |   48 +++++++
>  drivers/gpio/gpio-syscon.c                         |  140 ++++++++++++++++++++
>  3 files changed, 230 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-mctrl-keystone.txt

1. mctrl -> dsp in filenames
2. mctrl -> dsp in documentation.
3. Here is a more elegant solution for first part.

--- gpio-syscon.c.old	2014-08-19 09:46:09.000000000 +0400
+++ gpio-syscon.c	2014-08-21 20:45:49.357529323 +0400
@@ -111,7 +111,7 @@
 				   BIT(offs % SYSCON_REG_BITS));
 	}
 
-	syscon_gpio_set(chip, offset, val);
+	priv->data->set(chip, offset, val);
 
 	return 0;
 }
@@ -159,7 +159,7 @@
 	if (priv->data->flags & GPIO_SYSCON_FEAT_IN)
 		priv->chip.direction_input = syscon_gpio_dir_in;
 	if (priv->data->flags & GPIO_SYSCON_FEAT_OUT) {
-		priv->chip.set = syscon_gpio_set;
+		priv->chip.set = priv->data->set ? : syscon_gpio_set;
 		priv->chip.direction_output = syscon_gpio_dir_out;
 	}
 

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