[PATCH 1/3] gpio-rcar: Add support for IRQ_TYPE_EDGE_BOTH

[Magnus Damm]

On Mon, May 13, 2013 at 5:53 PM, Simon Horman
<horms+renesas at verge.net.au> wrote:
> As hardware support for this feature is not universal for all SoCs a flag,
> has_both_edge_trigger, has been added to the platform data of the driver to
> allow this feature to be enabled.
>
> The motivation for this is to allow use of the gpio-keys driver on the
> lager board which is based on the r8a7790 SoC. This patch has been lightly
> exercised using that driver on that board.
>
> Signed-off-by: Simon Horman <horms+renesas at verge.net.au>
> ---
>  drivers/gpio/gpio-rcar.c                | 27 ++++++++++++++++++++++-----
>  include/linux/platform_data/gpio-rcar.h |  1 +
>  2 files changed, 23 insertions(+), 5 deletions(-)

Thanks for the patch, Simon!

> diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
> index 0f3d647..33d8f6a 100644
> --- a/drivers/gpio/gpio-rcar.c
> +++ b/drivers/gpio/gpio-rcar.c
> @@ -49,6 +49,7 @@ struct gpio_rcar_priv {
>  #define POSNEG 0x20
>  #define EDGLEVEL 0x24
>  #define FILONOFF 0x28
> +#define BOTHEDGE 0x4c
>
>  static inline u32 gpio_rcar_read(struct gpio_rcar_priv *p, int offs)
>  {
> @@ -111,6 +113,11 @@ static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
>         /* Select "Interrupt Input Mode" in IOINTSEL */
>         gpio_rcar_modify_bit(p, IOINTSEL, hwirq, true);
>
> +       if (p->config.has_both_edge_trigger && !level_trigger) {
> +               /* Select one edge or both edges in BOTHEDGE */
> +               gpio_rcar_modify_bit(p, IOINTSEL, hwirq, both);
> +       }
> +
>         /* Write INTCLR in case of edge trigger */
>         if (!level_trigger)
>                 gpio_rcar_write(p, INTCLR, BIT(hwirq));

In your hunk above I suspect you want to setup the BOTHEDGE register
instead of IOINTSEL.

Also, I wonder how BOTHEDGE should be set in the case of level
trigger. Say that the user first selects edge trigger and then
reconfigures to level, then you probably want to make sure the
BOTHEDGE register is cleared.

So may want to do something like this (untested):

       if (p->config.has_both_edge_trigger) {
               /* Select one edge or both edges in BOTHEDGE */
               gpio_rcar_modify_bit(p, BOTHEDGE, hwirq, both);
       }

Also, please double check that the register access sequences in the
documentation are still kept, please see "6.7.1 Setting Edge-Sensitive
Interrupt Input Mode" in the H2 data sheet. It looks like you want to
move this setting so it happens before IOINTSEL.

Thanks!

/ magnus