[PATCH v2] gpio/omap: fix incorrect initialization of omap_gpio_mod_init

[Grazvydas Ignotas]

I've noticed that current mainline enables _all_ possible GPIO
interrupts, this patch fixes that problem.
Also Grant doesn't seem to be on CC so might not be able to pick this up.

On Mon, Apr 30, 2012 at 10:20 AM, Tarun Kanti DebBarma
<tarun.kanti at ti.com> wrote:
> Initialization of irqenable, irqstatus registers is the common
> operation done in this function for all OMAP platforms, viz. OMAP1,
> OMAP2+. The latter _gpio_rmw()'s which supposedly got introduced
> wrongly to take care of OMAP2+ platforms were overwriting initially
> programmed OMAP1 value breaking functionality on OMAP1.
> Somehow incorrect assumption was made that each _gpio_rmw()'s were
> mutually exclusive. On close observation it is found that the first
> _gpio_rmw() which is supposedly done to take care of OMAP1 platform
> is generic enough and takes care of OMAP2+ platform as well.
> Therefore remove the latter _gpio_rmw() to irqenable as they are
> redundant now.
>
> Writing to ctrl and debounce_en registers for OMAP2+ platforms are
> modified to match the original(pre-cleanup) code where the registers
> are initialized with 0. In the cleanup series since we are using
> _gpio_rmw(reg, 0, 1), instead of __raw_writel(), we are just reading
> and writing the same values to ctrl and debounce_en. This is not an
> issue for debounce_en register because it has 0x0 as the default value.
> But in the case of ctrl register the default value is 0x2 (GATINGRATIO
>  = 0x1) so that we end up writing 0x2 instead of intended 0 value.
> Therefore changing back to __raw_writel() as this is sufficient for
> this case besides simpler to understand.
>
> Also, change irqstatus initalization logic that avoids comparison
> with bool, besides making it fit in a single line.
>
> Cc: stable at vger.kernel.org
> Cc: Tony Lindgren <tony at atomide.com>
> Cc: Kevin Hilman <khilman at ti.com>
> Cc: Santosh Shilimkar <santosh.shilimkar at ti.com>
> Cc: Grant Likely <grant.likely at secretlab.ca>
> Reported-by: Janusz Krzysztofik <jkrzyszt at tis.icnet.pl>
> Signed-off-by: Tarun Kanti DebBarma <tarun.kanti at ti.com>
> ---
> v2:
> Avoid irqstatus initialization sequence change.
> Use __raw_writel() to update debounce_en and ctrl registers.
> Update changelog to elaborate how redundant _gpio_rmw() got added.
>
>  drivers/gpio/gpio-omap.c |    9 +++------
>  1 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index 59a4af1..9b71f04 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -957,18 +957,15 @@ static void omap_gpio_mod_init(struct gpio_bank *bank)
>        }
>
>        _gpio_rmw(base, bank->regs->irqenable, l, bank->regs->irqenable_inv);
> -       _gpio_rmw(base, bank->regs->irqstatus, l,
> -                                       bank->regs->irqenable_inv == false);
> -       _gpio_rmw(base, bank->regs->irqenable, l, bank->regs->debounce_en != 0);
> -       _gpio_rmw(base, bank->regs->irqenable, l, bank->regs->ctrl != 0);
> +       _gpio_rmw(base, bank->regs->irqstatus, l, !bank->regs->irqenable_inv);
>        if (bank->regs->debounce_en)
> -               _gpio_rmw(base, bank->regs->debounce_en, 0, 1);
> +               __raw_writel(0, base + bank->regs->debounce_en);
>
>        /* Save OE default value (0xffffffff) in the context */
>        bank->context.oe = __raw_readl(bank->base + bank->regs->direction);
>         /* Initialize interface clk ungated, module enabled */
>        if (bank->regs->ctrl)
> -               _gpio_rmw(base, bank->regs->ctrl, 0, 1);
> +               __raw_writel(0, base + bank->regs->ctrl);
>  }
>
>  static __devinit void
> --
> 1.7.0.4
>
> --
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-- 
Gražvydas