Re: [PATCH 7/9] gpio: pl061: convert to use generic irq chip

[Grant Likely <grant.likely@secretlab.ca>]

On Wed, Dec 14, 2011 at 8:28 AM, Rob Herring <robherring2@gmail.com> wrote:
> From: Rob Herring <rob.herring@calxeda.com>
>
> Convert the pl061 irq_chip code to use the generic irq chip code.
>
> This has the side effect of using 32-bit accesses rather than 8-bit
> accesses to interrupt registers. The h/w TRM and testing seem to indicate
> this is fine.
>
> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
> Cc: Grant Likely <grant.likely@secretlab.ca>

Acked-by: Grant Likely <grant.likely@secretlab.ca>

> Cc: Linus Walleij <linus.ml.walleij@gmail.com>
> ---
>  drivers/gpio/Kconfig      |    1 +
>  drivers/gpio/gpio-pl061.c |   74 ++++++++++++++++-----------------------------
>  2 files changed, 27 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 8482a23..4d433e2 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -138,6 +138,7 @@ config GPIO_MXS
>  config GPIO_PL061
>        bool "PrimeCell PL061 GPIO support"
>        depends on ARM_AMBA
> +       select GENERIC_IRQ_CHIP
>        help
>          Say yes here to support the PrimeCell PL061 GPIO device
>
> diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c
> index fe19dec..4a1874f 100644
> --- a/drivers/gpio/gpio-pl061.c
> +++ b/drivers/gpio/gpio-pl061.c
> @@ -50,7 +50,6 @@ struct pl061_gpio {
>         * the IRQ code simpler.
>         */
>        spinlock_t              lock;           /* GPIO registers */
> -       spinlock_t              irq_lock;       /* IRQ registers */
>
>        void __iomem            *base;
>        int                     irq_base;
> @@ -125,40 +124,10 @@ static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
>        return chip->irq_base + offset;
>  }
>
> -/*
> - * PL061 GPIO IRQ
> - */
> -static void pl061_irq_disable(struct irq_data *d)
> -{
> -       struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
> -       int offset = d->irq - chip->irq_base;
> -       unsigned long flags;
> -       u8 gpioie;
> -
> -       spin_lock_irqsave(&chip->irq_lock, flags);
> -       gpioie = readb(chip->base + GPIOIE);
> -       gpioie &= ~(1 << offset);
> -       writeb(gpioie, chip->base + GPIOIE);
> -       spin_unlock_irqrestore(&chip->irq_lock, flags);
> -}
> -
> -static void pl061_irq_enable(struct irq_data *d)
> -{
> -       struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
> -       int offset = d->irq - chip->irq_base;
> -       unsigned long flags;
> -       u8 gpioie;
> -
> -       spin_lock_irqsave(&chip->irq_lock, flags);
> -       gpioie = readb(chip->base + GPIOIE);
> -       gpioie |= 1 << offset;
> -       writeb(gpioie, chip->base + GPIOIE);
> -       spin_unlock_irqrestore(&chip->irq_lock, flags);
> -}
> -
>  static int pl061_irq_type(struct irq_data *d, unsigned trigger)
>  {
> -       struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
> +       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +       struct pl061_gpio *chip = gc->private;
>        int offset = d->irq - chip->irq_base;
>        unsigned long flags;
>        u8 gpiois, gpioibe, gpioiev;
> @@ -166,7 +135,7 @@ static int pl061_irq_type(struct irq_data *d, unsigned trigger)
>        if (offset < 0 || offset >= PL061_GPIO_NR)
>                return -EINVAL;
>
> -       spin_lock_irqsave(&chip->irq_lock, flags);
> +       raw_spin_lock_irqsave(&gc->lock, flags);
>
>        gpioiev = readb(chip->base + GPIOIEV);
>
> @@ -195,18 +164,11 @@ static int pl061_irq_type(struct irq_data *d, unsigned trigger)
>
>        writeb(gpioiev, chip->base + GPIOIEV);
>
> -       spin_unlock_irqrestore(&chip->irq_lock, flags);
> +       raw_spin_unlock_irqrestore(&gc->lock, flags);
>
>        return 0;
>  }
>
> -static struct irq_chip pl061_irqchip = {
> -       .name           = "GPIO",
> -       .irq_enable     = pl061_irq_enable,
> -       .irq_disable    = pl061_irq_disable,
> -       .irq_set_type   = pl061_irq_type,
> -};
> -
>  static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
>  {
>        struct list_head *chip_list = irq_get_handler_data(irq);
> @@ -232,6 +194,26 @@ static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
>        chained_irq_exit(irqchip, desc);
>  }
>
> +static void __init pl061_init_gc(struct pl061_gpio *chip, int irq_base)
> +{
> +       struct irq_chip_generic *gc;
> +       struct irq_chip_type *ct;
> +
> +       gc = irq_alloc_generic_chip("gpio-pl061", 1, irq_base,
> +                                   chip->base, handle_simple_irq);
> +       gc->private = chip;
> +
> +       ct = gc->chip_types;
> +       ct->chip.irq_mask = irq_gc_mask_clr_bit;
> +       ct->chip.irq_unmask = irq_gc_mask_set_bit;
> +       ct->chip.irq_set_type = pl061_irq_type;
> +       ct->chip.irq_set_wake = irq_gc_set_wake;
> +       ct->regs.mask = GPIOIE;
> +
> +       irq_setup_generic_chip(gc, IRQ_MSK(PL061_GPIO_NR),
> +                              IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0);
> +}
> +
>  static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
>  {
>        struct pl061_platform_data *pdata;
> @@ -269,7 +251,6 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
>        }
>
>        spin_lock_init(&chip->lock);
> -       spin_lock_init(&chip->irq_lock);
>        INIT_LIST_HEAD(&chip->list);
>
>        chip->gc.direction_input = pl061_direction_input;
> @@ -293,6 +274,8 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
>        if (chip->irq_base <= 0)
>                return 0;
>
> +       pl061_init_gc(chip, chip->irq_base);
> +
>        writeb(0, chip->base + GPIOIE); /* disable irqs */
>        irq = dev->irq[0];
>        if (irq < 0) {
> @@ -321,11 +304,6 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
>                        else
>                                pl061_direction_input(&chip->gc, i);
>                }
> -
> -               irq_set_chip_and_handler(i + chip->irq_base, &pl061_irqchip,
> -                                        handle_simple_irq);
> -               set_irq_flags(i+chip->irq_base, IRQF_VALID);
> -               irq_set_chip_data(i + chip->irq_base, chip);
>        }
>
>        return 0;
> --
> 1.7.5.4
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.