Re: [PATCH 6/7] gpio: dwapb: use a second irq chip

From: Sebastian Hesselbarth
Date: Tue Mar 25 2014 - 17:36:41 EST


On 03/22/2014 05:16 PM, Sebastian Andrzej Siewior wrote:
> Right new have one irq chip running always in level mode. It would nicer
> to have two irq chips where one is handling level type interrupts and
> the other one is doing edge interrupts. So we can have at runtime two users
> where one is using edge and the other level.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
> drivers/gpio/gpio-dwapb.c | 41 ++++++++++++++++++++++++++++-------------
> 1 file changed, 28 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> index 752ccb1..3c9cdda 100644
> --- a/drivers/gpio/gpio-dwapb.c
> +++ b/drivers/gpio/gpio-dwapb.c
> @@ -192,6 +192,8 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
> break;
> }
>
> + irq_setup_alt_chip(d, type);
> +
> writel(level, gpio->regs + GPIO_INTTYPE_LEVEL);
> writel(polarity, gpio->regs + GPIO_INT_POLARITY);
> irq_gc_unlock(igc);
> @@ -207,7 +209,7 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
> struct irq_chip_generic *irq_gc;
> unsigned int hwirq, ngpio = gc->ngpio;
> struct irq_chip_type *ct;
> - int err, irq;
> + int err, irq, i;
>
> irq = irq_of_parse_and_map(node, 0);
> if (!irq) {
> @@ -221,7 +223,7 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
> if (!gpio->domain)
> return;
>
> - err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 1,
> + err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 2,
> "gpio-dwapb", handle_level_irq,
> IRQ_NOREQUEST, 0,
> IRQ_GC_INIT_NESTED_LOCK);
> @@ -242,17 +244,28 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
> irq_gc->reg_base = gpio->regs;
> irq_gc->private = gpio;
>
> - ct = irq_gc->chip_types;
> - ct->chip.irq_ack = irq_gc_ack_set_bit;
> - ct->chip.irq_mask = irq_gc_mask_set_bit;
> - ct->chip.irq_unmask = irq_gc_mask_clr_bit;
> - ct->chip.irq_set_type = dwapb_irq_set_type;
> - ct->chip.irq_enable = dwapb_irq_enable;
> - ct->chip.irq_disable = dwapb_irq_disable;
> - ct->chip.irq_request_resources = dwapb_irq_reqres;
> - ct->chip.irq_release_resources = dwapb_irq_relres;
> - ct->regs.ack = GPIO_PORTA_EOI;
> - ct->regs.mask = GPIO_INTMASK;
> + for (i = 0; i < 2; i++) {
> +
> + ct = &irq_gc->chip_types[i];
> + ct->chip.irq_ack = irq_gc_ack_set_bit;
> + ct->chip.irq_mask = irq_gc_mask_set_bit;
> + ct->chip.irq_unmask = irq_gc_mask_clr_bit;
> + ct->chip.irq_set_type = dwapb_irq_set_type;
> + ct->chip.irq_enable = dwapb_irq_enable;
> + ct->chip.irq_disable = dwapb_irq_disable;
> + ct->chip.irq_request_resources = dwapb_irq_reqres;
> + ct->chip.irq_release_resources = dwapb_irq_relres;
> + ct->regs.ack = GPIO_PORTA_EOI;
> + ct->regs.mask = GPIO_INTMASK;
> +
> + if (i == 0) {
> + ct->type = IRQ_TYPE_LEVEL_MASK;
> + ct->handler = handle_level_irq;
> + } else {
> + ct->type = IRQ_TYPE_EDGE_BOTH;
> + ct->handler = handle_edge_irq;
> + }

Sebastian,

IMHO the loop looks strange, especially with the (i == 0) check.

How about unrolling it again and assign both chip_types independently?

Sebastian

> + }
>
> irq_set_chained_handler(irq, dwapb_irq_handler);
> irq_set_handler_data(irq, gpio);
>

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