[PATCH] Powerpc: Xilinx: Intc: Fix level irqs which have duplicates

[Grant Likely]

I think this looks good.  I'll need to pull it into my tree and try it out.

g.

On Fri, Apr 3, 2009 at 4:55 PM, John Linn <john.linn at xilinx.com> wrote:
> The interrupt controller was not handling level interrupts correctly
> such that duplicate interrupts were happening. This fixes the problem
> and adds edge type interrupts which are needed in Xilinx hardware.
>
> Signed-off-by: John Linn <john.linn at xilinx.com>
> ---
>  arch/powerpc/sysdev/xilinx_intc.c |  112 ++++++++++++++++++++++++++++++++++---
>  1 files changed, 103 insertions(+), 9 deletions(-)
>
> diff --git a/arch/powerpc/sysdev/xilinx_intc.c b/arch/powerpc/sysdev/xilinx_intc.c
> index a22e1a2..7c99a1e 100644
> --- a/arch/powerpc/sysdev/xilinx_intc.c
> +++ b/arch/powerpc/sysdev/xilinx_intc.c
> @@ -41,8 +41,30 @@
>
>  static struct irq_host *master_irqhost;
>
> +/* The following table allows the interrupt type, edge or level,
> + * to be cached after being read from the device tree until the interrupt
> + * is mapped
> + */
> +static int xilinx_intc_typetable[32];
> +
> +/* Map the interrupt type from the device tree to the interrupt types
> + * used by the interrupt subsystem
> + */
> +static unsigned char xilinx_intc_map_senses[] = {
> +       IRQ_TYPE_EDGE_RISING,
> +       IRQ_TYPE_EDGE_FALLING,
> +       IRQ_TYPE_LEVEL_HIGH,
> +       IRQ_TYPE_LEVEL_LOW,
> +};
> +
>  /*
> - * IRQ Chip operations
> + * The interrupt controller is setup such that it doesn't work well with
> + * the level interrupt handler in the kernel because the handler acks the
> + * interrupt before calling the application interrupt handler. To deal with
> + * that, we use 2 different irq chips so that different functions can be
> + * used for level and edge type interrupts.
> + *
> + * IRQ Chip common (across level and edge) operations
>  */
>  static void xilinx_intc_mask(unsigned int virq)
>  {
> @@ -52,15 +74,54 @@ static void xilinx_intc_mask(unsigned int virq)
>        out_be32(regs + XINTC_CIE, 1 << irq);
>  }
>
> -static void xilinx_intc_unmask(unsigned int virq)
> +static int xilinx_intc_set_type(unsigned int virq, unsigned int flow_type)
> +{
> +       struct irq_desc *desc = get_irq_desc(virq);
> +
> +       desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
> +       desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
> +       if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
> +               desc->status |= IRQ_LEVEL;
> +       return 0;
> +}
> +
> +/*
> + * IRQ Chip level operations
> + */
> +static void xilinx_intc_level_unmask(unsigned int virq)
>  {
>        int irq = virq_to_hw(virq);
>        void * regs = get_irq_chip_data(virq);
>        pr_debug("unmask: %d\n", irq);
>        out_be32(regs + XINTC_SIE, 1 << irq);
> +
> +       /* ack level irqs because they can't be acked during
> +        * ack function since the handle_level_irq function
> +        * acks the irq before calling the inerrupt handler
> +        */
> +       out_be32(regs + XINTC_IAR, 1 << irq);
> +}
> +
> +static struct irq_chip xilinx_intc_level_irqchip = {
> +       .typename = "Xilinx Level INTC",
> +       .mask = xilinx_intc_mask,
> +       .mask_ack = xilinx_intc_mask,
> +       .unmask = xilinx_intc_level_unmask,
> +       .set_type = xilinx_intc_set_type,
> +};
> +
> +/*
> + * IRQ Chip edge operations
> + */
> +static void xilinx_intc_edge_unmask(unsigned int virq)
> +{
> +       int irq = virq_to_hw(virq);
> +       void *regs = get_irq_chip_data(virq);
> +       pr_debug("unmask: %d\n", irq);
> +       out_be32(regs + XINTC_SIE, 1 << irq);
>  }
>
> -static void xilinx_intc_ack(unsigned int virq)
> +static void xilinx_intc_edge_ack(unsigned int virq)
>  {
>        int irq = virq_to_hw(virq);
>        void * regs = get_irq_chip_data(virq);
> @@ -68,27 +129,60 @@ static void xilinx_intc_ack(unsigned int virq)
>        out_be32(regs + XINTC_IAR, 1 << irq);
>  }
>
> -static struct irq_chip xilinx_intc_irqchip = {
> -       .typename = "Xilinx INTC",
> +static struct irq_chip xilinx_intc_edge_irqchip = {
> +       .typename = "Xilinx Edge  INTC",
>        .mask = xilinx_intc_mask,
> -       .unmask = xilinx_intc_unmask,
> -       .ack = xilinx_intc_ack,
> +       .unmask = xilinx_intc_edge_unmask,
> +       .ack = xilinx_intc_edge_ack,
> +       .set_type = xilinx_intc_set_type,
>  };
>
>  /*
>  * IRQ Host operations
>  */
> +
> +/**
> + * xilinx_intc_xlate - translate virq# from device tree interrupts property
> + */
> +static int xilinx_intc_xlate(struct irq_host *h, struct device_node *ct,
> +                               u32 *intspec, unsigned int intsize,
> +                               irq_hw_number_t *out_hwirq,
> +                               unsigned int *out_flags)
> +{
> +       if (intsize != 2)
> +               return -1;
> +
> +       /* keep a copy of the interrupt type til the interrupt is mapped
> +        */
> +       xilinx_intc_typetable[intspec[0]] = xilinx_intc_map_senses[intspec[1]];
> +
> +       /* Xilinx uses 2 interrupt entries, the 1st being the h/w
> +        * interrupt number, the 2nd being the interrupt type, edge or level
> +        */
> +       *out_hwirq = intspec[0];
> +       *out_flags = xilinx_intc_map_senses[intspec[1]];
> +
> +       return 0;
> +}
>  static int xilinx_intc_map(struct irq_host *h, unsigned int virq,
>                                  irq_hw_number_t irq)
>  {
>        set_irq_chip_data(virq, h->host_data);
> -       set_irq_chip_and_handler(virq, &xilinx_intc_irqchip, handle_level_irq);
> -       set_irq_type(virq, IRQ_TYPE_NONE);
> +
> +       if (xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_HIGH ||
> +           xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_LOW) {
> +               set_irq_chip_and_handler(virq, &xilinx_intc_level_irqchip,
> +                       handle_level_irq);
> +       } else {
> +               set_irq_chip_and_handler(virq, &xilinx_intc_edge_irqchip,
> +                       handle_edge_irq);
> +       }
>        return 0;
>  }
>
>  static struct irq_host_ops xilinx_intc_ops = {
>        .map = xilinx_intc_map,
> +       .xlate = xilinx_intc_xlate,
>  };
>
>  struct irq_host * __init
> --
> 1.6.2.1
>
>
>
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-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.