On Mon, Jun 16, 2014 at 04:53:16PM +0530, Sricharan R wrote:
> From: Nishanth Menon <nm@xxxxxx>
>
> On certain platforms such as DRA7, SPIs 0, 1, 2, 3, 5, 6, 10, 131,
> 132, 133 are direct wired to hardware blocks bypassing crossbar.
> This quirky implementation is *NOT* supposed to be the expectation
> of crossbar hardware usage. However, these are already marked in our
> description of the hardware with SKIP and RESERVED where appropriate.
>
> Unfortunately, we need to be able to refer to these hardwired IRQs.
> So, to request these, crossbar driver can use the existing information
> from it's table that these SKIP/RESERVED maps are direct wired sources
> and generic allocation/programming of crossbar should be avoided.
>
> Signed-off-by: Nishanth Menon <nm@xxxxxx>
> Signed-off-by: Sricharan R <r.sricharan@xxxxxx>
> ---
> .../devicetree/bindings/arm/omap/crossbar.txt | 12 ++++++++++--
> drivers/irqchip/irq-crossbar.c | 20 ++++++++++++++++++--
> 2 files changed, 28 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/arm/omap/crossbar.txt b/Documentation/devicetree/bindings/arm/omap/crossbar.txt
> index 8210ea4..438ccab 100644
> --- a/Documentation/devicetree/bindings/arm/omap/crossbar.txt
> +++ b/Documentation/devicetree/bindings/arm/omap/crossbar.txt
> @@ -42,8 +42,10 @@ Documentation/devicetree/bindings/arm/gic.txt for further details.
>
> An interrupt consumer on an SoC using crossbar will use:
> interrupts = <GIC_SPI request_number interrupt_level>
> -request number shall be between 0 to that described by
> -"ti,max-crossbar-sources"
> +When the request number is between 0 to that described by
> +"ti,max-crossbar-sources", it is assumed to be a crossbar mapping. If the
> +request_number is greater than "ti,max-crossbar-sources", then it is mapped as a
> +quirky hardware mapping direct to GIC.
>
> Example:
> device_x@0x4a023000 {
> @@ -51,3 +53,9 @@ Example:
> interrupts = <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>;
> ...
> };
> +
> + device_y@0x4a033000 {
> + /* Direct mapped GIC SPI 1 used */
> + interrupts = <GIC_SPI 401 IRQ_TYPE_LEVEL_HIGH>;
Ideally, I'd like to see a macro here so that it's clear that we crossed
a magic threshold. eg:
#define MAX_SOURCES 400
#define DIRECT_IRQ(irq) (MAX_SOURCES + irq)
...
interrupts = <GIC_SPI DIRECT_IRQ(1) IRQ_TYPE_LEVEL_HIGH>;
and, then:
ti,max-crossbar-sources = <MAX_SOURCES>;
> + ...
> + };
> diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
> index ef613c4..fff6218 100644
> --- a/drivers/irqchip/irq-crossbar.c
> +++ b/drivers/irqchip/irq-crossbar.c
> @@ -86,8 +86,13 @@ static inline int allocate_free_irq(int cb_no)
>
> static inline bool needs_crossbar_write(irq_hw_number_t hw)
> {
> - if (hw > GIC_IRQ_START)
> - return true;
> + int cb_no;
> +
> + if (hw > GIC_IRQ_START) {
> + cb_no = cb->irq_map[hw - GIC_IRQ_START];
> + if (cb_no != IRQ_RESERVED && cb_no != IRQ_SKIP)
> + return true;
> + }
>
> return false;
> }
> @@ -130,8 +135,19 @@ static int crossbar_domain_xlate(struct irq_domain *d,
> {
> int ret;
> int req_num = intspec[1];
> + int direct_map_num;
>
> if (req_num >= cb->max_crossbar_sources) {
> + direct_map_num = req_num - cb->max_crossbar_sources;
> + if (direct_map_num < cb->int_max) {
> + ret = cb->irq_map[direct_map_num];
> + if (ret == IRQ_RESERVED || ret == IRQ_SKIP) {
> + /* We use the interrupt num as h/w irq num */
> + ret = direct_map_num;
> + goto found;
> + }
> + }
> +
> pr_err("%s: requested crossbar number %d > max %d\n",
> __func__, req_num, cb->max_crossbar_sources);
> return -EINVAL;
thx,
Jason.
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