On Thu, Nov 14, 2013 at 04:41:41PM +0000, Sricharan R wrote: > Hi Mark, > > On Thursday 14 November 2013 07:42 PM, Mark Rutland wrote: > > On Thu, Nov 14, 2013 at 12:18:48PM +0000, Sricharan R wrote: > >> Some socs have a large number of interrupts requests to service > >> the needs of its many peripherals and subsystems. All of the > >> interrupt lines from the subsystems are not needed at the same > >> time, so they have to be muxed to the irq-controller appropriately. > >> In such places a interrupt controllers are preceded by an CROSSBAR > >> that provides flexibility in muxing the device requests to the controller > >> inputs. > >> > >> This driver takes care a allocating a free irq and then configuring the > >> crossbar IP as a part of the mpu's irqchip callbacks. crossbar_init should > >> be called right before the irqchip_init, so that it is setup to handle the > >> irqchip callbacks. > >> > >> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > >> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> > >> Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > >> Cc: Russell King <linux@xxxxxxxxxxxxxxxx> > >> Cc: Tony Lindgren <tony@xxxxxxxxxxx> > >> Cc: Rajendra Nayak <rnayak@xxxxxx> > >> Cc: Marc Zyngier <marc.zyngier@xxxxxxx> > >> Cc: Grant Likely <grant.likely@xxxxxxxxxx> > >> Cc: Rob Herring <rob.herring@xxxxxxxxxxx> > >> Signed-off-by: Sricharan R <r.sricharan@xxxxxx> > >> Acked-by: Kumar Gala <galak@xxxxxxxxxxxxxx> (for DT binding portion) > >> Acked-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > >> --- > >> [V2] Addressed Thomas Gleixner <tglx@xxxxxxxxxxxxx> comments > >> and renamed the bindings as per Kumar Gala <galak@xxxxxxxxxxxxxx> > >> comments. > >> [V3] Changed static inline const to static inline int and removed > >> unnecessary variable initialization as per > >> Thomas Gleixner <tglx@xxxxxxxxxxxxx>. Updated commit tags > >> [V4] Renamed crossbar_init as irqcrossbar_init as per > >> Rajendra Nayak <rnayak@xxxxxx> suggestion. > >> > >> .../devicetree/bindings/arm/omap/crossbar.txt | 27 +++ > >> drivers/irqchip/Kconfig | 8 + > >> drivers/irqchip/Makefile | 1 + > >> drivers/irqchip/irq-crossbar.c | 206 ++++++++++++++++++++ > >> include/linux/irqchip/irq-crossbar.h | 11 ++ > >> 5 files changed, 253 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/arm/omap/crossbar.txt > >> create mode 100644 drivers/irqchip/irq-crossbar.c > >> create mode 100644 include/linux/irqchip/irq-crossbar.h > >> > >> diff --git a/Documentation/devicetree/bindings/arm/omap/crossbar.txt b/Documentation/devicetree/bindings/arm/omap/crossbar.txt > >> new file mode 100644 > >> index 0000000..fb88585 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/arm/omap/crossbar.txt > >> @@ -0,0 +1,27 @@ > >> +Some socs have a large number of interrupts requests to service > >> +the needs of its many peripherals and subsystems. All of the > >> +interrupt lines from the subsystems are not needed at the same > >> +time, so they have to be muxed to the irq-controller appropriately. > >> +In such places a interrupt controllers are preceded by an CROSSBAR > >> +that provides flexibility in muxing the device requests to the controller > >> +inputs. > >> + > >> +Required properties: > >> +- compatible : Should be "ti,irq-crossbar" > >> +- reg: Base address and the size of the crossbar registers. > >> +- ti,max-irqs: Total number of irqs available at the interrupt controller. > >> +- ti,reg-size: Size of a individual register in bytes. Every individual > >> + register is assumed to be of same size. Valid sizes are 1, 2, 4. > >> +- ti,irqs-reserved: List of the reserved irq lines that are not muxed using > >> + crossbar. These interrupt lines are reserved in the soc, > >> + so crossbar bar driver should not consider them as free > >> + lines. > > The combination of the ti,max-irqs and ti,irqs-reserved properties seems > > backwards to me. Why can we not describe the set of IRQs that _can_ be > > used? > Total set of irqs that are usable is max - reserved. Since reserved irqs > are not continuous, we have to give the list. During the init we count > the total number of reserved and get the usable one. So why not describe the set of usable IRQs, rather than a set of IRQs for which only some are usable then subtracting the set of unusable IRQs? It seems backwards to me to have a binding for a device describe resources it doesn't have. > >> + > >> +Examples: > >> + crossbar_mpu: @4a020000 { > >> + compatible = "ti,irq-crossbar"; > >> + reg = <0x4a002a48 0x130>; > >> + ti,max-irqs = <160>; > >> + ti,reg-size = <2>; > >> + ti,irqs-reserved = <0 1 2 3 5 6 131 132 139 140>; > >> + }; > > [...] > > > >> + /* Get and mark reserved irqs */ > >> + irqsr = of_get_property(node, "ti,irqs-reserved", &size); > >> + if (irqsr) { > >> + size /= sizeof(__be32); > >> + > >> + for (i = 0; i < size; i++) { > >> + entry = be32_to_cpup(irqsr + i); > >> + if (entry > max) { > >> + pr_err("Invalid reserved entry\n"); > >> + goto err3; > >> + } > >> + cb->irq_map[entry] = 0; > >> + } > >> + } > > Don't deal with the raw DTB. Use of_property_read_u32_index. > Ok, i will correct this. > >> + > >> + cb->register_offsets = kzalloc(max * sizeof(int), GFP_KERNEL); > >> + if (!cb->register_offsets) > >> + goto err3; > >> + > >> + of_property_read_u32(node, "ti,reg-size", &size); > > If "ti,reg-size" isn't present, size is uninitialized. Please check the > > return value of of_property_read_u32. > Ok, will correct this. Cheers. Mark. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html