Subject: [PATCH v2 1/3] irqchip: irq-dove: Add PMU interrupt controller.

From: [email-masked] (Sebastian Hesselbarth)
Date: Mon, 21 Oct 2013 10:01:11 +0200

On 10/19/2013 06:49 PM, Andrew Lunn wrote:
> Dove has a Power Management Unit with its own interrupt
> controller. This is chained on the main interrupt controller.  Add a
> driver, making use of generic chip where possible.
>
> Signed-off-by: Andrew Lunn <[email-masked]>
> Tested-by: Sebastian Hesselbarth <[email-masked]>
>
> cc: devicetree at vger.kernel.org
> cc: pawel.moll at arm.com
> cc: mark.rutland at arm.com
> cc: swarren at wwwdotorg.org
> cc: ian.campbell at citrix.com
> ---
>
> Removed an unneeded blank line
> Added Sebastians Tested-By
>
>   .../interrupt-controller/marvell,dove-pmu-intc.txt |  17 +++
>   drivers/irqchip/Makefile                           |   1 +
>   drivers/irqchip/irq-dove.c                         | 126 +++++++++++++++++++++
>   3 files changed, 144 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/interrupt-controller/marvell,dove-pmu-intc.txt
>   create mode 100644 drivers/irqchip/irq-dove.c
>
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/marvell,dove-pmu-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/marvell,dove-pmu-intc.txt
> new file mode 100644
> index 0000000..1feb582
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/marvell,dove-pmu-intc.txt
> @@ -0,0 +1,17 @@
> +Marvell Dove Power Management Unit interrupt controller
> +
> +Required properties:
> +- compatible: shall be "marvell,dove-pmu-intc"
> +- reg: base address of PMU interrupt registers starting with CAUSE register

Andrew,

Mark Rutland complained about the way the above reg property is
described for the berlin patches. Maybe you should take the following
instead

"""
reg: physical base address of the PMU interrupt registers and length of
   memory mapped region starting with CAUSE register
""

> +- interrupts: PMU interrupt of the main interrupt controller
> +- interrupt-controller: identifies the node as an interrupt controller
> +- #interrupt-cells: number of cells to encode an interrupt source, shall be 1
> +
> +Example:
> +	pmu_intc: pmu-interrupt-ctrl at d0050 {
> +		compatible = "marvell,dove-pmu-intc";
> +		interrupt-controller;
> +		#interrupt-cells = <1>;
> +		reg = <0xd0050 0x8>;
> +		interrupts = <33>;
> +	};
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index c60b901..f743006 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -1,6 +1,7 @@
>   obj-$(CONFIG_IRQCHIP)			+= irqchip.o
>
>   obj-$(CONFIG_ARCH_BCM2835)		+= irq-bcm2835.o
> +obj-$(CONFIG_ARCH_DOVE)			+= irq-dove.o
>   obj-$(CONFIG_ARCH_EXYNOS)		+= exynos-combiner.o
>   obj-$(CONFIG_ARCH_MMP)			+= irq-mmp.o
>   obj-$(CONFIG_ARCH_MVEBU)		+= irq-armada-370-xp.o
> diff --git a/drivers/irqchip/irq-dove.c b/drivers/irqchip/irq-dove.c
> new file mode 100644
> index 0000000..788acd8
> --- /dev/null
> +++ b/drivers/irqchip/irq-dove.c
> @@ -0,0 +1,126 @@
> +/*
> + * Marvell Dove SoCs PMU IRQ chip driver.
> + *
> + * Andrew Lunn <[email-masked]>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2.  This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <asm/exception.h>
> +#include <asm/mach/irq.h>
> +
> +#include "irqchip.h"
> +
> +#define DOVE_PMU_IRQ_CAUSE	0x00
> +#define DOVE_PMU_IRQ_MASK	0x04
> +
> +static void dove_pmu_irq_handler(unsigned int irq, struct irq_desc *desc)
> +{
> +	struct irq_domain *d = irq_get_handler_data(irq);
> +	struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, 0);
> +	u32 stat = readl_relaxed(gc->reg_base + DOVE_PMU_IRQ_CAUSE) &
> +		   gc->mask_cache;
> +
> +	while (stat) {
> +		u32 hwirq = ffs(stat) - 1;
> +
> +		generic_handle_irq(irq_find_mapping(d, gc->irq_base + hwirq));
> +		stat &= ~(1 << hwirq);
> +	}
> +}
> +
> +static void pmu_irq_ack(struct irq_data *d)
> +{
> +	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +	struct irq_chip_type *ct = irq_data_get_chip_type(d);
> +	u32 mask = ~d->mask;
> +
> +	/*
> +	 * The PMU mask register is not RW0C: it is RW.	 This means that
> +	 * the bits take whatever value is written to them; if you write
> +	 * a '1', you will set the interrupt.
> +	 *
> +	 * Unfortunately this means there is NO race free way to clear
> +	 * these interrupts.
> +	 *
> +	 * So, let's structure the code so that the window is as small as
> +	 * possible.
> +	 */
> +	irq_gc_lock(gc);
> +	mask &= irq_reg_readl(gc->reg_base +  ct->regs.ack);
> +	irq_reg_writel(mask, gc->reg_base +  ct->regs.ack);
> +	irq_gc_unlock(gc);
> +}
> +
> +static int __init dove_pmu_irq_init(struct device_node *np,
> +				    struct device_node *parent)
> +{
> +	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
> +	struct resource r;
> +	struct irq_domain *domain;
> +	struct irq_chip_generic *gc;
> +	int ret, irq, nrirqs = 7;
> +
> +	domain = irq_domain_add_linear(np, nrirqs,
> +				       &irq_generic_chip_ops, NULL);
> +	if (!domain) {
> +		pr_err("%s: unable to add irq domain\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	ret = irq_alloc_domain_generic_chips(domain, nrirqs, 1, np->name,
> +			     handle_level_irq, clr, 0, IRQ_GC_INIT_MASK_CACHE);
> +	if (ret) {
> +		pr_err("%s: unable to alloc irq domain gc\n", np->name);

Cleanup path is missing from here on (actually there is no).

Sebastian

> +		return ret;
> +	}
> +
> +	ret = of_address_to_resource(np, 0, &r);
> +	if (ret) {
> +		pr_err("%s: unable to get resource\n", np->name);
> +		return ret;
> +	}
> +
> +	if (!request_mem_region(r.start, resource_size(&r), np->name)) {
> +		pr_err("%s: unable to request mem region\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	/* Map the parent interrupt for the chained handler */
> +	irq = irq_of_parse_and_map(np, 0);
> +	if (irq <= 0) {
> +		pr_err("%s: unable to parse irq\n", np->name);
> +		return -EINVAL;
> +	}
> +
> +	gc = irq_get_domain_generic_chip(domain, 0);
> +	gc->reg_base = ioremap(r.start, resource_size(&r));
> +	if (!gc->reg_base) {
> +		pr_err("%s: unable to map resource\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	gc->chip_types[0].regs.ack = DOVE_PMU_IRQ_CAUSE;
> +	gc->chip_types[0].regs.mask = DOVE_PMU_IRQ_MASK;
> +	gc->chip_types[0].chip.irq_ack = pmu_irq_ack;
> +	gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
> +	gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
> +
> +	/* mask and clear all interrupts */
> +	writel(0, gc->reg_base + DOVE_PMU_IRQ_MASK);
> +	writel(0, gc->reg_base + DOVE_PMU_IRQ_CAUSE);
> +
> +	irq_set_handler_data(irq, domain);
> +	irq_set_chained_handler(irq, dove_pmu_irq_handler);
> +
> +	return 0;
> +}
> +IRQCHIP_DECLARE(dove_pmu_intc,
> +		"marvell,dove-pmu-intc", dove_pmu_irq_init);
>