Re: [PATCH v2 1/7] ARM: mmp: parse irq from DT

[Haojian Zhuang <haojian.zhuang@gmail.com>]

On Sat, Jul 30, 2011 at 12:36 AM, Grant Likely
<grant.likely@secretlab.ca> wrote:
> On Thu, Jul 28, 2011 at 02:41:27PM +0800, Haojian Zhuang wrote:
>> Parse irq sepcifier from DT and translate it to Linux irq number.
>> Remove the definition of NR_IRQS in irqs.h. Since sparse irq is
>> enabled, nr_irqs will be calculated automatically.
>>
>> Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
>> ---
>>  .../devicetree/bindings/arm/marvell/intc.txt       |  114 ++++++++++
>>  arch/arm/Kconfig                                   |    1 +
>>  arch/arm/mach-mmp/Makefile                         |    2 +
>>  arch/arm/mach-mmp/common.h                         |    1 +
>>  arch/arm/mach-mmp/include/mach/irqs.h              |    2 +-
>>  arch/arm/mach-mmp/intc.c                           |  224 ++++++++++++++++++++
>>  6 files changed, 343 insertions(+), 1 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/arm/marvell/intc.txt
>>  create mode 100644 arch/arm/mach-mmp/intc.c
>>
>> diff --git a/Documentation/devicetree/bindings/arm/marvell/intc.txt b/Documentation/devicetree/bindings/arm/marvell/intc.txt
>> new file mode 100644
>> index 0000000..80cef58
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/marvell/intc.txt
>> @@ -0,0 +1,114 @@
>> +* Interrupt Controller Binding for ARCH-MMP
>> +
>> +This binding specifies what properties must be available in device tree representation of an ARCH-MMP compliant interrupt controller.
>> +
>> +Required properties:
>> +
>> +     - compatible: Specifies the compatibility list of the interrupt
>> +       controller. The type shall be <string> and the value shall be
>> +       "mrvl,pxa168-intc" or "mrvl,mmp2-mux-intc".
>> +       "mrvl,pxa168-intc" is the base interrupt controller. It must be
>> +       included. It's compatible for pxa910, mmp2. "mrvl,mmp2-mux-intc"
>> +       is the expanded interrupt controller, and it's optional.
>> +
>> +     - reg: Specified the base physical address(s) and size(s) of the
>> +       interrupt controller's addressable register space. The type
>> +       should be <prop-encoded-array>.
>> +
>> +     - interrupt-controller: The presence of this property identifies
>> +       the node as interrupt controller. No property value should be
>> +       defined.
>> +
>> +     - #interrupt-cells: Specifies the number of cells needed to encode
>> +       an interrupt source. The type should be <u32> and the value should
>> +       be 1.
>> +
>> +     - mrvl,intc-numbers: Specifies the number of interrupts is supported
>> +       in this interrupt controller. The type should be <u32>.
>> +
>> +Optional properties:
>> +
>> +     - mrvl,intc-priority: Specifies the which path the interrupt is routed
>> +       and the priority of this interrupt. The property is used in
>> +       pxa168-intc. The value should be <u32>.
>> +
>> +     - mrvl,status-offset: Specifies the offset of status register. The
>> +       property is used in mmp2-mux-intc. The type should be <u32>.
>> +
>> +     - mrvl,mask-offset: Specifies the offset of mask register. The
>> +       property is used in mmp2-mux-intc. The type should be <u32>.
>> +
>> +     - mrvl,mfp-edge: Specifies the address of mfp edge detection register.
>> +       The property is used while acking specified interrupt. The type
>> +       should be <prop-encoded-array>. The first cell indicates the address
>> +       of mfp edge detection register. The second cell indicates the
>> +       index of interrupt in current interrupt controller that should
>> +       handle mfp edge detection.
>> +
>> +* Examples
>> +
>> +Example 1:
>> +
>> +     /*
>> +      * base INTC
>> +      */
>> +     mmp_intc: interrupt-controller@d4282000 {
>> +             /* Compatible with pxa168-intc. */
>> +             compatible = "mrvl,pxa168-intc";
>> +             #address-cells = <1>;
>> +             #size-cells = <1>;
>> +             /* Offset address of 0xd4282000 and size of 0x400. */
>> +             reg = <0xd4282000 0x400>;
>> +
>> +             #interrupt-cells = <1>;
>> +             interrupt-controller;
>> +
>> +             /* 64 interrupts are supported in this INTC. */
>> +             mrvl,intc-numbers = <64>;
>> +
>> +             /* priority bits in configuration register */
>> +             mrvl,intc-priority = <0x20>;
>> +     };
>> +
>> +Example 2:
>> +
>> +     /*
>> +      * mux INTC that is internal wired to base INTC
>> +      */
>> +     mux_intc4: interrupt-controller@d4282150 {
>> +             compatible = "mrvl,mmp2-mux-intc";
>> +             #address-cells = <1>;
>> +             #size-cells = <1>;
>> +             reg = <0xd4282000 0x400>;
>> +
>> +             #interrupt-cells = <1>;
>> +             interrupt-controller;
>> +             interrupt-parent = <&mmp_intc>;
>> +
>> +             /* interrupt source '4' of parent INTC. */
>> +             interrupts = <4>;
>> +
>> +             /* 2 interrupts are supported in this INTC. */
>> +             mrvl,intc-numbers = <2>;
>> +
>> +             /* Status offset address of 0x150. */
>> +             mrvl,status-offset = <0x150>;
>> +
>> +             /* Mask offset address of 0x168. */
>> +             mrvl,mask-offset = <0x168>;
>> +
>> +             /* mfp register of 0xd401e2c4 & interrupt index of 1 */
>> +             mrvl,mfp-edge = <0xd401e2c4 1>;
>> +     };
>> +
>> +Example 3:
>> +     /*
>> +      * An interrupt generating device that is wired to an INTC.
>> +      */
>> +     uart0: uart@d4030000 {
>> +             /* parent's '#interrupt-cells' property. */
>> +             interrupts = <27>;
>> +
>> +             /* The INTC that this device is wired to. */
>> +             interrupt-parent = <&mmp_intc>;
>> +     };
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index 17507b8..f18eb14 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -542,6 +542,7 @@ config ARCH_MMP
>>       select ARCH_REQUIRE_GPIOLIB
>>       select CLKDEV_LOOKUP
>>       select GENERIC_CLOCKEVENTS
>> +     select GENERIC_IRQ_CHIP
>>       select HAVE_SCHED_CLOCK
>>       select TICK_ONESHOT
>>       select PLAT_PXA
>> diff --git a/arch/arm/mach-mmp/Makefile b/arch/arm/mach-mmp/Makefile
>> index 5c68382..e7862ea 100644
>> --- a/arch/arm/mach-mmp/Makefile
>> +++ b/arch/arm/mach-mmp/Makefile
>> @@ -4,6 +4,8 @@
>>
>>  obj-y                                += common.o clock.o devices.o time.o
>>
>> +obj-$(CONFIG_OF_IRQ)         += intc.o
>> +
>
> I'm still really confused about why an entirely new interrupt
> controller file is being added.  Drivers already exist in mach-mmp
> for the mux and pxa168 interrupt controllers, but this adds a whole
> new driver.  I would expect the existing drivers should be refactored
> to use irq generic chip, and then extend them to add DT support.
>
Before applying this patch, two irq (irq-pxa168.c & irq-mmp2.c) exists.
The block issue of merging them together is different register.
Now DT can resolve different register. I'm planning to remove both of
irq-pxa168.c & irq-mmp2.c after these DT patches.

>>  # SoC support
>>  obj-$(CONFIG_CPU_PXA168)     += pxa168.o irq-pxa168.o
>>  obj-$(CONFIG_CPU_PXA910)     += pxa910.o irq-pxa168.o
>> diff --git a/arch/arm/mach-mmp/common.h b/arch/arm/mach-mmp/common.h
>> index ec8d65d..1c563c2 100644
>> --- a/arch/arm/mach-mmp/common.h
>> +++ b/arch/arm/mach-mmp/common.h
>> @@ -6,3 +6,4 @@ extern void timer_init(int irq);
>>
>>  extern void __init icu_init_irq(void);
>>  extern void __init mmp_map_io(void);
>> +extern void __init mmp_init_intc(void);
>> diff --git a/arch/arm/mach-mmp/include/mach/irqs.h b/arch/arm/mach-mmp/include/mach/irqs.h
>> index a09d328..65ec176 100644
>> --- a/arch/arm/mach-mmp/include/mach/irqs.h
>> +++ b/arch/arm/mach-mmp/include/mach/irqs.h
>> @@ -224,6 +224,6 @@
>>
>>  #define IRQ_BOARD_START                      (IRQ_GPIO_START + IRQ_GPIO_NUM)
>>
>> -#define NR_IRQS                              (IRQ_BOARD_START)
>> +#define NR_IRQS                              0
>
> Why is NR_IRQs getting changed?  I think this will break
> !CONFIG_SPARSE_IRQS, and it shouldn't be necessary for this
> conversion.
>
If CONFIG_SPARSE_IRQ is enabled, arch_probe_nr_irqs() returns NR_IRQS in arm.
It results registering NR_IRQS in early_irq_init(). If NR_IRQS is 200,
200 irqs are
registered in early_irq_init(). It's not my requirement. What I need
is registering irq
from DT.

So I have to define NR_IRQS to 0. And CONFIG_SPARSE_IRQS is always enabled
in ARCH_MMP. So it's selected in Kconfig by default.

>>
>>
>> --
>> Regards,
>> Shawn
>>
>>  #endif /* __ASM_MACH_IRQS_H */
>> diff --git a/arch/arm/mach-mmp/intc.c b/arch/arm/mach-mmp/intc.c
>> new file mode 100644
>> index 0000000..2e44057
>> --- /dev/null
>> +++ b/arch/arm/mach-mmp/intc.c
>> @@ -0,0 +1,224 @@
>> +/*
>> + *  linux/arch/arm/mach-mmp/intc.c
>> + *
>> + *  Generic IRQ handling
>> + *
>> + *  Author:  Haojian Zhuang <haojian.zhuang@marvell.com>
>> + *  Copyright:       Marvell International Ltd. 2011
>> + *
>> + *  This program is free software; you can redistribute it and/or modify
>> + *  it under the terms of the GNU General Public License version 2 as
>> + *  published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/errno.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/slab.h>
>> +
>> +struct mmp_intc_info {
>> +     unsigned int            en_mask;
>> +     void __iomem            *virt_base;
>> +     void __iomem            *status;
>> +     void __iomem            *mfp_edge;
>> +     unsigned int            mfp_edge_index; /* index in irq domain */
>> +};
>> +
>> +static void mux_irq_ack(struct irq_data *d)
>> +{
>> +     struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
>> +     struct irq_chip_type *ct;
>> +     struct mmp_intc_info *info;
>> +     unsigned int data, irq_offs;
>> +
>> +     ct = gc->chip_types;
>> +     info = (struct mmp_intc_info *)ct->regs.ack;
>> +     irq_offs = d->irq - gc->irq_base;
>> +     /* clear MFP edge-detect */
>> +     if (info->mfp_edge && (info->mfp_edge_index == irq_offs)) {
>> +             data = __raw_readl(info->mfp_edge);
>> +             __raw_writel(data | (1 << 6), info->mfp_edge);
>> +             __raw_writel(data, info->mfp_edge);
>> +     }
>> +}
>> +
>> +static void mmp_irq_demux_handler(unsigned int irq, struct irq_desc *desc)
>> +{
>> +     struct irq_chip_generic *gc = irq_get_handler_data(irq);
>> +     struct irq_chip_type *ct;
>> +     struct mmp_intc_info *info;
>> +     unsigned long status, n;
>> +
>> +     ct = gc->chip_types;
>> +     info = (struct mmp_intc_info *)ct->regs.ack;
>> +     while (1) {
>> +             status = __raw_readl(info->status) & ~gc->mask_cache;
>> +             if (status == 0)
>> +                     break;
>> +             n = find_first_bit(&status, BITS_PER_LONG);
>> +             while (n < BITS_PER_LONG) {
>> +                     generic_handle_irq(gc->irq_base + n);
>> +                     n = find_next_bit(&status, BITS_PER_LONG, n + 1);
>> +             }
>> +     }
>> +}
>> +
>> +static void mux_init_intc(struct mmp_intc_info *mmp_info)
>> +{
>> +     struct device_node *np;
>> +     struct mmp_intc_info *mux_info;
>> +     struct irq_chip_generic *gc;
>> +     struct irq_chip_type *ct;
>> +     const __be32 *edge;
>> +     unsigned int addr = 0, offs = 0;
>> +     unsigned int status, mask, irq_base, nr, data;
>> +     int cascade;
>> +
>> +     for_each_compatible_node(np, NULL, "mrvl,mmp2-mux-intc") {
>> +             if (of_get_property(np, "interrupt-controller", NULL) == NULL)
>> +                     continue;
>> +             if (of_property_read_u32(np, "mrvl,intc-numbers", &nr) < 0) {
>> +                     pr_warn("intc-numbers property is missed\n");
>> +                     continue;
>> +             }
>> +             if (of_property_read_u32(np, "mrvl,status-offset", &status)
>> +                     < 0) {
>> +                     pr_warn("intc-status property is missed\n");
>> +                     continue;
>> +             }
>> +             if (of_property_read_u32(np, "mrvl,mask-offset", &mask) < 0) {
>> +                     pr_warn("intc-mask property is missed\n");
>> +                     continue;
>> +             }
>> +
>> +             mux_info = kzalloc(sizeof(*mux_info), GFP_KERNEL);
>> +             if (mux_info == NULL)
>> +                     goto out;
>> +             status += (unsigned int)mmp_info->virt_base;
>> +             mux_info->status = (void __iomem *)status;
>> +
>> +             edge = of_get_property(np, "mrvl,mfp-edge", NULL);
>> +             if (edge) {
>> +                     addr = be32_to_cpu(*edge) & PAGE_MASK;
>> +                     offs = be32_to_cpu(*edge) - addr;
>> +                     mux_info->mfp_edge = ioremap(addr, PAGE_SIZE) + offs;
>> +                     mux_info->mfp_edge_index = be32_to_cpu(*++edge);
>> +                     /* clear mfp edge detection for initialization */
>> +                     data = __raw_readl(mux_info->mfp_edge);
>> +                     __raw_writel(data | (1 << 6), mux_info->mfp_edge);
>> +                     __raw_writel(data, mux_info->mfp_edge);
>> +             }
>> +
>> +             /* allocate new irq */
>> +             cascade = irq_of_parse_and_map(np, 0);
>> +             irq_base = irq_alloc_descs(-1, 0, nr, 0);
>> +             irq_domain_add_simple(np, irq_base);
>> +
>> +             gc = irq_alloc_generic_chip("mux-intc", 1, irq_base,
>> +                                     mmp_info->virt_base, handle_level_irq);
>> +             ct = gc->chip_types;
>> +             ct->regs.ack = (unsigned int)mux_info;
>> +             ct->regs.mask = mask;
>> +             ct->chip.irq_ack = mux_irq_ack;
>> +             ct->chip.irq_mask = irq_gc_mask_set_bit;
>> +             ct->chip.irq_unmask = irq_gc_mask_clr_bit;
>> +             irq_setup_generic_chip(gc, IRQ_MSK(nr), IRQ_GC_INIT_MASK_CACHE,
>> +                                     IRQ_NOREQUEST | IRQ_NOPROBE, 0);
>> +
>> +             irq_set_handler_data(cascade, gc);
>> +             irq_set_chained_handler(cascade, mmp_irq_demux_handler);
>> +     }
>> +out:
>> +     return;
>> +}
>> +
>> +static void mmp_irq_unmask(struct irq_data *d)
>> +{
>> +     struct mmp_intc_info *info = irq_data_get_irq_chip_data(d);
>> +
>> +     /* ICU_INT_CONF */
>> +     __raw_writel(info->en_mask, info->virt_base + (d->irq << 2));
>> +}
>> +
>> +static void mmp_irq_mask(struct irq_data *d)
>> +{
>> +     struct mmp_intc_info *info = irq_data_get_irq_chip_data(d);
>> +
>> +     __raw_writel(0, info->virt_base + (d->irq << 2));
>> +}
>> +
>> +static struct irq_chip mmp_irq_chip = {
>> +     .name           = "mmp-intc",
>> +     .irq_unmask     = mmp_irq_unmask,
>> +     .irq_mask       = mmp_irq_mask,
>> +     .irq_ack        = mmp_irq_mask,
>> +};
>> +
>> +void __init mmp_init_intc(void)
>> +{
>> +     struct mmp_intc_info *info;
>> +     struct device_node *np;
>> +     struct resource rs;
>> +     unsigned int cells, nr, enable, irq_base;
>> +     int i;
>> +
>> +     np = of_find_compatible_node(NULL, NULL, "mrvl,pxa168-intc");
>> +
>> +     BUG_ON(!np);
>> +
>> +     of_node_get(np);
>> +     if (of_get_property(np, "interrupt-controller", NULL) == NULL)
>> +             goto out;
>> +     if (of_property_read_u32(np, "#interrupt-cells", &cells) < 0) {
>> +             pr_warn("mmp-intc: interrupt-cells property is missed\n");
>> +             goto out;
>> +     }
>> +     if (cells != 1) {
>> +             pr_warn("mmp-intc: interrupt-cells property is incorrect\n");
>> +             goto out;
>> +     }
>> +     if (of_property_read_u32(np, "mrvl,intc-numbers", &nr) < 0) {
>> +             pr_warn("mmp-intc: mrvl,intc-numbers property is missed\n");
>> +             goto out;
>> +     }
>> +     if (of_property_read_u32(np, "mrvl,intc-priority", &enable) < 0) {
>> +             pr_warn("mmp-intc: mrvl,intc-priority property is missed\n");
>> +             goto out;
>> +     }
>> +     if (of_address_to_resource(np, 0, &rs) < 0) {
>> +             pr_warn("mmp-intc: invalid reg property\n");
>> +             goto out;
>> +     }
>> +
>> +     info = kzalloc(sizeof(struct mmp_intc_info), GFP_KERNEL);
>> +     if (info == NULL)
>> +             goto out;
>> +     info->en_mask = enable;
>> +     info->virt_base = ioremap(rs.start, PAGE_SIZE);
>> +     if (info->virt_base == NULL) {
>> +             pr_warn("mmp-intc: failed to remap reg base\n");
>> +             goto out_mem;
>> +     }
>> +
>> +     /* allocate new irq */
>> +     irq_base = irq_alloc_descs(-1, 0, nr, 0);
>> +     irq_domain_add_simple(np, 0);
>> +
>> +     for (i = irq_base; i < irq_base + nr; i++) {
>> +             irq_set_chip_data(i, info);
>> +             mmp_irq_mask(irq_get_irq_data(i));
>> +             irq_set_chip_and_handler(i, &mmp_irq_chip, handle_level_irq);
>> +             set_irq_flags(i, IRQF_VALID);
>> +     }
>> +     mux_init_intc(info);
>> +     of_node_put(np);
>> +     return;
>> +out_mem:
>> +     kfree(info);
>> +out:
>> +     of_node_put(np);
>> +     return;
>> +}
>> --
>> 1.5.6.5
>>
>