.section .vectors, "ax", %progbits
.L__vectors_start:
    W(b)    vector_rst
    W(b)    vector_und
    W(ldr)  pc, .L__vectors_start + 0x1000
    W(b)    vector_pabt
    W(b)    vector_dabt
    W(b)    vector_addrexcptn
    W(b)    vector_irq <----发生中断时执行这条指令
    W(b)    vector_fiq

/*
 * Interrupt dispatcher
 */
    vector_stub irq, IRQ_MODE, 4   // 相当于 vector_irq: ..., 
                                   // 它会根据SPSR寄存器的值,
                                   // 判断被中断时CPU是处于USR状态还是SVC状态, 
                                   // 然后调用下面的__irq_usr或__irq_svc

    .long   __irq_usr               @  0  (USR_26 / USR_32)
    .long   __irq_invalid           @  1  (FIQ_26 / FIQ_32)
    .long   __irq_invalid           @  2  (IRQ_26 / IRQ_32)
    .long   __irq_svc               @  3  (SVC_26 / SVC_32)
    .long   __irq_invalid           @  4
    .long   __irq_invalid           @  5
    .long   __irq_invalid           @  6
    .long   __irq_invalid           @  7
    .long   __irq_invalid           @  8
    .long   __irq_invalid           @  9
    .long   __irq_invalid           @  a
    .long   __irq_invalid           @  b
    .long   __irq_invalid           @  c
    .long   __irq_invalid           @  d
    .long   __irq_invalid           @  e
    .long   __irq_invalid           @  f

__irq_usr

	.align	5
__irq_usr:
	usr_entry
	kuser_cmpxchg_check
	irq_handler
	get_thread_info tsk
	mov	why, #0
	b	ret_to_user_from_irq
 UNWIND(.fnend		)
ENDPROC(__irq_usr)

__irq_svc

	.align	5
__irq_svc:
	svc_entry
	irq_handler

#ifdef CONFIG_PREEMPT
	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count
	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
	teq	r8, #0				@ if preempt count != 0
	movne	r0, #0				@ force flags to 0
	tst	r0, #_TIF_NEED_RESCHED
	blne	svc_preempt
#endif

	svc_exit r5, irq = 1			@ return from exception
 UNWIND(.fnend		)
ENDPROC(__irq_svc)

    .macro  irq_handler
#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
    ldr r1, =handle_arch_irq
    mov r0, sp
    badr    lr, 9997f
    ldr pc, [r1]
#else
    arch_irq_handler_default
#endif
9997:
    .endm

 cpu
 ||
 \/
 INTC //读intc得到hwirq
 ||
 \/
 SUB INTC//读subintc 得到hwirq'

 virq = hwirq  + offset + 1
      = hwirq + 16
 virq = hwirq' + offset + 2
      = hwirq' + 58 + 16

 / # cat /proc/interrupts
           CPU0
 29:      17593       s3c  13 Edge      samsung_time_irq 
 42:          0       s3c  26 Edge      ohci_hcd:usb1
 43:          0       s3c  27 Edge      s3c2440-i2c.0
 74:         86  s3c-level   0 Edge      s3c2440-uart
 75:        561  s3c-level   1 Edge      s3c2440-uart
 83:          0  s3c-level   9 Edge      ts_pen
 84:          0  s3c-level  10 Edge      adc
 87:          0  s3c-level  13 Edge      s3c2410-wdt

 / # cat /proc/interrupts

           CPU0
  8:          0       s3c   8 Edge      s3c2410-rtc tick
 13:        936       s3c  13 Edge      samsung_time_irq
 30:          0       s3c  30 Edge      s3c2410-rtc alarm
 32:         15  s3c-level  32 Level     50000000.serial
 33:         60  s3c-level  33 Level     50000000.serial
 59:          0  s3c-level  59 Edge      53000000.watchdog

	srom-cs4@20000000 {
		compatible = "simple-bus";
		#address-cells = <1>;
		#size-cells = <1>;
		reg = <0x20000000 0x8000000>;
		ranges;

		ethernet@20000000 {
			compatible = "davicom,dm9000";
			reg = <0x20000000 0x2 0x20000004 0x2>;
			interrupt-parent = <&gpf>; /*使用gpf中断控制器*/
			interrupts = <7 IRQ_TYPE_EDGE_RISING>;/*使用gpf控制器中的第七号中断，IRQ_TYPE_EDGE_RISING为中断触发方式*/
			local-mac-address = [00 00 de ad be ef];
			davicom,no-eeprom;
		};
	};

	interrupt-controller@4a000000 {
		compatible = "samsung,s3c2410-irq";
		reg = <0x4a000000 0x100>;
		interrupt-controller;
		#interrupt-cells = <0x4>;
		phandle = <0x1>;
	};

		gpf {
			gpio-controller;
			#gpio-cells = <0x2>;
			interrupt-controller;
			#interrupt-cells = <0x2>;
			phandle = <0x6>;
		};

		gpg {
			gpio-controller;
			#gpio-cells = <0x2>;
			interrupt-controller;
			#interrupt-cells = <0x2>;
		};

100ask分享的所有文件
	009_UBOOT移植_LINUX移植_驱动移植(免费)
		源码文档图片.zip
			源码文档图片
				源码文档
					毕业班_文档_图片_源码_bin
						毕业班第4课移植驱动到3.4.2内核_文档_图片_源码
							drivers_and_test_new
								jz2440
									7th_buttons_all

100ask分享的所有文件
	018_设备树详解
		doc_and_sources_for_device_tree
			source_and_images
				第5,6课的源码及映像文件(使用了完全版的设备树)
					第5课第5节_按键驱动_源码_设备树
						000th_origin_code

interrupts-extended = <&pic 0xA 8>, <&gic 0xda>;

make dtbs   // 得到 arch/arm/boot/dts/jz2440_irq.dtb

export  PATH=PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/work/system/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabi/bin

cd 002th_buttons_drv

make   // 得到 buttons.ko

export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/local/arm/4.3.2/bin

cd 002th_buttons_drv

arm-linux-gcc -o buttons_test  buttons_test.c

insmod buttons.ko
./buttons_test &

start_kernel // init/main.c
    init_IRQ();
        if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
            irqchip_init();   // 一般使用它
        else
            machine_desc->init_irq();

irqchip_init // drivers/irqchip/irqchip.c
    of_irq_init(__irqchip_of_table);  // 对设备树文件中每一个中断控制器节点, 调用对应的处理函数
        为每一个符合的"interrupt-controller"节点,
        分配一个of_intc_desc结构体, desc->irq_init_cb = match->data; // = IRQCHIP_DECLARE中传入的函数
        并调用处理函数
        
        (先调用root irq controller对应的函数, 再调用子控制器的函数, 再调用更下一级控制器的函数...)

IRQCHIP_DECLARE(s3c2410_irq, "samsung,s3c2410-irq", s3c2410_init_intc_of);  //drivers/irqchip/irq-s3c24xx.c

#define IRQCHIP_DECLARE(name, compat, fn) OF_DECLARE_2(irqchip, name, compat, fn)
#define OF_DECLARE_2(table, name, compat, fn) \
        _OF_DECLARE(table, name, compat, fn, of_init_fn_2)
#define _OF_DECLARE(table, name, compat, fn, fn_type)           \
    static const struct of_device_id __of_table_##name      \
        __used __section(__##table##_of_table)          \
         = { .compatible = compat,              \
             .data = (fn == (fn_type)NULL) ? fn : fn  }

    static const struct of_device_id __of_table_s3c2410_irq     \
        __used __section("__irqchip_of_table")          \
         = { .compatible = "samsung,s3c2410-irq",               \
             .data = s3c2410_init_intc_of  }

s3c2410_init_intc_of  // drivers/irqchip/irq-s3c24xx.c
    // 初始化中断控制器: intc, subintc
    s3c_init_intc_of(np, interrupt_parent, s3c2410_ctrl, ARRAY_SIZE(s3c2410_ctrl));
                
        // 为中断控制器创建irq_domain
        domain = irq_domain_add_linear(np, num_ctrl * 32,
                                 &s3c24xx_irq_ops_of, NULL);

        intc->domain = domain;

        // 设置handle_arch_irq, 即中断处理的C语言总入口函数
        set_handle_irq(s3c24xx_handle_irq);

static struct platform_driver samsung_pinctrl_driver = {
    .probe      = samsung_pinctrl_probe,
    .driver = {
        .name   = "samsung-pinctrl",
        .of_match_table = samsung_pinctrl_dt_match, // 含有 { .compatible = "samsung,s3c2440-pinctrl", .data = &s3c2440_of_data },
        .suppress_bind_attrs = true,
        .pm = &samsung_pinctrl_pm_ops,
    },
};

pinctrl@56000000 {
    reg = <0x56000000 0x1000>;
    compatible = "samsung,s3c2440-pinctrl";  // 据此找到驱动

samsung_pinctrl_probe  // drivers/pinctrl/samsung/pinctrl-samsung.c
    最终会调用到 s3c24xx_eint_init // drivers/pinctrl/samsung/pinctrl-s3c24xx.c
    
        // eint0,1,2,3的处理函数在处理root irq controller时已经设置; 
        // 设置eint4_7, eint8_23的处理函数(它们是分发函数)
        for (i = 0; i < NUM_EINT_IRQ; ++i) {
            unsigned int irq;

            if (handlers[i]) /* add by weidongshan@qq.com, 不再设置eint0,1,2,3的处理函数 */
            {
                irq = irq_of_parse_and_map(eint_np, i);
                if (!irq) {
                    dev_err(dev, "failed to get wakeup EINT IRQ %d\n", i);
                    return -ENXIO;
                }

                eint_data->parents[i] = irq;
                irq_set_chained_handler_and_data(irq, handlers[i], eint_data);
            }
        }

        // 为GPF、GPG设置irq_domain
        for (i = 0; i < d->nr_banks; ++i, ++bank) {
        
            ops = (bank->eint_offset == 0) ? &s3c24xx_gpf_irq_ops
                               : &s3c24xx_gpg_irq_ops;

            bank->irq_domain = irq_domain_add_linear(bank->of_node, bank->nr_pins, ops, ddata);
        }

    buttons {
        compatible = "jz2440_button";
        eint-pins  = <&gpf 0 0>, <&gpf 2 0>, <&gpg 3 0>, <&gpg 11 0>;
        interrupts-extended = <&intc 0 0 0 3>,
                              <&intc 0 0 2 3>,
                              <&gpg 3 3>,
                              <&gpg 11 3>;
    };

of_device_alloc (drivers/of/platform.c)
    dev = platform_device_alloc("", PLATFORM_DEVID_NONE);  // 分配 platform_device
    
    num_irq = of_irq_count(np);  // 计算中断数
    
    of_irq_to_resource_table(np, res, num_irq) // drivers/of/irq.c, 根据设备节点中的中断信息, 构造中断资源
        of_irq_to_resource
            int irq = of_irq_get(dev, index);  // 获得virq, 中断号
                            rc = of_irq_parse_one(dev, index, &oirq); // drivers/of/irq.c, 解析设备树中的中断信息, 保存在of_phandle_args结构体中
                            
                            domain = irq_find_host(oirq.np);   // 查找irq_domain, 每一个中断控制器都对应一个irq_domain
                            
                            irq_create_of_mapping(&oirq);             // kernel/irq/irqdomain.c, 创建virq和中断信息的映射
                                irq_create_fwspec_mapping(&fwspec);
                                    irq_create_fwspec_mapping(&fwspec);
                                        irq_domain_translate(domain, fwspec, &hwirq, &type) // 调用irq_domain->ops->xlate, 把设备节点里的中断信息解析为hwirq, type
                                        
                                        virq = irq_find_mapping(domain, hwirq); // 看看这个hwirq是否已经映射, 如果virq非0就直接返回
                                        
                                        virq = irq_create_mapping(domain, hwirq); // 否则创建映射
                                                    virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), NULL);  // 返回未占用的virq
                                                    
                                                    irq_domain_associate(domain, virq, hwirq) // 调用irq_domain->ops->map(domain, virq, hwirq), 做必要的硬件设置