VIC 中断 与 gpio 中断 的硬件拓扑图描述

以下是 s3c6410a 的 irq 拓扑 描述,着重凸显了 gpio irq
以下 每个颜色 的gpio 共享一个vic 的中断线,共 5 个 中断线
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注意 : 在linux 里面,将每个 gpx 注册为了一个domain!!!

linux cascaded irq domain

• irq domain & 级联(cascaded)irq domain

irq domain 初始化时

s3c64xx_eint_eint0_init// 0. 处理 parents interrupt console 相关的 中断处理函数for (i = 0; i < NUM_EINT0_IRQ; ++i) { // 设置 parent 相关的irqirq = irq_of_parse_and_map(eint0_np, i);irq_set_chained_handler_and_data(irq, s3c64xx_eint0_handlers[i], data);}// 1. 创建 irq domainfor (i = 0; i < d->nr_banks; ++i, ++bank) bank->irq_domain = irq_domain_add_linear(bank->of_node, nr_eints, &s3c64xx_eint0_irqd_ops, ddata);// irq_domain_add_simple 的 第三个参数 first_irq如果为0 ,效果等同于 irq_domain_add_linear// first_irq: first number of irq block assigned to the domain,// pass zero to assign irqs on-the-fly. If first_irq is non-zero, then// pre-map all of the irqs in the domain to virqs starting at first_irq.// 如果第三个参数 不等于0 ,则 在该函数中 做 irq_create_mapping

获取 IRQ number(软件中断号) 时

使用domain 映射号码irq_create_mapping/irq_create_mapping_affinity// 2. 获取 软件中断号  并 创建 descsvirq = irq_find_mapping(domain, hwirq);virq = irq_domain_alloc_descs(-1, 1, hwirq, of_node_to_nid(of_node), affinity);// 3. 绑定 domain 中的软件中断号 和 硬件中断号// 用domain 的 map函数 设置 高层 handlerirq_domain_associate(domain, virq, hwirq)irq_set_chip_and_handler(virq, &s3c64xx_eint0_irq_chip, handle_level_irq);

中断发生时

• 非级联的中断发生流程

一旦发生硬件中断，经过CPU architecture相关的中断代码之后，会调用irq handler，该函数的一般过程如下：（1）首先找到root interrupt controller对应的irq domain。（2）根据HW 寄存器信息和irq domain信息获取HW interrupt ID（3）调用irq_find_mapping找到HW interrupt ID对应的irq number（4）调用handle_IRQ（对于ARM平台）来处理该irq number

• 级联中断发生流程

按照当前 gpio 级联到 vic
假设 vic0 是 A, GPN0-3的domain 是 B
假设 GPN0 发生了中断A.1首先找到root interrupt controller(在这里是vic)对应的irq domain  // 关注 irq_set_chip_data irq_get_chip_data 
A.2根据VIC HW 寄存器信息和irq domain信息获取HW interrupt ID  // VIC0的 0
A.3调用irq_find_mapping找到HW interrupt ID(在这里是0)对应的irq number
A.4调用irq domain B 注册 的 handler( irq_set_chained_handler 设定的gpio_handle_irq_cascaded)B.1gpio_handle_irq_cascaded找到gpio对应的irq domain // 和 A.1 中的irq domain完全不同// 关注 irq_set_chip_data irq_get_chip_data 
B.2根据GPIO HW 寄存器信息和irq domain信息获取HW interrupt ID // 和 A.2 中的HW interrupt ID完全不同
B.3调用irq_find_mapping找到HW interrupt ID对应的irq number // 和 A.3 中的 irq number 完全不同
B.4调用 驱动 注册 的 handler( request_irq 设定的) // 这个驱动对应的设备用到了 GPN0

如何调试

CONFIG_DYNAMIC_DEBUG=y
CONFIG_DEBUG_FS=y
CONFIG_GENERIC_IRQ_DEBUGFS=y
----------------
kernel/irq/Makefile
@@ -1,5 +1,6 @@# SPDX-License-Identifier: GPL-2.0+ccflags-y += -DDEBUG -DVERBOSE_DEBUG

# pwd
/sys/kernel/debug/irq
# ls
domains  irqs
# ls -l 
total 0
drwxr-xr-x    2 root     root             0 Jan  1 00:00 domains
drwxr-xr-x    2 root     root             0 Jan  1 00:00 irqs以下的文件都可以读./domains:
:soc:interrupt-controller@71200000  :soc:pinctrl@7f008000:gph
:soc:interrupt-controller@71300000  :soc:pinctrl@7f008000:gpl
:soc:pinctrl@7f008000:gpa           :soc:pinctrl@7f008000:gpm
:soc:pinctrl@7f008000:gpb           :soc:pinctrl@7f008000:gpn
:soc:pinctrl@7f008000:gpc           :soc:pinctrl@7f008000:gpo
:soc:pinctrl@7f008000:gpd           :soc:pinctrl@7f008000:gpp
:soc:pinctrl@7f008000:gpf           :soc:pinctrl@7f008000:gpq
:soc:pinctrl@7f008000:gpg           default./irqs:
0   10  12  14  16  18  2   21  23  25  27  29  30  32  4   6   8
1   11  13  15  17  19  20  22  24  26  28  3   31  33  5   7   9

linux irq domain 实例

irq: Added domain :soc:interrupt-controller@71200000
irq: Added domain :soc:interrupt-controller@71300000
irq: Added domain :soc:pinctrl@7f008000:gpa
irq: Added domain :soc:pinctrl@7f008000:gpb
irq: Added domain :soc:pinctrl@7f008000:gpc
irq: Added domain :soc:pinctrl@7f008000:gpd
irq: Added domain :soc:pinctrl@7f008000:gpf
irq: Added domain :soc:pinctrl@7f008000:gpg
irq: Added domain :soc:pinctrl@7f008000:gph
irq: Added domain :soc:pinctrl@7f008000:gpo
irq: Added domain :soc:pinctrl@7f008000:gpp
irq: Added domain :soc:pinctrl@7f008000:gpq
irq: Added domain :soc:pinctrl@7f008000:gpl
irq: Added domain :soc:pinctrl@7f008000:gpm
irq: Added domain :soc:pinctrl@7f008000:gpn

irq: Added domain :soc:pinctrl@7f008000:gpn
irq: -> using domain @c0889d80
SUD File: kernel/irq/irqdomain.c, Line: 00557: irq_domain_associate,domain:c0889d80,virq:33,hwirq:7
SUD File: kernel/irq/irqdomain.c, Line: 00559: irq_domain_associate,c024afa8 // s3c64xx_eint0_irq_map domain->ops->map
SUD File: kernel/irq/irqdomain.c, Line: 00499: irq_domain_set_mapping,7,16
irq: irq 7 on domain gpn mapped to virtual irq 33

VIC domain 与 gpio domain 的硬件拓扑语言描述

VIC 与 INT_EINTx 的关系

Int. No.	Sources	Description	Group
53	INT_EINT4	External interrupt Group 1 ~ Group 9	VIC1
33	INT_EINT3	External interrupt Group 0 20 ~ 27	VIC1
32	INT_EINT2	External interrupt Group 0 12 ~ 19	VIC1
1	INT_EINT1	External interrupt Group 0 4 ~ 11	VIC0
0	INT_EINT0	External interrupt Group 0 0 ~ 3	VIC0

INT_EINTx 与 GPIO的关系

INT_EINT0

External interrupt Group 0  0 - 15  <===> GPN0-GPN15GPN0-3			: 0GPN4-11			: 1GPN12-15 & GPL8-GPL11 : 32
External interrupt Group 0  16 - 22 <===> GPL8-GPL14GPL12-GPL14 & GPM0-GPM4 : 33
External interrupt Group 0  23 - 27 <===> GPM0-GPM4

INT_EINT1

External interrupt Group 0  0 - 15  <===> GPN0-GPN15
External interrupt Group 0  16 - 22 <===> GPL8-GPL14
External interrupt Group 0  23 - 27 <===> GPM0-GPM4

INT_EINT2

External interrupt Group 0  0 - 15  <===> GPN0-GPN15
External interrupt Group 0  16 - 22 <===> GPL8-GPL14
External interrupt Group 0  23 - 27 <===> GPM0-GPM4

INT_EINT3

External interrupt Group 0  0 - 15  <===> GPN0-GPN15
External interrupt Group 0  16 - 22 <===> GPL8-GPL14
External interrupt Group 0  23 - 27 <===> GPM0-GPM4

INT_EINT4

INT_EINT4 与 External interrupt Group1-9 的关系

External interrupt Group1

EINT1 0 - 7   <===> GPA 0 - 7
EINT1 8 - 14  <===> GPB 0 - 6

External interrupt Group2

EINT2 0 - 7   <===> GPC 0 - 7

External interrupt Group3

EINT3 0 - 4   <===> GPD 0 - 4

External interrupt Group4

EINT4 0 - 13   <===> GPF 0 - 13

External interrupt Group5

EINT5 0 - 6   <===> GPG 0 - 6

External interrupt Group6

EINT6 0 - 9   <===> GPH 0 - 9

External interrupt Group7

EINT7 0 - 15   <===> GPO 0 - 7

External interrupt Group8

EINT8 0 - 14   <===> GPP 0 - 7

External interrupt Group9

EINT9 0 - 8   <===> GPQ 0 - 8