添加: 08_RK3399_PCIe芯片手册解读
@@ -13,7 +13,7 @@
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开发板资料:
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* 芯片手册:Rockchip RK3399TRM V1.3 Part2.pdf
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* 芯片手册:Rockchip RK3399TRM V1.3 Part2.pdf 《Chapter 17 PCIe Controller》
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```shell
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doc_and_source_for_drivers\IMX6ULL\doc_pic\
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@@ -48,13 +48,7 @@ AXI相关:
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实际上,我们可以更深入一点,下图是STM32MP157的总线结构图(其他芯片没有画出总线结构图):
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本节视频我们只关心AXI总线,高速设备之间通过AXI总线连接。Master和Slave是多对多的关系,它们之间读、写可以同时进行的,内部结构图如下:
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实际芯片中,CPU与外设之间的连接更加复杂,高速设备之间通过AXI总线连接。AXI总线总传输数据的双方分为Master和Slave,Master发起传输,Slave回应传输。Master和Slave是多对多的关系,它们之间读、写可以同时进行的,内部结构图如下:
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@@ -110,26 +104,211 @@ RK3399的PCIe控制器就是挂在AXI总线上,在芯片手册中可以看到
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### 2. 地址空间
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### 2. 地址空间和寄存器介绍
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#### 2.1 想达到的目的
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使用PCIe时,我们编程时想达到这个目的:
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* CPU读写某个地址,就可以读写某个PCIe设备的配置空间:
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* CPU读写某个地址,就可以读写某个PCIe设备的内存、寄存器:
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简单地说,就是把CPU发出的addr,转换为右边的TLP头部:PCI地址、头部的其他信息。
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这涉及两部分:
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* 怎么把CPU地址转换为PCI地址
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* 怎么提供TLP头部信息中的其他部分
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#### 2.2 地址空间
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RK3399访问PCIe控制器时,CPU地址空间可以分为:
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* Client Register Set:地址范围 0xFD000000~0xFD7FFFFF
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* Core Register Set :地址范围 0xFD800000~0xFDFFFFFF
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* Region 0:0xF8000000~0xF9FFFFFF , 32MB
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* Region 1:0xFA000000~0xFA0FFFFF,1MB
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* Region 2:0xFA100000~0xFA1FFFFF,1MB
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* Client Register Set:地址范围 0xFD000000~0xFD7FFFFF,比如选择PCIe协议的版本(Gen1/Gen2)、电源控制等
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* Core Register Set :地址范围 0xFD800000~0xFDFFFFFF,所谓核心寄存器就是用来进行设置地址映射的寄存器等
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* Region 0:0xF8000000~0xF9FFFFFF , 32MB,用于访问外接的PCIe设备的配置空间
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* Region 1:0xFA000000~0xFA0FFFFF,1MB,用于地址转换
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* Region 2:0xFA100000~0xFA1FFFFF,1MB,用于地址转换
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* ……
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* Region 32:0xFBF00000~0xFBFFFFFF,1MB
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* Region 32:0xFBF00000~0xFBFFFFFF,1MB,用于地址转换
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其中Region 0大小为32MB,Region1~31大小分别为1MB。
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### 3. 访问流程
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CPU访问Region 0的地址时,将会导致PCIe控制器发出读写配置空间的TLP。
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CPU访问Region 1~32的地址时,将会导致PCIe控制器发出读写内存、IO空间的TLP。
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#### 2.3 寄存器介绍
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CPU访问一个地址,导致PCIe控制器发出TLP。TLP里含有PCIe地址、其他信息。
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这些寄存器必定涉及这2部分:
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* 地址转换:把CPU地址转换为PCIe地址
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* 提供TLP的其他信息
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Region0、Region1~32,每个Region都有类似的寄存器。
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一个Region,可以用于读写配置空间,可以用于读写内存空间、可以用于读写IO空间,还可以用于读写消息。
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这由Region对应的寄存器决定。
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每个Region都有一样寄存器,以Region 0为例,有6个寄存器:
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CPU访问某个Region时,它是想干嘛?
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* 读写配置空间、发出对应TLP?
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* 读写内存空间、发出对应TLP?
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* 读写IO空间、发出对应TLP?
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* 读写消息、发出对应TLP?
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到底是发出哪种TLP,由Region对应的ob_desc0寄存器决定:
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| ob_desc0[3:0] | 作用 |
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| ------------- | ----------------------------------- |
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| 1010 | 发出的TLP用于访问Type 0的配置空间 |
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| 1011 | 发出的TLP用于访问Type 1的配置空间 |
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| 0010 | 发出的TLP用于读写内存空间 |
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| 0110 | 发出的TLP用于读写IO空间 |
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| 1100 | 发出的TLP是"Normal Message" |
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| 1101 | 发出的TLP是"Vendor-Defined Message" |
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CPU访问某个Region时,最终都是要发出TLP,TLP的内容怎么确定?
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* 地址信息:ob_addr0/1把CPU地址转换为PCIe地址,提供TLP里面的地址信息
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* 其他信息:ob_desc0/1/2/3提供TLP的其他信息
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##### 2.3.1 用于配置空间
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Region0一般用于读写配置空间,它对应的寄存器如下:
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##### 2.3.2 用于内存和IO
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### 3. 访问示例
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#### 3.1 配置空间读写示例
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要读写设备的配置空间,首先要定位:Bus/Dev/Function/Reg:
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怎么发出这些"Bus/Dev/Function/Register"信息?如下图所示:
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当Region 0的寄存器ob_desc0[3:0]被配置为读写配置空间时, CPU发出Region 0的地址,地址里面隐含有这些信息:
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* Bus:cpu_addr[27:20]
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* Dev:cpu_addr[19:15]
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* Fun:cpu_addr[14:12]
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* Reg:cpu_addr[11:0]
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使用过程步骤如下。
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##### 3.1.1 配置Region 0用于读写配置空间
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##### 3.1.2 配置Region 0地址转换
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比如我们可以设置bit[5:0]为27,意味着cpu_addr[27:0]这28条地址线都会传入TLP。
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##### 3.1.3 CPU读写Region 0的地址
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Region 0的地址范围是:0xF8000000~0xF9FFFFFF。
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CPU想访问这个设备:Bus=bus,Dev=dev,Fun=fun,Reg=reg,那么CPU读写这个地址即可:
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```shell
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0xF8000000 + (bus<<20) | (dev<<15) | (fun<<12) | (reg)
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```
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#### 3.2 MEM/IO读写示例
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##### 3.2.1 配置Region 1用于内存读写
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##### 3.2.2 配置Region 1地址转换
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addr0、addr1寄存器里保存的是PCIe地址,也就是CPU发出这个Region的CPU地址后,将会转换为某个PCI地址。
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怎么转换?由addr0、addr1决定。
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Region 1的CPU地址范围是:0xFA000000~0xFA0FFFFF,是1M空间。
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我们一般会让PCI地址等于CPU地址,所以这样设置:
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* addr0:
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* [5:0]等于19,表示CPU_ADDR[19:0]共20位地址传入TLP
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* [31:8]等于0xFA0000
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* addr1:设置为0
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如上设置后,CPU读写地址时0xFA0?????,就会转换为PCI地址:0xFA0?????,转换过程如下:
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```shell
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pci_addr = cpu_addr[19:0] | (addr0[31:20] << 20) | (addr1<<32)
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= 0x????? + (0xFA0 << 20) | (0 << 32)
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= 0xFA0?????
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```
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#### 3.1 配置空间读写流程
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#### 3.2 MEM/IO读写流程
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@@ -47,20 +47,77 @@
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compatible = "rockchip,rk3399-pcie";
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#address-cells = <3>;
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#size-cells = <2>;
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aspm-no-l0s;
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clocks = <&cru ACLK_PCIE>, <&cru ACLK_PERF_PCIE>,
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<&cru PCLK_PCIE>, <&cru SCLK_PCIE_PM>;
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clock-names = "aclk", "aclk-perf",
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"hclk", "pm";
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bus-range = <0x0 0x1f>;
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...... /* 省略 */
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max-link-speed = <1>;
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linux,pci-domain = <0>;
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msi-map = <0x0 &its 0x0 0x1000>;
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interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH 0>,
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<GIC_SPI 50 IRQ_TYPE_LEVEL_HIGH 0>,
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<GIC_SPI 51 IRQ_TYPE_LEVEL_HIGH 0>;
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interrupt-names = "sys", "legacy", "client";
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#interrupt-cells = <1>;
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interrupt-map-mask = <0 0 0 7>;
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interrupt-map = <0 0 0 1 &pcie0_intc 0>,
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<0 0 0 2 &pcie0_intc 1>,
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<0 0 0 3 &pcie0_intc 2>,
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<0 0 0 4 &pcie0_intc 3>;
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phys = <&pcie_phy>;
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phy-names = "pcie-phy";
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ranges = <0x83000000 0x0 0xfa000000 0x0 0xfa000000 0x0 0x1e00000
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0x81000000 0x0 0xfbe00000 0x0 0xfbe00000 0x0 0x100000>;
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reg = <0x0 0xf8000000 0x0 0x2000000>,
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<0x0 0xfd000000 0x0 0x1000000>;
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...... /* 省略 */
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};
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reg-names = "axi-base", "apb-base";
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resets = <&cru SRST_PCIE_CORE>, <&cru SRST_PCIE_MGMT>,
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<&cru SRST_PCIE_MGMT_STICKY>, <&cru SRST_PCIE_PIPE>,
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<&cru SRST_PCIE_PM>, <&cru SRST_P_PCIE>,
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<&cru SRST_A_PCIE>;
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reset-names = "core", "mgmt", "mgmt-sticky", "pipe",
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"pm", "pclk", "aclk";
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status = "disabled";
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pcie0_intc: interrupt-controller {
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interrupt-controller;
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#address-cells = <0>;
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#interrupt-cells = <1>;
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};
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};
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```
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#### 2.1 设备树解析过程
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##### 2.1.1 地址解析
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寄存器地址:
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```c
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regs = platform_get_resource_byname(pdev,
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IORESOURCE_MEM,
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"apb-base"); // 0xfd000000
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rockchip->apb_base = devm_ioremap_resource(dev, regs);
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```
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ECAM地址:[PCIe ECAM介绍](https://zhuanlan.zhihu.com/p/176988002)
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```c
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regs = platform_get_resource_byname(pdev,
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IORESOURCE_MEM,
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"axi-base"); // 0xf8000000
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rockchip->reg_base = devm_ioremap_resource(dev, regs);
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```
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```c
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rockchip_pcie_probe
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resource_size_t io_base;
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@@ -109,6 +166,139 @@ rockchip_pcie_probe
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##### 2.1.2 地址映射
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MEM空间映射:
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```c
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// rockchip->mem_bus_addr = 0xfa000000
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// rockchip->mem_size = 0x1e00000
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// 设置Region1、2、……的映射关系
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for (reg_no = 0; reg_no < (rockchip->mem_size >> 20); reg_no++) {
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err = rockchip_pcie_prog_ob_atu(rockchip, reg_no + 1,
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AXI_WRAPPER_MEM_WRITE,
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20 - 1,
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rockchip->mem_bus_addr +
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(reg_no << 20),
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0);
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```
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IO空间映射:
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```c
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offset = rockchip->mem_size >> 20;
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for (reg_no = 0; reg_no < (rockchip->io_size >> 20); reg_no++) {
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err = rockchip_pcie_prog_ob_atu(rockchip,
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reg_no + 1 + offset,
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AXI_WRAPPER_IO_WRITE,
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20 - 1,
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rockchip->io_bus_addr +
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(reg_no << 20),
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0);
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if (err) {
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dev_err(dev, "program RC io outbound ATU failed\n");
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return err;
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}
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}
|
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```
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Message空间映射:
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```c
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/* assign message regions */
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rockchip_pcie_prog_ob_atu(rockchip, reg_no + 1 + offset,
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AXI_WRAPPER_NOR_MSG,
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20 - 1, 0, 0);
|
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|
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rockchip->msg_bus_addr = rockchip->mem_bus_addr +
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((reg_no + offset) << 20);
|
||||
```
|
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|
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|
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|
||||
|
||||
|
||||
```c
|
||||
|
||||
static int rockchip_pcie_prog_ob_atu(struct rockchip_pcie *rockchip,
|
||||
int region_no, int type, u8 num_pass_bits,
|
||||
u32 lower_addr, u32 upper_addr)
|
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{
|
||||
u32 ob_addr_0;
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u32 ob_addr_1;
|
||||
u32 ob_desc_0;
|
||||
u32 aw_offset;
|
||||
|
||||
if (region_no >= MAX_AXI_WRAPPER_REGION_NUM)
|
||||
return -EINVAL;
|
||||
if (num_pass_bits + 1 < 8)
|
||||
return -EINVAL;
|
||||
if (num_pass_bits > 63)
|
||||
return -EINVAL;
|
||||
if (region_no == 0) {
|
||||
if (AXI_REGION_0_SIZE < (2ULL << num_pass_bits))
|
||||
return -EINVAL;
|
||||
}
|
||||
if (region_no != 0) {
|
||||
if (AXI_REGION_SIZE < (2ULL << num_pass_bits))
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
aw_offset = (region_no << OB_REG_SIZE_SHIFT);
|
||||
|
||||
ob_addr_0 = num_pass_bits & PCIE_CORE_OB_REGION_ADDR0_NUM_BITS;
|
||||
ob_addr_0 |= lower_addr & PCIE_CORE_OB_REGION_ADDR0_LO_ADDR;
|
||||
ob_addr_1 = upper_addr;
|
||||
ob_desc_0 = (1 << 23 | type);
|
||||
|
||||
rockchip_pcie_write(rockchip, ob_addr_0,
|
||||
PCIE_CORE_OB_REGION_ADDR0 + aw_offset);
|
||||
rockchip_pcie_write(rockchip, ob_addr_1,
|
||||
PCIE_CORE_OB_REGION_ADDR1 + aw_offset);
|
||||
rockchip_pcie_write(rockchip, ob_desc_0,
|
||||
PCIE_CORE_OB_REGION_DESC0 + aw_offset);
|
||||
rockchip_pcie_write(rockchip, 0,
|
||||
PCIE_CORE_OB_REGION_DESC1 + aw_offset);
|
||||
|
||||
return 0;
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
##### 2.1.3 配置
|
||||
|
||||
Region 0:
|
||||
|
||||
```c
|
||||
rockchip_pcie_write(rockchip,
|
||||
(RC_REGION_0_ADDR_TRANS_L + RC_REGION_0_PASS_BITS),
|
||||
PCIE_CORE_OB_REGION_ADDR0);
|
||||
rockchip_pcie_write(rockchip, RC_REGION_0_ADDR_TRANS_H,
|
||||
PCIE_CORE_OB_REGION_ADDR1);
|
||||
rockchip_pcie_write(rockchip, 0x0080000a, PCIE_CORE_OB_REGION_DESC0);
|
||||
rockchip_pcie_write(rockchip, 0x0, PCIE_CORE_OB_REGION_DESC1);
|
||||
|
||||
```
|
||||
|
||||
|
||||
|
||||
读写配置空间:
|
||||
|
||||
```c
|
||||
busdev = PCIE_ECAM_ADDR(bus->number, PCI_SLOT(devfn),
|
||||
PCI_FUNC(devfn), where);
|
||||
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
#### 2.2 扫描总线过程
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```c
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After Width: | Height: | Size: 122 KiB |
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Before Width: | Height: | Size: 268 KiB After Width: | Height: | Size: 268 KiB |
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After Width: | Height: | Size: 112 KiB |
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After Width: | Height: | Size: 194 KiB |
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After Width: | Height: | Size: 206 KiB |
BIN
IMX6ULL/doc_pic/10_PCI_PCIe/pic/10_PCI_PCIe/61_region_regs.png
Normal file
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After Width: | Height: | Size: 74 KiB |
|
After Width: | Height: | Size: 227 KiB |
|
After Width: | Height: | Size: 213 KiB |
BIN
IMX6ULL/doc_pic/10_PCI_PCIe/pic/10_PCI_PCIe/64_config_devs.png
Normal file
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After Width: | Height: | Size: 263 KiB |
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After Width: | Height: | Size: 144 KiB |
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After Width: | Height: | Size: 198 KiB |
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After Width: | Height: | Size: 153 KiB |
|
After Width: | Height: | Size: 157 KiB |