[Mod] 更新文档

spi/ReadMe.md

@@ -2,6 +2,7 @@
 
 
 ## 参考
+
  - linux_5.10/Documentation/spi/spi-summary.rst
 
 
@@ -15,10 +16,12 @@
 ### 两种SPI驱动
 
 #### Controller drivers ...
+
    此类驱动的对象为SOC片上的SPI控制器，这些控制器通常支持“Master”与“Slave”角色切换。
 此类驱动常直接访问硬件寄存器并使用DMA来提高数据传递效率，或许也可以通过CPU控制数据的每一位来控制可编程GPIO管脚。
 
 #### Protocol drivers ...
+
    此类驱动的对象为SOC片外接的SPI设备，这些设备以“Master”或“Slave”角色接入SPI控制器,进而完成数据的传输。
    在SPI驱动之上，可能被具象化为MTD、Audio等设备接入更上一级的子系统。
 
@@ -56,13 +59,16 @@ SPI设备必须管理以下两种类型内存：
 
 ## 示例
 
-### 静态定义
+### 设备
 
-#### 板级设备
+#### 板级静态定义
 
 ##### Master
-"struct platform_device"
+
+- `struct platform_device`, 基于平台设备开发;
+
 路径：`arch/.../mach-*/board-*.c`:
+
 ```c
 	#include <mach/spi.h>	/* for mysoc_spi_data */
 
@@ -105,8 +111,11 @@ SPI设备必须管理以下两种类型内存：
 		...
 	}
 ```
+
 ##### Slave
+
 文件：`arch/.../mach-*/board-*.c`：
+
 ```c
 	static struct ads7846_platform_data ads_info = {
 		.vref_delay_usecs	= 100,
@@ -131,13 +140,121 @@ SPI设备必须管理以下两种类型内存：
 	spi_register_board_info(spi_board_info, ARRAY_SIZE(spi_board_info));
 ```
 
-### 非静态定义
+#### DTS动态定义
 
-使用`spi_busnum_to_master()`查找目标SPI控制器；
+##### Master
-使用`spi_new_device()`创建;
-使用`spi_unregister_device()`销毁；
 
-### SPI Controller Driver
+```dts
+#---- build/boards/default/dts/cv181x/cv181x_base.dtsi
+/ {
+	spi3:spi3@041B0000 {
+		interrupts = <57 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-parent = <&plic0>;
+	};	
+	...
+```
+
+##### Slave
+
+- 独占总线
+
+  ```dts
+  #---- build/boards/default/dts/cv181x/cv181x_asic_bga.dtsi
+  &spi3 {
+  	status = "okay";
+  	num-cs = <1>;
+  	spidev@0 {
+  		compatible = "rohm,dh2228fv";
+  		spi-max-frequency = <1000000>;
+  		reg = <0>;
+  	};
+  };
+  
+  #---- build/boards/cv181x/cv1813h_milkv_duos_sd/dts_riscv/cv1813h_milkv_duos_sd.dts
+  &spi3 {
+  	status = "okay";
+  
+  	spidev@0 {
+  		status = "okay";
+  	};
+  };
+  ```
+
+- 多设备
+
+  参考内核文档：
+
+  1. linux_5.10/Documentation/devicetree/bindings/spi/spi-bus.txt；
+  2. linux_5.10/arch/arm/boot/dts/imx6ul-imx6ull-opos6uldev.dtsi
+
+  ```dts
+  #---- linux_5.10/arch/arm/boot/dts/imx6ull-opos6uldev.dts
+  /dts-v1/;
+  #include "imx6ull-opos6ul.dtsi"								# 1
+  #	include "imx6ul.dtsi"									# 1.1
+  #include "imx6ul-imx6ull-opos6uldev.dtsi"					# 2
+  
+  / {
+  	model = "Armadeus Systems OPOS6UL SoM (i.MX6ULL) on OPOS6ULDev board";
+  	compatible = "armadeus,imx6ull-opos6uldev", "armadeus,imx6ull-opos6ul", "fsl,imx6ull";
+  };
+  
+  #1.1- linux_5.10/arch/arm/boot/dts/imx6ul.dtsi
+  / {
+  	...
+  	soc {
+  		...
+  		aips1: bus@2000000 {
+  			...
+  			spba-bus@2000000 {
+  				...
+  				ecspi4: spi@2014000 {
+  					#address-cells = <1>;
+  					#size-cells = <0>;
+  					compatible = "fsl,imx6ul-ecspi", "fsl,imx51-ecspi";
+  					reg = <0x02014000 0x4000>;
+  					interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
+  					clocks = <&clks IMX6UL_CLK_ECSPI4>,
+  						 <&clks IMX6UL_CLK_ECSPI4>;
+  					clock-names = "ipg", "per";
+  					dmas = <&sdma 9 7 1>, <&sdma 10 7 2>;
+  					dma-names = "rx", "tx";
+  					status = "disabled";
+  				};
+  
+  #2--- linux_5.10/arch/arm/boot/dts/imx6ul-imx6ull-opos6uldev.dtsi
+  &ecspi4 {
+  	pinctrl-names = "default";
+  	pinctrl-0 = <&pinctrl_ecspi4>;
+  	num-cs = 2;
+  	cs-gpios = <&gpio4 9 GPIO_ACTIVE_LOW>, <&gpio4 3 GPIO_ACTIVE_LOW>;
+  	status = "okay";
+  
+  	spidev0: spi@0 {
+  		compatible = "spidev";
+  		reg = <0>;
+  		spi-max-frequency = <5000000>;
+  	};
+  
+  	spidev1: spi@1 {
+  		compatible = "spidev";
+  		reg = <1>;
+  		spi-max-frequency = <5000000>;
+  	};
+  };
+  ```
+
+#### 总结
+
+1. `spi-max-frequency`，多通道时，需要定义设备允许的最大速率；---- 待确认；
+
+### 驱动
+
+- `spi_busnum_to_master()`, 查找目标SPI控制器；
+- `spi_new_device()`, 创建;
+- `spi_unregister_device()`销毁；
+
+#### SPI Controller Driver
 
 ```c
 	struct spi_master	*master;
@@ -152,14 +269,14 @@ SPI设备必须管理以下两种类型内存：
 
 - `spi_[un]register_master()`注册至系统；
 
-#### 接口
+master操作集
 
 - `master->setup(struct spi_device *spi)`, clock rate, SPI mode, and word sizes.
 - `master->cleanup(struct spi_device *spi)`, 清除之前由`spi_device.controller_state`锁定的状态；
   ...
 - `master->transfer_one_message(struct spi_master *master, struct spi_message *mesg)`, 发送一个mesg；
 
-### SPI Protocol Driver
+#### SPI Protocol Driver
 
 ```c
 	static int CHIP_probe(struct spi_device *spi)
@@ -193,7 +310,9 @@ SPI设备必须管理以下两种类型内存：
 		.remove		= CHIP_remove,
 	};
 ```
+
 spi_setup(),
+
 ## 属性
 
 - `spi_message.is_dma_mapped`，

spi/pn5180.c

@@ -53,7 +53,7 @@ static const struct of_device_id CHIP_of_match[] = {
 	{ }
 };
 
-MODULE_DEVICE_TABLE(of, CHIP_of_match);
+MODULE_DEVICE_TABLE(of, CHIP_of_match);			// Used by file2alias, which indicated what devices are support with this drive.
 #endif // CONFIG_OF
 
 static struct spi_driver CHIP_driver = {