From 618b26c8c4d21c3e01e169a0d95d6bbadc803d2a Mon Sep 17 00:00:00 2001 From: gaoyang3513 Date: Tue, 9 Jul 2024 20:09:50 +0800 Subject: [PATCH] =?UTF-8?q?[Mod]=20=E6=9B=B4=E6=96=B0=E6=96=87=E6=A1=A3?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- spi/ReadMe.md | 143 +++++++++++++++++++++++++++++++++++++++++++++----- spi/pn5180.c | 2 +- 2 files changed, 132 insertions(+), 13 deletions(-) diff --git a/spi/ReadMe.md b/spi/ReadMe.md index a990e62f4..da90e12a8 100644 --- a/spi/ReadMe.md +++ b/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。 @@ -51,18 +54,21 @@ SPI设备必须管理以下两种类型内存： - I/O 数据； - spi_message\spi_transfer数据； - 可以使用spi_message_alloc()、spi_message_free()代为管理。 + 可以使用spi_message_alloc()、spi_message_free()代为管理。 ## 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 /* 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； -使用`spi_new_device()`创建; -使用`spi_unregister_device()`销毁； +##### Master -### 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 = ; + 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`， diff --git a/spi/pn5180.c b/spi/pn5180.c index a370ce8b1..621edce28 100644 --- a/spi/pn5180.c +++ b/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 = {