英文:
Devicetree overlay for STM32 DAC using Zephyr
问题
我正在尝试在STM32F4 Discovery板上的PA4上使用DAC与Zephyr。为了做到这一点，我创建了以下的dtoverlay文件。我在这里尝试了几种不同的叠加配置，因为在主的stm32f4_disco板的dts文件中似乎没有配置任何DAC，所以我最终选择了这个配置：
/ {
soc {
dac1: dac@40007400 {
compatible = "st,stm32-dac";
reg = <0x40007400 0x400>;
status = "okay";
label = "DAC_1";
clocks = <&rcc STM32_CLOCK_BUS_APB1 0x20000000>;
pinctrl-0 = <&dac_out1_pa4>;
pinctrl-names = "default";
};
};
};
我还在prj.conf中启用了DAC，添加了以下内容：
CONFIG_DAC=y
CONFIG_DAC_STM32=y
以下是我正在尝试构建的程序：
#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/drivers/dac.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define DAC_DEVICE_NODE DT_NODELABEL(dac1)
#define DAC_CHANNEL_ID 0 // 使用DAC_OUT1 (PA4) 作为输出引脚
#define DAC_RESOLUTION 12 // 12位分辨率
static const struct device *const dac_dev = DEVICE_DT_GET(DAC_DEVICE_NODE);
int main(void) {
if (!dac_dev) {
printk("找不到 %s!\n", DAC_DEVICE_NODE);
return 1;
}
struct dac_channel_cfg channel_cfg = {
.channel_id = DAC_CHANNEL_ID,
.resolution = DAC_RESOLUTION,
};
if (dac_channel_setup(dac_dev, &channel_cfg) != 0) {
printk("设置通道 %d 失败！\n", DAC_CHANNEL_ID);
return 1;
}
/*
.... 做一些事情..
*/
return 0;
}
然而，当我构建时，出现以下错误：
$ west build -b stm32f4_disco -p auto
[28/40] Building C object CMakeFiles/app.dir/src/main.c.obj
FAILED: CMakeFiles/app.dir/src/main.c.obj
ccache /home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc -DCORE_CM4 -DHSE_VALUE=8000000 -DKERNEL -DSTM32F407xx -DUSE_FULL_LL_DRIVER -DUSE_HAL_DRIVER -D__PROGRAM_START -D__ZEPHYR__=1 -I/home/mitch/git/myproject/zephyr/include -I/home/mitch/git/myproject/build/zephyr/include/generated -I/home/mitch/git/myproject/zephyr/soc/arm/st_stm32/stm32f4 -I/home/mitch/git/myproject/zephyr/drivers -I/home/mitch/git/myproject/zephyr/soc/arm/st_stm32/common -I/home/mitch/git/myproject/modules/hal/cmsis/CMSIS/Core/Include -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/stm32f4xx/soc -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/stm32f4xx/drivers/include -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/stm32f4xx/drivers/include/Legacy -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/common_ll/include -isystem /home/mitch/git/myproject/zephyr/lib/libc/minimal/include -isystem /home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/include -isystem /home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/include-fixed -fno-strict-aliasing -Os -imacros /home/mitch/git/myproject/build/zephyr/include/generated/autoconf.h -ffreestanding -fno-common -g -gdwarf-4 -fdiagnostics-color=always -mcpu=cortex-m4 -mthumb -mabi=aapcs --sysroot=/home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/arm-zephyr-eabi -imacros /home/mitch/git/myproject/zephyr/include/zephyr/toolchain/zephyr_stdint.h -Wall -Wformat -Wformat-security -Wno-format-zero-length -Wno-pointer-sign -Wpointer-arith -Wexpansion-to-defined -Wno-unused-but-set-variable -Werror=implicit-int -fno-pic -fno-pie -fno-asynchronous-unwind-tables -fno-reorder-functions --param=min-pagesize=0 -fno-defer-pop -fmacro-prefix-map=/home/mitch/git/myproject=CMAKE_SOURCE_DIR -fmacro-prefix-map=/home/mitch/git/myproject/zephyr=ZEPHYR_BASE -fmacro-prefix-map=/home/mitch/git/myproject=WEST_TOPDIR -ffunction-sections -fdata-sections -std=c99 -nostdinc -MD -MT CMakeFiles/app.dir/src/main.c.obj -MF CMakeFiles/app.dir/src/main.c.obj.d -o CMakeFiles/app.dir/src/main.c.obj -c /home/mitch/git/myproject/src/main.c
In file included from /home/mitch/git/myproject/zephyr/include/zephyr/devicetree.h:19,
from /home/mitch/git/myproject/zephyr/include/zephyr/arch/arm/aarch32/arch.h:20,
from /home/mitch/git/myproject/zephyr/include/zephyr/arch/cpu.h:19,
from /home/mitch/git/myproject/zephyr/include/zephyr/kernel_includes.h:33,
from /home/mitch/git/myproject/zephyr/include/zephyr/kernel.h:17,
from /home/mitch/git/myproject/src/main.c:1:
/home/mitch/git/myproject/src/main.c: In function 'main':
/home/mitch/git/myproject/build/zephyr/include/generated/devicetree_generated.h:4816:34: error: 'DT_N_S_soc_S_dac_40007400' undeclared (first use in this function); did you mean 'DT_N_S_soc_S_dac_40007400_ORD'?
4816 | #define DT_N_NODELABEL_dac1 DT_N_S_soc_S_dac_40007400
| ^~~~~~~~~~~~~~~~~~~~~~~~~
/home/mitch/git/myproject/zephyr/include/zephyr/devicetree.h:4096:24: note
<details>
<summary>英文:</summary>
I'm trying to use the DAC on PA4 of the STM32F4 Discovery board with Zephyr.
In order to do that, I have created the following dtoverlay file. I have tried a handful of different overlay configurations here and this is what I have landed with since it didn't appear as if any DAC was configured in the main dts file for the stm32f4_disco board:
/ {
soc {
dac1: dac@40007400 {
compatible = "st,stm32-dac";
reg = <0x40007400 0x400>;
status = "okay";
label = "DAC_1";
clocks = <&rcc STM32_CLOCK_BUS_APB1 0x20000000>;
pinctrl-0 = <&dac_out1_pa4>;
pinctrl-names = "default";
};
};
};
I have also enabled the DAC in the prj.conf by adding the following:
CONFIG_DAC=y
CONFIG_DAC_STM32=y
Here is the program I'm trying to build:
#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/drivers/dac.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define DAC_DEVICE_NODE DT_NODELABEL(dac1)
#define DAC_CHANNEL_ID 0 // Use DAC_OUT1 (PA4) as the output pin
#define DAC_RESOLUTION 12 // 12-bit resolution
static const struct device *const dac_dev = DEVICE_DT_GET(DAC_DEVICE_NODE);
int main(void) {
if (!dac_dev) {
printk("Cannot find %s!\n", DAC_DEVICE_NODE);
return 1;
}
struct dac_channel_cfg channel_cfg = {
.channel_id = DAC_CHANNEL_ID,
.resolution = DAC_RESOLUTION,
};
if (dac_channel_setup(dac_dev, &channel_cfg) != 0) {
printk("Setting up of channel %d failed!\n", DAC_CHANNEL_ID);
return 1;
}
/*
.... do something..
*/
return 0;
}
However, when I build it, I get the following error:
$ west build -b stm32f4_disco -p auto
[28/40] Building C object CMakeFiles/app.dir/src/main.c.obj
FAILED: CMakeFiles/app.dir/src/main.c.obj
ccache /home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc -DCORE_CM4 -DHSE_VALUE=8000000 -DKERNEL -DSTM32F407xx -DUSE_FULL_LL_DRIVER -DUSE_HAL_DRIVER -D__PROGRAM_START -D__ZEPHYR__=1 -I/home/mitch/git/myproject/zephyr/include -I/home/mitch/git/myproject/build/zephyr/include/generated -I/home/mitch/git/myproject/zephyr/soc/arm/st_stm32/stm32f4 -I/home/mitch/git/myproject/zephyr/drivers -I/home/mitch/git/myproject/zephyr/soc/arm/st_stm32/common -I/home/mitch/git/myproject/modules/hal/cmsis/CMSIS/Core/Include -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/stm32f4xx/soc -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/stm32f4xx/drivers/include -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/stm32f4xx/drivers/include/Legacy -I/home/mitch/git/myproject/modules/hal/stm32/stm32cube/common_ll/include -isystem /home/mitch/git/myproject/zephyr/lib/libc/minimal/include -isystem /home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/include -isystem /home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/include-fixed -fno-strict-aliasing -Os -imacros /home/mitch/git/myproject/build/zephyr/include/generated/autoconf.h -ffreestanding -fno-common -g -gdwarf-4 -fdiagnostics-color=always -mcpu=cortex-m4 -mthumb -mabi=aapcs --sysroot=/home/mitch/bin/zephyr-sdk-0.16.0/arm-zephyr-eabi/arm-zephyr-eabi -imacros /home/mitch/git/myproject/zephyr/include/zephyr/toolchain/zephyr_stdint.h -Wall -Wformat -Wformat-security -Wno-format-zero-length -Wno-pointer-sign -Wpointer-arith -Wexpansion-to-defined -Wno-unused-but-set-variable -Werror=implicit-int -fno-pic -fno-pie -fno-asynchronous-unwind-tables -fno-reorder-functions --param=min-pagesize=0 -fno-defer-pop -fmacro-prefix-map=/home/mitch/git/myproject=CMAKE_SOURCE_DIR -fmacro-prefix-map=/home/mitch/git/myproject/zephyr=ZEPHYR_BASE -fmacro-prefix-map=/home/mitch/git/myproject=WEST_TOPDIR -ffunction-sections -fdata-sections -std=c99 -nostdinc -MD -MT CMakeFiles/app.dir/src/main.c.obj -MF CMakeFiles/app.dir/src/main.c.obj.d -o CMakeFiles/app.dir/src/main.c.obj -c /home/mitch/git/myproject/src/main.c
In file included from /home/mitch/git/myproject/zephyr/include/zephyr/devicetree.h:19,
from /home/mitch/git/myproject/zephyr/include/zephyr/arch/arm/aarch32/arch.h:20,
from /home/mitch/git/myproject/zephyr/include/zephyr/arch/cpu.h:19,
from /home/mitch/git/myproject/zephyr/include/zephyr/kernel_includes.h:33,
from /home/mitch/git/myproject/zephyr/include/zephyr/kernel.h:17,
from /home/mitch/git/myproject/src/main.c:1:
/home/mitch/git/myproject/src/main.c: In function 'main':
/home/mitch/git/myproject/build/zephyr/include/generated/devicetree_generated.h:4816:34: error: 'DT_N_S_soc_S_dac_40007400' undeclared (first use in this function); did you mean 'DT_N_S_soc_S_dac_40007400_ORD'?
4816 | #define DT_N_NODELABEL_dac1 DT_N_S_soc_S_dac_40007400
| ^~~~~~~~~~~~~~~~~~~~~~~~~
/home/mitch/git/myproject/zephyr/include/zephyr/devicetree.h:4096:24: note: in expansion of macro 'DT_N_NODELABEL_dac1'
4096 | #define DT_CAT(a1, a2) a1 ## a2
| ^~
/home/mitch/git/myproject/zephyr/include/zephyr/devicetree.h:192:29: note: in expansion of macro 'DT_CAT'
192 | #define DT_NODELABEL(label) DT_CAT(DT_N_NODELABEL_, label)
| ^~~~~~
/home/mitch/git/myproject/src/main.c:13:25: note: in expansion of macro 'DT_NODELABEL'
13 | #define DAC_DEVICE_NODE DT_NODELABEL(dac1)
| ^~~~~~~~~~~~
/home/mitch/git/myproject/src/main.c:103:33: note: in expansion of macro 'DAC_DEVICE_NODE'
103 | printk("Cannot find %s!\n", DAC_DEVICE_NODE);
| ^~~~~~~~~~~~~~~
/home/mitch/git/myproject/build/zephyr/include/generated/devicetree_generated.h:4816:34: note: each undeclared identifier is reported only once for each function it appears in
4816 | #define DT_N_NODELABEL_dac1 DT_N_S_soc_S_dac_40007400
| ^~~~~~~~~~~~~~~~~~~~~~~~~
/home/mitch/git/myproject/zephyr/include/zephyr/devicetree.h:4096:24: note: in expansion of macro 'DT_N_NODELABEL_dac1'
4096 | #define DT_CAT(a1, a2) a1 ## a2
| ^~
/home/mitch/git/myproject/zephyr/include/zephyr/devicetree.h:192:29: note: in expansion of macro 'DT_CAT'
192 | #define DT_NODELABEL(label) DT_CAT(DT_N_NODELABEL_, label)
| ^~~~~~
/home/mitch/git/myproject/src/main.c:13:25: note: in expansion of macro 'DT_NODELABEL'
13 | #define DAC_DEVICE_NODE DT_NODELABEL(dac1)
| ^~~~~~~~~~~~
/home/mitch/git/myproject/src/main.c:103:33: note: in expansion of macro 'DAC_DEVICE_NODE'
103 | printk("Cannot find %s!\n", DAC_DEVICE_NODE);
| ^~~~~~~~~~~~~~~
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: /usr/bin/cmake --build /home/mitch/git/myproject/build
This seems to be caused by the ability to find that device node in the the device tree binary. But I haven't been able to figure out why. The board's documentation does say that there is DAC support on PA4 and PA5.
Would appreciate any help on this. Thanks
</details>
# 答案1
**得分**: 1
问题在于`DAC_DEVICE_NODE`被用作字符串，但实际上它是一个节点标识符。您应该使用`DEVICE_DT_NAME(DAC_DEVICE_NODE)`：
```c
if (!dac_dev) {
// 无需使用%s，因为DEVICE_DT_NAME在编译时生成字符串文字
printk("找不到 " DEVICE_DT_NAME(DAC_DEVICE_NODE) "!\n");
return 1;
}
实际上，dac_dev不能为NULL，因为如果DEVICE_DT_GET(DAC_DEVICE_NODE)无法找到有效节点，它将无法连接。如果出于某种原因需要不同的行为，可以使用DEVICE_DT_GET_OR_NULL(DAC_DEVICE_NODE)。
参见：https://docs.zephyrproject.org/apidoc/latest/group__device__model.html
英文:
The problem is thatDAC_DEVICE_NODE is being used as a string when it is really a node identifier. You should use DEVICE_DT_NAME(DAC_DEVICE_NODE):
if (!dac_dev) {
// No need to use %s since DEVICE_DT_NAME gives a string literal at compile time
printk("Cannot find " DEVICE_DT_NAME(DAC_DEVICE_NODE) "!\n");
return 1;
}
In fact, dac_dev cannot be NULL as it would fail to link if DEVICE_DT_GET(DAC_DEVICE_NODE) was unable to locate a valid node. You can use DEVICE_DT_GET_OR_NULL(DAC_DEVICE_NODE) if you need different behavior for some reason.
See: https://docs.zephyrproject.org/apidoc/latest/group__device__model.html
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