Raspberry Pi:SPI 不工作，spi_bcm2835 不显示与 lsmod [英] Raspberry Pi: SPI not working, spi_bcm2835 not showing with lsmod
问题描述
我正在尝试使用 Raspberry Pi 4 通过 SPI 接口控制我的 WS2801 LED 条纹.
I'm trying to control my WS2801 LED Stripe with my Raspberry Pi 4 over the SPI interface.
Pi 正在运行 Ubuntu 20.04 内核版本:Linux ubuntu 5.3.0-1030-raspi2 #32-Ubuntu SMP Sun Jul 12 21:20:28 UTC 2020 aarch64aarch64 aarch64 GNU/Linux
The Pi is running un Ubuntu 20.04 with the kernel version: Linux ubuntu 5.3.0-1030-raspi2 #32-Ubuntu SMP Sun Jul 12 21:20:28 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux
LED 灯条的设置和连接应该没问题.我已经在我的 Pi3 上使用测试脚本对其进行了验证，并且它运行正常.在 PI 上运行测试脚本时没有错误，但 LED 条上没有任何反应.
The setup and connection to the LED Strip should be fine. I've validated it with a test script on my Pi3 and it worked properly. With the test script running on the PI there is no error, but nothing happens on the LED stripe.
到目前为止，我了解到为了通过 SPI 进行通信，我们需要加载 spidev 和 spi-bcm2835 模块.lsmod | 的输出grep spi:
So far, I have the understanding that in order to communicate over the SPI we need the spidev and the spi-bcm2835 module to be loaded.
Output of lsmod | grep spi:
spidev 28672 0
IMO，也应该有 spi_bcm2835.在 /dev/ 文件夹中有 spidev0.0 和 spidev0.1 ，应该是这样.调用 sudo modprobe spi_bcm2835 不会出错，但不能解决问题.
IMO, there should be spi_bcm2835 as well. In the /dev/ folder there is spidev0.0 and spidev0.1, as it should be. Calling sudo modprobe spi_bcm2835 gives no error but does not solve the issue.
我的/boot/firmware/config.txt:
[pi4]
kernel=uboot_rpi_4.bin
max_framebuffers=2
[pi3]
kernel=uboot_rpi_3.bin
[all]
arm_64bit=1
device_tree_address=0x03000000
start_x=1
gpu_mem=512
dtparam=spi=on
dtparam=sound=on
dtparam=i2c_arm=on
dtparam=i2s=on
dtoverlay=spi-bcm2835
我的/etc/modules:
i2c-dev
spi-bcm2835
spi-dev
snd-bcm2835
/etc/modeprob.d/ 文件中没有关于 spi 的黑名单条目.
There is no blacklist entry with respect to the spi inside the /etc/modeprob.d/ files.
dmesg 中唯一相关的条目是 [1.559971] spi-bcm2835 fe204000.spi: could not get clk: -517.但据我所知，-517 意味着该模块稍后加载，因为它在这个时间步还没有准备好.
The only related entry in dmesg is [ 1.559971] spi-bcm2835 fe204000.spi: could not get clk: -517. But as far as I know -517 means that the module is just loaded later because it's not ready at this timestep.
有人知道这里可能有什么问题吗?谢谢！
Does anybody know what the issue might be here? Thanks!
这是我的测试脚本:
/******************************************************************************/
/* */
/* FILE: ledstrip.cpp */
/* */
/* Displays the contents of a file on a LED strip */
/* ============================================== */
/* */
/* V0.01 18-DEC-2015 Te */
/* */
/******************************************************************************/
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/spi/spidev.h>
static const char *device = "/dev/spidev0.0" ;
static uint32_t speed = 500000 ;
static uint8_t mode = SPI_MODE_0 ;
static uint8_t bits = 8 ;
static unsigned char tx[75] ;
static unsigned char rx[75] ;
static struct spi_ioc_transfer parameters[1];
static int offset = 0 ;
static int spi ;
/*************/
int OpenSPI()
/*************/
{
spi = open( device, O_RDWR ) ;
if( spi < 0 )
{
fprintf( stderr, "can't open device\n" ) ;
return 1 ;
}
int ret = ioctl( spi, SPI_IOC_WR_MODE, &mode ) ;
if( ret == -1 )
{
close( spi ) ;
fprintf( stderr, "can't set mode\n" ) ;
return 2 ;
}
ret = ioctl( spi, SPI_IOC_WR_BITS_PER_WORD, &bits ) ;
if( ret == -1 )
{
close( spi ) ;
fprintf( stderr, "can't set bits\n" ) ;
return 3 ;
}
ret = ioctl( spi, SPI_IOC_WR_MAX_SPEED_HZ, &speed ) ;
if( ret == -1 )
{
close( spi ) ;
fprintf( stderr, "can't set speed\n" ) ;
return 4 ;
}
memset( ¶meters, 0, sizeof(spi) ) ;
parameters[0].tx_buf = (unsigned long)tx ;
parameters[0].rx_buf = (unsigned long)rx ;
parameters[0].len = 75 ;
parameters[0].delay_usecs = 0 ;
parameters[0].speed_hz = speed ;
parameters[0].bits_per_word = bits ;
parameters[0].cs_change = 0 ;
return 0 ;
}
/***************/
void CloseSPI()
/***************/
{
close( spi ) ;
}
/*****************/
void ResetState()
/*****************/
{
memset( tx, 0, sizeof(tx) ) ;
}
/****************/
void ShowState()
/****************/
{
if( ioctl(spi,SPI_IOC_MESSAGE(1),¶meters) == -1 )
fprintf( stderr, "can't transfer data\n" ) ;
}
/*******************************/
void Token( const char *token )
/*******************************/
{
if( isdigit(*token) )
{
int value = atoi( token ) - 1 ;
if( (value >= 0) && (value <= 24) )
tx[value*3+offset] = 255 ;
}
else
{
switch( tolower(*token) )
{
case 'r' : offset = 0 ;
break ;
case 'g' : offset = 1 ;
break ;
case 'b' : offset = 2 ;
break ;
}
}
}
/***************************/
void Line( const char *ps )
/***************************/
{
ResetState() ;
char token[25] ;
size_t i = 0 ;
while( *ps != '\0' )
{
if( isspace(*ps) )
{
if( i > 0 )
{
token[i] = '\0' ;
Token( token ) ;
}
i = 0 ;
}
else
{
if( i < sizeof(token) - 1 )
token[i++] = *ps ;
}
++ps ;
}
ShowState() ;
}
/***************************/
void ReadFile( FILE *file )
/***************************/
{
char line[1024] ;
struct timespec in ;
struct timespec out ;
while( fgets(line,sizeof(line),file) != NULL )
{
Line( line ) ;
in.tv_sec = 0 ;
in.tv_nsec = 125000000 ;
nanosleep( &in, &out ) ;
}
}
/*********************************/
void File( const char *filename )
/*********************************/
{
FILE *file = fopen( filename, "r" ) ;
if( file != NULL )
{
ReadFile( file ) ;
fclose( file ) ;
}
}
/**********************************/
int main( int argc, char *argv[] )
/**********************************/
{
if( OpenSPI() != 0 )
return 1 ;
if( argc == 1 )
ReadFile( stdin ) ;
else
{
for( int i = 1; i < argc; i++ )
File( argv[i] ) ;
}
CloseSPI() ;
return 0 ;
}
推荐答案
我遇到了类似的问题.这个答案帮助了我.
I had a similar problem. This answer has helped me.
更改 usercfg.txt 而不是 config.txt.
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