How to execute linux userspace driver code for infinite time on the target board?
The below code is used to test the uart driver on linux-jetson board which runs only one time,if needed to run multiple times on the board the device needs to be restarted.
include <stdio.h>
include <stdlib.h>
include <fcntl.h>
include <termios.h>
include <string.h>
include <errno.h>
include <limits.h>
include <stdbool.h>
include <unistd.h>
define LOOPBACK_FORMAT "loopback: %s\r\n"
define LOOPBACK_FORMAT_LEN strlen(LOOPBACK_FORMAT)
define MAX_READ_SIZE 235
define MAX_LOOPBACK_SIZE MAX_READ_SIZE + LOOPBACK_FORMAT_LEN
define DEBUG
struct UartDevice {
char* filename;
int rate;
int fd;
struct termios *tty;
};
int uart_start(struct UartDevice* dev, bool canonical) {
struct termios *tty;
int fd;
int rc;
fd = open(dev->filename, O_RDWR | O_NOCTTY);
if (fd < 0) {
printf("%s: failed to open UART device\r\n", func);
return fd;
}
tty = malloc(sizeof(*tty));
if (!tty) {
printf("%s: failed to allocate UART TTY instance\r\n", func);
memset(tty, 0, sizeof(*tty));
/*
- Set baud-rate.
*/
tty->c_cflag |= dev->rate;
/* Ignore framing and parity errors in input. */
tty->c_iflag |= IGNPAR;
/* Use 8-bit characters. This too may affect standard streams,
- but any sane C library can deal with 8-bit characters. */
tty->c_cflag |= CS8;
/* Enable receiver. */
tty->c_cflag |= CREAD;
if (canonical) {
/* Enable canonical mode.
This is the most important bit, as it enables line buffering etc. /
tty->c_lflag |= ICANON;
} else {
/ To maintain best compatibility with normal behaviour of terminals,we set TIME=0 and MAX=1 in noncanonical mode. This means that
- read() will block until at least one byte is available. */
tty->c_cc[VTIME] = 0;
tty->c_cc[VMIN] = 1;
}
/*
- Flush port.
*/
tcflush(fd, TCIFLUSH);
/*
- Apply attributes.
*/
rc = tcsetattr(fd, TCSANOW, tty);
if (rc) {
printf("%s: failed to set attributes\r\n", func);
return rc;
}
dev->fd = fd;
dev->tty = tty;
return 0;
}/*
- Read a string from the UART device.
@param dev points to the UART device to be read from
@param buf points to the start of buffer to be read into
- @param buf_len length of the buffer to be read
@return - number of bytes read if the read procedure succeeded
- negative if the read procedure failed
/
int uart_reads(struct UartDevice dev, char *buf, size_t buf_len) {
int rc;
- negative if the read procedure failed
rc = read(dev->fd, buf, buf_len - 1);
if (rc < 0) {
printf("%s: failed to read uart data\r\n", func);
return rc;
}
buf[rc] = '\0';
return rc;
}
/*
- Write data to the UART device.
@param dev points to the UART device to be written to
@param buf points to the start of buffer to be written from
- @param buf_len length of the buffer to be written
@return - number of bytes written if the write procedure succeeded
- negative if the write procedure failed
/
int uart_writen(struct UartDevice dev, char *buf, size_t buf_len) {
return write(dev->fd, buf, buf_len);
}
- negative if the write procedure failed
/*
- Write a string to the UART device.
@param dev points to the UART device to be written to
@param string points to the start of buffer to be written from
@return - number of bytes written if the write procedure succeeded
- negative if the write procedure failed
/
int uart_writes(struct UartDevice dev, char *string) {
size_t len = strlen(string);
return uart_writen(dev, string, len);
}
- negative if the write procedure failed
/*
- Stop the UART device.
- @param dev points to the UART device to be stopped
/
void uart_stop(struct UartDevice dev) {
close(dev->fd);
free(dev->tty);
}
int main()
{
struct UartDevice dev;
int rc;
dev.filename = "/dev/ttyTHS2";
dev.rate = B115200;
rc = uart_start(&dev, false);
if (rc) {
return rc;
}
char read_data[MAX_READ_SIZE];
char loopback_data[MAX_LOOPBACK_SIZE];
size_t read_data_len;
printf("UART DEMO\r\n");
uart_writes(&dev, "UART DEMO\r\n");
while (1)
{
read_data_len = uart_reads(&dev, read_data, MAX_READ_SIZE);
if (read_data_len > 0) {
printf("%s", read_data);
snprintf(loopback_data, MAX_LOOPBACK_SIZE, LOOPBACK_FORMAT, read_data);
uart_writes(&dev, loopback_data);
}
}
uart_stop(&dev);
return 0;
}
Could anyone please help me out what are the changes to be done to execute the above code infinite times?
Thanks and regards,
Imran patan,
India.
Categories
- All Categories
- 50 LFX Mentorship
- 103 LFX Mentorship: Linux Kernel
- 576 Linux Foundation IT Professional Programs
- 304 Cloud Engineer IT Professional Program
- 125 Advanced Cloud Engineer IT Professional Program
- 53 DevOps Engineer IT Professional Program
- 61 Cloud Native Developer IT Professional Program
- 5 Express Training Courses
- 5 Express Courses - Discussion Forum
- 2K Training Courses
- 19 LFC110 Class Forum
- 7 LFC131 Class Forum
- 27 LFD102 Class Forum
- 157 LFD103 Class Forum
- 20 LFD121 Class Forum
- 1 LFD137 Class Forum
- 61 LFD201 Class Forum
- 1 LFD210 Class Forum
- LFD210-CN Class Forum
- 1 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum
- LFD237 Class Forum
- 23 LFD254 Class Forum
- 611 LFD259 Class Forum
- 105 LFD272 Class Forum
- 1 LFD272-JP クラス フォーラム
- 1 LFD273 Class Forum
- 2 LFS145 Class Forum
- 24 LFS200 Class Forum
- 739 LFS201 Class Forum
- 1 LFS201-JP クラス フォーラム
- 11 LFS203 Class Forum
- 75 LFS207 Class Forum
- 300 LFS211 Class Forum
- 54 LFS216 Class Forum
- 47 LFS241 Class Forum
- 41 LFS242 Class Forum
- 37 LFS243 Class Forum
- 11 LFS244 Class Forum
- 36 LFS250 Class Forum
- 1 LFS250-JP クラス フォーラム
- LFS251 Class Forum
- 140 LFS253 Class Forum
- LFS254 Class Forum
- 1.1K LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 93 LFS260 Class Forum
- 132 LFS261 Class Forum
- 33 LFS262 Class Forum
- 80 LFS263 Class Forum
- 15 LFS264 Class Forum
- 11 LFS266 Class Forum
- 18 LFS267 Class Forum
- 17 LFS268 Class Forum
- 23 LFS269 Class Forum
- 203 LFS272 Class Forum
- 1 LFS272-JP クラス フォーラム
- LFS274 Class Forum
- LFS281 Class Forum
- 235 LFW211 Class Forum
- 172 LFW212 Class Forum
- 7 SKF100 Class Forum
- SKF200 Class Forum
- 902 Hardware
- 219 Drivers
- 74 I/O Devices
- 44 Monitors
- 115 Multimedia
- 209 Networking
- 101 Printers & Scanners
- 85 Storage
- 763 Linux Distributions
- 88 Debian
- 66 Fedora
- 15 Linux Mint
- 13 Mageia
- 24 openSUSE
- 142 Red Hat Enterprise
- 33 Slackware
- 13 SUSE Enterprise
- 357 Ubuntu
- 479 Linux System Administration
- 41 Cloud Computing
- 70 Command Line/Scripting
- Github systems admin projects
- 95 Linux Security
- 78 Network Management
- 108 System Management
- 49 Web Management
- 68 Mobile Computing
- 23 Android
- 30 Development
- 1.2K New to Linux
- 1.1K Getting Started with Linux
- 537 Off Topic
- 131 Introductions
- 217 Small Talk
- 21 Study Material
- 826 Programming and Development
- 278 Kernel Development
- 514 Software Development
- 928 Software
- 260 Applications
- 184 Command Line
- 3 Compiling/Installing
- 76 Games
- 316 Installation
- 62 All In Program
- 62 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)