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px4-firmware/apps/examples/pwm/pwm_main.c

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/****************************************************************************
* examples/pwm/pwm_main.c
*
* Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include <string.h>
#include <nuttx/pwm.h>
#include "pwm.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
struct pwm_state_s
{
bool initialized;
FAR char *devpath;
uint8_t duty;
uint32_t freq;
#ifdef CONFIG_PWM_PULSECOUNT
uint32_t count;
#endif
int duration;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
static struct pwm_state_s g_pwmstate;
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: pwm_devpath
****************************************************************************/
static void pwm_devpath(FAR struct pwm_state_s *pwm, FAR const char *devpath)
{
/* Get rid of any old device path */
if (pwm->devpath)
{
free(pwm->devpath);
}
/* Then set-up the new device path by copying the string */
pwm->devpath = strdup(devpath);
}
/****************************************************************************
* Name: pwm_help
****************************************************************************/
static void pwm_help(FAR struct pwm_state_s *pwm)
{
message("Usage: pwm [OPTIONS]\n");
message("\nArguments are \"sticky\". For example, once the PWM frequency is\n");
message("specified, that frequency will be re-used until it is changed.\n");
message("\n\"sticky\" OPTIONS include:\n");
message(" [-p devpath] selects the PWM device. "
"Default: %s Current: %s\n",
CONFIG_EXAMPLES_PWM_DEVPATH, pwm->devpath ? pwm->devpath : "NONE");
message(" [-f addr] selects the pulse frequency. "
"Default: %d Hz Current: %d Hz\n",
CONFIG_EXAMPLES_PWM_FREQUENCY, pwm->freq);
message(" [-d duty] selcts the pulse duty as a percentage. "
"Default: %d %% Current: %d %%\n",
CONFIG_EXAMPLES_PWM_DUTYPCT, pwm->duty);
#ifdef CONFIG_PWM_PULSECOUNT
message(" [-n count] selects the pulse count. "
"Default: %d Current: %d\n",
CONFIG_EXAMPLES_PWM_COUNT, pwm->count);
#endif
message(" [-t duration] is the duration of the pulse train in seconds. "
"Default: %d Current: %d\n",
CONFIG_EXAMPLES_PWM_DURATION, pwm->duration);
message(" [-h] shows this message and exits\n");
}
/****************************************************************************
* Name: arg_string
****************************************************************************/
static int arg_string(FAR char **arg, FAR char **value)
{
FAR char *ptr = *arg;
if (ptr[2] == '\0')
{
*value = arg[1];
return 2;
}
else
{
*value = &ptr[2];
return 1;
}
}
/****************************************************************************
* Name: arg_decimal
****************************************************************************/
static int arg_decimal(FAR char **arg, FAR long *value)
{
FAR char *string;
int ret;
ret = arg_string(arg, &string);
*value = strtol(string, NULL, 10);
return ret;
}
/****************************************************************************
* Name: parse_args
****************************************************************************/
static void parse_args(FAR struct pwm_state_s *pwm, int argc, FAR char **argv)
{
FAR char *ptr;
FAR char *str;
long value;
int index;
int nargs;
for (index = 1; index < argc; )
{
ptr = argv[index];
if (ptr[0] != '-')
{
message("Invalid options format: %s\n", ptr);
exit(0);
}
switch (ptr[1])
{
case 'f':
nargs = arg_decimal(&argv[index], &value);
if (value < 1)
{
message("Frequency out of range: %ld\n", value);
exit(1);
}
pwm->freq = (uint32_t)value;
index += nargs;
break;
case 'd':
nargs = arg_decimal(&argv[index], &value);
if (value < 1 || value > 99)
{
message("Duty out of range: %ld\n", value);
exit(1);
}
pwm->duty = (uint8_t)value;
index += nargs;
break;
#ifdef CONFIG_PWM_PULSECOUNT
case 'n':
nargs = arg_decimal(&argv[index], &value);
if (value < 0)
{
message("Count must be non-negative: %ld\n", value);
exit(1);
}
pwm->count = (uint32_t)value;
index += nargs;
break;
#endif
case 'p':
nargs = arg_string(&argv[index], &str);
pwm_devpath(pwm, str);
index += nargs;
break;
case 't':
nargs = arg_decimal(&argv[index], &value);
if (value < 1 || value > INT_MAX)
{
message("Duration out of range: %ld\n", value);
exit(1);
}
pwm->duration = (int)value;
index += nargs;
break;
case 'h':
pwm_help(pwm);
exit(0);
default:
message("Unsupported option: %s\n", ptr);
pwm_help(pwm);
exit(1);
}
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pwm_main
****************************************************************************/
int pwm_main(int argc, char *argv[])
{
struct pwm_info_s info;
int fd;
int ret;
/* Initialize the state data */
if (!g_pwmstate.initialized)
{
g_pwmstate.duty = CONFIG_EXAMPLES_PWM_DUTYPCT;
g_pwmstate.freq = CONFIG_EXAMPLES_PWM_FREQUENCY;
g_pwmstate.duration = CONFIG_EXAMPLES_PWM_DURATION;
#ifdef CONFIG_PWM_PULSECOUNT
g_pwmstate.count = CONFIG_EXAMPLES_PWM_COUNT;
#endif
g_pwmstate.initialized = true;
}
/* Parse the command line */
parse_args(&g_pwmstate, argc, argv);
/* Has a device been assigned? */
if (!g_pwmstate.devpath)
{
/* No.. use the default device */
pwm_devpath(&g_pwmstate, CONFIG_EXAMPLES_PWM_DEVPATH);
}
/* Initialization of the PWM hardware is performed by logic external to
* this test.
*/
ret = pwm_devinit();
if (ret != OK)
{
message("pwm_main: pwm_devinit failed: %d\n", ret);
goto errout;
}
/* Open the PWM device for reading */
fd = open(g_pwmstate.devpath, O_RDONLY);
if (fd < 0)
{
message("pwm_main: open %s failed: %d\n", g_pwmstate.devpath, errno);
goto errout;
}
/* Configure the characteristics of the pulse train */
info.frequency = g_pwmstate.freq;
info.duty = ((uint32_t)g_pwmstate.duty << 16) / 100;
#ifdef CONFIG_PWM_PULSECOUNT
info.count = g_pwmstate.count;
message("pwm_main: starting output with frequency: %d duty: %08x count: %d\n",
info.frequency, info.duty, info.count);
#else
message("pwm_main: starting output with frequency: %d duty: %08x\n",
info.frequency, info.duty);
#endif
ret = ioctl(fd, PWMIOC_SETCHARACTERISTICS, (unsigned long)((uintptr_t)&info));
if (ret < 0)
{
message("pwm_main: ioctl(PWMIOC_SETCHARACTERISTICS) failed: %d\n", errno);
goto errout_with_dev;
}
/* Then start the pulse train. Since the driver was opened in blocking
* mode, this call will block if the count value is greater than zero.
*/
ret = ioctl(fd, PWMIOC_START, 0);
if (ret < 0)
{
message("pwm_main: ioctl(PWMIOC_START) failed: %d\n", errno);
goto errout_with_dev;
}
/* It a non-zero count was not specified, then wait for the selected
* duration, then stop the PWM output.
*/
#ifdef CONFIG_PWM_PULSECOUNT
if (info.count == 0)
#endif
{
/* Wait for the specified duration */
sleep(g_pwmstate.duration);
/* Then stop the pulse train */
message("pwm_main: stopping output\n", info.frequency, info.duty);
ret = ioctl(fd, PWMIOC_STOP, 0);
if (ret < 0)
{
message("pwm_main: ioctl(PWMIOC_STOP) failed: %d\n", errno);
goto errout_with_dev;
}
}
close(fd);
msgflush();
return OK;
errout_with_dev:
close(fd);
errout:
msgflush();
return ERROR;
}
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