From 0a1fbef8c8980856967ac42a065df3e40abcf966 Mon Sep 17 00:00:00 2001
From: David Sidrane <david_s5@nscdg.com>
Date: Mon, 24 Apr 2017 15:54:26 -1000
Subject: [PATCH] pwm:ensure that a rate of 0 will invoke the ioctl
Prior to onshot being added to the system. The -r of the
"rate" command would not invoke the ioctl PWM_SERVO_SET_UPDATE_RATE
when -r was not provided on the command line. This may have been a
feature or a bug.
When onshot was added to the pwm command a bug was intorduced
that precluded the ioctl PWM_SERVO_SET_UPDATE_RATE from being
called on -r 0.
This commit fixes that issue, and preserves the "prio to oneshot"
behavior of the "rate" command when -r is not specified.
---
src/systemcmds/pwm/pwm.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/src/systemcmds/pwm/pwm.c b/src/systemcmds/pwm/pwm.c
index 974b40f404..0aa4a26e28 100644
--- a/src/systemcmds/pwm/pwm.c
+++ b/src/systemcmds/pwm/pwm.c
@@ -92,7 +92,7 @@ usage(const char *reason)
"\t[-g <channel group>]\t(e.g. 0,1,2)\n"
"\t[-m <channel mask> ]\t(e.g. 0xF)\n"
"\t[-a]\t\t\tConfigure all outputs\n"
- "\t-r <alt_rate>\t\tPWM rate (50 to 400 Hz)\n"
+ "\t-r <alt_rate>\t\tPWM rate (0 - oneshot, 50 to 400 Hz)\n"
"\n"
"failsafe ...\t\t\tFailsafe PWM\n"
"disarmed ...\t\t\tDisarmed PWM\n"
@@ -169,7 +169,7 @@ int
pwm_main(int argc, char *argv[])
{
const char *dev = PWM_OUTPUT0_DEVICE_PATH;
- unsigned alt_rate = 0;
+ int alt_rate = -1; // Default to indicate not set.
uint32_t alt_channel_groups = 0;
bool alt_channels_set = false;
bool print_verbose = false;
@@ -262,7 +262,6 @@ pwm_main(int argc, char *argv[])
case 'r':
alt_rate = get_parameter_value(myoptarg, "PWM Rate");
-
break;
default:
@@ -347,8 +346,14 @@ pwm_main(int argc, char *argv[])
} else if (oneshot || !strcmp(command, "rate")) {
- /* change alternate PWM rate or set oneshot */
- if (oneshot || alt_rate > 0) {
+ /* Change alternate PWM rate or set oneshot
+ * Either the "oneshot" command was used
+ * and/OR -r was provided on command line and has changed the alt_rate
+ * to the non default of -1, so we will issue the PWM_SERVO_SET_UPDATE_RATE
+ * ioctl
+ */
+
+ if (oneshot || alt_rate >= 0) {
ret = px4_ioctl(fd, PWM_SERVO_SET_UPDATE_RATE, oneshot ? 0 : alt_rate);
if (ret != OK) {
--
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