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pwm1 and pwm0 working on chip pro. thanks ntc for the awesome led's on the devkit, they're super helpful

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This commit is contained in:
Robert Wolterman
2017-02-21 05:26:56 +00:00
parent ca7d221b33
commit f66740b797
1 changed files with 47 additions and 51 deletions
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98
source/c_pwm.c
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@ -47,35 +47,13 @@ SOFTWARE.
#define DISABLE 0
// Global variables
int pwm_initialized = 0;
// pwm devices (future chip pro use)
struct pwm_dev
{
char key[KEYLEN+1]; /* leave room for terminating NUL byte */
int gpio;
int initialized;
struct pwm_dev *next;
};
struct pwm_dev *initialized_pwms = NULL;
struct pwm_dev *lookup_initialized_pwm(const char *key)
{
struct pwm_dev *dev = initialized_pwms;
while (dev != NULL)
{
if (strcmp(dev->key, key) == 0) {
return dev;
}
dev = dev->next;
}
return NULL;
}
// pwm exports
struct pwm_exp
{
char key[KEYLEN+1]; /* leave room for terminating NUL byte */
int gpio;
int initialized;
int period_fd;
int duty_fd;
int polarity_fd;
@ -101,15 +79,12 @@ struct pwm_exp *lookup_exported_pwm(const char *key)
return NULL; /* standard for pointers */
}
int initialize_pwm(void)
int initialize_pwm(int *initialized, int gpio)
{
int e_no;
if (!pwm_initialized) {
if (!*initialized) {
int fd, len;
char str_gpio[80];
// Per https://github.com/NextThingCo/CHIP-linux/pull/4
// we need to export 0 here to enable pwm0
int gpio = 0;
if (DEBUG)
printf(" ** initialize_pwm **\n");
@ -134,7 +109,7 @@ int initialize_pwm(void)
if (DEBUG)
printf(" ** initialize_pwm: export pin: s = %d, len = %d\n", s, len);
pwm_initialized = 1;
*initialized = 1;
return 1;
} else {
if (DEBUG)
@ -169,7 +144,7 @@ int pwm_set_frequency(const char *key, float freq) {
len = snprintf(buffer, sizeof(buffer), "%lu", period_ns); BUF2SMALL(buffer);
ssize_t s = write(pwm->period_fd, buffer, len); e_no = errno;
if (DEBUG) {
printf(" ** pwm_set_frequency: pwm_initialized = %d\n", pwm_initialized);
printf(" ** pwm_set_frequency: pwm_initialized = %d\n", pwm->initialized);
printf(" ** pwm_set_frequency: buffer: %s\n", buffer);
printf(" ** pwm_set_frequency: s = %d, len = %d\n", s, len);
}
@ -212,7 +187,7 @@ int pwm_set_period_ns(const char *key, unsigned long period_ns) {
len = snprintf(buffer, sizeof(buffer), "%lu", period_ns); BUF2SMALL(buffer);
ssize_t s = write(pwm->period_fd, buffer, len); e_no = errno;
if (DEBUG) {
printf(" ** pwm_set_period_ns: pwm_initialized = %d\n", pwm_initialized);
printf(" ** pwm_set_period_ns: pwm_initialized = %d\n", pwm->initialized);
printf(" ** pwm_set_period_ns: buffer: %s\n", buffer);
printf(" ** pwm_set_period_ns: s = %d, len = %d\n", s, len);
}
@ -280,7 +255,7 @@ int pwm_set_polarity(const char *key, int polarity) {
}
ssize_t s = write(pwm->polarity_fd, buffer, len); e_no = errno;
if (DEBUG) {
printf(" ** pwm_set_polarity: pwm_initialized = %d\n", pwm_initialized);
printf(" ** pwm_set_polarity: pwm_initialized = %d\n", pwm->initialized);
printf(" ** pwm_set_polarity: buffer: %s\n", buffer);
printf(" ** pwm_set_polarity: s = %d, len = %d\n", s, len);
}
@ -320,7 +295,7 @@ int pwm_set_duty_cycle(const char *key, float duty) {
len = snprintf(buffer, sizeof(buffer), "%lu", pwm->duty); BUF2SMALL(buffer);
ssize_t s = write(pwm->duty_fd, buffer, len); e_no = errno;
if (DEBUG) {
printf(" ** pwm_set_duty_cycle: pwm_initialized = %d\n", pwm_initialized);
printf(" ** pwm_set_duty_cycle: pwm_initialized = %d\n", pwm->initialized);
printf(" ** pwm_set_duty_cycle: buffer: %s\n", buffer);
printf(" ** pwm_set_duty_cycle: s = %d, len = %d\n", s, len);
}
@ -360,7 +335,7 @@ int pwm_set_pulse_width_ns(const char *key, unsigned long pulse_width_ns) {
len = snprintf(buffer, sizeof(buffer), "%lu", pwm->duty); BUF2SMALL(buffer);
ssize_t s = write(pwm->duty_fd, buffer, len); e_no = errno;
if (DEBUG) {
printf(" ** pwm_set_pulse_width_ns: pwm_initialized = %d\n", pwm_initialized);
printf(" ** pwm_set_pulse_width_ns: pwm_initialized = %d\n", pwm->initialized);
printf(" ** pwm_set_pulse_width_ns: buffer: %s\n", buffer);
printf(" ** pwm_set_pulse_width_ns: s = %d, len = %d\n", s, len);
}
@ -405,7 +380,7 @@ int pwm_set_enable(const char *key, int enable)
len = snprintf(buffer, sizeof(buffer), "%d", enable); BUF2SMALL(buffer);
ssize_t s = write(pwm->enable_fd, buffer, len); e_no = errno;
if (DEBUG) {
printf(" ** pwm_set_enable: pwm_initialized = %d\n", pwm_initialized);
printf(" ** pwm_set_enable: pwm_initialized = %d\n", pwm->initialized);
printf(" ** pwm_set_enable: buffer: %s\n", buffer);
printf(" ** pwm_set_enable: s = %d, len = %d\n", s, len);
}
@ -435,21 +410,31 @@ int pwm_start(const char *key, float duty, float freq, int polarity)
char polarity_path[80];
int period_fd, duty_fd, polarity_fd, enable_fd;
struct pwm_exp *new_pwm, *pwm;
int gpio = 0;
int initialized = 0;
if (DEBUG)
printf(" ** pwm_start: pwm_initialized = %d\n", pwm_initialized);
if(!pwm_initialized) {
initialize_pwm();
// Figure out which pin we are
if (strcmp(key,"U13_18") == 0) {
gpio = 0;
} else if (strcmp(key,"EINT13") == 0) {
gpio = 1;
}
// Try to get the pwm
pwm = lookup_exported_pwm(key);
if (pwm == NULL) {
initialize_pwm(&initialized, gpio);
if (DEBUG)
printf(" ** pwm_start: pwm(%d) initialized = %d\n", gpio, initialized);
} else {
if (DEBUG)
printf(" ** pwm_start: pwm already initialized, cleaning up **");
printf(" ** pwm_start: pwm(%d) already initialized, cleaning up **", gpio);
pwm_cleanup();
}
if (DEBUG)
printf(" ** pwm_start: pwm_initialized = %d\n", pwm_initialized);
//setup the pwm base path, the chip only has one pwm
snprintf(pwm_base_path, sizeof(pwm_base_path), "/sys/class/pwm/pwmchip0/pwm%d", 0); BUF2SMALL(pwm_base_path);
snprintf(pwm_base_path, sizeof(pwm_base_path), "/sys/class/pwm/pwmchip0/pwm%d", gpio); BUF2SMALL(pwm_base_path);
//create the path for the period and duty
snprintf(enable_path, sizeof(enable_path), "%s/enable", pwm_base_path); BUF2SMALL(enable_path);
@ -515,6 +500,8 @@ int pwm_start(const char *key, float duty, float freq, int polarity)
printf(" ** pwm_start: sysfs files opened successfully **\n");
strncpy(new_pwm->key, key, KEYLEN); /* can leave string unterminated */
new_pwm->key[KEYLEN] = '\0'; /* terminate string */
new_pwm->gpio = gpio;
new_pwm->initialized = initialized;
new_pwm->period_fd = period_fd;
new_pwm->duty_fd = duty_fd;
new_pwm->polarity_fd = polarity_fd;
@ -534,6 +521,10 @@ int pwm_start(const char *key, float duty, float freq, int polarity)
}
int rtnval = 0;
// Always set polarity first
if (ISCHIPPRO == 1) {
rtnval = pwm_set_polarity(key, polarity);
}
rtnval = pwm_set_enable(key, ENABLE);
// Fix for issue #53
if (rtnval != -1) {
@ -541,8 +532,6 @@ int pwm_start(const char *key, float duty, float freq, int polarity)
rtnval = pwm_set_frequency(key, freq);
if (rtnval != -1) {
rtnval = 0;
//rtnval = pwm_set_polarity(key, polarity);
//rtnval = 0;
rtnval = pwm_set_duty_cycle(key, duty);
}
}
@ -555,15 +544,22 @@ int pwm_disable(const char *key)
int fd, len, e_no;
char str_gpio[80];
// Per https://github.com/NextThingCo/CHIP-linux/pull/4
// we need to export 0 here to enable pwm0
int gpio = 0;
pwm = lookup_exported_pwm(key);
if (pwm == NULL) {
if (DEBUG)
printf(" ** pwm_disable: pwm struct is null **\n");
return -1;
}
// Disable the PWM
pwm_set_frequency(key, 0);
//pwm_set_polarity(key, 0);
pwm_set_duty_cycle(key, 0);
pwm_set_enable(key, DISABLE);
if (ISCHIPPRO == 1) {
pwm_set_polarity(key, 0);
}
if ((fd = open("/sys/class/pwm/pwmchip0/unexport", O_WRONLY)) < 0)
{
@ -572,7 +568,7 @@ int pwm_disable(const char *key)
add_error_msg(err);
return -1;
}
len = snprintf(str_gpio, sizeof(str_gpio), "%d", gpio); BUF2SMALL(str_gpio);
len = snprintf(str_gpio, sizeof(str_gpio), "%d", pwm->gpio); BUF2SMALL(str_gpio);
ssize_t s = write(fd, str_gpio, len); e_no = errno;
close(fd);
if (s != len) {