2 * Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
3 * Copyright (c) 2014 Intel Corporation.
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
13 * The above copyright notice and this permission notice shall be
14 * included in all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 #include "mraa_internal.h"
34 #define SYSFS_PWM "/sys/class/pwm"
37 mraa_pwm_setup_duty_fp(mraa_pwm_context dev)
40 snprintf(bu, MAX_SIZE, "/sys/class/pwm/pwmchip%d/pwm%d/duty_cycle", dev->chipid, dev->pin);
42 dev->duty_fp = open(bu, O_RDWR);
43 if (dev->duty_fp == -1) {
50 mraa_pwm_write_period(mraa_pwm_context dev, int period)
52 if (advance_func->pwm_period_replace != NULL) {
53 mraa_result_t result = advance_func->pwm_period_replace(dev, period);
54 if (result == MRAA_SUCCESS) {
60 snprintf(bu, MAX_SIZE, "/sys/class/pwm/pwmchip%d/pwm%d/period", dev->chipid, dev->pin);
62 int period_f = open(bu, O_RDWR);
64 syslog(LOG_ERR, "pwm: Failed to open period for writing");
65 return MRAA_ERROR_INVALID_RESOURCE;
68 int length = snprintf(out, MAX_SIZE, "%d", period);
69 if (write(period_f, out, length * sizeof(char)) == -1) {
71 return MRAA_ERROR_INVALID_RESOURCE;
80 mraa_pwm_write_duty(mraa_pwm_context dev, int duty)
82 if (dev->duty_fp == -1) {
83 if (mraa_pwm_setup_duty_fp(dev) == 1) {
84 return MRAA_ERROR_INVALID_HANDLE;
88 int length = sprintf(bu, "%d", duty);
89 if (write(dev->duty_fp, bu, length * sizeof(char)) == -1)
90 return MRAA_ERROR_INVALID_RESOURCE;
95 mraa_pwm_read_period(mraa_pwm_context dev)
98 char output[MAX_SIZE];
99 snprintf(bu, MAX_SIZE, "/sys/class/pwm/pwmchip%d/pwm%d/period", dev->chipid, dev->pin);
101 int period_f = open(bu, O_RDWR);
102 if (period_f == -1) {
103 syslog(LOG_ERR, "pwm: Failed to open period for reading");
106 off_t size = lseek(period_f, 0, SEEK_END);
107 lseek(period_f, 0, SEEK_SET);
109 ssize_t rb = read(period_f, output, size + 1);
113 syslog(LOG_ERR, "pwm: Error in reading period");
118 long int ret = strtol(output, &endptr, 10);
119 if ('\0' != *endptr && '\n' != *endptr) {
120 syslog(LOG_ERR, "pwm: Error in string conversion");
122 } else if (ret > INT_MAX || ret < INT_MIN) {
123 syslog(LOG_ERR, "pwm: Number is invalid");
126 dev->period = (int) ret;
131 mraa_pwm_read_duty(mraa_pwm_context dev)
133 if (dev->duty_fp == -1) {
134 if (mraa_pwm_setup_duty_fp(dev) == 1) {
135 return MRAA_ERROR_INVALID_HANDLE;
138 lseek(dev->duty_fp, 0, SEEK_SET);
140 off_t size = lseek(dev->duty_fp, 0, SEEK_END);
141 lseek(dev->duty_fp, 0, SEEK_SET);
142 char output[MAX_SIZE];
143 ssize_t rb = read(dev->duty_fp, output, size + 1);
145 syslog(LOG_ERR, "pwm: Error in reading duty");
150 long int ret = strtol(output, &endptr, 10);
151 if ('\0' != *endptr && '\n' != *endptr) {
152 syslog(LOG_ERR, "pwm: Error in string converstion");
154 } else if (ret > INT_MAX || ret < INT_MIN) {
155 syslog(LOG_ERR, "pwm: Number is invalid");
162 mraa_pwm_init(int pin)
164 if (advance_func->pwm_init_pre != NULL) {
165 if (advance_func->pwm_init_pre(pin) != MRAA_SUCCESS)
169 syslog(LOG_ERR, "pwm: Platform Not Initialised");
172 if (plat->pins[pin].capabilites.pwm != 1) {
173 syslog(LOG_ERR, "pwm: pin not capable of pwm");
177 if (plat->pins[pin].capabilites.gpio == 1) {
178 // This deserves more investigation
179 mraa_gpio_context mux_i;
180 mux_i = mraa_gpio_init_raw(plat->pins[pin].gpio.pinmap);
182 syslog(LOG_ERR, "pwm: error in gpio->pwm transition");
185 if (mraa_gpio_dir(mux_i, MRAA_GPIO_OUT) != MRAA_SUCCESS) {
186 syslog(LOG_ERR, "pwm: error in gpio->pwm transition");
189 if (mraa_gpio_write(mux_i, 1) != MRAA_SUCCESS) {
190 syslog(LOG_ERR, "pwm: error in gpio->pwm transition");
193 if (mraa_gpio_close(mux_i) != MRAA_SUCCESS) {
194 syslog(LOG_ERR, "pwm: error in gpio->pwm transition");
199 if (plat->pins[pin].pwm.mux_total > 0) {
200 if (mraa_setup_mux_mapped(plat->pins[pin].pwm) != MRAA_SUCCESS) {
201 syslog(LOG_ERR, "pwm: Failed to set-up multiplexer");
206 int chip = plat->pins[pin].pwm.parent_id;
207 int pinn = plat->pins[pin].pwm.pinmap;
209 if (advance_func->pwm_init_post != NULL) {
210 mraa_pwm_context pret = mraa_pwm_init_raw(chip, pinn);
211 mraa_result_t ret = advance_func->pwm_init_post(pret);
212 if (ret != MRAA_SUCCESS) {
218 return mraa_pwm_init_raw(chip, pinn);
222 mraa_pwm_init_raw(int chipin, int pin)
224 mraa_pwm_context dev = (mraa_pwm_context) malloc(sizeof(struct _pwm));
228 dev->chipid = chipin;
232 char directory[MAX_SIZE];
233 snprintf(directory, MAX_SIZE, SYSFS_PWM "/pwmchip%d/pwm%d", dev->chipid, dev->pin);
235 if (stat(directory, &dir) == 0 && S_ISDIR(dir.st_mode)) {
236 syslog(LOG_NOTICE, "pwm: Pin already exported, continuing");
237 dev->owner = 0; // Not Owner
239 char buffer[MAX_SIZE];
240 snprintf(buffer, MAX_SIZE, "/sys/class/pwm/pwmchip%d/export", dev->chipid);
241 int export_f = open(buffer, O_WRONLY);
242 if (export_f == -1) {
243 syslog(LOG_ERR, "pwm: Failed to open export for writing");
249 int size = snprintf(out, MAX_SIZE, "%d", dev->pin);
250 if (write(export_f, out, size * sizeof(char)) == -1) {
251 syslog(LOG_WARNING, "pwm: Failed to write to export! Potentially already enabled");
257 mraa_pwm_period_us(dev, plat->pwm_default_period);
260 mraa_pwm_setup_duty_fp(dev);
265 mraa_pwm_write(mraa_pwm_context dev, float percentage)
267 if (dev->period == -1) {
268 if (mraa_pwm_read_period(dev) <= 0)
269 return MRAA_ERROR_NO_DATA_AVAILABLE;
272 if (percentage >= 1.0f) {
273 return mraa_pwm_write_duty(dev, dev->period);
275 return mraa_pwm_write_duty(dev, percentage * dev->period);
279 mraa_pwm_read(mraa_pwm_context dev)
281 int period = mraa_pwm_read_period(dev);
283 return (mraa_pwm_read_duty(dev) / (float) period);
289 mraa_pwm_period(mraa_pwm_context dev, float seconds)
291 return mraa_pwm_period_ms(dev, seconds * 1000);
295 mraa_pwm_period_ms(mraa_pwm_context dev, int ms)
297 return mraa_pwm_period_us(dev, ms * 1000);
301 mraa_pwm_period_us(mraa_pwm_context dev, int us)
303 if (us < plat->pwm_min_period || us > plat->pwm_max_period) {
304 syslog(LOG_ERR, "pwm: period value outside platform range");
305 return MRAA_ERROR_INVALID_PARAMETER;
307 return mraa_pwm_write_period(dev, us * 1000);
311 mraa_pwm_pulsewidth(mraa_pwm_context dev, float seconds)
313 return mraa_pwm_pulsewidth_ms(dev, seconds * 1000);
317 mraa_pwm_pulsewidth_ms(mraa_pwm_context dev, int ms)
319 return mraa_pwm_pulsewidth_us(dev, ms * 1000);
323 mraa_pwm_pulsewidth_us(mraa_pwm_context dev, int us)
325 return mraa_pwm_write_duty(dev, us * 1000);
329 mraa_pwm_enable(mraa_pwm_context dev, int enable)
338 snprintf(bu, MAX_SIZE, "/sys/class/pwm/pwmchip%d/pwm%d/enable", dev->chipid, dev->pin);
340 int enable_f = open(bu, O_RDWR);
342 if (enable_f == -1) {
343 syslog(LOG_ERR, "pwm: Failed to open enable for writing");
344 return MRAA_ERROR_INVALID_RESOURCE;
347 int size = snprintf(out, sizeof(out), "%d", enable);
348 if (write(enable_f, out, size * sizeof(char)) == -1) {
349 syslog(LOG_ERR, "pwm: Failed to write to enable");
351 return MRAA_ERROR_INVALID_RESOURCE;
358 mraa_pwm_unexport_force(mraa_pwm_context dev)
360 char filepath[MAX_SIZE];
361 snprintf(filepath, MAX_SIZE, "/sys/class/pwm/pwmchip%d/unexport", dev->chipid);
363 int unexport_f = open(filepath, O_WRONLY);
364 if (unexport_f == -1) {
365 syslog(LOG_ERR, "pwm: Failed to open unexport for writing");
366 return MRAA_ERROR_INVALID_RESOURCE;
370 int size = snprintf(out, MAX_SIZE, "%d", dev->pin);
371 if (write(unexport_f, out, size * sizeof(char)) == -1) {
372 syslog(LOG_ERR, "pwm: Failed to write to unexport");
374 return MRAA_ERROR_INVALID_RESOURCE;
382 mraa_pwm_unexport(mraa_pwm_context dev)
384 mraa_pwm_enable(dev, 0);
386 return mraa_pwm_unexport_force(dev);
388 return MRAA_ERROR_INVALID_RESOURCE;
392 mraa_pwm_close(mraa_pwm_context dev)
394 mraa_pwm_unexport(dev);
400 mraa_pwm_owner(mraa_pwm_context dev, mraa_boolean_t owner_new)
403 return MRAA_ERROR_INVALID_RESOURCE;
404 dev->owner = owner_new;
409 mraa_pwm_config_ms(mraa_pwm_context dev, int ms, float ms_float)
411 int old_dutycycle, old_period, status;
412 old_dutycycle = mraa_pwm_read_duty(dev);
413 old_period = mraa_pwm_read_period(dev);
414 status = mraa_pwm_period_us(dev, ms * 1000);
415 if (status != MRAA_SUCCESS) {
416 mraa_pwm_write_duty(dev, old_dutycycle);
419 status = mraa_pwm_write_duty(dev, 0);
420 if (status != MRAA_SUCCESS) {
423 status = mraa_pwm_pulsewidth_us(dev, ms_float * 1000);
424 if (status != MRAA_SUCCESS) {
425 mraa_pwm_write_duty(dev, old_dutycycle);
426 mraa_pwm_write_period(dev, old_period);
433 mraa_pwm_config_percent(mraa_pwm_context dev, int ms, float percentage)
435 int old_dutycycle, old_period, status;
436 old_dutycycle = mraa_pwm_read_duty(dev);
437 old_period = mraa_pwm_read_period(dev);
438 status = mraa_pwm_period_us(dev, ms * 1000);
439 if (status != MRAA_SUCCESS) {
440 mraa_pwm_write_duty(dev, old_dutycycle);
443 status = mraa_pwm_write_duty(dev, 0);
444 if (status != MRAA_SUCCESS) {
447 status = mraa_pwm_pulsewidth_us(dev, (ms * 1000) * percentage);
448 if (status != MRAA_SUCCESS) {
449 mraa_pwm_write_duty(dev, old_dutycycle);
450 mraa_pwm_write_period(dev, old_period);