add pwm api

cores/k210/wiring_pulse.c

@@ -22,4 +22,106 @@
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
- */
+ */
+#include "Arduino.h"
+#include <timer.h>
+#include <pwm.h>
+#include <plic.h>
+#include <sysctl.h>
+#include <fpioa.h>
+
+unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout)
+{
+    uint32_t cpu_freq = sysctl_clock_get_freq(SYSCTL_CLOCK_CPU);
+    uint32_t loops = 0;
+    uint32_t max_timeout = timeout * (cpu_freq / 1000000L) / 16;
+    uint32_t start, end;
+
+    // wait for any previous pulse to end
+    while (digitalRead(pin) == state)
+        if (loops++ == max_timeout)
+            return 0;
+
+    // wait for the pulse to start
+    while (digitalRead(pin) != state)
+        if (loops++ == max_timeout)
+            return 0;
+
+    // wait for the pulse to stop
+    start = micros();
+    while (digitalRead(pin) == state)
+        if (loops++ == max_timeout)
+            return 0;
+    end = micros();
+
+    return (end - start);
+}
+
+unsigned long pulseInLong(uint8_t pin, uint8_t state, unsigned long timeout)
+{
+    return pulseIn(pin, state, timeout);
+}
+
+int __attribute__((weak)) pwm_callback(void *ctx)
+{
+#if 0
+    static double cnt = 0.01;
+    static int flag = 0;
+
+    pwm_set_frequency(TIMER_PWM, TIMER_PWM_CHN, 200000, cnt);
+
+    flag ? (cnt -= 0.01) : (cnt += 0.01);
+    if (cnt > 1.0)
+    {
+        cnt = 1.0;
+        flag = 1;
+    }
+    else if (cnt < 0.0)
+    {
+        cnt = 0.0;
+        flag = 0;
+    }
+#endif
+    return 0;
+}
+
+#ifndef TIMER_NOR
+#define TIMER_NOR 0
+#endif
+
+#ifndef TIMER_CHN
+#define TIMER_CHN 0
+#endif
+
+#ifndef TIMER_PWM
+#define TIMER_PWM 1
+#endif
+
+#ifndef TIMER_PWM_CHN
+#define TIMER_PWM_CHN 0
+#endif
+
+void tone(uint8_t _pin, unsigned int frequency, unsigned long duration)
+{
+    /* Init FPIOA pin mapping for PWM*/
+    fpioa_set_function(_pin, pin_map[_pin]);
+    /* Init timer */
+    timer_init(TIMER_NOR);
+    /* Set timer interval to 10ms (1e7ns) */
+    timer_set_interval(TIMER_NOR, TIMER_CHN, 1e7);
+    /* Set timer callback function with repeat method */
+    timer_irq_register(TIMER_NOR, TIMER_CHN, 0, 1, pwm_callback, NULL);
+    /* Enable timer */
+    timer_set_enable(TIMER_NOR, TIMER_CHN, 1);
+    /* Init PWM */
+    pwm_init(TIMER_PWM);
+    /* Set PWM to 200000Hz */
+    pwm_set_frequency(TIMER_PWM, TIMER_PWM_CHN, frequency, duration);
+    /* Enable PWM */
+    pwm_set_enable(TIMER_PWM, TIMER_PWM_CHN, 1);
+}
+void noTone(uint8_t _pin)
+{
+    /* Disable PWM */
+    pwm_set_enable(TIMER_PWM, TIMER_PWM_CHN, 0);
+}