From e5a8945f0314d4a7b9b81ff198f8cdebeabcefc0 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Mon, 3 Feb 2014 19:35:37 +0100
Subject: [PATCH] Initial import of low-level PWM driver interface
---
drivers/include/periph/pwm.h | 100 +++++++++++++++++++++++++++++++++++
1 file changed, 100 insertions(+)
create mode 100644 drivers/include/periph/pwm.h
diff --git a/drivers/include/periph/pwm.h b/drivers/include/periph/pwm.h
new file mode 100644
index 0000000000..3e9c4b5933
--- /dev/null
+++ b/drivers/include/periph/pwm.h
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2014 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the LGPLv2 License.
+ * See the file LICENSE in the top level directory for more details.
+ */
+
+/**
+ * @ingroup driver_periph
+ * @brief Low-level PWM periphial driver
+ * @{
+ *
+ * @file pwm.h
+ * @brief Low-level PWM periphial driver interface definitions
+ *
+ * @author Hauke Petersen <hauke.petersen@fu-berlin.de>
+ */
+
+#ifndef __PWM_H
+#define __PWM_H
+
+#include "periph_conf.h"
+
+
+/**
+ * @brief Definition of available PWM devices
+ */
+#ifdef PWM_NUMOF
+typedef enum {
+#ifdef PWM_0_EN
+ PWM_0, ///< first PWM device
+#endif
+#ifdef PWM_1_EN
+ PWM_1 ///< Second PWM device
+#endif
+} pwm_t;
+#endif
+
+/**
+ * @brief Definition of availabe PWM modes
+ */
+typedef enum {
+ PWM_LEFT, ///< use left aligned PWM
+ PWM_RIGHT, ///< use right aligned PWM
+ PWM_CENTER ///< use center aligned PWM
+} pwm_mode_t;
+
+
+/**
+ * @brief Initialize a PWM device
+ *
+ * The PWM module is based on virtual PWM devices, which can have one or more channels.
+ * The PWM devices can be configured to run with a given frequency and resolution, which
+ * are always identical for the complete device, hence for every channel on a device.
+ *
+ * The desired frequency and resolution may not be possible on a given device when chosen
+ * to large. In this case the PWM driver will always keep the resolution and decrease the
+ * frequency if needed. To veryfy the correct settings compare the returned value which
+ * is the actually set frequency.
+ *
+ * @param dev PWM channel to initialize
+ * @param mode PWM mode, left, right or center aligned
+ * @param frequency the PWM frequency in Hz
+ * @param resolution the PWM resolution
+ * @return the acutally set frequency,
+ * 0 if frequency and resolution settings are not applicable,
+ * -1 on error
+ */
+int pwm_init(pwm_t dev, pwm_mode_t mode, unsigned int frequency, unsigned int resolution);
+
+/**
+ * @brief Set the duty-cycle for a given channel of the given PWM device
+ *
+ * The duty-cycle is set in relation to the chosen resolution of the given device. If
+ * value > resolution, value is set to resolution.
+ *
+ * @param dev the PWM device to set
+ * @param channel the channel of the given device to set
+ * @param value the desired duty-cycle to set
+ * @return the acutally set duty-cycle, -1 on invalic device or channel
+ */
+int pwm_set(pwm_t dev, int channel, unsigned int value);
+
+/**
+ * @brief Start PWM generation on the given device
+ *
+ * @param dev device to start
+ */
+void pwm_start(pwm_t dev);
+
+/**
+ * @brief Stop PWM generation on the given deivce
+ *
+ * @param dev device to stop
+ */
+void pwm_stop(pwm_t dev);
+
+
+#endif /* __PWM_H */
+/** @} */
--
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