[DeviceDrivers] add pwm driver framework.

components/drivers/include/drivers/rt_drv_pwm.h

@@ -0,0 +1,54 @@
+/*
+ * File      : rt_drv_pwm.h
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2018, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-05-07     aozima       the first version
+ */
+
+#ifndef __DRV_PWM_H_INCLUDE__
+#define __DRV_PWM_H_INCLUDE__
+
+#define PWM_CMD_ENABLE      (128 + 0)
+#define PWM_CMD_DISABLE     (128 + 1)
+#define PWM_CMD_SET         (128 + 2)
+#define PWM_CMD_GET         (128 + 3)
+
+struct rt_pwm_configuration
+{
+    rt_uint32_t channel; /* 0-n */
+    rt_uint32_t period;  /* unit:ns 1ns~4.29s:1Ghz~0.23hz */
+    rt_uint32_t pulse;   /* unit:ns (pulse<=period) */
+};
+
+struct rt_device_pwm;
+struct rt_pwm_ops
+{
+    rt_err_t (*control)(struct rt_device_pwm *device, int cmd, void *arg);
+};
+
+struct rt_device_pwm
+{
+    struct rt_device parent;
+    const struct rt_pwm_ops *ops;
+};
+
+extern rt_err_t rt_device_pwm_register(struct rt_device_pwm *device, const char *name, const struct rt_pwm_ops *ops, const void *user_data);
+
+#endif /* __DRV_PWM_H_INCLUDE__ */

components/drivers/include/rtdevice.h

@@ -112,6 +112,10 @@ extern "C" {
 #include "drivers/cputime.h"
 #endif
 
+#ifdef RT_USING_PWM
+#include "drivers/rt_drv_pwm.h"
+#endif
+
 #ifdef __cplusplus
 }
 #endif