nucleo-f334r8: Add OPAMP support

configs/nucleo-f334r8/include/board.h

@@ -237,8 +237,14 @@
 #define GPIO_USART1_RX GPIO_USART1_RX_1 /* PA10 */
 #define GPIO_USART1_TX GPIO_USART1_TX_1 /* PA9 */
 
-/* HRTIM */
+/* COMP */
 
+/* OPAMP */
+
+#define OPAMP2_VMSEL OPAMP2_VMSEL_PC5
+#define OPAMP2_VPSEL OPAMP2_VPSEL_PB14
+
+/* HRTIM */
 
 /* DMA channels *************************************************************/
 /* ADC */

configs/nucleo-f334r8/src/nucleo-f334r8.h

@@ -202,4 +202,16 @@ int stm32_can_setup(void);
 int stm32_comp_setup(void);
 #endif
 
+/****************************************************************************
+ * Name: stm32_opamp_setup
+ *
+ * Description:
+ *  Initialize OPAMP peripheral for the board.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_OPAMP
+int stm32_opamp_setup(void);
+#endif
+
 #endif /* __CONFIGS_NUCLEO_F334R8_SRC_NUCLEO_F334R8_H */

configs/nucleo-f334r8/src/stm32_appinit.c

@@ -137,6 +137,16 @@ int board_app_initialize(uintptr_t arg)
     }
 #endif
 
+#ifdef CONFIG_OPAMP
+  /* Initialize OPAMP and register the OPAMP driver. */
+
+  ret = stm32_opamp_setup();
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: stm32_opamp_setup failed: %d\n", ret);
+    }
+#endif
+
   UNUSED(ret);
   return OK;
 }

configs/nucleo-f334r8/src/stm32_opamp.c

@@ -0,0 +1,99 @@
+/****************************************************************************
+ * configs/nucleo-f334r8/src/stm32_opamp.c
+ *
+ *   Copyright (C) 2017 Gregory Nutt. All rights reserved.
+ *   Author: Mateusz Szafoni <raiden00@railab.me>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/board.h>
+#include <nuttx/analog/opamp.h>
+
+#include "stm32.h"
+
+#if defined(CONFIG_OPAMP) && defined(CONFIG_STM32_OPAMP2)
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_opamp_setup
+ *
+ * Description:
+ *   Initialize OPAMP
+ *
+ ****************************************************************************/
+
+int stm32_opamp_setup(void)
+{
+  static bool initialized = false;
+  struct opamp_dev_s* opamp = NULL;
+  int ret;
+
+  if (!initialized)
+    {
+      /* Get the OPAMP interface */
+
+#ifdef CONFIG_STM32_OPAMP2
+      opamp = stm32_opampinitialize(2);
+      if (opamp == NULL)
+        {
+          aerr("ERROR: Failed to get OPAMP%d interface\n", 2);
+          return -ENODEV;
+        }
+#endif
+
+      /* Register the OPAMP character driver at /dev/opamp0 */
+
+      ret = opamp_register("/dev/opamp0", opamp);
+      if (ret < 0)
+        {
+          aerr("ERROR: opamp_register failed: %d\n", ret);
+          return ret;
+        }
+
+      initialized = true;
+    }
+
+  return OK;
+}
+
+#endif /* CONFIG_OPAMP && CONFIG_STM32_OPAMP2 */