Added spi_api.c implementation

Author: AGlass0fMilk

targets/TARGET_STM/TARGET_STM32G4/spi_api.c

@@ -0,0 +1,89 @@
+/* mbed Microcontroller Library
+ *******************************************************************************
+ * Copyright (c) 2020, STMicroelectronics
+ * All rights reserved.
+ *
+ * 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 of STMicroelectronics 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 HOLDER 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.
+ *******************************************************************************
+ */
+#include "mbed_assert.h"
+#include "mbed_error.h"
+#include "spi_api.h"
+
+#if DEVICE_SPI
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include "PeripheralPins.h"
+
+
+#if DEVICE_SPI_ASYNCH
+#define SPI_S(obj)    (( struct spi_s *)(&(obj->spi)))
+#else
+#define SPI_S(obj)    (( struct spi_s *)(obj))
+#endif
+
+/*
+ * Only the frequency is managed in the family specific part
+ * the rest of SPI management is common to all STM32 families
+ */
+int spi_get_clock_freq(spi_t *obj)
+{
+    struct spi_s *spiobj = SPI_S(obj);
+    int spi_hz = 0;
+
+    /* Get source clock depending on SPI instance */
+    switch ((int)spiobj->spi) {
+#if defined SPI1_BASE
+        case SPI_1:
+            /* SPI_1. Source CLK is PCKL2 */
+            spi_hz = HAL_RCC_GetPCLK2Freq();
+            break;
+#endif
+#if defined SPI2_BASE
+        case SPI_2:
+            /* SPI_2 and SPI_3. Source CLK is PCKL1 */
+            spi_hz = HAL_RCC_GetPCLK1Freq();
+            break;
+#endif
+#if defined SPI3_BASE
+        case SPI_3:
+            /* SPI_2 and SPI_3. Source CLK is PCKL1 */
+            spi_hz = HAL_RCC_GetPCLK1Freq();
+            break;
+#endif
+#if defined SPI4_BASE
+        case SPI_4:
+            /* SPI_4. Source CLK is PCKL2 */
+            spi_hz = HAL_RCC_GetPCLK2Freq();
+            break;
+#endif
+        default:
+            error("CLK: SPI instance not set");
+            break;
+    }
+    return spi_hz;
+}
+
+#endif