STM32F0: Add Flash API support

Author: bcostm

targets/TARGET_STM/TARGET_STM32F0/common_objects.h

@@ -136,6 +136,13 @@ struct can_s {
 };
 #endif
 
+#if DEVICE_FLASH
+struct flash_s {
+    /*  nothing to be stored for now */
+    uint32_t dummy;
+};
+#endif
+
 #ifdef __cplusplus
 }
 #endif

targets/TARGET_STM/TARGET_STM32F0/flash_api.c

@@ -0,0 +1,226 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "flash_api.h"
+#include "mbed_critical.h"
+
+#if DEVICE_FLASH
+#include "mbed_assert.h"
+#include "cmsis.h"
+
+#ifndef FLASH_SIZE
+#define FLASH_SIZE (uint32_t)(*((uint16_t *)FLASHSIZE_BASE) * 1024U)
+#endif
+
+// Minimum number of bytes to be programmed at a time
+#define MIN_PROG_SIZE (4U)
+
+/** Initialize the flash peripheral and the flash_t object
+ *
+ * @param obj The flash object
+ * @return 0 for success, -1 for error
+ */
+int32_t flash_init(flash_t *obj)
+{
+    return 0;
+}
+
+/** Uninitialize the flash peripheral and the flash_t object
+ *
+ * @param obj The flash object
+ * @return 0 for success, -1 for error
+ */
+int32_t flash_free(flash_t *obj)
+{
+    return 0;
+}
+
+static int32_t flash_unlock(void)
+{
+    /* Allow Access to Flash control registers and user Falsh */
+    if (HAL_FLASH_Unlock()) {
+        return -1;
+    } else {
+        return 0;
+    }
+}
+
+static int32_t flash_lock(void)
+{
+    /* Disable the Flash option control register access (recommended to protect
+    the option Bytes against possible unwanted operations) */
+    if (HAL_FLASH_Lock()) {
+        return -1;
+    } else {
+        return 0;
+    }
+}
+
+/** Erase one sector starting at defined address
+ *
+ * The address should be at sector boundary. This function does not do any check for address alignments
+ * @param obj The flash object
+ * @param address The sector starting address
+ * @return 0 for success, -1 for error
+ */
+int32_t flash_erase_sector(flash_t *obj, uint32_t address)
+{
+    uint32_t PAGEError = 0;
+    FLASH_EraseInitTypeDef EraseInitStruct;
+    int32_t status = 0;
+
+    if (!(IS_FLASH_PROGRAM_ADDRESS(address))) {
+        return -1;
+    }
+
+    if (flash_unlock() != HAL_OK) {
+        return -1;
+    }
+
+    // Clear Flash status register's flags
+    __HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_WRPERR | FLASH_FLAG_PGERR);
+
+    /* MBED HAL erases 1 sector at a time */
+    /* Fill EraseInit structure*/
+    EraseInitStruct.TypeErase   = FLASH_TYPEERASE_PAGES;
+    EraseInitStruct.PageAddress = address;
+    EraseInitStruct.NbPages     = 1;
+
+    /* Note: If an erase operation in Flash memory also concerns data in the data or instruction cache,
+     you have to make sure that these data are rewritten before they are accessed during code
+     execution. If this cannot be done safely, it is recommended to flush the caches by setting the
+     DCRST and ICRST bits in the FLASH_CR register. */
+
+    if (HAL_FLASHEx_Erase(&EraseInitStruct, &PAGEError) != HAL_OK) {
+        status = -1;
+    }
+
+    flash_lock();
+
+    return status;
+}
+
+/** Program one page starting at defined address
+ *
+ * The page should be at page boundary, should not cross multiple sectors.
+ * This function does not do any check for address alignments or if size
+ * is aligned to a page size.
+ * @param obj The flash object
+ * @param address The sector starting address
+ * @param data The data buffer to be programmed
+ * @param size The number of bytes to program
+ * @return 0 for success, -1 for error
+ */
+int32_t flash_program_page(flash_t *obj, uint32_t address,
+        const uint8_t *data, uint32_t size)
+{
+    uint32_t StartAddress = 0;
+    int32_t status = 0;
+
+    if (!(IS_FLASH_PROGRAM_ADDRESS(address))) {
+        return -1;
+    }
+
+    if ((size % MIN_PROG_SIZE) != 0) {
+        return -1;
+    }
+
+    if (flash_unlock() != HAL_OK) {
+        return -1;
+    }
+
+    /* Program the user Flash area word by word */
+    StartAddress = address;
+
+    /* HW needs an aligned address to program flash, which data parameter doesn't ensure */
+    if ((uint32_t) data % 4 != 0) {
+
+        volatile uint32_t data32;
+        while (address < (StartAddress + size) && (status == 0)) {
+            for (uint8_t i = 0; i < MIN_PROG_SIZE; i++) {
+                *(((uint8_t *) &data32) + i) = *(data + i);
+            }
+
+            if (HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, address, data32) == HAL_OK) {
+                address = address + MIN_PROG_SIZE;
+                data = data + MIN_PROG_SIZE;
+            } else {
+                status = -1;
+            }
+        }
+    } else { /*  case where data is aligned, so let's avoid any copy */
+        while ((address < (StartAddress + size)) && (status == 0)) {
+            if (HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, address, *((uint32_t*) data)) == HAL_OK) {
+                address = address + MIN_PROG_SIZE;
+                data = data + MIN_PROG_SIZE;
+            } else {
+                status = -1;
+            }
+        }
+    }
+
+    flash_lock();
+
+    return status;
+}
+
+/** Get sector size
+ *
+ * @param obj The flash object
+ * @param address The sector starting address
+ * @return The size of a sector (in our case considering 1 sector = 1 page)
+ */
+uint32_t flash_get_sector_size(const flash_t *obj, uint32_t address) 
+{
+    if (!(IS_FLASH_PROGRAM_ADDRESS(address))) {
+        return MBED_FLASH_INVALID_SIZE;
+    } else {
+        return FLASH_PAGE_SIZE;
+    }
+}
+
+/** Get page size
+ *
+ * @param obj The flash object
+ * @param address The page starting address
+ * @return The size of a page (in our case the minimum programmable size)
+ */
+uint32_t flash_get_page_size(const flash_t *obj)
+{
+    return MIN_PROG_SIZE;
+}
+
+/** Get start address for the flash region
+ *
+ * @param obj The flash object
+ * @return The start address for the flash region
+ */
+uint32_t flash_get_start_address(const flash_t *obj) 
+{
+    return FLASH_BASE;
+}
+
+/** Get the flash region size
+ *
+ * @param obj The flash object
+ * @return The flash region size
+ */
+uint32_t flash_get_size(const flash_t *obj) 
+{
+    return FLASH_SIZE;
+}
+
+#endif

targets/targets.json

@@ -823,7 +823,7 @@
         },
         "detect_code": ["0755"],
         "macros_add": ["CMSIS_VECTAB_VIRTUAL", "CMSIS_VECTAB_VIRTUAL_HEADER_FILE=\"cmsis_nvic.h\""],
-        "device_has_add": ["LOWPOWERTIMER", "SERIAL_FC", "SERIAL_ASYNCH"],
+        "device_has_add": ["LOWPOWERTIMER", "SERIAL_FC", "SERIAL_ASYNCH", "FLASH"],
         "release_versions": ["2", "5"],
         "device_name": "STM32F070RB"
     },
@@ -841,7 +841,7 @@
         },
         "detect_code": ["0730"],
         "macros_add": ["CMSIS_VECTAB_VIRTUAL", "CMSIS_VECTAB_VIRTUAL_HEADER_FILE=\"cmsis_nvic.h\""],
-        "device_has_add": ["ANALOGOUT", "CAN", "LOWPOWERTIMER", "SERIAL_FC", "SERIAL_ASYNCH"],
+        "device_has_add": ["ANALOGOUT", "CAN", "LOWPOWERTIMER", "SERIAL_FC", "SERIAL_ASYNCH", "FLASH"],
         "release_versions": ["2", "5"],
         "device_name": "STM32F072RB"
     },
@@ -859,7 +859,7 @@
         },
         "detect_code": ["0750"],
         "macros_add": ["CMSIS_VECTAB_VIRTUAL", "CMSIS_VECTAB_VIRTUAL_HEADER_FILE=\"cmsis_nvic.h\""],
-        "device_has_add": ["ANALOGOUT", "CAN", "LOWPOWERTIMER", "SERIAL_FC", "SERIAL_ASYNCH"],
+        "device_has_add": ["ANALOGOUT", "CAN", "LOWPOWERTIMER", "SERIAL_FC", "SERIAL_ASYNCH", "FLASH"],
         "release_versions": ["2", "5"],
         "device_name": "STM32F091RC"
     },