Add more example snippets (#110)

* add Port In and Out example

* add QSPIBlockdevice example

* fix a bug

Author: Qinghao Shi

APIs_Drivers/PortInOut_ex_1/main.cpp

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+// Switch on an LED if any of mbed pins 21-26 is high
+PortIn     p(PortA, 0x0000003F);   // p21-p26
+DigitalOut ind(LED4);
+
+int main()
+{
+    while (1) {
+        int pins = p.read();
+        if (pins) {
+            ind = 1;
+        } else {
+            ind = 0;
+        }
+    }
+}

APIs_Drivers/PortIn_ex_1/main.cpp

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+// Toggle all four LEDs
+// LED1 = P1.18  LED2 = P1.20  LED3 = P1.21  LED4 = P1.23
+#define LED_MASK 0x00B40000
+
+PortInOut ledport(PortA, LED_MASK);
+
+int main()
+{
+    int v = ledport;
+    ledport.output();
+    while (1) {
+        ledport = LED_MASK;
+        ThisThread::sleep_for(500);
+        ledport = 0;
+        ThisThread::sleep_for(1000);
+    }
+}

APIs_Drivers/PortOut_ex_1/main.cpp

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mbed.h"
+
+// Toggle all four LEDs
+// LED1 = P1.18  LED2 = P1.20  LED3 = P1.21  LED4 = P1.23
+#define LED_MASK 0x00B40000
+
+PortOut ledport(PortA, LED_MASK);
+
+int main()
+{
+    while (1) {
+        ledport = LED_MASK;
+        ThisThread::sleep_for(1000);
+        ledport = 0;
+        ThisThread::sleep_for(1000);
+    }
+}

APIs_Storage/QSPIFBlockDevice_ex_1/main.cpp

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2006-2020 Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#if !DEVICE_QSPI
+#error [NOT_SUPPORTED] QSPI not supported for this target
+#endif
+
+#include "mbed.h"
+#include <stdio.h>
+#include <algorithm>
+#include "QSPIFBlockDevice.h"
+
+QSPIFBlockDevice bd(QSPI_FLASH1_IO0, QSPI_FLASH1_IO1, QSPI_FLASH1_IO2, QSPI_FLASH1_IO3,
+                    QSPI_FLASH1_SCK, QSPI_FLASH1_CSN, QSPIF_POLARITY_MODE_0, MBED_CONF_QSPIF_QSPI_FREQ);
+
+// Entry point for the example
+int main()
+{
+    printf("--- Mbed OS QSPIF block device example ---\n");
+
+    // Initialize the block device
+    int err = bd.init();
+    printf("bd.init -> %d\n", err);
+
+    int erase_val = bd.get_erase_value();
+
+    // Get device geometry
+    bd_size_t read_size    = bd.get_read_size();
+    bd_size_t program_size = bd.get_program_size();
+    bd_size_t erase_size   = bd.get_erase_size();
+    bd_size_t size         = bd.size();
+
+    printf("--- Block device geometry ---\n");
+    printf("read_size:    %lld B\n", read_size);
+    printf("program_size: %lld B\n", program_size);
+    printf("erase_size:   %lld B\n", erase_size);
+    printf("size:         %lld B\n", size);
+    printf("---\n");
+
+    // Allocate a block with enough space for our data, aligned to the
+    // nearest program_size. This is the minimum size necessary to write
+    // data to a block.
+    size_t buffer_size = sizeof("Hello Storage!") + program_size - 1;
+    buffer_size = buffer_size - (buffer_size % program_size);
+    char *buffer = new char[buffer_size];
+
+    // Read what is currently stored on the block device. We haven't written
+    // yet so this may be garbage
+    printf("bd.read(%p, %d, %d)\n", buffer, 0, buffer_size);
+    err = bd.read(buffer, 0, buffer_size);
+    printf("bd.read -> %d\n", err);
+
+    printf("--- Stored data ---\n");
+    for (size_t i = 0; i < buffer_size; i += 16) {
+        for (size_t j = 0; j < 16; j++) {
+            if (i + j < buffer_size) {
+                printf("%02x ", buffer[i + j]);
+            } else {
+                printf("   ");
+            }
+        }
+
+        printf(" %.*s\n", buffer_size - i, &buffer[i]);
+    }
+    printf("---\n");
+
+    // Update buffer with our string we want to store
+    strncpy(buffer, "Hello Storage!", buffer_size);
+
+    // Write data to first block, write occurs in two parts,
+    // an erase followed by a program
+    printf("bd.erase(%d, %lld)\n", 0, erase_size);
+    err = bd.erase(0, erase_size);
+    printf("bd.erase -> %d\n", err);
+
+    printf("bd.program(%p, %d, %d)\n", buffer, 0, buffer_size);
+    err = bd.program(buffer, 0, buffer_size);
+    printf("bd.program -> %d\n", err);
+
+    // Clobber the buffer so we don't get old data
+    memset(buffer, 0xcc, buffer_size);
+
+    // Read the data from the first block, note that the program_size must be
+    // a multiple of the read_size, so we don't have to check for alignment
+    printf("bd.read(%p, %d, %d)\n", buffer, 0, buffer_size);
+    err = bd.read(buffer, 0, buffer_size);
+    printf("bd.read -> %d\n", err);
+
+    printf("--- Stored data ---\n");
+    for (size_t i = 0; i < buffer_size; i += 16) {
+        for (size_t j = 0; j < 16; j++) {
+            if (i + j < buffer_size) {
+                printf("%02x ", buffer[i + j]);
+            } else {
+                printf("   ");
+            }
+        }
+
+        printf(" %.*s\n", buffer_size - i, &buffer[i]);
+    }
+    printf("---\n");
+
+    // Deinitialize the block device
+    printf("bd.deinit()\n");
+    err = bd.deinit();
+    printf("bd.deinit -> %d\n", err);
+
+    printf("--- done! ---\n");
+}