FatFs integration (SDIO backend) (#242)

examples/fatfs_rtc/Makefile

@@ -0,0 +1,8 @@
+PROGRAM = fatfs
+EXTRA_COMPONENTS = extras/sdio extras/fatfs extras/i2c extras/ds1307
+ESPBAUD = 460800
+
+# We provide uint32_t get_fattime() based on the RTC
+FATFS_FS_NORTC = 0
+
+include ../../common.mk

examples/fatfs_rtc/README.md

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+This example shows how to use real-time clock (e.g. ds1307)
+with FatFs for real timestamps on the filesystem objects.
+
+1. Set `FATFS_FS_NORTC` to 0 (it's 1 by default) in application makefile.
+2. Define function `uint32_t get_fattime()` which will return current time in
+timestamp format:
+
+ Bits   | Date part
+ -------|----------
+ 0..4   | Second / 2 (0..29)
+ 5..10  | Minute (0..59)
+ 11..15 | Hour (0..23)
+ 16..20 | Day (1..31)
+ 21..24 | Month (1..12)
+ 25..31 | Year origin from 1980 (0..127)

examples/fatfs_rtc/main.c

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+/*
+ * Example of using FatFs with RTC clock
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2016 Ruslan V. Uss <unclerus@gmail.com>
+ * BSD Licensed as described in the file LICENSE
+ */
+#include <esp/uart.h>
+#include <espressif/esp_common.h>
+#include <stdio.h>
+#include <fatfs/ff.h>
+#include <FreeRTOS.h>
+#include <task.h>
+#include <i2c/i2c.h>
+#include <ds1307/ds1307.h>
+
+// SD card
+#define CS_GPIO_PIN 2
+
+// ds1307
+#define SCL_PIN 5
+#define SDA_PIN 4
+
+#define TEST_FILENAME "/test_rtc_file.txt"
+#define TEST_CONTENTS "Hello! It's a test file and it can be deleted!"
+#define DELAY_MS 3000
+
+// This function called by FatFs
+uint32_t get_fattime()
+{
+    struct tm time;
+    ds1307_get_time(&time);
+
+    return ((uint32_t)(time.tm_year - 1980) << 25)
+        | ((uint32_t)time.tm_mon << 21)
+        | ((uint32_t)time.tm_mday << 16)
+        | ((uint32_t)time.tm_hour << 11)
+        | ((uint32_t)time.tm_min << 5)
+        | ((uint32_t)time.tm_sec >> 1);
+}
+
+static const char contents[] = TEST_CONTENTS;
+static FATFS fs;
+
+static void dump_fileinfo()
+{
+    FILINFO info;
+    printf("File: %s\n", TEST_FILENAME);
+    if (f_stat(TEST_FILENAME, &info) != FR_OK)
+    {
+        printf("Cannot get file status\n");
+        return;
+    }
+    printf("File size: %u bytes\n", (uint32_t)info.fsize);
+    printf(
+        "Modified: %04d-%02d-%02d %02d:%02d:%02d\n",
+        (info.fdate >> 9) + 1980, // year
+        (info.fdate >> 5) & 0x0f, // month
+        info.fdate & 0x1f,        // day
+        info.ftime >> 11,         // hours
+        (info.ftime >> 5) & 0x3F, // minutes
+        (info.ftime & 0x1f) << 1  // seconds
+    );
+
+}
+
+void rewrite_file_task(void *p)
+{
+    const char *volume = f_gpio_to_volume(CS_GPIO_PIN);
+
+    while (true)
+    {
+        do
+        {
+            if (f_mount(&fs, volume, 1) != FR_OK)
+            {
+                printf("Cannot mount volume %s\n", volume);
+                break;
+            }
+
+            if (f_chdrive(volume) != FR_OK)
+            {
+                printf("Cannot set default drive %s\n", volume);
+                break;
+            }
+
+            printf("\nTest file\n----------------------------\n");
+
+            dump_fileinfo();
+
+            printf("\nRe-creating test file\n----------------------------\n");
+
+            FIL f; //< It's big and it's on the stack! We need larger stack size
+
+            if (f_open(&f, TEST_FILENAME, FA_WRITE | FA_CREATE_ALWAYS) != FR_OK)
+            {
+                printf("Cannot create file %s\n", TEST_FILENAME);
+                break;
+            }
+
+            size_t bw;
+            if (f_write(&f, contents, sizeof(contents) - 1, &bw))
+            {
+                printf("Cannot write to file\n");
+                break;
+            }
+            printf("Bytes written: %d\n", bw);
+
+            if (f_close(&f) != FR_OK)
+            {
+                printf("Cannot close file\n");
+                break;
+            }
+
+            dump_fileinfo();
+
+            f_mount(NULL, volume, 0);
+        }
+        while (false);
+
+        vTaskDelay(DELAY_MS / portTICK_RATE_MS);
+    }
+}
+
+void user_init(void)
+{
+    uart_set_baud(0, 115200);
+    printf("SDK version:%s\n\n", sdk_system_get_sdk_version());
+
+    i2c_init (SCL_PIN, SDA_PIN);
+
+    xTaskCreate(rewrite_file_task, (signed char *)"task1", 512, NULL, 2, NULL);
+}