Add some logic related to initialization:

- Add an initialization flag on which read/program/erase actions depend.
- Add an init reference count.

Author: David Saada

SPIFBlockDevice.cpp

@@ -15,7 +15,7 @@
  */
 
 #include "SPIFBlockDevice.h"
-
+#include "mbed_critical.h"
 
 // Read/write/erase sizes
 #define SPIF_READ_SIZE  1
@@ -49,14 +49,24 @@ enum ops {
 
 SPIFBlockDevice::SPIFBlockDevice(
     PinName mosi, PinName miso, PinName sclk, PinName cs, int freq)
-    : _spi(mosi, miso, sclk), _cs(cs), _size(0)
+    : _spi(mosi, miso, sclk), _cs(cs), _size(0), _is_initialized(false), _init_ref_count(0)
 {
     _cs = 1;
     _spi.frequency(freq);
 }
 
 int SPIFBlockDevice::init()
 {
+    if (!_is_initialized) {
+        _init_ref_count = 0;
+    }
+
+    uint32_t val = core_util_atomic_incr_u32(&_init_ref_count, 1);
+
+    if (val != 1) {
+        return BD_ERROR_OK;
+    }
+
     // Check for vendor specific hacks, these should move into more general
     // handling when possible. RDID is not used to verify a device is attached.
     uint8_t id[3];
@@ -125,11 +135,23 @@ int SPIFBlockDevice::init()
         (table[4] << 0 ));
     _size = (density/8) + 1;
 
+    _is_initialized = true;
     return 0;
 }
 
 int SPIFBlockDevice::deinit()
 {
+    if (!_is_initialized) {
+        _init_ref_count = 0;
+        return 0;
+    }
+
+    uint32_t val = core_util_atomic_decr_u32(&_init_ref_count, 1);
+
+    if (val) {
+        return 0;
+    }
+
     // Latch write disable just to keep noise
     // from changing the device
     _cmdwrite(SPIF_WRDI, 0, 0, 0x0, NULL);
@@ -249,6 +271,10 @@ int SPIFBlockDevice::_wren()
 
 int SPIFBlockDevice::read(void *buffer, bd_addr_t addr, bd_size_t size)
 {
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
     // Check the address and size fit onto the chip.
     MBED_ASSERT(is_valid_read(addr, size));
 
@@ -261,6 +287,10 @@ int SPIFBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size)
     // Check the address and size fit onto the chip.
     MBED_ASSERT(is_valid_program(addr, size));
 
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
     while (size > 0) {
         int err = _wren();
         if (err) {
@@ -292,6 +322,10 @@ int SPIFBlockDevice::erase(bd_addr_t addr, bd_size_t size)
     // Check the address and size fit onto the chip.
     MBED_ASSERT(is_valid_erase(addr, size));
 
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
     while (size > 0) {
         int err = _wren();
         if (err) {
@@ -336,6 +370,10 @@ bd_size_t SPIFBlockDevice::get_erase_size(bd_addr_t addr) const
 
 bd_size_t SPIFBlockDevice::size() const
 {
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
     return _size;
 }
 

SPIFBlockDevice.h

@@ -163,6 +163,9 @@ class SPIFBlockDevice : public BlockDevice {
     // Device configuration discovered through sfdp
     bd_size_t _size;
 
+    bool _is_initialized;
+    uint32_t _init_ref_count;
+
     // Internal functions
     int _wren();
     int _sync();