teensy-serial-flash/SerialFlash.h

/* SerialFlash Library - for filesystem-like access to SPI Serial Flash memory
 * https://github.com/PaulStoffregen/SerialFlash
 * Copyright (C) 2015, Paul Stoffregen, paul@pjrc.com
 *
 * Development of this library was funded by PJRC.COM, LLC by sales of Teensy.
 * Please support PJRC's efforts to develop open source software by purchasing
 * Teensy or other genuine PJRC products.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice, development funding notice, and this permission
 * notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef SerialFlash_h_
#define SerialFlash_h_

#include <Arduino.h>
#include <SPI.h>

class SerialFlashFile;

class SerialFlashChip
{
public:
	static bool begin();
	static uint32_t capacity();
	static uint32_t blockSize();
	static void readID(uint8_t *buf);
	static void read(void *buf, uint32_t addr, uint32_t len);
	static bool ready();
	static void wait();
	static void write(const void *buf, uint32_t addr, uint32_t len);
	static void eraseAll();
	static void eraseBlock(uint32_t addr);

	static SerialFlashFile open(const char *filename);
	static bool create(const char *filename, uint32_t length, uint32_t align = 0);
	static bool createErasable(const char *filename, uint32_t length) {
		return create(filename, length, blockSize());
	}
	static void opendir() { dirindex = 0; }
	static bool readdir(char *filename, uint32_t strsize, uint32_t &filesize);
private:
	static uint16_t dirindex;    // current position for readdir()
	static uint8_t fourbytemode; // 0=use 24 bit address, 1=use 32 bit address
	static uint8_t busy;         // 0 = ready, 1 = suspendable busy, 2 = busy for realz
};

extern SerialFlashChip SerialFlash;


class SerialFlashFile
{
public:
	SerialFlashFile() : address(0) {
	}
	operator bool() {
		if (address > 0) return true;
		return false;
	}
	uint32_t read(uint8_t *buf, uint32_t rdlen) {
		if (offset + rdlen > length) {
			if (offset >= length) return 0;
			rdlen = length - offset;
		}
		SerialFlash.read(buf, address + offset, rdlen);
		offset += rdlen;
		return rdlen;
	}
	uint32_t write(const void *buf, uint32_t wrlen) {
		if (offset + wrlen > length) {
			if (offset >= length) return 0;
			wrlen = length - offset;
		}
		SerialFlash.write(buf, address + offset, wrlen);
		offset += wrlen;
		return wrlen;
	}
	void seek(uint32_t n) {
		offset = n;
	}
	uint32_t position() {
		return offset;
	}
	uint32_t size() {
		return length;
	}
	uint32_t available() {
		if (offset >= length) return 0;
		return length - offset;
	}
	void erase();
	void flush() {
	}
	void close() {
	}
	uint32_t getFlashAddress() {
		return address;
	}
protected:
	friend class SerialFlashChip;
	uint32_t address;  // where this file's data begins in the Flash, or zero
	uint32_t length;   // total length of the data in the Flash chip
	uint32_t offset; // current read/write offset in the file
};


#endif