drv_m25p16.c

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/*
   drv_m25p16.c : driver for Micron Technology MP25P16 flash memory

   Adapted from https://github.com/cleanflight/cleanflight/blob/master/src/main/drivers/flash_m25p16.c

   This file is part of BreezySTM32.

   BreezySTM32 is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   BreezySTM32 is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with BreezySTM32.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>

#include "stm32f10x_conf.h"
#include "stm32f10x_gpio.h"
#include "core_cm3.h"

// Chip Unique ID on F103
#define U_ID_0 (*(uint32_t*)0x1FFFF7E8)
#define U_ID_1 (*(uint32_t*)0x1FFFF7EC)
#define U_ID_2 (*(uint32_t*)0x1FFFF7F0)

#define NAZE_SPI_INSTANCE     SPI2
#define NAZE_SPI_CS_GPIO      GPIOB
#define NAZE_SPI_CS_PIN       GPIO_Pin_12
#define NAZE_CS_GPIO_CLK_PERIPHERAL RCC_APB2Periph_GPIOB

// We either have this 16mbit flash chip on SPI or the MPU6500 acc/gyro depending on board revision:
#define M25P16_CS_GPIO        NAZE_SPI_CS_GPIO
#define M25P16_CS_PIN         NAZE_SPI_CS_PIN
#define M25P16_SPI_INSTANCE   NAZE_SPI_INSTANCE


#include "drv_m25p16.h"

#include <drv_spi.h>
#include <drv_system.h>

#define M25P16_INSTRUCTION_RDID             0x9F
#define M25P16_INSTRUCTION_READ_BYTES       0x03
#define M25P16_INSTRUCTION_READ_STATUS_REG  0x05
#define M25P16_INSTRUCTION_WRITE_STATUS_REG 0x01
#define M25P16_INSTRUCTION_WRITE_ENABLE     0x06
#define M25P16_INSTRUCTION_WRITE_DISABLE    0x04
#define M25P16_INSTRUCTION_PAGE_PROGRAM     0x02
#define M25P16_INSTRUCTION_SECTOR_ERASE     0xD8
#define M25P16_INSTRUCTION_BULK_ERASE       0xC7

#define M25P16_STATUS_FLAG_WRITE_IN_PROGRESS 0x01
#define M25P16_STATUS_FLAG_WRITE_ENABLED     0x02

// Format is manufacturer, memory type, then capacity
#define JEDEC_ID_MICRON_M25P16         0x202015
#define JEDEC_ID_MICRON_N25Q064        0x20BA17
#define JEDEC_ID_WINBOND_W25Q64        0xEF4017
#define JEDEC_ID_MICRON_N25Q128        0x20ba18
#define JEDEC_ID_WINBOND_W25Q128       0xEF4018

#define DISABLE_M25P16       GPIO_SetBits(M25P16_CS_GPIO,   M25P16_CS_PIN)
#define ENABLE_M25P16        GPIO_ResetBits(M25P16_CS_GPIO, M25P16_CS_PIN)

// The timeout we expect between being able to issue page program instructions
#define DEFAULT_TIMEOUT_MILLIS       6

// These take sooooo long:
#define SECTOR_ERASE_TIMEOUT_MILLIS  5000
#define BULK_ERASE_TIMEOUT_MILLIS    21000

static flashGeometry_t geometry = {.pageSize = M25P16_PAGESIZE};

/*
 * Whether we've performed an action that could have made the device busy for writes.
 *
 * This allows us to avoid polling for writable status when it is definitely ready already.
 */
static bool couldBeBusy = false;

static void m25p16_performOneByteCommand(uint8_t command)
{
    ENABLE_M25P16;

    spiTransferByte(M25P16_SPI_INSTANCE, command);

    DISABLE_M25P16;
}

static void m25p16_writeEnable()
{
    m25p16_performOneByteCommand(M25P16_INSTRUCTION_WRITE_ENABLE);

    // Assume that we're about to do some writing, so the device is just about to become busy
    couldBeBusy = true;
}

static uint8_t m25p16_readStatus()
{
    uint8_t command[2] = {M25P16_INSTRUCTION_READ_STATUS_REG, 0};
    uint8_t in[2];

    ENABLE_M25P16;

    spiTransfer(M25P16_SPI_INSTANCE, in, command, sizeof(command));

    DISABLE_M25P16;

    return in[1];
}

bool m25p16_isReady()
{
    // If couldBeBusy is false, don't bother to poll the flash chip for its status
    couldBeBusy = couldBeBusy && ((m25p16_readStatus() & M25P16_STATUS_FLAG_WRITE_IN_PROGRESS) != 0);

    return !couldBeBusy;
}

bool m25p16_waitForReady(uint32_t timeoutMillis)
{
    uint32_t time = millis();
    while (!m25p16_isReady()) {
        if (millis() - time > timeoutMillis) {
            return false;
        }
    }

    return true;
}

static bool m25p16_readIdentification()
{
    uint8_t out[] = { M25P16_INSTRUCTION_RDID, 0, 0, 0};
    uint8_t in[4];
    uint32_t chipID;

    delay(50); // short delay required after initialisation of SPI device instance.

    /* Just in case transfer fails and writes nothing, so we don't try to verify the ID against random garbage
     * from the stack:
     */
    in[1] = 0;

    ENABLE_M25P16;

    spiTransfer(M25P16_SPI_INSTANCE, in, out, sizeof(out));

    // Clearing the CS bit terminates the command early so we don't have to read the chip UID:
    DISABLE_M25P16;

    // Manufacturer, memory type, and capacity
    chipID = (in[1] << 16) | (in[2] << 8) | (in[3]);

    // All supported chips use the same pagesize of 256 bytes

    switch (chipID) {
        case JEDEC_ID_MICRON_M25P16:
            geometry.sectors = 32;
            geometry.pagesPerSector = 256;
        break;
        case JEDEC_ID_MICRON_N25Q064:
        case JEDEC_ID_WINBOND_W25Q64:
            geometry.sectors = 128;
            geometry.pagesPerSector = 256;
        break;
        case JEDEC_ID_MICRON_N25Q128:
        case JEDEC_ID_WINBOND_W25Q128:
            geometry.sectors = 256;
            geometry.pagesPerSector = 256;
        break;
        default:
            // Unsupported chip or not an SPI NOR flash
            geometry.sectors = 0;
            geometry.pagesPerSector = 0;

            geometry.sectorSize = 0;
            geometry.totalSize = 0;
            return false;
    }

    geometry.sectorSize = geometry.pagesPerSector * geometry.pageSize;
    geometry.totalSize = geometry.sectorSize * geometry.sectors;

    couldBeBusy = true; // Just for luck we'll assume the chip could be busy even though it isn't specced to be

    return true;
}

bool m25p16_init()
{
    //Maximum speed for standard READ command is 20mHz, other commands tolerate 25mHz
    spiSetDivisor(M25P16_SPI_INSTANCE, SPI_18MHZ_CLOCK_DIVIDER);

    return m25p16_readIdentification();
}

void m25p16_eraseSector(uint32_t address)
{
    uint8_t out[] = { M25P16_INSTRUCTION_SECTOR_ERASE, (address >> 16) & 0xFF, (address >> 8) & 0xFF, address & 0xFF};

    m25p16_waitForReady(SECTOR_ERASE_TIMEOUT_MILLIS);

    m25p16_writeEnable();

    ENABLE_M25P16;

    spiTransfer(M25P16_SPI_INSTANCE, NULL, out, sizeof(out));

    DISABLE_M25P16;
}

void m25p16_eraseCompletely()
{
    m25p16_waitForReady(BULK_ERASE_TIMEOUT_MILLIS);

    m25p16_writeEnable();

    m25p16_performOneByteCommand(M25P16_INSTRUCTION_BULK_ERASE);
}

void m25p16_pageProgramBegin(uint32_t address)
{
    uint8_t command[] = { M25P16_INSTRUCTION_PAGE_PROGRAM, (address >> 16) & 0xFF, (address >> 8) & 0xFF, address & 0xFF};

    m25p16_waitForReady(DEFAULT_TIMEOUT_MILLIS);

    m25p16_writeEnable();

    ENABLE_M25P16;

    spiTransfer(M25P16_SPI_INSTANCE, NULL, command, sizeof(command));
}

void m25p16_pageProgramContinue(const uint8_t *data, int length)
{
    spiTransfer(M25P16_SPI_INSTANCE, NULL, data, length);
}

void m25p16_pageProgramFinish()
{
    DISABLE_M25P16;
}

void m25p16_pageProgram(uint32_t address, const uint8_t *data, int length)
{
    m25p16_pageProgramBegin(address);

    m25p16_pageProgramContinue(data, length);

    m25p16_pageProgramFinish();
}

int m25p16_readBytes(uint32_t address, uint8_t *buffer, int length)
{
    uint8_t command[] = { M25P16_INSTRUCTION_READ_BYTES, (address >> 16) & 0xFF, (address >> 8) & 0xFF, address & 0xFF};

    if (!m25p16_waitForReady(DEFAULT_TIMEOUT_MILLIS)) {
        return 0;
    }

    ENABLE_M25P16;

    spiTransfer(M25P16_SPI_INSTANCE, NULL, command, sizeof(command));
    spiTransfer(M25P16_SPI_INSTANCE, buffer, NULL, length);

    DISABLE_M25P16;

    return length;
}

const flashGeometry_t* m25p16_getGeometry()
{
    return &geometry;
}