flash_at91.c

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#include "flash_at91.h"

#include "cfg/cfg_flash_at91.h"
#include <cfg/macros.h>

#include "hw/hw_boot.h"

// Define log settings for cfg/log.h
#define LOG_LEVEL    CONFIG_FLASH_AT91_LOG_LEVEL
#define LOG_FORMAT   CONFIG_FLASH_AT91_LOG_FORMAT
#include <cfg/log.h>


#include <cpu/irq.h>
#include <cpu/attr.h>
#include <cpu/power.h>

#include <kern/kfile.h>

#include <io/arm.h>

#include <drv/timer.h>

#include <string.h>

/*
 * Check if flash memory is ready to accept other commands.
 */
RAM_FUNC static bool flash_at91_isReady(void)
{
    return (MC_FSR & BV(MC_FRDY));
}

RAM_FUNC static void flash_at91_sendWRcmd(uint32_t page)
{
    cpu_flags_t flags;

    // Wait for end of command
    while(!flash_at91_isReady())
    {
        cpu_relax();
    }

    IRQ_SAVE_DISABLE(flags);

    // Send the 'write page' command
    MC_FCR = MC_KEY | MC_FCMD_WP | (MC_PAGEN_MASK & (page << 8));

    // Wait for end of command
    while(!flash_at91_isReady())
    {
        cpu_relax();
    }

    IRQ_RESTORE(flags);
}

RAM_FUNC static int flash_at91_getStatus(struct KFile *_fd)
{
    (void)_fd;


    /*
     * This bit is set to one if we programming of at least one locked lock
     * region.
     */
    if(MC_FSR & BV(MC_LOCKE))
        return -1;

    /*
     * This bit is set to one if an invalid command and/or a bad keywords was/were
     * written in the Flash Command Register.
     */
    if(MC_FSR & BV(MC_PROGE))
        return -2;

    return 0;
}


RAM_FUNC static void flash_at91_flush(FlashAt91 *fd)
{
    if (fd->page_dirty)
    {
        //Compute page address of current page.
        arm_page_addr_t *addr = (arm_page_addr_t *)((fd->curr_page * FLASH_PAGE_SIZE_BYTES) + FLASH_BASE);

        //Copy modified page into internal latch.
        for (arm_page_addr_t page_addr = 0; page_addr < FLASH_PAGE_SIZE_BYTES; page_addr += 4)
        {
            uint32_t data;
            memcpy(&data, &fd->page_buf[page_addr], sizeof(data));
            *addr = data;
            addr++;
        }

        // Send write command to transfer page from latch to internal flash memory.
        flash_at91_sendWRcmd(fd->curr_page);
    }
}

static int flash_at91_kfileFlush(struct KFile *_fd)
{
    FlashAt91 *fd = FLASHAT91_CAST(_fd);
    flash_at91_flush(fd);
    return 0;
}


static void flash_at91_loadPage(FlashAt91 *fd, arm_page_t page)
{
    if (page != fd->curr_page)
    {
        flash_at91_flush(fd);
        // Load page
        memcpy(fd->page_buf, (const char *)((page * FLASH_PAGE_SIZE_BYTES) + FLASH_BASE), FLASH_PAGE_SIZE_BYTES);
        fd->curr_page = page;
        LOG_INFO("Loaded page %lu\n", fd->curr_page);
    }
}


static size_t flash_at91_write(struct KFile *_fd, const void *_buf, size_t size)
{
    FlashAt91 *fd = FLASHAT91_CAST(_fd);
    const uint8_t *buf =(const uint8_t *)_buf;

    arm_page_t page;
    arm_page_addr_t page_addr;
    size_t total_write = 0;

    size = MIN((kfile_off_t)size, (kfile_off_t)(fd->fd.size - (fd->fd.seek_pos - FLASH_BASE)));

    LOG_INFO("Writing at pos[%lu]\n", fd->fd.seek_pos);
    while (size)
    {
        page = (fd->fd.seek_pos - FLASH_BASE) / FLASH_PAGE_SIZE_BYTES;
        page_addr = (fd->fd.seek_pos - FLASH_BASE) % FLASH_PAGE_SIZE_BYTES;

        flash_at91_loadPage(fd, page);

        size_t wr_len = MIN(size, (size_t)(FLASH_PAGE_SIZE_BYTES - page_addr));

        memcpy(fd->page_buf + page_addr, buf, wr_len);
        fd->page_dirty = true;

        buf += wr_len;
        fd->fd.seek_pos += wr_len;
        size -= wr_len;
        total_write += wr_len;
    }
    LOG_INFO("written %u bytes\n", total_write);
    return total_write;
}

static int flash_at91_close(struct KFile *_fd)
{
    FlashAt91 *fd = FLASHAT91_CAST(_fd);
    flash_at91_flush(fd);
    LOG_INFO("Flash file closed\n");

    return 0;
}

static void flash_at91_open(struct FlashAt91 *fd)
{
    fd->fd.size = FLASH_BASE + FLASH_MEM_SIZE;
    fd->fd.seek_pos = FLASH_BASE + FLASH_BOOT_SIZE;
    fd->curr_page = (fd->fd.seek_pos - FLASH_BASE) / FLASH_PAGE_SIZE_BYTES;

    memcpy(fd->page_buf, (const char *)((fd->curr_page * FLASH_PAGE_SIZE_BYTES) + FLASH_BASE), FLASH_PAGE_SIZE_BYTES);

    fd->page_dirty = false;
    LOG_INFO("Flash file opened\n");
}


static kfile_off_t flash_at91_seek(struct KFile *_fd, kfile_off_t offset, KSeekMode whence)
{
    FlashAt91 *fd = FLASHAT91_CAST(_fd);
    kfile_off_t seek_pos;

    switch (whence)
    {

    case KSM_SEEK_SET:
        seek_pos = FLASH_BASE + FLASH_BOOT_SIZE;
        break;
    case KSM_SEEK_END:
        seek_pos = fd->fd.size;
        break;
    case KSM_SEEK_CUR:
        seek_pos = fd->fd.seek_pos;
        break;
    default:
        ASSERT(0);
        return EOF;
        break;
    }

    #if LOG_LEVEL >= LOG_LVL_INFO
    /* Bound check */
    if (seek_pos + offset > fd->fd.size)
        LOG_INFO("seek outside EOF\n");
    #endif

    fd->fd.seek_pos = seek_pos + offset;

    return fd->fd.seek_pos - (FLASH_BASE + FLASH_BOOT_SIZE);
}

static struct KFile *flash_at91_reopen(struct KFile *_fd)
{
    FlashAt91 *fd = FLASHAT91_CAST(_fd);
    flash_at91_close(_fd);
    flash_at91_open(fd);

    return _fd;
}

static size_t flash_at91_read(struct KFile *_fd, void *_buf, size_t size)
{
    FlashAt91 *fd = FLASHAT91_CAST(_fd);
    uint8_t *buf =(uint8_t *)_buf;

    size = MIN((kfile_off_t)size, fd->fd.size - fd->fd.seek_pos);

    LOG_INFO("Reading at pos[%lu]\n", fd->fd.seek_pos);

    // Flush current buffered page (if modified).
    flash_at91_flush(fd);

    uint32_t *addr = (uint32_t *)fd->fd.seek_pos;
    memcpy(buf, (uint8_t *)addr, size);

    fd->fd.seek_pos += size;

    LOG_INFO("Read %u bytes\n", size);
    return size;
}


void flash_at91_init(FlashAt91 *fd)
{
    memset(fd, 0, sizeof(*fd));
    DB(fd->fd._type = KFT_FLASHAT91);

    // Set up flash programming functions.
    fd->fd.reopen = flash_at91_reopen;
    fd->fd.close = flash_at91_close;
    fd->fd.write = flash_at91_write;
    fd->fd.read = flash_at91_read;
    fd->fd.seek = flash_at91_seek;
    fd->fd.error = flash_at91_getStatus;
    fd->fd.flush = flash_at91_kfileFlush;

    flash_at91_open(fd);

    uint32_t fmcn;
    uint32_t fws = 0;


    /*
     * Compute values to insert into mode register.
     */

    /* main clocks in 1.5uS */
    fmcn = (CPU_FREQ/1000000ul) + (CPU_FREQ/2000000ul) + 1;

    /* hard overclocking */
    if (fmcn > 0xFF)
        fmcn = 0xFF;

    /* Only allow fmcn=0 if clock period is > 30 us = 33kHz. */
    if (CPU_FREQ <= 33333ul)
        fmcn = 0;

    /* Only allow fws=0 if clock frequency is < 30 MHz. */
    if (CPU_FREQ > 30000000ul)
    {
        fws = 1;
    }

    // Set wait states and number of MCK cycles in 1.5 usecs
    MC_FMR = fmcn << 16 | fws << 8;

}