max80_fw/rv32/romcopy.c

#include "fw.h"
#include "console.h"
#include "io.h"
#include "spiflash.h"

#define SPIROM_DUAL_MODE 1

void __hot romcopy_download(void *dst, size_t offset, size_t len)
{
    unsigned int cmd;
    unsigned int flags = ROMCOPY_SPI_CMDLEN(5) | ROMCOPY_WRITE_RAM;

    if (!len)
	return;
    
    if (SPIROM_DUAL_MODE) {
	cmd = ROM_FAST_READ_DUAL;
	flags |= ROMCOPY_SPI_DUAL;
    } else {
	cmd = ROM_FAST_READ;
    }

    ROMCOPY_RAMADDR = (size_t)dst;
    ROMCOPY_ROMCMD  = __rom_offset + offset + (cmd << 24);
    ROMCOPY_DATALEN = len | flags;
}

void __hot romcopy_bzero(void *dst, size_t len)
{
    if (!len)
	return;
    
    ROMCOPY_RAMADDR = (size_t)dst;
    ROMCOPY_ROMCMD  = 0;
    ROMCOPY_DATALEN = len | ROMCOPY_ZERO_BUFFER | ROMCOPY_WRITE_RAM;
}

/*
 * Read unique serial number programmed into ROM
 *
 */
char __bss_hot rom_serial_str[16];
qword_t __bss_hot rom_serial;

static __must_inline void rom_read_serial(void)
{
    ROMCOPY_ROMCMD  = ROM_READ_UNIQUE_ID << 24;
    ROMCOPY_DATALEN = ROMCOPY_SPI_CMDLEN(5) | ROMCOPY_SPI_MORE;
    waitfor(ROMCOPY_IRQ);

    ROMCOPY_DATALEN = ROMCOPY_SPI_CMDLEN(4) | ROMCOPY_SPI_MORE;
    waitfor(ROMCOPY_IRQ);

    rom_serial.l[1] = ROMCOPY_INPUT;
    ROMCOPY_DATALEN = ROMCOPY_SPI_CMDLEN(4);
    waitfor(ROMCOPY_IRQ);

    rom_serial.l[0] = ROMCOPY_INPUT;
}

/*
 * Convert the ROM serial number to a hex string and poke it into the
 * USB descriptor "ROM". Used to use base36, but this has to be done
 * very early, and it has turned out that making it consistent with
 * what one can easily get out of a debugger is really useful.
 *
 * Doing this as early as possible means a much better chance to see
 * the proper serial number during USB enumeration, so doing it
 * immediately after SPI ROM conditioning is a great time.
 */
static __must_inline void rom_mangle_serial(void)
{
    volatile uint32_t *udp = &usbdesc_rom[2];

    for (int i = 7; i >= 0; i--) {
	unsigned int v = rom_serial.b[i];
	unsigned int c;

	c = (v >> 4)+'0';
	if (c > '9')
	    c += 'A'-'9'-1;

	udp[0] = c;

	c = (v & 15)+'0';
	if (c > '9')
	    c += 'A'-'9'-1;

	udp[2] = c;

	udp += 4;
    }
}

void rom_print_serial(void)
{
    /* Print the ROM serial when we actually can */
    con_printf("ROM serial: %08X%08X (%08x-%08x)\n",
	       rom_serial.l[1], rom_serial.l[0],
	       rom_serial.l[1], rom_serial.l[0]);
}

static __must_inline void romcopy_config_flash(void)
{
    /* Enable writing volatile status register bits */
    ROMCOPY_ROMCMD = ROM_VOLATILE_SR_WRITE_ENABLE << 24;
    ROMCOPY_DATALEN = ROMCOPY_SPI_CMDLEN(1);
    waitfor(ROMCOPY_IRQ);

    /* Write SR3 = 0; this sets the drive strength to maximum */
    ROMCOPY_ROMCMD = ROM_WRITE_SR3 << 24;
    ROMCOPY_DATALEN = ROMCOPY_SPI_CMDLEN(2);
    waitfor(ROMCOPY_IRQ);
}

IRQHANDLER(romcopy,0)
{
    static __sbss unsigned int romcopy_state;
    size_t len;

    switch (romcopy_state++) {
    case 0:
	/* Condition flash ROM */
	romcopy_config_flash();

	/* Read serial number */
	rom_read_serial();

	/* Start copy DRAM data */
	len = __dram_init_end - __dram_init_start;
	romcopy_download(__dram_init_start, 0, len);

	/* Convert serial number and export to USB */
	rom_mangle_serial();
	break;
    case 1:
	/* Zero .dram.bss */
	len = __dram_bss_end - __dram_bss_start;
	romcopy_bzero(__dram_bss_start, len);
	break;
    default:
	mask_irq(ROMCOPY_IRQ);
	break;
    }
}

/*
 * SPI flash parameters and routines (for spiflash.c)
 */
static const struct spiflash_ops max80_spiflash_ops;
static const struct spiflash_param max80_spiflash_param;

/*
 * SPI flash operations
 */
static int max80_spi_write_buffer(const void *buf, unsigned int buflen,
				  bool more)
{
    const uint8_t *p = buf;
    uint32_t cmd = 0;
    unsigned int bytecmd = 0;
    unsigned int bitpos = 24;

    while (buflen) {
	cmd |= *p++ << bitpos;
	buflen--;
	bitpos -= 8;
	bytecmd += ROMCOPY_SPI_CMDLEN(1);

	if (!(buflen & 3)) {
	    if (buflen || more)
		bytecmd |= ROMCOPY_SPI_MORE;
	    waitfor(ROMCOPY_IRQ);
	    ROMCOPY_ROMCMD  = cmd;
	    ROMCOPY_DATALEN = bytecmd;
	    bytecmd = cmd = 0;
	    bitpos = 24;
	}
    }

    return 0;
}

static int max80_spi_read_buffer(void *buf, unsigned int buflen, bool more)
{
    uint8_t *p = buf;
    unsigned int bytecmd;
    uint32_t v;

    if (!buflen)
	return 0;

    waitfor(ROMCOPY_IRQ);
    ROMCOPY_ROMCMD = 0;

    while (buflen > 4) {
	ROMCOPY_DATALEN = ROMCOPY_SPI_CMDLEN(4) | ROMCOPY_SPI_MORE;
	waitfor(ROMCOPY_IRQ);
	v = ROMCOPY_INPUT;
	p[0] = v >> 24;
	p[1] = v >> 16;
	p[2] = v >> 8;
	p[3] = v;
	p += 4;
	buflen -= 4;
    }

    bytecmd = ROMCOPY_SPI_CMDLEN(buflen);
    if (more)
	bytecmd |= ROMCOPY_SPI_MORE;

    ROMCOPY_DATALEN = bytecmd;
    waitfor(ROMCOPY_IRQ);
    v = ROMCOPY_INPUT;
    while (buflen) {
	p[--buflen] = v;
	v >>= 8;
    }
    return 0;
}

static int max80_spi_write(void *cookie,
			   const void *cmd, unsigned int cmd_len,
			   const void *data, unsigned int data_len,
			   int tshsl)
{
    (void)cookie;
    (void)tshsl;		/* Enforced in hardware */

    waitfor(ROMCOPY_IRQ);
    udelay(1);

    if (cmd_len)
	max80_spi_write_buffer(cmd, cmd_len, !!data_len);

    if (data_len)
	max80_spi_write_buffer(data, data_len, false);

    return 0;
}

static int max80_spi_read(void *cookie,
		    const void *cmd, unsigned int cmd_len,
		    void *data, unsigned int data_len,
		    int tshsl)
{
    (void)cookie;
    (void)tshsl;		/* Enforced in hardware */

    waitfor(ROMCOPY_IRQ);
    udelay(1);

    if (cmd_len)
	max80_spi_write_buffer(cmd, cmd_len, !!data_len);

    if (data_len)
	max80_spi_read_buffer(data, data_len, false);

    return 0;
}

static const struct spiflash_ops max80_spiflash_ops = {
    .read_data  = NULL,		/* From memory buffer */
    .close_data = NULL,		/* Nothing to do */
    .spi_write  = max80_spi_write,
    .spi_read   = max80_spi_read,
    .yield      = NULL		/* Nothing to yield to... */
};

/* Winbond W25Q128JV @ 3.3V */
#define NS(x) (((x)*(unsigned long long)CPU_HZ + 999999999ULL)/1000000000ULL)
#define US(x) (((x)*(unsigned long long)CPU_HZ + 999999ULL)/1000000ULL)
#define MS(x) (((x)*(unsigned long long)CPU_HZ + 999ULL)/1000ULL)
static const struct spiflash_param max80_spiflash_param = {
    /*
     * For W25Q128JV _DYNAMIC is equivalent to _24BIT, but specifying
     * it as dynamic would most of the time support larger parts
     * transparently.
     */
    .addr   = SPIFLASH_ADDR_DYNAMIC,

    .tshsl  = NS(3),
    .tshsl1 = NS(10),
    .tshsl2 = NS(50),

    .trst   = NS(30000),
    .tw     = MS(10),		/* persistent; typ, max = 15 */
    .tpp    = NS(400),		/* typ, max = 3000 */
    .tse    = MS(45),		/* typ, max = 400 */
    .tbe1   = MS(120),		/* typ, max = 1600 */
    .tbe2   = MS(150),		/* typ, max = 2000 */
    .tce    = MS(40000),	/* typ, max = 200000 */
};

static struct spiflash max80_flash = {
    .ops    = &max80_spiflash_ops,
    .cookie = NULL,
    .param  = &max80_spiflash_param
};

/*
 * Flash an image into SPI flash, and reload the FPGA if successful,
 * returns on failure only.
 */
void rom_flash_from_memory(void *buf, size_t buflen)
{
    const struct spiflash_header *hdr = buf;
    uint32_t romid[2];

    for (int i = 0; i < 8; i++)
	con_printf("%08x ", ((const uint32_t *)buf)[i]);
    con_putc('\n');

    if (hdr->magic != SPIFLASH_MAGIC) {
	con_printf("update: no flash update data found in memory at %p\n", hdr);
	return;
    }

    memset(romid, 0, sizeof romid);
    spiflash_read_id(&max80_flash, romid);
    con_printf("update: ROM serial number %08x-%08x\n", romid[0], romid[1]);

    if (spiflash_flash_files(&max80_flash, buf, buflen)) {
	con_puts("update: flash update data invalid\n");
	return;
    }

    con_puts("update: Flash complete, restarting in 5 s...\n");
    udelay(5000000);

    reset(SYS_RESET_RECONFIG);
}