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/* -*- c++ -*- */
/*
* Copyright 2009 Free Software Foundation, Inc.
* Copyright 2009 Ettus Research LLC
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "spi_flash_private.h"
#include <stdlib.h> // abort
#include <nonstdio.h>
uint32_t
spi_flash_rdid(void)
{
return spif_transact(SPI_TXRX, SPI_SS_FLASH, RDID_CMD << 24, 32, FLAGS) & 0xffffff;
}
static size_t _spi_flash_log2_memory_size, _spi_flash_log2_sector_size;
void spi_flash_init(void)
{
uint32_t id = spi_flash_rdid();
uint8_t type = (id >> 8) & 0xff;
uint8_t size = (id >> 0) & 0xff;
if (type != 0x20 || size < 22 || size > 24)
abort();
_spi_flash_log2_memory_size = size;
static unsigned char log2_sector_size[3] = {
16, /* M25P32 */
16, /* M25P64 */
18, /* M25P128 */
};
_spi_flash_log2_sector_size = log2_sector_size[_spi_flash_log2_memory_size - 22];
}
size_t spi_flash_log2_sector_size(void)
{
return _spi_flash_log2_sector_size;
}
size_t spi_flash_sector_size(void)
{
return ((size_t) 1) << _spi_flash_log2_sector_size;
}
size_t spi_flash_memory_size(void)
{
return ((size_t) 1) << _spi_flash_log2_memory_size;
}
void
spi_flash_read(uint32_t flash_addr, size_t nbytes, void *buf)
{
/*
* We explicitly control the slave select here (/S), so that we can
* do the entire read operation as a single transaction from
* device's point of view. (The most our SPI peripheral can transfer
* in a single shot is 16 bytes.)
*/
spif_wait();
spif_regs->ss = 0;
spif_regs->ctrl = FLAGS; // ASS is now clear and no chip select is enabled.
/*
* Do the 5 byte instruction tranfer:
* FAST_READ_CMD, ADDR2, ADDR1, ADDR0, DUMMY
*/
spif_regs->txrx1 = FAST_READ_CMD;
spif_regs->txrx0 = ((flash_addr & 0x00ffffff) << 8);
spif_regs->ss = SPI_SS_FLASH; // assert chip select
spif_regs->ctrl = FLAGS | LEN(5 * 8);
spif_regs->ctrl = FLAGS | LEN(5 * 8) | SPI_CTRL_GO_BSY;
spif_wait();
/*
* Read up to 16 bytes at a time until done
*/
unsigned char *dst = (unsigned char *) buf;
size_t m;
for (size_t n = 0; n < nbytes; n += m){
spif_regs->ctrl = FLAGS | LEN(16 * 8); // xfer 16 bytes
spif_regs->ctrl = FLAGS | LEN(16 * 8) | SPI_CTRL_GO_BSY;
spif_wait();
uint32_t w[4];
w[0] = spif_regs->txrx3; // txrx3 has first bits in it
w[1] = spif_regs->txrx2;
w[2] = spif_regs->txrx1;
w[3] = spif_regs->txrx0;
unsigned char *src = (unsigned char *) &w[0];
m = min(nbytes - n, 16);
for (size_t i = 0; i < m; i++)
*(dst++) = src[i];
}
spif_regs->ss = 0; // deassert chip select
}
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