mirror of
https://github.com/saymrwulf/uhd.git
synced 2026-05-16 21:10:10 +00:00
69 lines
1.8 KiB
C
69 lines
1.8 KiB
C
/*
|
|
* Copyright 2007,2008,2009 Free Software Foundation, Inc.
|
|
* Copyright 2009-2011 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/>.
|
|
*/
|
|
|
|
/*
|
|
* Code for the Flash SPI bus
|
|
*/
|
|
|
|
#include "spi.h"
|
|
#include "spi_flash.h"
|
|
#include "memory_map.h"
|
|
|
|
void
|
|
spif_init(void)
|
|
{
|
|
/*
|
|
* f_sclk = f_wb / ((div + 1) * 2)
|
|
*/
|
|
spif_regs->div = 1; // 0 = Div by 2 (31.25 MHz); 1 = Div-by-4 (15.625 MHz)
|
|
|
|
// run dummy transaction to work around invalid initial clock state
|
|
spif_transact(SPI_TXONLY, 0, 0, 8, SPIF_PUSH_FALL | SPIF_LATCH_RISE);
|
|
}
|
|
|
|
inline void
|
|
spif_wait(void)
|
|
{
|
|
while (spif_regs->ctrl & SPI_CTRL_GO_BSY)
|
|
;
|
|
}
|
|
|
|
uint32_t
|
|
spif_transact(bool readback_, int slave, uint32_t data, int length, uint32_t flags)
|
|
{
|
|
flags &= (SPI_CTRL_TXNEG | SPI_CTRL_RXNEG);
|
|
int ctrl = SPI_CTRL_ASS | (SPI_CTRL_CHAR_LEN_MASK & length) | flags;
|
|
|
|
spif_wait();
|
|
|
|
// Data we will send
|
|
spif_regs->txrx0 = data;
|
|
|
|
// Run it -- write once and rewrite with GO set
|
|
spif_regs->ctrl = ctrl;
|
|
// Tell it which SPI slave device to access
|
|
spif_regs->ss = slave & 0xff;
|
|
spif_regs->ctrl = ctrl | SPI_CTRL_GO_BSY;
|
|
|
|
if(readback_) {
|
|
spif_wait();
|
|
return spif_regs->txrx0;
|
|
}
|
|
else
|
|
return 0;
|
|
}
|