diff options
author | Josh Blum <josh@joshknows.com> | 2010-12-22 19:19:14 -0800 |
---|---|---|
committer | Josh Blum <josh@joshknows.com> | 2010-12-22 19:19:14 -0800 |
commit | 22ed61f97815856bf74cec25ae6bca88bfbe5f44 (patch) | |
tree | 7d87d49b46f9507ff10486097e6d79e4bee4cb81 /firmware/zpu/usrp2p/spif.c | |
parent | 71fc99d006f2347a356c5339905593f64ff902ec (diff) | |
download | uhd-22ed61f97815856bf74cec25ae6bca88bfbe5f44.tar.gz uhd-22ed61f97815856bf74cec25ae6bca88bfbe5f44.tar.bz2 uhd-22ed61f97815856bf74cec25ae6bca88bfbe5f44.zip |
zpu: renamed the directory for the usrp2 fw to zpu to reflect the cpu type
Diffstat (limited to 'firmware/zpu/usrp2p/spif.c')
-rw-r--r-- | firmware/zpu/usrp2p/spif.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/firmware/zpu/usrp2p/spif.c b/firmware/zpu/usrp2p/spif.c new file mode 100644 index 000000000..1c1a348f4 --- /dev/null +++ b/firmware/zpu/usrp2p/spif.c @@ -0,0 +1,68 @@ +/* + * Copyright 2007,2008,2009 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/>. + */ + +/* + * Code for the Flash SPI bus + */ + +#include "spi.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; +} |