rockbox/firmware/target/arm/olympus/mrobe-500/spi-mr500.c

77 lines
2.5 KiB
C

/*
* SPI interface driver for the DM320 SoC
*
* Copyright (C) 2007 shirour <mrobefan@gmail.com>
* Copyright (C) 2007 Catalin Patulea <cat@vv.carleton.ca>
*
* 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 2 of the License, or (at your
* option) any later version.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "system.h"
#define GIO_TS_ENABLE (1<<2)
#define clr_gio_enable() IO_GIO_BITSET1=GIO_TS_ENABLE
#define set_gio_enable() IO_GIO_BITCLR1=GIO_TS_ENABLE
int spi_block_transfer(const uint8_t *tx_bytes, unsigned int tx_size,
uint8_t *rx_bytes, unsigned int rx_size)
{
/* Activate the slave select pin */
set_gio_enable();
while (tx_size--)
{
/* Send one byte */
IO_SERIAL0_TX_DATA = *tx_bytes++;
/* Wait until transfer finished */
while (IO_SERIAL0_RX_DATA & 0x100);
}
while (rx_size--)
{
/* Make the clock tick */
IO_SERIAL0_TX_DATA = 0;
/* Wait until transfer finished */
unsigned short data;
while ((data = IO_SERIAL0_RX_DATA) & 0x100);
*rx_bytes++ = data & 0xff;
}
clr_gio_enable();
return 0;
}
void spi_init(void)
{
/* Set SCLK idle level = 0 */
IO_SERIAL0_MODE |= (1<<10);
/* Enable TX */
IO_SERIAL0_TX_ENABLE = 0x0001;
/* Set GIO 18 to output for touch screen slave enable */
IO_GIO_DIR1&=~GIO_TS_ENABLE;
clr_gio_enable();
}