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

   1 /*
   2  * SPI interface driver for the DM320 SoC
   3  *
   4  * Copyright (C) 2007 shirour <mrobefan@gmail.com>
   5  * Copyright (C) 2007 Catalin Patulea <cat@vv.carleton.ca>
   6  *
   7  *  This program is free software; you can redistribute  it and/or modify it
   8  *  under  the terms of  the GNU General  Public License as published by the
   9  *  Free Software Foundation;  either version 2 of the License, or (at your
  10  *  option) any later version.
  11  *
  12  *  THIS  SOFTWARE  IS PROVIDED   ``AS IS'' AND   ANY EXPRESS OR IMPLIED
  13  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  14  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  15  *  NO EVENT  SHALL   THE AUTHOR  BE  LIABLE FOR ANY   DIRECT, INDIRECT,
  16  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  17  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS OR SERVICES; LOSS OF
  18  *  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  19  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  20  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  21  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  22  *
  23  *  You should have received a copy of the  GNU General Public License along
  24  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  25  *  675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #include "system.h"
  29
  30 #define GIO_TS_ENABLE (1<<2)
  31 #define clr_gio_enable() outw(GIO_TS_ENABLE, IO_GIO_BITSET1)
  32 #define set_gio_enable() outw(GIO_TS_ENABLE, IO_GIO_BITCLR1)
  33
  34 int spi_block_transfer(const uint8_t *tx_bytes, unsigned int tx_size,
  35                              uint8_t *rx_bytes, unsigned int rx_size)
  36 {
  37     /* Activate the slave select pin */
  38     set_gio_enable();
  39
  40     while (tx_size--)
  41     {
  42         /* Send one byte */
  43         IO_SERIAL0_TX_DATA = *tx_bytes++;
  44
  45         /* Wait until transfer finished */
  46         while (IO_SERIAL0_RX_DATA & 0x100);
  47     }
  48
  49     while (rx_size--)
  50     {
  51         /* Make the clock tick */
  52         IO_SERIAL0_TX_DATA = 0;
  53
  54         /* Wait until transfer finished */
  55         unsigned short data;
  56         while ((data = IO_SERIAL0_RX_DATA) & 0x100);
  57
  58         *rx_bytes++ = data & 0xff;
  59     }
  60
  61     clr_gio_enable();
  62
  63     return 0;
  64 }
  65
  66 void spi_init(void)
  67 {
  68     /* Set SCLK idle level = 0 */
  69     IO_SERIAL0_MODE |= (1<<10);
  70
  71     /* Enable TX */
  72     IO_SERIAL0_TX_ENABLE = 0x0001;
  73
  74     /* Set GIO 18 to output for touch screen slave enable */
  75     outw(inw(IO_GIO_DIR1)&~GIO_TS_ENABLE, IO_GIO_DIR1);
  76     clr_gio_enable();
  77 }