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authorNicolas Schodet2009-04-17 00:25:25 +0200
committerNicolas Schodet2009-04-17 00:25:25 +0200
commit06ae1ef9e5fe5ecaddce8408f8bd9df8bd08fb2f (patch)
treea010a5e0dfdc66f4322fde4e877b68235d739615 /digital/avr/modules/spi/spi_soft.avr.c
parentbdd377580a0374cc2893d386eb0f47b802232ac9 (diff)
* digital/avr/modules/spi:
- added software driver.
Diffstat (limited to 'digital/avr/modules/spi/spi_soft.avr.c')
-rw-r--r--digital/avr/modules/spi/spi_soft.avr.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/digital/avr/modules/spi/spi_soft.avr.c b/digital/avr/modules/spi/spi_soft.avr.c
new file mode 100644
index 00000000..d73b4de8
--- /dev/null
+++ b/digital/avr/modules/spi/spi_soft.avr.c
@@ -0,0 +1,101 @@
+/* spi_soft.avr.c - SPI driver using regular GPIO. */
+/* avr.spi - SPI AVR module. {{{
+ *
+ * Copyright (C) 2009 Nicolas Schodet
+ *
+ * APBTeam:
+ * Web: http://apbteam.org/
+ * Email: team AT apbteam DOT org
+ *
+ * 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 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * }}} */
+#include "common.h"
+
+#include "io.h"
+#include "modules/utils/utils.h"
+
+#include "spi.h"
+
+#if SPI0_DRIVER == SPI_DRIVER_SOFT || SPI1_DRIVER == SPI_DRIVER_SOFT
+
+#if SPI0_DRIVER == SPI_DRIVER_SOFT
+# define SPI_SCK_IO AC_SPI0_SOFT_SCK_IO
+# define SPI_MOSI_IO AC_SPI0_SOFT_MOSI_IO
+# define SPI_MISO_IO AC_SPI0_SOFT_MISO_IO
+#else
+# define SPI_SCK_IO AC_SPI1_SOFT_SCK_IO
+# define SPI_MOSI_IO AC_SPI1_SOFT_MOSI_IO
+# define SPI_MISO_IO AC_SPI1_SOFT_MISO_IO
+#endif
+
+/** SPI speed, SCK period (us). */
+static uint8_t spi_speed;
+
+void
+spi_soft_init_ (uint8_t speed)
+{
+ /* Set ports. */
+ IO_DDR (SPI_MISO_IO) &= ~IO_BV (SPI_MISO_IO);
+ IO_PORT (SPI_MISO_IO) |= IO_BV (SPI_MISO_IO);
+ IO_PORT (SPI_MOSI_IO) &= ~IO_BV (SPI_MOSI_IO);
+ IO_DDR (SPI_MOSI_IO) |= IO_BV (SPI_MOSI_IO);
+ IO_PORT (SPI_SCK_IO) &= ~IO_BV (SPI_SCK_IO);
+ IO_DDR (SPI_SCK_IO) |= IO_BV (SPI_SCK_IO);
+ /* Store speed. */
+ spi_speed = speed;
+}
+
+void
+spi_soft_send (uint8_t data)
+{
+ spi_soft_send_and_recv (data);
+}
+
+uint8_t
+spi_soft_recv (void)
+{
+ return spi_soft_send_and_recv (0);
+}
+
+uint8_t
+spi_soft_send_and_recv (uint8_t data)
+{
+ uint8_t recv, i, j;
+ recv = 0;
+ for (i = 0x80; i; i >>= 1)
+ {
+ /* Setup data. */
+ if (data & i)
+ IO_PORT (SPI_MOSI_IO) |= IO_BV (SPI_MOSI_IO);
+ else
+ IO_PORT (SPI_MOSI_IO) &= ~IO_BV (SPI_MOSI_IO);
+ /* Delay with SCK low. */
+ for (j = 0; j < spi_speed; j++)
+ utils_delay_us (0.5);
+ /* SCK high, sample. */
+ if (IO_PIN (SPI_MISO_IO) & IO_BV (SPI_MISO_IO))
+ recv |= i;
+ IO_PORT (SPI_SCK_IO) |= IO_BV (SPI_SCK_IO);
+ /* Delay with SCK high. */
+ for (j = 0; j < spi_speed; j++)
+ utils_delay_us (0.5);
+ /* SCK low. */
+ IO_PORT (SPI_SCK_IO) &= ~IO_BV (SPI_SCK_IO);
+ }
+ return recv;
+}
+
+#endif /* SPI0_DRIVER == SPI_DRIVER_SOFT || SPI1_DRIVER == SPI_DRIVER_SOFT */