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-rwxr-xr-xfirmware/drivers/generic_i2c.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/firmware/drivers/generic_i2c.c b/firmware/drivers/generic_i2c.c
new file mode 100755
index 0000000000..8475f00ee6
--- /dev/null
+++ b/firmware/drivers/generic_i2c.c
@@ -0,0 +1,204 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Copyright (C) 2006 by Linus Nielsen Feltzing
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "config.h"
+#include "cpu.h"
+#include <stdbool.h>
+#include <stdlib.h>
+#include "debug.h"
+#include "logf.h"
+#include "generic_i2c.h"
+
+int i2c_num_ifs = 0;
+struct i2c_interface *i2c_if[5];
+
+static void i2c_start(struct i2c_interface *iface)
+{
+ iface->sda_hi();
+ iface->scl_hi();
+ iface->sda_lo();
+ iface->delay_hd_sta();
+ iface->scl_lo();
+}
+
+static void i2c_stop(struct i2c_interface *iface)
+{
+ iface->sda_lo();
+ iface->scl_hi();
+ iface->delay_su_sto();
+ iface->sda_hi();
+}
+
+static void i2c_ack(struct i2c_interface *iface, bool ack)
+{
+ iface->scl_lo();
+ if ( ack )
+ iface->sda_lo();
+ else
+ iface->sda_hi();
+
+ iface->delay_su_dat();
+ iface->scl_hi();
+ iface->delay_thigh();
+ iface->scl_lo();
+}
+
+static int i2c_getack(struct i2c_interface *iface)
+{
+ int ret = 1;
+
+ iface->sda_input();
+ iface->delay_su_dat();
+ iface->scl_hi();
+
+ if (iface->sda())
+ ret = 0; /* ack failed */
+
+ iface->delay_thigh();
+ iface->scl_lo();
+ iface->sda_hi();
+ iface->sda_output();
+ iface->delay_hd_dat();
+ return ret;
+}
+
+static unsigned char i2c_inb(struct i2c_interface *iface, bool ack)
+{
+ int i;
+ unsigned char byte = 0;
+
+ /* clock in each bit, MSB first */
+ for ( i=0x80; i; i>>=1 ) {
+ iface->sda_input();
+ iface->scl_hi();
+ iface->delay_thigh();
+ if (iface->sda())
+ byte |= i;
+ iface->scl_lo();
+ iface->delay_hd_dat();
+ iface->sda_output();
+ }
+
+ i2c_ack(iface, ack);
+
+ return byte;
+}
+
+static void i2c_outb(struct i2c_interface *iface, unsigned char byte)
+{
+ int i;
+
+ /* clock out each bit, MSB first */
+ for (i=0x80; i; i>>=1) {
+ if (i & byte)
+ iface->sda_hi();
+ else
+ iface->sda_lo();
+ iface->delay_su_dat();
+ iface->scl_hi();
+ iface->delay_thigh();
+ iface->scl_lo();
+ iface->delay_hd_dat();
+ }
+
+ iface->sda_hi();
+}
+
+static struct i2c_interface *find_if(int address)
+{
+ int i;
+
+ for(i = 0;i < i2c_num_ifs;i++) {
+ if(i2c_if[i]->address == address)
+ return i2c_if[i];
+ }
+ return NULL;
+}
+
+int i2c_write_data(int bus_address, int address,
+ const unsigned char* buf, int count)
+{
+ int i;
+ int ret = 0;
+ struct i2c_interface *iface = find_if(bus_address);
+ if(!iface)
+ return -1;
+
+ i2c_start(iface);
+ i2c_outb(iface, iface->address & 0xfe);
+ if (i2c_getack(iface)) {
+ i2c_outb(iface, address);
+ if (i2c_getack(iface)) {
+ for(i = 0;i < count;i++) {
+ i2c_outb(iface, buf[i]);
+ if (!i2c_getack(iface)) {
+ ret = -3;
+ break;
+ }
+ }
+ } else {
+ ret = -2;
+ }
+ } else {
+ logf("i2c_write_data() - no ack\n");
+ ret = -1;
+ }
+
+ i2c_stop(iface);
+ return ret;
+}
+
+int i2c_read_data(int bus_address, int address,
+ unsigned char* buf, int count)
+{
+ int i;
+ int ret = 0;
+ struct i2c_interface *iface = find_if(bus_address);
+ if(!iface)
+ return -1;
+
+ i2c_start(iface);
+ i2c_outb(iface, iface->address & 0xfe);
+ if (i2c_getack(iface)) {
+ i2c_outb(iface, address);
+ if (i2c_getack(iface)) {
+ i2c_start(iface);
+ i2c_outb(iface, iface->address | 1);
+ if (i2c_getack(iface)) {
+ for(i = 0;i < count-1;i++)
+ buf[i] = i2c_inb(iface, true);
+
+ buf[i] = i2c_inb(iface, false);
+ } else {
+ ret = -3;
+ }
+ } else {
+ ret = -2;
+ }
+ } else {
+ ret = -1;
+ }
+
+ i2c_stop(iface);
+ return ret;
+}
+
+void i2c_add_node(struct i2c_interface *iface)
+{
+ i2c_if[i2c_num_ifs++] = iface;
+}