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-rw-r--r--sys/dev/i2c/files.i2c4
-rw-r--r--sys/dev/i2c/i2c_bitbang.c179
-rw-r--r--sys/dev/i2c/i2c_bitbang.h63
3 files changed, 245 insertions, 1 deletions
diff --git a/sys/dev/i2c/files.i2c b/sys/dev/i2c/files.i2c
index 3a0b718af89..30a3a46327d 100644
--- a/sys/dev/i2c/files.i2c
+++ b/sys/dev/i2c/files.i2c
@@ -1,12 +1,14 @@
-# $OpenBSD: files.i2c,v 1.26 2006/01/02 19:49:26 miod Exp $
+# $OpenBSD: files.i2c,v 1.27 2006/01/13 23:56:46 grange Exp $
# $NetBSD: files.i2c,v 1.3 2003/10/20 16:24:10 briggs Exp $
define i2c {[addr = -1], [size = -1]}
+define i2c_bitbang
device iic: i2c
attach iic at i2cbus
file dev/i2c/i2c.c iic | i2cbus
file dev/i2c/i2c_exec.c iic | i2cbus
file dev/i2c/i2c_scan.c iic | i2cbus
+file dev/i2c/i2c_bitbang.c i2c_bitbang
#
# I2C client devices
diff --git a/sys/dev/i2c/i2c_bitbang.c b/sys/dev/i2c/i2c_bitbang.c
new file mode 100644
index 00000000000..5a865b0af9c
--- /dev/null
+++ b/sys/dev/i2c/i2c_bitbang.c
@@ -0,0 +1,179 @@
+/* $OpenBSD: i2c_bitbang.c,v 1.3 2006/01/13 23:56:46 grange Exp $ */
+/* $NetBSD: i2c_bitbang.c,v 1.1 2003/09/30 00:35:31 thorpej Exp $ */
+
+/*
+ * Copyright (c) 2003 Wasabi Systems, Inc.
+ * All rights reserved.
+ *
+ * Written by Jason R. Thorpe for Wasabi Systems, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed for the NetBSD Project by
+ * Wasabi Systems, Inc.
+ * 4. The name of Wasabi Systems, Inc. may not be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
+ * 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.
+ */
+
+/*
+ * Common module for bit-bang'ing an I2C bus.
+ */
+
+#include <sys/param.h>
+
+#include <dev/i2c/i2cvar.h>
+#include <dev/i2c/i2c_bitbang.h>
+
+#define BB_SET(x) ops->ibo_set_bits(v, (x))
+#define BB_DIR(x) ops->ibo_set_dir(v, (x))
+#define BB_READ ops->ibo_read_bits(v)
+
+#define SDA ops->ibo_bits[I2C_BIT_SDA] /* i2c signal */
+#define SCL ops->ibo_bits[I2C_BIT_SCL] /* i2c signal */
+#define OUTPUT ops->ibo_bits[I2C_BIT_OUTPUT] /* SDA is output */
+#define INPUT ops->ibo_bits[I2C_BIT_INPUT] /* SDA is input */
+
+/*ARGSUSED*/
+int
+i2c_bitbang_send_start(void *v, int flags, i2c_bitbang_ops_t ops)
+{
+
+ BB_DIR(OUTPUT);
+
+ BB_SET(SDA | SCL);
+ delay(5); /* bus free time (4.7 uS) */
+ BB_SET( SCL);
+ delay(4); /* start hold time (4.0 uS) */
+ BB_SET( 0);
+ delay(5); /* clock low time (4.7 uS) */
+
+ return (0);
+}
+
+/*ARGSUSED*/
+int
+i2c_bitbang_send_stop(void *v, int flags, i2c_bitbang_ops_t ops)
+{
+
+ BB_DIR(OUTPUT);
+
+ BB_SET( SCL);
+ delay(4); /* stop setup time (4.0 uS) */
+ BB_SET(SDA | SCL);
+
+ return (0);
+}
+
+int
+i2c_bitbang_initiate_xfer(void *v, i2c_addr_t addr, int flags,
+ i2c_bitbang_ops_t ops)
+{
+ int i2caddr;
+
+ /* XXX Only support 7-bit addressing for now. */
+ if ((addr & 0x78) == 0x78)
+ return (EINVAL);
+
+ i2caddr = (addr << 1) | ((flags & I2C_F_READ) ? 1 : 0);
+
+ (void) i2c_bitbang_send_start(v, flags, ops);
+ return (i2c_bitbang_write_byte(v, i2caddr, flags & ~I2C_F_STOP, ops));
+}
+
+int
+i2c_bitbang_read_byte(void *v, uint8_t *valp, int flags,
+ i2c_bitbang_ops_t ops)
+{
+ int i;
+ uint8_t val = 0;
+ uint32_t bit;
+
+ BB_DIR(INPUT);
+ BB_SET(SDA );
+
+ for (i = 0; i < 8; i++) {
+ val <<= 1;
+ BB_SET(SDA | SCL);
+ delay(4); /* clock high time (4.0 uS) */
+ if (BB_READ & SDA)
+ val |= 1;
+ BB_SET(SDA );
+ delay(5); /* clock low time (4.7 uS) */
+ }
+
+ bit = (flags & I2C_F_LAST) ? SDA : 0;
+ BB_DIR(OUTPUT);
+ BB_SET(bit );
+ delay(1); /* data setup time (250 nS) */
+ BB_SET(bit | SCL);
+ delay(4); /* clock high time (4.0 uS) */
+ BB_SET(bit );
+ delay(5); /* clock low time (4.7 uS) */
+
+ BB_DIR(INPUT);
+ BB_SET(SDA );
+ delay(5);
+
+ if ((flags & (I2C_F_STOP | I2C_F_LAST)) == (I2C_F_STOP | I2C_F_LAST))
+ (void) i2c_bitbang_send_stop(v, flags, ops);
+
+ *valp = val;
+ return (0);
+}
+
+int
+i2c_bitbang_write_byte(void *v, uint8_t val, int flags,
+ i2c_bitbang_ops_t ops)
+{
+ uint32_t bit;
+ uint8_t mask;
+ int error;
+
+ BB_DIR(OUTPUT);
+
+ for (mask = 0x80; mask != 0; mask >>= 1) {
+ bit = (val & mask) ? SDA : 0;
+ BB_SET(bit );
+ delay(1); /* data setup time (250 nS) */
+ BB_SET(bit | SCL);
+ delay(4); /* clock high time (4.0 uS) */
+ BB_SET(bit );
+ delay(5); /* clock low time (4.7 uS) */
+ }
+
+ BB_DIR(INPUT);
+
+ BB_SET(SDA );
+ delay(5);
+ BB_SET(SDA | SCL);
+ delay(4);
+ error = (BB_READ & SDA) ? EIO : 0;
+ BB_SET(SDA );
+ delay(5);
+
+ if (flags & I2C_F_STOP)
+ (void) i2c_bitbang_send_stop(v, flags, ops);
+
+ return (error);
+}
diff --git a/sys/dev/i2c/i2c_bitbang.h b/sys/dev/i2c/i2c_bitbang.h
new file mode 100644
index 00000000000..a10eb425547
--- /dev/null
+++ b/sys/dev/i2c/i2c_bitbang.h
@@ -0,0 +1,63 @@
+/* $OpenBSD: i2c_bitbang.h,v 1.3 2006/01/13 23:56:46 grange Exp $ */
+/* $NetBSD: i2c_bitbang.h,v 1.1 2003/09/30 00:35:31 thorpej Exp $ */
+
+/*
+ * Copyright (c) 2003 Wasabi Systems, Inc.
+ * All rights reserved.
+ *
+ * Written by Jason R. Thorpe for Wasabi Systems, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed for the NetBSD Project by
+ * Wasabi Systems, Inc.
+ * 4. The name of Wasabi Systems, Inc. may not be used to endorse
+ * or promote products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
+ * 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.
+ */
+
+#ifndef _DEV_I2C_I2C_BITBANG_H_
+#define _DEV_I2C_I2C_BITBANG_H_
+
+#define I2C_BIT_SDA 0 /* SDA signal */
+#define I2C_BIT_SCL 1 /* SCL signal */
+#define I2C_BIT_OUTPUT 2 /* controller: SDA is output */
+#define I2C_BIT_INPUT 3 /* controller: SDA is input */
+#define I2C_NBITS 4
+
+struct i2c_bitbang_ops {
+ void (*ibo_set_bits)(void *, uint32_t);
+ void (*ibo_set_dir)(void *, uint32_t);
+ uint32_t (*ibo_read_bits)(void *);
+ uint32_t ibo_bits[I2C_NBITS];
+};
+
+typedef const struct i2c_bitbang_ops *i2c_bitbang_ops_t;
+
+int i2c_bitbang_send_start(void *, int, i2c_bitbang_ops_t);
+int i2c_bitbang_send_stop(void *, int, i2c_bitbang_ops_t);
+int i2c_bitbang_initiate_xfer(void *, i2c_addr_t, int, i2c_bitbang_ops_t);
+int i2c_bitbang_read_byte(void *, uint8_t *, int, i2c_bitbang_ops_t);
+int i2c_bitbang_write_byte(void *, uint8_t, int, i2c_bitbang_ops_t);
+
+#endif /* _DEV_I2C_I2C_BITBANG_H_ */
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