Generic bitbang I2C driver

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8782 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 53 insertions, 0 deletions

diff --git a/firmware/export/generic_i2c.h b/firmware/export/generic_i2c.h
new file mode 100755
index 0000000..5570d94
--- /dev/null
+++ b/firmware/export/generic_i2c.h
@@ -0,0 +1,53 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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.
+ *
+ ****************************************************************************/
+#ifndef _GEN_I2C_
+#define _GEN_I2C_
+
+struct i2c_interface
+{
+    unsigned char address; /* Address of the chip that this interface
+                              describes */
+
+    void (*scl_hi)(void);  /* Drive SCL high, might sleep on clk stretch */
+    void (*scl_lo)(void);  /* Drive SCL low */
+    void (*sda_hi)(void);  /* Drive SDA high */
+    void (*sda_lo)(void);  /* Drive SDA low */
+    void (*sda_input)(void);  /* Set SDA as input */
+    void (*sda_output)(void); /* Set SDA as output */
+    void (*scl_input)(void);  /* Set SCL as input */
+    void (*scl_output)(void); /* Set SCL as output */
+    int (*scl)(void);      /* Read SCL, returns 0 or non-zero */
+    int (*sda)(void);      /* Read SDA, returns 0 or non-zero */
+
+    /* These are the delays specified in the I2C specification, the
+       time pairs to the right are the minimum 100kHz and 400kHz specs */
+    void (*delay_hd_sta)(void); /* START SDA hold (tHD:SDA)    4.0us/0.6us */
+    void (*delay_hd_dat)(void); /* SDA hold (tHD:DAT)          5.0us/0us   */
+    void (*delay_su_dat)(void); /* SDA setup (tSU:DAT)         250ns/100ns */
+    void (*delay_su_sto)(void); /* STOP setup (tSU:STO)        4.0us/0.6us */
+    void (*delay_su_sta)(void); /* Rep. START setup (tSU:STA)  4.7us/0.6us */
+    void (*delay_thigh)(void);  /* SCL high period (tHIGH)     4.0us/0.6us */
+};
+
+extern void i2c_add_node(struct i2c_interface *iface);
+extern int i2c_write_data(int bus_address, int address,
+                          const unsigned char* buf, int count);
+extern int i2c_read_data(int bus_address, int address,
+                         unsigned char* buf, int count);
+#endif