1 files changed, 144 insertions, 0 deletions

diff --git a/firmware/target/arm/s3c2440/i2c-s3c2440.c b/firmware/target/arm/s3c2440/i2c-s3c2440.c
new file mode 100644
index 0000000000..4669186a4c
--- /dev/null
+++ b/firmware/target/arm/s3c2440/i2c-s3c2440.c
@@ -0,0 +1,144 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2007 by Michael Sevakis
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "system.h"
+#include "i2c-s3c2440.h"
+
+static struct wakeup i2c_wake; /* Transfer completion signal */
+static struct mutex i2c_mtx;   /* Mutual exclusion */
+static unsigned char *buf_ptr; /* Next byte to transfer */
+static int buf_count;          /* Number of bytes remaining to transfer */
+
+static void i2c_stop(void)
+{
+    /* Generate STOP */
+    IICSTAT = I2C_MODE_MASTER | I2C_MODE_TX | I2C_RXTX_ENB;
+
+    /* No more interrupts, clear pending interrupt to continue */
+    IICCON &= ~(I2C_TXRX_INTPND | I2C_TXRX_INTENB);
+}
+
+void i2c_write(int addr, const unsigned char *buf, int count)
+{
+    if (count <= 0)
+        return;
+
+    mutex_lock(&i2c_mtx);
+
+    /* Turn on I2C clock */
+    s3c_regset32(&CLKCON, 1 << 16);
+
+    /* Set mode to master transmitter and enable lines */
+    IICSTAT = I2C_MODE_MASTER | I2C_MODE_TX | I2C_RXTX_ENB;
+
+    /* Set buffer start and count */
+    buf_ptr = (unsigned char *)buf;
+    buf_count = count;
+
+    /* Send slave address and then data */
+    SRCPND = IIC_MASK;
+    INTPND = IIC_MASK;
+
+    IICCON |= I2C_TXRX_INTENB;
+
+    /* Load slave address into shift register */
+    IICDS = addr & 0xfe;
+
+    /* Generate START */
+    IICSTAT = I2C_MODE_MASTER | I2C_MODE_TX | I2C_START | I2C_RXTX_ENB;
+
+    if (wakeup_wait(&i2c_wake, HZ) != OBJ_WAIT_SUCCEEDED)
+    {
+        /* Something went wrong - stop transmission */
+        int oldlevel = disable_irq_save();
+        i2c_stop();
+        restore_irq(oldlevel);
+    }
+
+    /* Go back to slave receive mode and disable lines */
+    IICSTAT = 0;
+
+    /* Turn off I2C clock */
+    s3c_regclr32(&CLKCON, 1 << 16);
+
+    mutex_unlock(&i2c_mtx);
+}
+
+void i2c_init(void)
+{
+    /* Init kernel objects */
+    wakeup_init(&i2c_wake);
+    mutex_init(&i2c_mtx);
+
+    /* Clear pending source */
+    SRCPND = IIC_MASK;
+    INTPND = IIC_MASK;
+
+    /* Enable i2c interrupt in controller */
+    s3c_regclr32(&INTMOD, IIC_MASK);
+    s3c_regclr32(&INTMSK, IIC_MASK);
+
+    /* Turn on I2C clock */
+    s3c_regset32(&CLKCON, 1 << 16);
+
+    /* Set GPE15 (IICSDA) and GPE14 (IICSCL) to IIC */
+    GPECON = (GPECON & ~((3 << 30) | (3 << 28))) |
+                ((2 << 30) | (2 << 28));
+
+    /* Bus ACK, IICCLK: fPCLK / 16, Rx/Tx Int: Disable, Tx clock: IICCLK/8 */
+    /* OF PCLK: 49.1568MHz / 16 / 8 = 384.0375 kHz */
+    IICCON = (7 << 0);
+
+    /* SDA line delayed 0 PCLKs */
+    IICLC = (0 << 0);
+
+    /* Turn off I2C clock */
+    s3c_regclr32(&CLKCON, 1 << 16);
+}
+
+void IIC(void)
+{
+    for (;;)
+    {
+        /* If ack was received from last byte and bytes are remaining */
+        if (--buf_count >= 0 && (IICSTAT & I2C_ACK_L) == 0)
+        {
+            /* Write next byte to shift register */
+            IICDS = *buf_ptr++;
+
+            /* Clear pending interrupt to continue */
+            IICCON &= ~I2C_TXRX_INTPND;
+            break;
+        }
+
+        /* Finished */
+
+        /* Generate STOP */
+        i2c_stop();
+
+        /* Signal thread */
+        wakeup_signal(&i2c_wake);
+        break;
+    }
+
+    /* Ack */
+    SRCPND = IIC_MASK;
+    INTPND = IIC_MASK;
+}