1 files changed, 225 insertions, 0 deletions

diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/sc606-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/sc606-meg-fx.c
new file mode 100644
index 0000000000..e69eab432a
--- /dev/null
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/sc606-meg-fx.c
@@ -0,0 +1,225 @@
+#include "config.h"
+#include "cpu.h"
+#include <stdbool.h>
+#include "kernel.h"
+#include "system.h"
+#include "logf.h"
+#include "debug.h"
+#include "string.h"
+
+#define SLAVE_ADDRESS 0xCC
+
+#define SDA_LO     (GPHDAT &= ~(1 << 9))
+#define SDA_HI     (GPHDAT |= (1 << 9))
+#define SDA_INPUT  (GPHCON &= ~(3 << 18))
+#define SDA_OUTPUT (GPHCON |= (1 << 18))
+#define SDA        (GPHDAT & (1 << 9))
+
+#define SCL_LO     (GPHDAT &= ~(1 << 10))
+#define SCL_HI     (GPHDAT |= (1 << 10))
+#define SCL_INPUT  (GPHCON &= ~(3 << 20))
+#define SCL_OUTPUT (GPHCON |= (1 << 20))
+#define SCL        (GPHDAT & (1 << 10))
+
+#define SCL_SDA_HI (GPHDAT |= (3 << 9))
+
+/* The SC606 can clock at 400KHz: */
+/* Clock period high is 600nS and low is 1300nS */
+/* The high and low times are different enough to need different timings */
+/* cycles delayed = 30 + 7 * loops */
+/* 100MHz = 10nS per cycle: LO:1300nS=130:14  HI:600nS=60:9 */
+/* 300MHz = 3.36nS per cycle: LO:1300nS=387:51  HI:600nS=179:21 */
+#define DELAY_LO do{int x;for(x=51;x;x--);} while (0)
+#define DELAY    do{int x;for(x=35;x;x--);} while (0)
+#define DELAY_HI do{int x;for(x=21;x;x--);} while (0)
+
+
+
+static void sc606_i2c_start(void)
+{
+    SCL_SDA_HI;
+    DELAY;
+    SDA_LO;
+    DELAY;
+    SCL_LO;
+}
+
+static void sc606_i2c_restart(void)
+{
+    SCL_SDA_HI;
+    DELAY;
+    SDA_LO;
+    DELAY;
+    SCL_LO;
+}
+
+static void sc606_i2c_stop(void)
+{
+    SDA_LO;
+    SCL_HI;
+    DELAY_HI;
+    SDA_HI;
+}
+
+static void sc606_i2c_ack(void)
+{
+
+    SDA_LO;
+    SCL_HI;
+    DELAY_HI;
+    SCL_LO;
+}
+
+
+
+static int sc606_i2c_getack(void)
+{
+    int ret;
+
+    /* Don't need a delay since follows a data bit with a delay on the end */
+    SDA_INPUT;   /* And set to input */
+    DELAY;
+    SCL_HI;
+
+    ret = (SDA != 0);   /* ack failed if SDA is not low */
+    DELAY_HI;
+
+    SCL_LO;
+    DELAY_LO;
+
+    SDA_HI;
+    SDA_OUTPUT;
+    DELAY_LO;
+
+    return ret;
+}
+
+
+
+static void sc606_i2c_outb(unsigned char byte)
+{
+    int i;
+
+    /* clock out each bit, MSB first */
+    for (i = 0x80; i; i >>= 1)
+    {
+        if (i & byte)
+        {
+            SDA_HI;
+        }
+        else
+        {
+            SDA_LO;
+        }
+        DELAY;
+
+        SCL_HI;
+        DELAY_HI;
+
+        SCL_LO;
+        DELAY_LO;
+    }
+
+    SDA_HI;
+
+}
+
+
+
+static unsigned char sc606_i2c_inb(void)
+{
+   int i;
+   unsigned char byte = 0;
+
+   SDA_INPUT;   /* And set to input */
+   /* clock in each bit, MSB first */
+   for (i = 0x80; i; i >>= 1) {
+       SCL_HI;
+
+       if (SDA)
+           byte |= i;
+
+       SCL_LO;
+   }
+   SDA_OUTPUT;
+
+   sc606_i2c_ack();
+
+   return byte;
+}
+
+
+
+/* returns number of acks that were bad */
+int sc606_write(unsigned char reg, unsigned char data)
+{
+    int x;
+
+    sc606_i2c_start();
+
+    sc606_i2c_outb(SLAVE_ADDRESS);
+    x = sc606_i2c_getack();
+
+    sc606_i2c_outb(reg);
+    x += sc606_i2c_getack();
+
+    sc606_i2c_restart();
+
+    sc606_i2c_outb(SLAVE_ADDRESS);
+    x += sc606_i2c_getack();
+
+    sc606_i2c_outb(data);
+    x += sc606_i2c_getack();
+
+    sc606_i2c_stop();
+
+    return x;
+}
+
+
+
+int sc606_read(unsigned char reg, unsigned char* data)
+{
+    int x;
+
+    sc606_i2c_start();
+    sc606_i2c_outb(SLAVE_ADDRESS);
+    x = sc606_i2c_getack();
+
+    sc606_i2c_outb(reg);
+    x += sc606_i2c_getack();
+
+    sc606_i2c_restart();
+    sc606_i2c_outb(SLAVE_ADDRESS | 1);
+    x += sc606_i2c_getack();
+
+    *data = sc606_i2c_inb();
+    sc606_i2c_stop();
+
+    return x;
+}
+
+
+
+void sc606_init(void)
+{
+    volatile int i;
+
+    /* Set GPB2 (EN) to 1 */
+    GPBCON = (GPBCON & ~(3<<4)) | 1<<4;
+
+    /* Turn enable line on */
+    GPBDAT |= 1<<2;
+    /* OFF GPBDAT &= ~(1 << 2); */
+
+    /* About 400us - needs 350us */
+    for (i = 200; i; i--)
+    {
+        DELAY_LO;
+    }
+
+    /* Set GPH9 (SDA) and GPH10 (SCL) to 1 */
+    GPHUP &= ~(3<<9);
+    GPHCON = (GPHCON & ~(0xF<<18)) | 5<<18;
+}
+