H300: First lame attempt to a pcf50606 driver

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7873 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 298 insertions, 0 deletions

diff --git a/firmware/drivers/pcf50606.c b/firmware/drivers/pcf50606.c
new file mode 100644
index 0000000000..993e56800d
--- /dev/null
+++ b/firmware/drivers/pcf50606.c
@@ -0,0 +1,298 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 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 "kernel.h"
+#include "system.h"
+#include "hwcompat.h"
+#include "logf.h"
+#include "string.h"
+
+/* TODO: merge all bit-banged I2C into a generic I2C driver */
+
+
+#define SDA_LO     and_l(~0x00002000, &GPIO1_OUT)
+#define SDA_HI      or_l( 0x00002000, &GPIO1_OUT)
+#define SDA_INPUT  and_l(~0x00002000, &GPIO1_ENABLE)
+#define SDA_OUTPUT  or_l( 0x00002000, &GPIO1_ENABLE)
+#define SDA             ( 0x00002000 & GPIO1_READ)
+
+/* SCL is GPIO, 3 */
+#define SCL_INPUT  and_l(~0x00001000, &GPIO_ENABLE)
+#define SCL_OUTPUT  or_l( 0x00001000, &GPIO_ENABLE)
+#define SCL_LO     and_l(~0x00001000, &GPIO_OUT)
+#define SCL_HI      or_l( 0x00001000, &GPIO_OUT)
+#define SCL             ( 0x00001000 & GPIO_READ)
+
+/* delay loop to achieve 400kHz at 120MHz CPU frequency */
+#define DELAY    do { int _x; for(_x=0;_x<22;_x++);} while(0)
+
+
+static void pcf50606_i2c_start(void)
+{
+    SDA_OUTPUT;
+    SCL_OUTPUT;
+    SDA_HI;
+    SCL_HI;
+    DELAY;
+    SDA_LO;
+    DELAY;
+    SCL_LO;
+}
+
+static void pcf50606_i2c_stop(void)
+{
+   SDA_LO;
+   SCL_HI;
+   DELAY;
+   SDA_HI;
+}
+
+
+static void pcf50606_i2c_ack(bool ack)
+{
+    /* Here's the deal. The slave is slow, and sometimes needs to wait
+       before it can receive the acknowledge. Therefore it forces the clock
+       low until it is ready. We need to poll the clock line until it goes
+       high before we release the ack.
+
+       In their infinite wisdom, iriver didn't pull up the SCL line, so
+       we have to drive the SCL high repeatedly to simulate a pullup. */
+    
+    SCL_LO;      /* Set the clock low */
+    if(ack)
+        SDA_LO;
+    else
+        SDA_HI;
+    
+    SCL_INPUT;   /* Set the clock to input */
+    while(!SCL)  /* and wait for the slave to release it */
+    {
+        SCL_OUTPUT;  /* Set the clock to output */
+        SCL_HI;
+        SCL_INPUT;   /* Set the clock to input */
+        DELAY;
+    }
+
+    DELAY;
+    SCL_OUTPUT;
+    SCL_LO;
+}
+
+static int pcf50606_i2c_getack(void)
+{
+    int ret = 1;
+
+    /* Here's the deal. The slave is slow, and sometimes needs to wait
+       before it can send the acknowledge. Therefore it forces the clock
+       low until it is ready. We need to poll the clock line until it goes
+       high before we read the ack.
+
+       In their infinite wisdom, iriver didn't pull up the SCL line, so
+       we have to drive the SCL high repeatedly to simulate a pullup. */
+
+    SDA_INPUT;   /* And set to input */
+    SCL_INPUT;   /* Set the clock to input */
+    while(!SCL)  /* and wait for the slave to release it */
+    {
+        SCL_OUTPUT;  /* Set the clock to output */
+        SCL_HI;
+        SCL_INPUT;   /* Set the clock to input */
+        DELAY;
+    }
+
+    if (SDA)
+        /* ack failed */
+        ret = 0;
+    
+    SCL_OUTPUT;
+    SCL_LO;
+    SDA_HI;
+    SDA_OUTPUT;
+
+    return ret;
+}
+
+static void pcf50606_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;
+      SCL_LO;
+   }
+
+   SDA_HI;
+}
+
+static unsigned char pcf50606_i2c_inb(bool ack)
+{
+   int i;
+   unsigned char byte = 0;
+
+   /* clock in each bit, MSB first */
+   for ( i=0x80; i; i>>=1 ) {
+       SDA_INPUT;   /* And set to input */
+       SCL_HI;
+       DELAY;
+       if ( SDA )
+           byte |= i;
+       SCL_LO;
+       DELAY;
+       SDA_OUTPUT;
+   }
+
+   pcf50606_i2c_ack(ack);
+   
+   return byte;
+}
+
+int pcf50606_i2c_write(int address, const unsigned char* buf, int count)
+{
+    int i,x=0;
+
+    pcf50606_i2c_start();
+    pcf50606_i2c_outb(address & 0xfe);
+    if (pcf50606_i2c_getack())
+    {
+        for (i=0; i<count; i++)
+        {
+            pcf50606_i2c_outb(buf[i]);
+            if (!pcf50606_i2c_getack())
+            {
+                x=-2;
+                break;
+            }
+        }
+    }
+    else
+    {
+        logf("pcf50606_i2c_write() - no ack\n");
+        x=-1;
+    }
+    return x;
+}
+
+int pcf50606_read(int address, unsigned char* buf, int count)
+{
+    int i=0;
+    int ret = 0;
+    unsigned char obuf[1];
+
+    obuf[0] = address;
+
+    /* send read command */
+    if (pcf50606_i2c_write(0x10, obuf, 1) >= 0)
+    {
+        pcf50606_i2c_start();
+        pcf50606_i2c_outb(0x11);
+        if (pcf50606_i2c_getack())
+        {
+            for(i = 0;i < count-1;i++)
+                buf[i] = pcf50606_i2c_inb(true);
+            
+            buf[i] = pcf50606_i2c_inb(false);
+        }
+        else
+        {
+            ret = -1;
+        }
+    }
+
+    pcf50606_i2c_stop();
+
+    return ret;
+}
+
+int pcf50606_write(int address, const unsigned char* buf, int count)
+{
+    unsigned char obuf[1];
+    int i;
+    int ret = 0;
+
+    obuf[0] = address;
+    
+    /* send write command */
+    if (pcf50606_i2c_write(0x10, obuf, 1) >= 0)
+    {
+        for (i=0; i<count; i++)
+        {
+            pcf50606_i2c_outb(buf[i]);
+            if (!pcf50606_i2c_getack())
+            {
+                ret = -2;
+                break;
+            }
+        }
+    }
+    else
+    {
+        ret = -1;
+    }
+
+    pcf50606_i2c_stop();
+    return ret;
+}
+
+/* These voltages were determined by measuring the output of the PCF50606
+   on a running H300, and verified by disassembling the original firmware */
+static void set_voltages(void)
+{
+    static const unsigned char buf[5] =
+        {
+            0xf4,   /* IOREGC = 3.3V, ON in all states */
+            0xef,   /* D1REGC = 2.4V, ON in all states */
+            0x18,   /* D2REGC = 3.3V, OFF in all states */
+            0xf0,   /* D3REGC = 2.5V, ON in all states */
+            0xef,   /* LPREGC1 = 2.4V, ON in all states */
+        };
+    
+    pcf50606_write(0x23, buf, 5);
+}
+
+void pcf50606_init(void)
+{
+    unsigned char c;
+    
+    /* Bit banged I2C */
+    or_l(0x00002000, &GPIO1_OUT);
+    or_l(0x00001000, &GPIO_OUT);
+    or_l(0x00002000, &GPIO1_ENABLE);
+    or_l(0x00001000, &GPIO_ENABLE);
+    or_l(0x00002000, &GPIO1_FUNCTION);
+    or_l(0x00001000, &GPIO_FUNCTION);
+
+    set_voltages();
+
+    /* Backlight PWM = 512Hz 50/50 */
+    c = 0x13;
+    pcf50606_write(0x35, &c, 1);
+}