Initial revision

1 files changed, 257 insertions, 0 deletions

diff --git a/board/pcippc2/i2c.c b/board/pcippc2/i2c.c
new file mode 100644
index 0000000..36b1d0f
--- /dev/null
+++ b/board/pcippc2/i2c.c
@@ -0,0 +1,257 @@
+/*
+ * (C) Copyright 2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <config.h>
+#include <common.h>
+#include <asm/io.h>
+
+#include "hardware.h"
+#include "i2c.h"
+
+static void		i2c_start	(void);
+static void		i2c_stop	(void);
+static int		i2c_write	(u8		data);
+static void		i2c_read	(u8 *		data);
+
+static inline void	i2c_port_start  (void);
+static inline void	i2c_clock	(unsigned int	val);
+static inline void	i2c_data	(unsigned int	val);
+static inline unsigned int
+			i2c_in		(void);
+static inline void	i2c_write_bit	(unsigned int	val);
+static inline unsigned int
+			i2c_read_bit	(void);
+
+static inline void	i2c_udelay	(unsigned int	time);
+
+int i2c_read_byte (
+  u8 *			data,
+  u8			dev,
+  u8			offset)
+{
+  int			err = 0;
+
+  i2c_start();
+
+  err = ! i2c_write(dev);
+
+  if (! err)
+  {
+    err = ! i2c_write(offset);
+  }
+
+  if (! err)
+  {
+    i2c_start();
+  }
+
+  if (! err)
+  {
+    err = ! i2c_write(dev | 0x01);
+  }
+
+  if (! err)
+  {
+    i2c_read(data);
+  }
+
+  i2c_stop();
+
+  return ! err;
+}
+
+static inline void i2c_udelay (
+  unsigned int		time)
+{
+  int			v;
+
+  asm volatile("mtdec %0" : : "r" (time * ((CFG_BUS_CLK / 4) / 1000000)));
+
+  do
+  {
+    asm volatile("isync; mfdec %0" : "=r" (v));
+  } while (v >= 0);
+}
+
+  /* Low-level hardware access
+   */
+
+#define BIT_GPDATA		0x80000000
+#define BIT_GPCLK		0x40000000
+
+static inline void i2c_port_start (void)
+{
+  out32(REG(CPC0, GPDIR), in32(REG(CPC0, GPDIR)) & ~(BIT_GPCLK | BIT_GPDATA));
+  out32(REG(CPC0, GPOUT), in32(REG(CPC0, GPOUT)) & ~(BIT_GPCLK | BIT_GPDATA));
+  iobarrier_rw();
+
+  i2c_udelay(1);
+}
+
+static inline void i2c_clock (
+  unsigned int		val)
+{
+  if (val)
+  {
+    out32(REG(CPC0, GPDIR), in32(REG(CPC0, GPDIR)) & ~BIT_GPCLK);
+  }
+  else
+  {
+    out32(REG(CPC0, GPDIR), in32(REG(CPC0, GPDIR)) | BIT_GPCLK);
+  }
+
+  iobarrier_rw();
+
+  i2c_udelay(1);
+}
+
+static inline void i2c_data (
+  unsigned int		val)
+{
+  if (val)
+  {
+    out32(REG(CPC0, GPDIR), in32(REG(CPC0, GPDIR)) & ~BIT_GPDATA);
+  }
+  else
+  {
+    out32(REG(CPC0, GPDIR), in32(REG(CPC0, GPDIR)) | BIT_GPDATA);
+  }
+
+  iobarrier_rw();
+
+  i2c_udelay(1);
+}
+
+static inline unsigned int i2c_in (void)
+{
+  unsigned int		val = ((in32(REG(CPC0, GPIN)) & BIT_GPDATA) != 0)?1:0;
+
+  iobarrier_rw();
+
+  return val;
+}
+
+
+  /* Protocol implementation
+   */
+
+static inline void i2c_write_bit (
+  unsigned int		val)
+{
+  i2c_data(val);
+  i2c_udelay(10);
+  i2c_clock(1);
+  i2c_udelay(10);
+  i2c_clock(0);
+  i2c_udelay(10);
+}
+
+static inline unsigned int i2c_read_bit (void)
+{
+  unsigned int		val;
+
+  i2c_data(1);
+  i2c_udelay(10);
+
+  i2c_clock(1);
+  i2c_udelay(10);
+
+  val = i2c_in();
+
+  i2c_clock(0);
+  i2c_udelay(10);
+
+  return val;
+}
+
+unsigned int i2c_reset (void)
+{
+  unsigned int		val;
+  int i;
+
+  i2c_port_start();
+
+  i=0;
+  do {
+    i2c_udelay(10);
+    i2c_clock(0);
+    i2c_udelay(10);
+    i2c_clock(1);
+    i2c_udelay(10);
+    val = i2c_in();
+    i++;
+  }  while ((i<9)&&(val==0));
+  return (val);
+}
+
+
+static void i2c_start (void)
+{
+  i2c_data(1);
+  i2c_clock(1);
+  i2c_udelay(10);
+  i2c_data(0);
+  i2c_udelay(10);
+  i2c_clock(0);
+  i2c_udelay(10);
+}
+
+static void i2c_stop (void)
+{
+  i2c_data(0);
+  i2c_udelay(10);
+  i2c_clock(1);
+  i2c_udelay(10);
+  i2c_data(1);
+  i2c_udelay(10);
+}
+
+static int i2c_write (
+  u8			data)
+{
+  unsigned int		i;
+
+  for (i = 0; i < 8; i++)
+  {
+    i2c_write_bit(data >> 7);
+    data <<= 1;
+  }
+
+  return i2c_read_bit() == 0;
+}
+
+static void i2c_read (
+  u8 *			data)
+{
+  unsigned int		i;
+  u8			val = 0;
+
+  for (i = 0; i < 8; i++)
+  {
+    val <<= 1;
+    val |= i2c_read_bit();
+  }
+
+  *data = val;
+  i2c_write_bit(1); /* NoAck */
+}