1 files changed, 450 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/arm/beagle/misc/i2c.c b/c/src/lib/libbsp/arm/beagle/misc/i2c.c
new file mode 100644
index 0000000000..322c501d3c
--- /dev/null
+++ b/c/src/lib/libbsp/arm/beagle/misc/i2c.c
@@ -0,0 +1,450 @@
+/**
+ * @file
+ *
+ * @ingroup beagle_i2c
+ *
+ * @brief I2C support implementation.
+ */
+
+/*
+ * Copyright (c) 2012 Claas Ziemke. All rights reserved.
+ *
+ *  Claas Ziemke
+ *  Kernerstrasse 11
+ *  70182 Stuttgart
+ *  Germany
+ *  <claas.ziemke@gmx.net>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#include <rtems.h>
+
+#include <bsp.h>
+#include <bsp/i2c.h>
+
+static struct i2c *i2c_base = (struct i2c *)I2C_DEFAULT_BASE;
+
+static unsigned short wait_for_pin( void ) {
+
+  unsigned short status;
+  int timeout = I2C_TIMEOUT;
+
+  do {
+    udelay( 1000 );
+    status = readw( &i2c_base->stat );
+  } while( !( status &
+        ( I2C_STAT_ROVR | I2C_STAT_XUDF | I2C_STAT_XRDY |
+        I2C_STAT_RRDY | I2C_STAT_ARDY | I2C_STAT_NACK |
+        I2C_STAT_AL ) ) && timeout-- );
+
+  if( timeout <= 0 ) {
+    printk( "timed out in wait_for_pin: I2C_STAT = %x\n",
+      readw( &i2c_base->stat ) );
+    writew( 0xFFFF, &i2c_base->stat );  /* clear current interrupts...*/
+    status = 0;
+  }
+
+  return status;
+}
+
+static void wait_for_bb( void ) {
+
+  int timeout = I2C_TIMEOUT;
+  unsigned short status;
+
+  writew( 0xFFFF, &i2c_base->stat );  /* clear current interrupts...*/
+  while( ( status = readw( &i2c_base->stat ) & I2C_STAT_BB ) && timeout-- ) {
+    writew( status, &i2c_base->stat );
+    udelay( 1000 );
+  }
+
+  if( timeout <= 0 ) {
+    printk( "timed out in wait_for_bb: I2C_STAT = %x\n",
+      readw( &i2c_base->stat ) );
+  }
+  writew( 0xFFFF, &i2c_base->stat );   /* clear delayed stuff*/
+}
+
+static void flush_fifo( void ) {
+
+  unsigned short status;
+
+  /* note: if you try and read data when its not there or ready
+   * you get a bus error
+   */
+  while( 1 ) {
+    status = readw( &i2c_base->stat );
+    if( status == I2C_STAT_RRDY ) {
+      readw( &i2c_base->data );
+      writew( I2C_STAT_RRDY, &i2c_base->stat );
+      udelay( 1000 );
+    } else {
+      break;
+    }
+  }
+}
+
+void i2c_init( int speed, int slaveadd ) {
+
+  int psc, fsscll, fssclh;
+  int hsscll = 0, hssclh = 0;
+  unsigned int scll, sclh;
+  int timeout = I2C_TIMEOUT;
+
+  // Only handle standard, fast and high speeds
+  if( ( speed != OMAP_I2C_STANDARD   ) &&
+      ( speed != OMAP_I2C_FAST_MODE  ) &&
+      ( speed != OMAP_I2C_HIGH_SPEED ) ) {
+    printk( "Error : I2C unsupported speed %d\n", speed );
+    return;
+  }
+
+  psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
+  psc -= 1;
+  if( psc < I2C_PSC_MIN ) {
+    printk( "Error : I2C unsupported prescalar %d\n", psc );
+    return;
+  }
+
+  if( speed == OMAP_I2C_HIGH_SPEED ) {
+    // High speed
+
+    // For first phase of HS mode
+    fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK / ( 2 * OMAP_I2C_FAST_MODE );
+
+    fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
+    fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
+    if( ( ( fsscll < 0 ) || ( fssclh < 0 ) ) || ( ( fsscll > 255 ) ||
+      ( fssclh > 255 ) ) ) {
+      printk( "Error : I2C initializing first phase clock\n" );
+      return;
+    }
+
+    // For second phase of HS mode
+    hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / ( 2 * speed );
+
+    hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM;
+    hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
+    if( ( ( fsscll < 0 ) || ( fssclh < 0 ) ) || ( ( fsscll > 255 ) ||
+      ( fssclh > 255 ) ) ) {
+      printk( "Error : I2C initializing second phase clock\n" );
+      return;
+    }
+
+    scll = ( unsigned int ) hsscll << 8 | ( unsigned int ) fsscll;
+    sclh = ( unsigned int ) hssclh << 8 | ( unsigned int ) fssclh;
+
+  } else {
+    // Standard and fast speed
+    fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK / ( 2 * speed );
+
+    fsscll -= I2C_FASTSPEED_SCLL_TRIM;
+    fssclh -= I2C_FASTSPEED_SCLH_TRIM;
+    if( ( ( fsscll < 0 ) || ( fssclh < 0 ) ) || ( ( fsscll > 255 ) ||
+      ( fssclh > 255 ) ) ) {
+      printk( "Error : I2C initializing clock\n" );
+      return;
+    }
+
+    scll = ( unsigned int ) fsscll;
+    sclh = ( unsigned int ) fssclh;
+  }
+
+  if( readw( &i2c_base->con ) & I2C_CON_EN ) {
+    writew( 0, &i2c_base->con );
+    udelay( 50000  );
+  }
+
+  writew( 0x2, &i2c_base->sysc ); /* for ES2 after soft reset */
+  udelay( 1000 );
+
+  writew( I2C_CON_EN, &i2c_base->con );
+  while( !( readw( &i2c_base->syss ) & I2C_SYSS_RDONE ) && timeout-- ) {
+    if (timeout <= 0) {
+      printk( "ERROR: Timeout in soft-reset\n" );
+      return;
+    }
+    udelay( 1000 );
+  }
+
+  writew( 0, &i2c_base->con );
+  writew( psc, &i2c_base->psc );
+  writew( scll, &i2c_base->scll );
+  writew( sclh, &i2c_base->sclh );
+
+  /* own address */
+  writew( slaveadd, &i2c_base->oa );
+  writew( I2C_CON_EN, &i2c_base->con );
+
+  /* have to enable intrrupts or OMAP i2c module doesn't work */
+  writew( I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE | I2C_IE_NACK_IE |
+          I2C_IE_AL_IE, &i2c_base->ie );
+  udelay( 1000 );
+  flush_fifo();
+  writew( 0xFFFF, &i2c_base->stat );
+  writew( 0, &i2c_base->cnt );
+
+  //if( gd->flags & GD_FLG_RELOC ) bus_initialized[ current_bus ] = 1;
+}
+
+static int i2c_read_byte(
+  unsigned char devaddr,
+  unsigned char regoffset,
+  unsigned char *value
+)
+{
+  int i2c_error = 0;
+  unsigned short status;
+
+  /* wait until bus not busy */
+  wait_for_bb();
+
+  /* one byte only */
+  writew(1, &i2c_base->cnt);
+  /* set slave address */
+  writew(devaddr, &i2c_base->sa);
+  /* no stop bit needed here */
+  writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
+        I2C_CON_TRX, &i2c_base->con);
+
+  /* send register offset */
+  while (1) {
+    status = wait_for_pin();
+    if (status == 0 || status & I2C_STAT_NACK) {
+      i2c_error = 1;
+      goto read_exit;
+    }
+    if (status & I2C_STAT_XRDY) {
+      /* Important: have to use byte access */
+      writeb(regoffset, &i2c_base->data);
+      writew(I2C_STAT_XRDY, &i2c_base->stat);
+    }
+    if (status & I2C_STAT_ARDY) {
+      writew(I2C_STAT_ARDY, &i2c_base->stat);
+      break;
+    }
+  }
+
+  /* set slave address */
+  writew(devaddr, &i2c_base->sa);
+  /* read one byte from slave */
+  writew(1, &i2c_base->cnt);
+  /* need stop bit here */
+  writew(I2C_CON_EN | I2C_CON_MST |
+    I2C_CON_STT | I2C_CON_STP,
+    &i2c_base->con);
+
+  /* receive data */
+  while (1) {
+    status = wait_for_pin();
+    if (status == 0 || status & I2C_STAT_NACK) {
+      i2c_error = 1;
+      goto read_exit;
+    }
+    if (status & I2C_STAT_RRDY) {
+      *value = readw(&i2c_base->data);
+      writew(I2C_STAT_RRDY, &i2c_base->stat);
+    }
+    if (status & I2C_STAT_ARDY) {
+      writew(I2C_STAT_ARDY, &i2c_base->stat);
+      break;
+    }
+  }
+
+read_exit:
+  flush_fifo();
+  writew(0xFFFF, &i2c_base->stat);
+  writew(0, &i2c_base->cnt);
+  return i2c_error;
+}
+
+int i2c_write(
+  unsigned char chip,
+  unsigned int addr,
+  int alen,
+  unsigned char *buffer,
+  int len
+)
+{
+  int i;
+  unsigned short status;
+  int i2c_error = 0;
+
+  if (alen > 1) {
+    printk("I2C write: addr len %d not supported\n", alen);
+    return 1;
+  }
+
+  if (addr + len > 256) {
+    printk("I2C write: address 0x%x + 0x%x out of range\n",
+        addr, len);
+    return 1;
+  }
+
+  /* wait until bus not busy */
+  wait_for_bb();
+
+  /* start address phase - will write regoffset + len bytes data */
+  writew(alen + len, &i2c_base->cnt);
+  /* set slave address */
+  writew(chip, &i2c_base->sa);
+  /* stop bit needed here */
+  writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
+    I2C_CON_STP, &i2c_base->con);
+
+  /* Send address byte */
+  status = wait_for_pin();
+
+  if (status == 0 || status & I2C_STAT_NACK) {
+    i2c_error = 1;
+    printk("error waiting for i2c address ACK (status=0x%x)\n",
+          status);
+    goto write_exit;
+  }
+
+  if (status & I2C_STAT_XRDY) {
+    writeb(addr & 0xFF, &i2c_base->data);
+    writew(I2C_STAT_XRDY, &i2c_base->stat);
+  } else {
+    i2c_error = 1;
+    printk("i2c bus not ready for transmit (status=0x%x)\n",
+          status);
+    goto write_exit;
+  }
+
+  /* address phase is over, now write data */
+  for (i = 0; i < len; i++) {
+    status = wait_for_pin();
+
+    if (status == 0 || status & I2C_STAT_NACK) {
+      i2c_error = 1;
+      printk("i2c error waiting for data ACK (status=0x%x)\n",
+          status);
+      goto write_exit;
+    }
+
+    if (status & I2C_STAT_XRDY) {
+      writeb(buffer[i], &i2c_base->data);
+      writew(I2C_STAT_XRDY, &i2c_base->stat);
+    } else {
+      i2c_error = 1;
+      printk("i2c bus not ready for Tx (i=%d)\n", i);
+      goto write_exit;
+    }
+  }
+
+write_exit:
+  flush_fifo();
+  writew(0xFFFF, &i2c_base->stat);
+  return i2c_error;
+}
+
+int i2c_read(
+  unsigned char chip,
+  uint addr,
+  int alen,
+  unsigned char *buffer,
+  int len
+)
+{
+  int i;
+
+  if (alen > 1) {
+    printk("I2C read: addr len %d not supported\n", alen);
+    return 1;
+  }
+
+  if (addr + len > 256) {
+    printk("I2C read: address out of range\n");
+    return 1;
+  }
+
+  for (i = 0; i < len; i++) {
+    if (i2c_read_byte(chip, addr + i, &buffer[i])) {
+      printk("I2C read: I/O error\n");
+      i2c_init( CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE );
+      return 1;
+    }
+  }
+
+  return 0;
+}
+
+/* Write (fill) memory
+ *
+ * Syntax:
+ *  i2c mw {i2c_chip} {addr}{.0, .1, .2} {data} [{count}]
+ */
+static int imw ( unsigned char  chip, unsigned long addr, unsigned char byte )
+{
+
+  unsigned int  alen;
+  int count;
+
+  alen = 1;
+  count = 1;
+
+  while (count-- > 0) {
+    if (i2c_write(chip, addr++, alen, &byte, 1) != 0)
+      printk("Error writing the chip.\n");
+    /*
+     * Wait for the write to complete.  The write can take
+     * up to 10mSec (we allow a little more time).
+     */
+  }
+
+  return (0);
+}
+
+/*
+ * Syntax:
+ *  i2c md {i2c_chip} {addr}{.0, .1, .2} {len}
+ */
+static int imd( unsigned char chip, unsigned int addr, unsigned int length )
+{
+  int j, nbytes, linebytes;
+
+  unsigned int alen = 0;
+  if (alen > 3) return 0;
+
+  /*
+   * Print the lines.
+   *
+   * We buffer all read data, so we can make sure data is read only
+   * once.
+   */
+  nbytes = length;
+  do {
+    unsigned char linebuf[DISP_LINE_LEN];
+    unsigned char *cp;
+
+    linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes;
+
+    if (i2c_read(chip, addr, alen, linebuf, linebytes) != 0)
+      printk ("Error reading the chip.\n");
+    else {
+      printk("%04x:", addr);
+      cp = linebuf;
+      for (j=0; j<linebytes; j++) {
+        printk(" %02x", *cp++);
+        addr++;
+      }
+      printk ("    ");
+      cp = linebuf;
+      for (j=0; j<linebytes; j++) {
+        if ((*cp < 0x20) || (*cp > 0x7e))
+          printk (".");
+        else
+          printk("%c", *cp);
+        cp++;
+      }
+      printk ("\n");
+    }
+    nbytes -= linebytes;
+  } while (nbytes > 0);
+
+  return 0;
+}