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-rw-r--r--cpu/mpc85xx/i2c.c288
1 files changed, 288 insertions, 0 deletions
diff --git a/cpu/mpc85xx/i2c.c b/cpu/mpc85xx/i2c.c
new file mode 100644
index 0000000..ae08d18
--- /dev/null
+++ b/cpu/mpc85xx/i2c.c
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+/*
+ * (C) Copyright 2003,Motorola Inc.
+ * Xianghua Xiao <x.xiao@motorola.com>
+ * Adapted for Motorola 85xx chip.
+ *
+ * (C) Copyright 2003
+ * Gleb Natapov <gnatapov@mrv.com>
+ * Some bits are taken from linux driver writen by adrian@humboldt.co.uk
+ *
+ * Hardware I2C driver for MPC107 PCI bridge.
+ *
+ * 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 <common.h>
+#include <command.h>
+
+#define DEBUG
+
+#if defined(DEBUG)
+#define DEB(x) x
+#else
+#define DEB(x)
+#endif
+
+#ifdef CONFIG_HARD_I2C
+#include <i2c.h>
+
+#define TIMEOUT (CFG_HZ/4)
+
+#define I2C_Addr ((unsigned *)(CFG_CCSRBAR + 0x3000))
+
+#define I2CADR &I2C_Addr[0]
+#define I2CFDR &I2C_Addr[1]
+#define I2CCCR &I2C_Addr[2]
+#define I2CCSR &I2C_Addr[3]
+#define I2CCDR &I2C_Addr[4]
+#define I2CDFSRR &I2C_Addr[5]
+
+#define I2C_READ 1
+#define I2C_WRITE 0
+
+/* taken from linux include/asm-ppc/io.h */
+inline unsigned in_le32(volatile unsigned *addr)
+{
+ unsigned ret;
+
+ __asm__ __volatile__("lwbrx %0,0,%1;\n"
+ "twi 0,%0,0;\n"
+ "isync" : "=r" (ret) :
+ "r" (addr), "m" (*addr));
+ return ret;
+}
+
+inline void out_le32(volatile unsigned *addr, int val)
+{
+ __asm__ __volatile__("stwbrx %1,0,%2; eieio" : "=m" (*addr) :
+ "r" (val), "r" (addr));
+}
+
+#define writel(val, addr) out_le32(addr, val)
+#define readl(addr) in_le32(addr)
+
+void
+i2c_init(int speed, int slaveadd)
+{
+ /* stop I2C controller */
+ writel (0x0, I2CCCR);
+ /* set clock */
+ writel (0x3f, I2CFDR);
+ /* set default filter */
+ writel (0x10,I2CDFSRR);
+ /* write slave address */
+ writel (slaveadd, I2CADR);
+ /* clear status register */
+ writel (0x0, I2CCSR);
+ /* start I2C controller */
+ writel (MPC85xx_I2CCR_MEN, I2CCCR);
+}
+
+static __inline__ int
+i2c_wait4bus (void)
+{
+ ulong timeval = get_timer (0);
+
+ while (readl (I2CCSR) & MPC85xx_I2CSR_MBB)
+ if (get_timer (timeval) > TIMEOUT)
+ return -1;
+
+ return 0;
+}
+
+static __inline__ int
+i2c_wait (int write)
+{
+ u32 csr;
+ ulong timeval = get_timer (0);
+
+ do
+ {
+ csr = readl (I2CCSR);
+
+ if (!(csr & MPC85xx_I2CSR_MIF))
+ continue;
+
+ writel (0x0, I2CCSR);
+
+ if (csr & MPC85xx_I2CSR_MAL)
+ {
+ DEB(printf ("i2c_wait: MAL\n"));
+ return -1;
+ }
+
+ if (!(csr & MPC85xx_I2CSR_MCF))
+ {
+ DEB(printf ("i2c_wait: unfinished\n"));
+ return -1;
+ }
+
+ if (write == I2C_WRITE && (csr & MPC85xx_I2CSR_RXAK))
+ {
+ DEB(printf ("i2c_wait: No RXACK\n"));
+ return -1;
+ }
+
+ return 0;
+ } while (get_timer (timeval) < TIMEOUT);
+
+ DEB(printf ("i2c_wait: timed out\n"));
+ return -1;
+}
+
+static __inline__ int
+i2c_write_addr (u8 dev, u8 dir, int rsta)
+{
+ writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX |
+ (rsta?MPC85xx_I2CCR_RSTA:0), I2CCCR);
+
+ writel ((dev << 1) | dir, I2CCDR);
+
+ if (i2c_wait (I2C_WRITE) < 0)
+ return 0;
+
+ return 1;
+}
+
+static __inline__ int
+__i2c_write (u8 *data, int length)
+{
+ int i;
+
+ writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX, I2CCCR);
+
+ for (i=0; i < length; i++)
+ {
+ writel (data[i], I2CCDR);
+
+ if (i2c_wait (I2C_WRITE) < 0)
+ break;
+ }
+
+ return i;
+}
+
+static __inline__ int
+__i2c_read (u8 *data, int length)
+{
+ int i;
+
+ writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA |
+ ((length == 1) ? MPC85xx_I2CCR_TXAK : 0), I2CCCR);
+
+ /* dummy read */
+ readl (I2CCDR);
+
+ for (i=0; i < length; i++)
+ {
+ if (i2c_wait (I2C_READ) < 0)
+ break;
+
+ /* Generate ack on last next to last byte */
+ if (i == length - 2)
+ writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA |
+ MPC85xx_I2CCR_TXAK, I2CCCR);
+
+ /* Generate stop on last byte */
+ if (i == length - 1)
+ writel (MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_TXAK, I2CCCR);
+
+ data[i] = readl (I2CCDR);
+ }
+
+ return i;
+}
+
+int
+i2c_read (u8 dev, uint addr, int alen, u8 *data, int length)
+{
+ int i = 0;
+ u8 *a = (u8*)&addr;
+
+ if (i2c_wait4bus () < 0)
+ goto exit;
+
+ if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
+ goto exit;
+
+ if (__i2c_write (&a[4 - alen], alen) != alen)
+ goto exit;
+
+ if (i2c_write_addr (dev, I2C_READ, 1) == 0)
+ goto exit;
+
+ i = __i2c_read (data, length);
+
+ exit:
+ writel (MPC85xx_I2CCR_MEN, I2CCCR);
+
+ return !(i == length);
+}
+
+int
+i2c_write (u8 dev, uint addr, int alen, u8 *data, int length)
+{
+ int i = 0;
+ u8 *a = (u8*)&addr;
+
+ if (i2c_wait4bus () < 0)
+ goto exit;
+
+ if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
+ goto exit;
+
+ if (__i2c_write (&a[4 - alen], alen) != alen)
+ goto exit;
+
+ i = __i2c_write (data, length);
+
+ exit:
+ writel (MPC85xx_I2CCR_MEN, I2CCCR);
+
+ return !(i == length);
+}
+
+int i2c_probe (uchar chip)
+{
+ int tmp;
+
+ /*
+ * Try to read the first location of the chip. The underlying
+ * driver doesn't appear to support sending just the chip address
+ * and looking for an <ACK> back.
+ */
+ udelay(10000);
+ return i2c_read (chip, 0, 1, (char *)&tmp, 1);
+}
+
+uchar i2c_reg_read (uchar i2c_addr, uchar reg)
+{
+ char buf[1];
+
+ i2c_read (i2c_addr, reg, 1, buf, 1);
+
+ return (buf[0]);
+}
+
+void i2c_reg_write (uchar i2c_addr, uchar reg, uchar val)
+{
+ i2c_write (i2c_addr, reg, 1, &val, 1);
+}
+
+#endif /* CONFIG_HARD_I2C */