1 files changed, 270 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc824x/drivers/i2c/i2c.c b/arch/powerpc/cpu/mpc824x/drivers/i2c/i2c.c
new file mode 100644
index 0000000000..637ae4c1b1
--- /dev/null
+++ b/arch/powerpc/cpu/mpc824x/drivers/i2c/i2c.c
@@ -0,0 +1,270 @@
+/*
+ * (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>
+
+#undef I2CDBG
+
+#ifdef CONFIG_HARD_I2C
+#include <i2c.h>
+
+#define TIMEOUT (CONFIG_SYS_HZ/4)
+
+#define I2C_Addr ((unsigned *)(CONFIG_SYS_EUMB_ADDR + 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 MPC107_CCR_MEN  0x80
+#define MPC107_CCR_MIEN 0x40
+#define MPC107_CCR_MSTA 0x20
+#define MPC107_CCR_MTX  0x10
+#define MPC107_CCR_TXAK 0x08
+#define MPC107_CCR_RSTA 0x04
+
+#define MPC107_CSR_MCF  0x80
+#define MPC107_CSR_MAAS 0x40
+#define MPC107_CSR_MBB  0x20
+#define MPC107_CSR_MAL  0x10
+#define MPC107_CSR_SRW  0x04
+#define MPC107_CSR_MIF  0x02
+#define MPC107_CSR_RXAK 0x01
+
+#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 (0x1020, I2CFDR);
+	/* write slave address */
+	writel (slaveadd, I2CADR);
+	/* clear status register */
+	writel (0x0, I2CCSR);
+	/* start I2C controller */
+	writel (MPC107_CCR_MEN, I2CCCR);
+
+	return;
+}
+
+static __inline__ int i2c_wait4bus (void)
+{
+	ulong timeval = get_timer (0);
+
+	while (readl (I2CCSR) & MPC107_CSR_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 & MPC107_CSR_MIF))
+			continue;
+
+		writel (0x0, I2CCSR);
+
+		if (csr & MPC107_CSR_MAL) {
+#ifdef I2CDBG
+			printf ("i2c_wait: MAL\n");
+#endif
+			return -1;
+		}
+
+		if (!(csr & MPC107_CSR_MCF)) {
+#ifdef I2CDBG
+			printf ("i2c_wait: unfinished\n");
+#endif
+			return -1;
+		}
+
+		if (write == I2C_WRITE && (csr & MPC107_CSR_RXAK)) {
+#ifdef I2CDBG
+			printf ("i2c_wait: No RXACK\n");
+#endif
+			return -1;
+		}
+
+		return 0;
+	} while (get_timer (timeval) < TIMEOUT);
+
+#ifdef I2CDBG
+	printf ("i2c_wait: timed out\n");
+#endif
+	return -1;
+}
+
+static __inline__ int i2c_write_addr (u8 dev, u8 dir, int rsta)
+{
+	writel (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_MTX |
+		(rsta ? MPC107_CCR_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 (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_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 (MPC107_CCR_MEN | MPC107_CCR_MSTA |
+		((length == 1) ? MPC107_CCR_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 (MPC107_CCR_MEN | MPC107_CCR_MSTA |
+				MPC107_CCR_TXAK, I2CCCR);
+
+		/* Generate stop on last byte */
+		if (i == length - 1)
+			writel (MPC107_CCR_MEN | MPC107_CCR_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 (MPC107_CCR_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 (MPC107_CCR_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, (uchar *) &tmp, 1);
+}
+
+#endif /* CONFIG_HARD_I2C */