Patch by TsiChung Liew, 23 Sep 2004:

- add support for MPC8220 CPU
- Add support for Alaska and Yukon boards

1 files changed, 403 insertions, 0 deletions

diff --git a/cpu/mpc8220/i2c.c b/cpu/mpc8220/i2c.c
new file mode 100644
index 0000000..e9d0771
--- /dev/null
+++ b/cpu/mpc8220/i2c.c
@@ -0,0 +1,403 @@
+/*
+ * (C) Copyright 2004, Freescale, Inc
+ * TsiChung Liew, Tsi-Chung.Liew@freescale.com.
+ *
+ * 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>
+
+#ifdef CONFIG_HARD_I2C
+
+#include <mpc8220.h>
+#include <i2c.h>
+
+typedef struct mpc8220_i2c {
+	volatile u32 adr;	/* I2Cn + 0x00 */
+	volatile u32 fdr;	/* I2Cn + 0x04 */
+	volatile u32 cr;	/* I2Cn + 0x08 */
+	volatile u32 sr;	/* I2Cn + 0x0C */
+	volatile u32 dr;	/* I2Cn + 0x10 */
+} i2c_t;
+
+/* I2Cn control register bits */
+#define I2C_EN      0x80
+#define I2C_IEN     0x40
+#define I2C_STA     0x20
+#define I2C_TX      0x10
+#define I2C_TXAK    0x08
+#define I2C_RSTA    0x04
+#define I2C_INIT_MASK   (I2C_EN | I2C_STA | I2C_TX | I2C_RSTA)
+
+/* I2Cn status register bits */
+#define I2C_CF      0x80
+#define I2C_AAS     0x40
+#define I2C_BB      0x20
+#define I2C_AL      0x10
+#define I2C_SRW     0x04
+#define I2C_IF      0x02
+#define I2C_RXAK    0x01
+
+#define I2C_TIMEOUT 100
+#define I2C_RETRIES 1
+
+struct mpc8220_i2c_tap {
+	int scl2tap;
+	int tap2tap;
+};
+
+static int mpc_reg_in (volatile u32 * reg);
+static void mpc_reg_out (volatile u32 * reg, int val, int mask);
+static int wait_for_bb (void);
+static int wait_for_pin (int *status);
+static int do_address (uchar chip, char rdwr_flag);
+static int send_bytes (uchar chip, char *buf, int len);
+static int receive_bytes (uchar chip, char *buf, int len);
+static int mpc_get_fdr (int);
+
+static int mpc_reg_in (volatile u32 * reg)
+{
+	return *reg >> 24;
+	__asm__ __volatile__ ("eieio");
+}
+
+static void mpc_reg_out (volatile u32 * reg, int val, int mask)
+{
+	int tmp;
+
+	if (!mask) {
+		*reg = val << 24;
+	} else {
+		tmp = mpc_reg_in (reg);
+		*reg = ((tmp & ~mask) | (val & mask)) << 24;
+	}
+	__asm__ __volatile__ ("eieio");
+
+	return;
+}
+
+static int wait_for_bb (void)
+{
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int timeout = I2C_TIMEOUT;
+	int status;
+
+	status = mpc_reg_in (&regs->sr);
+
+	while (timeout-- && (status & I2C_BB)) {
+#if 1
+		volatile int temp;
+
+		mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
+		temp = mpc_reg_in (&regs->dr);
+		mpc_reg_out (&regs->cr, 0, I2C_STA);
+		mpc_reg_out (&regs->cr, 0, 0);
+		mpc_reg_out (&regs->cr, I2C_EN, 0);
+#endif
+		udelay (1000);
+		status = mpc_reg_in (&regs->sr);
+	}
+
+	return (status & I2C_BB);
+}
+
+static int wait_for_pin (int *status)
+{
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int timeout = I2C_TIMEOUT;
+
+	*status = mpc_reg_in (&regs->sr);
+
+	while (timeout-- && !(*status & I2C_IF)) {
+		udelay (1000);
+		*status = mpc_reg_in (&regs->sr);
+	}
+
+	if (!(*status & I2C_IF)) {
+		return -1;
+	}
+
+	mpc_reg_out (&regs->sr, 0, I2C_IF);
+	return 0;
+}
+
+static int do_address (uchar chip, char rdwr_flag)
+{
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int status;
+
+	chip <<= 1;
+
+	if (rdwr_flag)
+		chip |= 1;
+
+	mpc_reg_out (&regs->cr, I2C_TX, I2C_TX);
+	mpc_reg_out (&regs->dr, chip, 0);
+
+	if (wait_for_pin (&status))
+		return -2;
+	if (status & I2C_RXAK)
+		return -3;
+	return 0;
+}
+
+static int send_bytes (uchar chip, char *buf, int len)
+{
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int wrcount;
+	int status;
+
+	for (wrcount = 0; wrcount < len; ++wrcount) {
+
+		mpc_reg_out (&regs->dr, buf[wrcount], 0);
+
+		if (wait_for_pin (&status))
+			break;
+
+		if (status & I2C_RXAK)
+			break;
+
+	}
+
+	return !(wrcount == len);
+	return 0;
+}
+
+static int receive_bytes (uchar chip, char *buf, int len)
+{
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int dummy = 1;
+	int rdcount = 0;
+	int status;
+	int i;
+
+	mpc_reg_out (&regs->cr, 0, I2C_TX);
+
+	for (i = 0; i < len; ++i) {
+		buf[rdcount] = mpc_reg_in (&regs->dr);
+
+		if (dummy)
+			dummy = 0;
+		else
+			rdcount++;
+
+		if (wait_for_pin (&status))
+			return -4;
+	}
+
+	mpc_reg_out (&regs->cr, I2C_TXAK, I2C_TXAK);
+	buf[rdcount++] = mpc_reg_in (&regs->dr);
+
+	if (wait_for_pin (&status))
+		return -5;
+
+	mpc_reg_out (&regs->cr, 0, I2C_TXAK);
+	return 0;
+}
+
+/**************** I2C API ****************/
+
+void i2c_init (int speed, int saddr)
+{
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+
+	mpc_reg_out (&regs->cr, 0, 0);
+	mpc_reg_out (&regs->adr, saddr << 1, 0);
+
+	/* Set clock
+	 */
+	mpc_reg_out (&regs->fdr, mpc_get_fdr (speed), 0);
+
+	/* Enable module
+	 */
+	mpc_reg_out (&regs->cr, I2C_EN, I2C_INIT_MASK);
+	mpc_reg_out (&regs->sr, 0, I2C_IF);
+	return;
+}
+
+static int mpc_get_fdr (int speed)
+{
+	DECLARE_GLOBAL_DATA_PTR;
+	static int fdr = -1;
+
+	if (fdr == -1) {
+		ulong best_speed = 0;
+		ulong divider;
+		ulong ipb, scl;
+		ulong bestmatch = 0xffffffffUL;
+		int best_i = 0, best_j = 0, i, j;
+		int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8 };
+		struct mpc8220_i2c_tap scltap[] = {
+			{4, 1},
+			{4, 2},
+			{6, 4},
+			{6, 8},
+			{14, 16},
+			{30, 32},
+			{62, 64},
+			{126, 128}
+		};
+
+		ipb = gd->bus_clk;
+		for (i = 7; i >= 0; i--) {
+			for (j = 7; j >= 0; j--) {
+				scl = 2 * (scltap[j].scl2tap +
+					   (SCL_Tap[i] -
+					    1) * scltap[j].tap2tap + 2);
+				if (ipb <= speed * scl) {
+					if ((speed * scl - ipb) < bestmatch) {
+						bestmatch = speed * scl - ipb;
+						best_i = i;
+						best_j = j;
+						best_speed = ipb / scl;
+					}
+				}
+			}
+		}
+		divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2);
+		if (gd->flags & GD_FLG_RELOC) {
+			fdr = divider;
+		} else {
+			printf ("%ld kHz, ", best_speed / 1000);
+			return divider;
+		}
+	}
+
+	return fdr;
+}
+
+int i2c_probe (uchar chip)
+{
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int i;
+
+	for (i = 0; i < I2C_RETRIES; i++) {
+		mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
+
+		if (!do_address (chip, 0)) {
+			mpc_reg_out (&regs->cr, 0, I2C_STA);
+			break;
+		}
+
+		mpc_reg_out (&regs->cr, 0, I2C_STA);
+		udelay (50);
+	}
+
+	return (i == I2C_RETRIES);
+}
+
+int i2c_read (uchar chip, uint addr, int alen, uchar * buf, int len)
+{
+	uchar xaddr[4];
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int ret = -1;
+
+	xaddr[0] = (addr >> 24) & 0xFF;
+	xaddr[1] = (addr >> 16) & 0xFF;
+	xaddr[2] = (addr >> 8) & 0xFF;
+	xaddr[3] = addr & 0xFF;
+
+	if (wait_for_bb ()) {
+		printf ("i2c_read: bus is busy\n");
+		goto Done;
+	}
+
+	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
+	if (do_address (chip, 0)) {
+		printf ("i2c_read: failed to address chip\n");
+		goto Done;
+	}
+
+	if (send_bytes (chip, &xaddr[4 - alen], alen)) {
+		printf ("i2c_read: send_bytes failed\n");
+		goto Done;
+	}
+
+	mpc_reg_out (&regs->cr, I2C_RSTA, I2C_RSTA);
+	if (do_address (chip, 1)) {
+		printf ("i2c_read: failed to address chip\n");
+		goto Done;
+	}
+
+	if (receive_bytes (chip, buf, len)) {
+		printf ("i2c_read: receive_bytes failed\n");
+		goto Done;
+	}
+
+	ret = 0;
+      Done:
+	mpc_reg_out (&regs->cr, 0, I2C_STA);
+	return ret;
+}
+
+int i2c_write (uchar chip, uint addr, int alen, uchar * buf, int len)
+{
+	uchar xaddr[4];
+	i2c_t *regs = (i2c_t *) MMAP_I2C;
+	int ret = -1;
+
+	xaddr[0] = (addr >> 24) & 0xFF;
+	xaddr[1] = (addr >> 16) & 0xFF;
+	xaddr[2] = (addr >> 8) & 0xFF;
+	xaddr[3] = addr & 0xFF;
+
+	if (wait_for_bb ()) {
+		printf ("i2c_write: bus is busy\n");
+		goto Done;
+	}
+
+	mpc_reg_out (&regs->cr, I2C_STA, I2C_STA);
+	if (do_address (chip, 0)) {
+		printf ("i2c_write: failed to address chip\n");
+		goto Done;
+	}
+
+	if (send_bytes (chip, &xaddr[4 - alen], alen)) {
+		printf ("i2c_write: send_bytes failed\n");
+		goto Done;
+	}
+
+	if (send_bytes (chip, buf, len)) {
+		printf ("i2c_write: send_bytes failed\n");
+		goto Done;
+	}
+
+	ret = 0;
+      Done:
+	mpc_reg_out (&regs->cr, 0, I2C_STA);
+	return ret;
+}
+
+uchar i2c_reg_read (uchar chip, uchar reg)
+{
+	char buf;
+
+	i2c_read (chip, reg, 1, &buf, 1);
+
+	return buf;
+}
+
+void i2c_reg_write (uchar chip, uchar reg, uchar val)
+{
+	i2c_write (chip, reg, 1, &val, 1);
+
+	return;
+}
+
+#endif /* CONFIG_HARD_I2C */