[POWERPC] Add bootwrapper support for Marvell/mv64x60 I2C

Some platforms support a variety processor modules with no method of
determining which exact processor module is being used except by
examining Vital Product Data (VPD).  The modules may have different
amounts of memory, clock frequencies, etc. so reading the VPD becomes
necessary to correctly set properties in the device tree before its
passed to the kernel.

Often the VPD is stored in I2C EEPROMs so an I2C driver becomes necessary.
This I2C driver is for the I2C controller that's embedded on the Marvel
mv64x60 line of host bridges.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 207 insertions, 1 deletions

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 71b284b2f179..12fd57e11fa5 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -43,7 +43,7 @@ $(addprefix $(obj)/,$(zlib) gunzip_util.o main.o): \
 src-wlib := string.S crt0.S stdio.c main.c flatdevtree.c flatdevtree_misc.c \
 		ns16550.c serial.c simple_alloc.c div64.S util.S \
 		gunzip_util.c elf_util.c $(zlib) devtree.c \
-		44x.c ebony.c mv64x60.c mpsc.c
+		44x.c ebony.c mv64x60.c mpsc.c mv64x60_i2c.c
 src-plat := of.c cuboot-83xx.c cuboot-85xx.c holly.c \
 		cuboot-ebony.c treeboot-ebony.c
 src-boot := $(src-wlib) $(src-plat) empty.c
diff --git a/arch/powerpc/boot/mv64x60_i2c.c b/arch/powerpc/boot/mv64x60_i2c.c
new file mode 100644
index 000000000000..435fe8528680
--- /dev/null
+++ b/arch/powerpc/boot/mv64x60_i2c.c
@@ -0,0 +1,206 @@
+/*
+ * Bootloader version of the i2c driver for the MV64x60.
+ *
+ * Author: Dale Farnsworth <dfarnsworth@mvista.com>
+ * Maintained by: Mark A. Greer <mgreer@mvista.com>
+ *
+ * 2003, 2007 (c) MontaVista, Software, Inc.  This file is licensed under
+ * the terms of the GNU General Public License version 2.  This program is
+ * licensed "as is" without any warranty of any kind, whether express or
+ * implied.
+ */
+
+#include <stdarg.h>
+#include <stddef.h>
+#include "types.h"
+#include "elf.h"
+#include "page.h"
+#include "string.h"
+#include "stdio.h"
+#include "io.h"
+#include "ops.h"
+#include "mv64x60.h"
+
+extern void udelay(long);
+
+/* Register defines */
+#define MV64x60_I2C_REG_SLAVE_ADDR			0x00
+#define MV64x60_I2C_REG_DATA				0x04
+#define MV64x60_I2C_REG_CONTROL				0x08
+#define MV64x60_I2C_REG_STATUS				0x0c
+#define MV64x60_I2C_REG_BAUD				0x0c
+#define MV64x60_I2C_REG_EXT_SLAVE_ADDR			0x10
+#define MV64x60_I2C_REG_SOFT_RESET			0x1c
+
+#define MV64x60_I2C_CONTROL_ACK				0x04
+#define MV64x60_I2C_CONTROL_IFLG			0x08
+#define MV64x60_I2C_CONTROL_STOP			0x10
+#define MV64x60_I2C_CONTROL_START			0x20
+#define MV64x60_I2C_CONTROL_TWSIEN			0x40
+#define MV64x60_I2C_CONTROL_INTEN			0x80
+
+#define MV64x60_I2C_STATUS_BUS_ERR			0x00
+#define MV64x60_I2C_STATUS_MAST_START			0x08
+#define MV64x60_I2C_STATUS_MAST_REPEAT_START		0x10
+#define MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK		0x18
+#define MV64x60_I2C_STATUS_MAST_WR_ADDR_NO_ACK		0x20
+#define MV64x60_I2C_STATUS_MAST_WR_ACK			0x28
+#define MV64x60_I2C_STATUS_MAST_WR_NO_ACK		0x30
+#define MV64x60_I2C_STATUS_MAST_LOST_ARB		0x38
+#define MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK		0x40
+#define MV64x60_I2C_STATUS_MAST_RD_ADDR_NO_ACK		0x48
+#define MV64x60_I2C_STATUS_MAST_RD_DATA_ACK		0x50
+#define MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK		0x58
+#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_ACK		0xd0
+#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK	0xd8
+#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_ACK		0xe0
+#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK	0xe8
+#define MV64x60_I2C_STATUS_NO_STATUS			0xf8
+
+static u8 *ctlr_base;
+
+static int mv64x60_i2c_wait_for_status(int wanted)
+{
+	int i;
+	int status;
+
+	for (i=0; i<1000; i++) {
+		udelay(10);
+		status = in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_STATUS))
+			& 0xff;
+		if (status == wanted)
+			return status;
+	}
+	return -status;
+}
+
+static int mv64x60_i2c_control(int control, int status)
+{
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
+	return mv64x60_i2c_wait_for_status(status);
+}
+
+static int mv64x60_i2c_read_byte(int control, int status)
+{
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
+	if (mv64x60_i2c_wait_for_status(status) < 0)
+		return -1;
+	return in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA)) & 0xff;
+}
+
+static int mv64x60_i2c_write_byte(int data, int control, int status)
+{
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA), data & 0xff);
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
+	return mv64x60_i2c_wait_for_status(status);
+}
+
+int mv64x60_i2c_read(u32 devaddr, u8 *buf, u32 offset, u32 offset_size,
+		 u32 count)
+{
+	int i;
+	int data;
+	int control;
+	int status;
+
+	if (ctlr_base == NULL)
+		return -1;
+
+	/* send reset */
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SOFT_RESET), 0);
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SLAVE_ADDR), 0);
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_EXT_SLAVE_ADDR), 0);
+	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_BAUD), (4 << 3) | 0x4);
+
+	if (mv64x60_i2c_control(MV64x60_I2C_CONTROL_TWSIEN,
+				MV64x60_I2C_STATUS_NO_STATUS) < 0)
+		return -1;
+
+	/* send start */
+	control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_MAST_START;
+	if (mv64x60_i2c_control(control, status) < 0)
+		return -1;
+
+	/* select device for writing */
+	data = devaddr & ~0x1;
+	control = MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK;
+	if (mv64x60_i2c_write_byte(data, control, status) < 0)
+		return -1;
+
+	/* send offset of data */
+	control = MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_MAST_WR_ACK;
+	if (offset_size > 1) {
+		if (mv64x60_i2c_write_byte(offset >> 8, control, status) < 0)
+			return -1;
+	}
+	if (mv64x60_i2c_write_byte(offset, control, status) < 0)
+		return -1;
+
+	/* resend start */
+	control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_MAST_REPEAT_START;
+	if (mv64x60_i2c_control(control, status) < 0)
+		return -1;
+
+	/* select device for reading */
+	data = devaddr | 0x1;
+	control = MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK;
+	if (mv64x60_i2c_write_byte(data, control, status) < 0)
+		return -1;
+
+	/* read all but last byte of data */
+	control = MV64x60_I2C_CONTROL_ACK | MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_MAST_RD_DATA_ACK;
+
+	for (i=1; i<count; i++) {
+		data = mv64x60_i2c_read_byte(control, status);
+		if (data < 0) {
+			printf("errors on iteration %d\n", i);
+			return -1;
+		}
+		*buf++ = data;
+	}
+
+	/* read last byte of data */
+	control = MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK;
+	data = mv64x60_i2c_read_byte(control, status);
+	if (data < 0)
+		return -1;
+	*buf++ = data;
+
+	/* send stop */
+	control = MV64x60_I2C_CONTROL_STOP | MV64x60_I2C_CONTROL_TWSIEN;
+	status = MV64x60_I2C_STATUS_NO_STATUS;
+	if (mv64x60_i2c_control(control, status) < 0)
+		return -1;
+
+	return count;
+}
+
+int mv64x60_i2c_open(void)
+{
+	u32 v;
+	void *devp;
+
+	devp = finddevice("/mv64x60/i2c");
+	if (devp == NULL)
+		goto err_out;
+	if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
+		goto err_out;
+
+	ctlr_base = (u8 *)v;
+	return 0;
+
+err_out:
+	return -1;
+}
+
+void mv64x60_i2c_close(void)
+{
+	ctlr_base = NULL;
+}