lenovo: Handle EEPROM/RFID chip.

EEPROM/RFID chip present in thinkpad should be locked in a way to avoid
any potential RFID access.

Read serial number, UUID and P/N from EEPROM.

This info is stored on AT24RF08 chip acessible through SMBUS.

Change-Id: Ia3e766d90a094f63c8c854cd37e165221ccd8acd
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/4774
Tested-by: build bot (Jenkins)
Reviewed-by: Rudolf Marek <r.marek@assembler.cz>

src/drivers/i2c/at24rf08c/Makefile.inc

@@ -0,0 +1,2 @@
+ramstage-$(CONFIG_VENDOR_LENOVO) += at24rf08c.c
+ramstage-$(CONFIG_VENDOR_LENOVO) += lenovo_serials.c

src/drivers/i2c/at24rf08c/at24rf08c.c

@@ -0,0 +1,74 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Vladimir Serbinenko
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <types.h>
+#include <string.h>
+#include <arch/io.h>
+#include <device/device.h>
+#include <device/smbus.h>
+#include <smbios.h>
+#include <console/console.h>
+
+static void at24rf08c_init(device_t dev)
+{
+	int i, j;
+
+	if (!dev->enabled)
+		return;
+
+        /* Ensure that EEPROM/RFID chip is not accessible through RFID.
+	   Need to do it only on 5c.  */
+	if (dev->path.type != DEVICE_PATH_I2C || dev->path.i2c.device != 0x5c)
+		return;
+
+	printk (BIOS_DEBUG, "Locking EEPROM RFID\n");
+
+	for (i = 0; i < 8; i++)
+	{
+		/* After a register write AT24RF08C sometimes stops responding.
+		   Retry several times in case of failure.
+		 */
+		for (j = 0; j < 100; j++)
+			if (smbus_write_byte(dev, i, 0x0f) >= 0)
+				break;
+	}
+
+	printk (BIOS_DEBUG, "init EEPROM done\n");
+}
+
+static void at24rf08c_noop(device_t dummy)
+{
+}
+
+static struct device_operations at24rf08c_operations = {
+	.read_resources = at24rf08c_noop,
+	.set_resources = at24rf08c_noop,
+	.enable_resources = at24rf08c_noop,
+	.init = at24rf08c_init,
+};
+
+static void enable_dev(device_t dev)
+{
+	dev->ops = &at24rf08c_operations;
+}
+
+struct chip_operations drivers_i2c_at24rf08c_ops = {
+	CHIP_NAME("AT24RF08C")
+	.enable_dev = enable_dev,
+};

src/drivers/i2c/at24rf08c/lenovo_serials.c

@@ -0,0 +1,137 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Vladimir Serbinenko
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <types.h>
+#include <string.h>
+#include <arch/io.h>
+#include <device/device.h>
+#include <device/smbus.h>
+#include <smbios.h>
+#include <console/console.h>
+
+static void at24rf08c_read_string(u8 bank, u8 start, u8 len, char *result)
+{
+	int i;
+	device_t dev;
+
+	dev = dev_find_slot_on_smbus(1, 0x54 | bank);
+	if (dev == 0) {
+		printk(BIOS_WARNING, "EEPROM not found\n");
+		memcpy(result, "*INVALID*", sizeof ("*INVALID*"));
+		return;
+	} 
+
+	for (i = 0; i < len; i++) {
+		int t;
+		int j;
+		/* After a register write AT24RF08C (which we issued in init function) sometimes stops responding.
+		   Retry several times in case of failure.
+		*/
+		for (j = 0; j < 100; j++) {
+			t = smbus_read_byte(dev, start + i);
+			if (t >= 0)
+				break;
+		}
+		if (t < 0x20 || t > 0x7f) {
+			memcpy(result, "*INVALID*", sizeof ("*INVALID*"));
+			return;
+		}
+		result[i] = t;
+	}
+}
+
+const char *smbios_mainboard_serial_number(void)
+{
+	static char result[12];
+	static int already_read;
+
+	if (already_read)
+		return result;
+
+	memset(result, 0, sizeof (result));
+	at24rf08c_read_string(0, 0x2e, 7, result);
+
+	already_read = 1;
+	return result;
+}
+
+const char *smbios_mainboard_product_name(void)
+{
+	static char result[12];
+	static int already_read;
+
+	if (already_read)
+		return result;
+
+	memset (result, 0, sizeof (result));
+	at24rf08c_read_string(0, 0x27, 7, result);
+
+	already_read = 1;
+	return result;
+}
+
+void smbios_mainboard_set_uuid(u8 *uuid)
+{
+	static char result[16];
+	unsigned i;
+	static int already_read;
+	device_t dev;
+	const int remap[16] = {
+		/* UUID byteswap.  */
+		3, 2, 1, 0, 5, 4, 7, 6, 8, 9, 10, 11, 12, 13, 14, 15
+	};
+
+
+	if (already_read) {
+		memcpy (uuid, result, 16);
+		return;
+	}
+
+	memset (result, 0, sizeof (result));
+
+	dev = dev_find_slot_on_smbus(1, 0x56);
+	if (dev == 0) {
+		printk(BIOS_WARNING, "eeprom not found\n");
+		already_read = 1;
+		memset (uuid, 0, 16);
+		return;
+	}
+
+	for (i = 0; i < 16; i++) {
+		int t;
+		int j;
+		/* After a register write AT24RF08C (which we issued in init function) sometimes stops responding.
+		   Retry several times in case of failure.
+		*/
+		for (j = 0; j < 100; j++) {
+			t = smbus_read_byte(dev, 0x12 + i);
+			if (t >= 0)
+				break;
+		}
+		if (t < 0) {
+			memset (result, 0, sizeof (result));
+			break;
+		}
+		result[remap[i]] = t;
+	}
+
+	already_read = 1;
+
+	memcpy (uuid, result, 16);
+}