drivers/net/r8168: Add driver for realtek nic

One thing that is vital to this patch is the MAC address setting
in case the EEPROM/efuse is unconfigured.
Linux now recognises the default MAC address on GA-G41M-ES2L which
does rely on the default bios settings for the MAC address.

Change-Id: I32e070b545b4c6369686a7087b7ff838d00764e3
Signed-off-by: Damien Zammit <damien@zamaudio.com>
Reviewed-on: https://review.coreboot.org/14927
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/drivers/net/Kconfig

@@ -0,0 +1,5 @@
+config REALTEK_8168_RESET
+	bool "Realtek 8168 reset"
+	help
+	  This forces a realtek 10ec:8168 card to reset to ensure power state
+	  is correct at boot.

src/drivers/net/Makefile.inc

@@ -1,2 +1,3 @@
 romstage-$(CONFIG_CONSOLE_NE2K) += ne2k.c
 ramstage-$(CONFIG_CONSOLE_NE2K) += ne2k.c
+ramstage-$(CONFIG_REALTEK_8168_RESET) += r8168.c

src/drivers/net/r8168.c

@@ -0,0 +1,94 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2016 Damien Zammit <damien@zamaudio.com>
+ *
+ * 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.
+ */
+
+/*
+ * This driver forces the 10ec:8168 device to reset so that it goes
+ * into a proper power state, also programs a default MAC address
+ * so that if the EEPROM/efuse is unconfigured it still has a default MAC.
+ */
+
+#include <arch/io.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ops.h>
+#include <device/pci_def.h>
+#include <delay.h>
+#include <console/console.h>
+
+#define NIC_TIMEOUT		1000
+
+#define CMD_REG			0x37
+#define  CMD_REG_RESET		0x10
+
+#define CFG_9346		0x50
+#define  CFG_9346_LOCK		0x00
+#define  CFG_9346_UNLOCK	0xc0
+
+static void r8168_init(struct device *dev)
+{
+	u32 i;
+	const u8 mac[6] = { 0x00, 0xe0, 0x4c, 0x00, 0xc0, 0xb0 };
+
+	/* Get the resource of the NIC mmio */
+	struct resource *nic_res = find_resource(dev, PCI_BASE_ADDRESS_0);
+	u16 nic_port = (u16)nic_res->base;
+
+	/* Set bus master */
+	pci_write_config16(dev, PCI_COMMAND, PCI_COMMAND_MASTER
+					| PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
+
+	/* Reset NIC */
+	printk(BIOS_DEBUG, "r8168: Resetting NIC...");
+	outb(CMD_REG_RESET, nic_port + CMD_REG);
+
+	i = 0;
+	/* Poll for reset, with 1s timeout */
+	while (i < NIC_TIMEOUT && (inb(nic_port + CMD_REG) & CMD_REG_RESET)) {
+		udelay(1000);
+		if (++i >= NIC_TIMEOUT)
+			printk(BIOS_DEBUG, "timeout waiting for nic to reset\n");
+	}
+	if (i < NIC_TIMEOUT)
+		printk(BIOS_DEBUG, "done\n");
+
+	/* Unlock config regs */
+	outb(CFG_9346_UNLOCK, nic_port + CFG_9346);
+
+	/* Set MAC address 00:e0:4c:00:c0:b0
+	 * NB: only 4-byte write accesses allowed
+	 */
+	outl(mac[4] | mac[5] << 8, nic_port + 4);
+	inl(nic_port + 4);
+
+	outl(mac[0] | mac[1] << 8 | mac[2] << 16 | mac[3] << 24, nic_port);
+	inl(nic_port);
+
+	/* Lock config regs */
+	outb(CFG_9346_LOCK, nic_port + CFG_9346);
+}
+
+static struct device_operations r8168_ops  = {
+       .read_resources   = pci_dev_read_resources,
+       .set_resources    = pci_dev_set_resources,
+       .enable_resources = pci_dev_enable_resources,
+       .init             = r8168_init,
+       .scan_bus         = 0,
+};
+
+static const struct pci_driver r8168_driver __pci_driver = {
+        .ops    = &r8168_ops,
+        .vendor = 0x10ec,
+        .device = 0x8168,
+};