mb/siemens/mc_rpl1: Enable Intel I210 MACPHY driver

Enable the i210 driver for this variant which uses I210 MACPHYs.
Additionally, add a function to retrieve a valid MAC Address for the
given MACPHY.

Change-Id: If519194f52910e4ace59095a997bafff7eab44ca
Signed-off-by: Kilian Krause <kilian.krause@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/88887
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>

src/mainboard/siemens/mc_rpl/mainboard.c

@@ -6,6 +6,85 @@
 #include <soc/gpio.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <hwilib.h>
+#include <i210.h>
+
+
+#define MAX_PATH_DEPTH		12
+#define MAX_NUM_MAPPINGS	10
+
+/** \brief This function can decide if a given MAC address is valid or not.
+*	  Currently, addresses filled with 0xff or 0x00 are not valid.
+ * @param  mac	Buffer to the MAC address to check
+ * @return 0	if address is not valid, otherwise 1
+ */
+static uint8_t is_mac_adr_valid(uint8_t mac[MAC_ADDR_LEN])
+{
+	for (size_t i = 0; i < MAC_ADDR_LEN; i++) {
+		if (mac[i] != 0x00 && mac[i] != 0xff)
+			return 1;
+		if (mac[i] != mac[0])
+			return 1;
+	}
+	return 0;
+}
+
+/** \brief This function will search for a MAC address which can be assigned
+ *	   to a MACPHY.
+ * @param  dev	   pointer to PCI device
+ * @param  mac	   buffer where to store the MAC address
+ * @return cb_err  CB_ERR or CB_SUCCESS
+ */
+
+enum cb_err mainboard_get_mac_address(struct device *dev, uint8_t mac[MAC_ADDR_LEN])
+{
+	struct bus *parent = dev->upstream;
+	uint8_t buf[16], mapping[16], i = 0, chain_len = 0;
+
+	memset(buf, 0, sizeof(buf));
+	memset(mapping, 0, sizeof(mapping));
+
+	/* The first entry in the tree is the device itself. */
+	buf[0] = dev->path.pci.devfn;
+	chain_len = 1;
+	for (i = 1; i < MAX_PATH_DEPTH && parent->dev->upstream->subordinate; i++) {
+		buf[i] = parent->dev->path.pci.devfn;
+		chain_len++;
+		parent = parent->dev->upstream;
+	}
+	if (i == MAX_PATH_DEPTH) {
+		/* The path is deeper than MAX_PATH_DEPTH devices, error. */
+		printk(BIOS_ERR, "Too many bridges for %s\n", dev_path(dev));
+		return CB_ERR;
+	}
+	/*
+	* Now construct the mapping based on the device chain starting from
+	* root bridge device to the device itself.
+	*/
+	mapping[0] = 1;
+	mapping[1] = chain_len;
+	for (i = 0; i < chain_len; i++)
+		mapping[i + 4] = buf[chain_len - i - 1];
+
+	/* Open main hwinfo block */
+	if (hwilib_find_blocks("hwinfo.hex") != CB_SUCCESS)
+		return CB_ERR;
+	/* Now try to find a valid MAC address in hwinfo for this mapping. */
+	for (i = 0; i < MAX_NUM_MAPPINGS; i++) {
+		if (hwilib_get_field(XMac1Mapping + i, buf, 16) != 16)
+			continue;
+		if (memcmp(buf, mapping, chain_len + 4))
+			continue;
+		/* There is a matching mapping available, get MAC address. */
+		if (hwilib_get_field(XMac1 + i, mac, MAC_ADDR_LEN) == MAC_ADDR_LEN) {
+			if (is_mac_adr_valid(mac))
+				return CB_SUCCESS;
+		}
+		return CB_ERR;
+	}
+	/* No MAC address found for */
+	return CB_ERR;
+}
 
 static void mainboard_init(void *chip_info)
 {

src/mainboard/siemens/mc_rpl/variants/mc_rpl1/Kconfig

@@ -9,6 +9,7 @@ config BOARD_SPECIFIC_OPTIONS
 	select MEMORY_MAPPED_TPM
 	select TPM_MEASURED_BOOT
 	select TPM_MEASURED_BOOT_INIT_BOOTBLOCK
+	select DRIVER_INTEL_I210
 
 config UART_FOR_CONSOLE
 	int