soc/cavium: dynamic UART initialization for cavium cn8100

Now only those UARTs that are enabled in devicetree.cb are initialized.

Tested on Opencellular Elgon.

Change-Id: I145c224148f0cc078bb1c76f588f603e73121a62
Signed-off-by: Jens Drenhaus <jens.drenhaus@9elements.com>
Reviewed-on: https://review.coreboot.org/28975
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/src/soc/cavium/cn81xx/soc.c b/src/soc/cavium/cn81xx/soc.c
index d9eb052..0bf76f7 100644
--- a/src/soc/cavium/cn81xx/soc.c
+++ b/src/soc/cavium/cn81xx/soc.c
@@ -24,6 +24,7 @@
 #include <soc/clock.h>
 #include <soc/sdram.h>
 #include <soc/timer.h>
+#include <soc/uart.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
@@ -207,6 +208,21 @@
 		printk(BIOS_ERR, "%s: Node not found. OS might miss-behave !\n",
 		       __func__);
 
+	/* Remove unused UART entries */
+	for (i = 0; i < 4; i++) {
+		char path[32];
+		const uint64_t addr = UAAx_PF_BAR0(i);
+		/* Remove the node */
+		snprintf(path, sizeof(path), "soc@0/serial@%llx", addr);
+		dt_node = dt_find_node_by_path(tree->root, path, NULL, NULL, 0);
+		if (!dt_node || uart_is_enabled(i)) {
+			printk(BIOS_INFO, "%s: ignoring %s\n", __func__, path);
+			continue;
+		}
+		printk(BIOS_INFO, "%s: Removing node %s\n", __func__, path);
+		list_remove(&dt_node->list_node);
+	}
+
 	/* Remove unused PEM entries */
 	for (i = 0; i < 8; i++) {
 		char path[32];
@@ -374,6 +390,18 @@
 		}
 	}
 
+	/* Init UARTs */
+	size_t i;
+	struct device *uart_dev;
+	for (i = 0; i <= 3; i++) {
+		uart_dev = dev_find_slot(1, PCI_DEVFN(8, i));
+		/* using device enable state from devicetree.cb */
+		if (uart_dev && uart_dev->enabled) {
+			if (!uart_is_enabled(i))
+				uart_setup(i, 0);
+		}
+	}
+
 	if (IS_ENABLED(CONFIG_ARM64_USE_ARM_TRUSTED_FIRMWARE))
 		soc_init_atf();
 }