dm: eth: Add support for aliases

Allow network devices to be referred to as "eth0" instead of
"eth@12345678" when specified in ethact.

Add tests to verify this behavior.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/configs/sandbox.h

@@ -178,7 +178,7 @@
 
 #define SANDBOX_ETH_SETTINGS		"ethaddr=00:00:11:22:33:44\0" \
 					"eth1addr=00:00:11:22:33:45\0" \
-					"eth2addr=00:00:11:22:33:46\0" \
+					"eth5addr=00:00:11:22:33:46\0" \
 					"ipaddr=1.2.3.4\0"
 
 #define CONFIG_EXTRA_ENV_SETTINGS	SANDBOX_SERIAL_SETTINGS \

include/net.h

@@ -124,6 +124,11 @@ struct eth_ops {
 #define eth_get_ops(dev) ((struct eth_ops *)(dev)->driver->ops)
 
 struct udevice *eth_get_dev(void); /* get the current device */
+/*
+ * The devname can be either an exact name given by the driver or device tree
+ * or it can be an alias of the form "eth%d"
+ */
+struct udevice *eth_get_dev_by_name(const char *devname);
 unsigned char *eth_get_ethaddr(void); /* get the current device MAC */
 /* Used only when NetConsole is enabled */
 int eth_init_state_only(void); /* Set active state */

net/eth.c

@@ -135,6 +135,39 @@ static void eth_set_dev(struct udevice *dev)
 	eth_get_uclass_priv()->current = dev;
 }
 
+/*
+ * Find the udevice that either has the name passed in as devname or has an
+ * alias named devname.
+ */
+struct udevice *eth_get_dev_by_name(const char *devname)
+{
+	int seq = -1;
+	char *endp = NULL;
+	const char *startp = NULL;
+	struct udevice *it;
+	struct uclass *uc;
+
+	/* Must be longer than 3 to be an alias */
+	if (strlen(devname) > strlen("eth")) {
+		startp = devname + strlen("eth");
+		seq = simple_strtoul(startp, &endp, 10);
+	}
+
+	uclass_get(UCLASS_ETH, &uc);
+	uclass_foreach_dev(it, uc) {
+		/* We need the seq to be valid, so make sure it's probed */
+		device_probe(it);
+		/*
+		 * Check for the name or the sequence number to match
+		 */
+		if (strcmp(it->name, devname) == 0 ||
+		    (endp > startp && it->seq == seq))
+			return it;
+	}
+
+	return NULL;
+}
+
 unsigned char *eth_get_ethaddr(void)
 {
 	struct eth_pdata *pdata;
@@ -421,6 +454,7 @@ UCLASS_DRIVER(eth) = {
 	.pre_remove	= eth_pre_remove,
 	.priv_auto_alloc_size = sizeof(struct eth_uclass_priv),
 	.per_device_auto_alloc_size = sizeof(struct eth_device_priv),
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
 };
 #endif
 
@@ -453,6 +487,11 @@ static void eth_set_current_to_next(void)
 	eth_current = eth_current->next;
 }
 
+static void eth_set_dev(struct eth_device *dev)
+{
+	eth_current = dev;
+}
+
 struct eth_device *eth_get_dev_by_name(const char *devname)
 {
 	struct eth_device *dev, *target_dev;
@@ -869,7 +908,6 @@ void eth_set_current(void)
 {
 	static char *act;
 	static int  env_changed_id;
-	void *old_current;
 	int	env_id;
 
 	env_id = get_env_id();
@@ -877,14 +915,8 @@ void eth_set_current(void)
 		act = getenv("ethact");
 		env_changed_id = env_id;
 	}
-	if (act != NULL) {
-		old_current = eth_get_dev();
-		do {
-			if (strcmp(eth_get_name(), act) == 0)
-				return;
-			eth_set_current_to_next();
-		} while (old_current != eth_get_dev());
-	}
+	if (act != NULL)
+		eth_set_dev(eth_get_dev_by_name(act));
 
 	eth_current_changed();
 }

test/dm/eth.c

@@ -36,3 +36,27 @@ static int dm_test_eth(struct dm_test_state *dms)
 	return 0;
 }
 DM_TEST(dm_test_eth, DM_TESTF_SCAN_FDT);
+
+static int dm_test_eth_alias(struct dm_test_state *dms)
+{
+	NetPingIP = string_to_ip("1.1.2.2");
+	setenv("ethact", "eth0");
+	ut_assertok(NetLoop(PING));
+	ut_asserteq_str("eth@10002000", getenv("ethact"));
+
+	setenv("ethact", "eth1");
+	ut_assertok(NetLoop(PING));
+	ut_asserteq_str("eth@10004000", getenv("ethact"));
+
+	/* Expected to fail since eth2 is not defined in the device tree */
+	setenv("ethact", "eth2");
+	ut_assertok(NetLoop(PING));
+	ut_asserteq_str("eth@10002000", getenv("ethact"));
+
+	setenv("ethact", "eth5");
+	ut_assertok(NetLoop(PING));
+	ut_asserteq_str("eth@10003000", getenv("ethact"));
+
+	return 0;
+}
+DM_TEST(dm_test_eth_alias, DM_TESTF_SCAN_FDT);

test/dm/test.dts

@@ -18,6 +18,8 @@
 		testfdt3 = "/b-test";
 		testfdt5 = "/some-bus/c-test@5";
 		testfdt8 = "/a-test";
+		eth0 = "/eth@10002000";
+		eth5 = &eth_5;
 	};
 
 	uart0: serial {
@@ -172,7 +174,7 @@
 		fake-host-hwaddr = <0x00 0x00 0x66 0x44 0x22 0x00>;
 	};
 
-	eth@10003000 {
+	eth_5: eth@10003000 {
 		compatible = "sandbox,eth";
 		reg = <0x10003000 0x1000>;
 		fake-host-hwaddr = <0x00 0x00 0x66 0x44 0x22 0x11>;