[PATCH v1 3/8] ARM: boards: skov-imx6: add switch detection

[Oleksij Rempel]

There are board variants with same board ID but not switch. Detect this
variants.

Signed-off-by: Oleksij Rempel <o.rempel at pengutronix.de>
---
 arch/arm/boards/skov-imx6/board.c | 159 +++++++++++++++++++++++++-----
 1 file changed, 135 insertions(+), 24 deletions(-)

diff --git a/arch/arm/boards/skov-imx6/board.c b/arch/arm/boards/skov-imx6/board.c
index 030ac62c52..2bd21adaeb 100644
--- a/arch/arm/boards/skov-imx6/board.c
+++ b/arch/arm/boards/skov-imx6/board.c
@@ -11,6 +11,7 @@
 #include <net.h>
 #include <of_gpio.h>
 #include <gpio.h>
+#include <linux/micrel_phy.h>
 
 #include "version.h"
 
@@ -130,6 +131,9 @@ copy_mac_from_eth0:
 	return eth_of_fixup_node_from_eth_device(root, node_path, ethname);
 }
 
+#define SKOV_GPIO_MDIO_BUS	0
+#define SKOV_LAN1_PHY_ADDR	1
+
 #define MAX_V_GPIO 8
 
 struct board_description {
@@ -303,20 +307,121 @@ static const struct board_description imx6_variants[] = {
 };
 
 static int skov_board_no = -1;
+static bool skov_no_switch = false;
+static const char *no_switch_suffix = "-noswitch";
 
-static int skov_imx6_fixup(struct device_node *root, void *unused)
+static void fixup_machine_compatible(const char *compat,
+				     struct device_node *root)
 {
+	int cclen = 0, clen = strlen(compat) + 1;
+	const char *curcompat;
+	void *buf;
+
+	if (!root) {
+		root = of_get_root_node();
+		if (!root)
+			return;
+	}
+
+	curcompat = of_get_property(root, "compatible", &cclen);
+
+	buf = xzalloc(cclen + clen);
+
+	memcpy(buf, compat, clen);
+	memcpy(buf + clen, curcompat, cclen);
+
+	/*
+	 * Prepend the compatible from board entry to the machine compatible.
+	 * Used to match bootspec entries against it.
+	 */
+	of_set_property(root, "compatible", buf, cclen + clen, true);
+
+	free(buf);
+}
+
+static void fixup_noswitch_machine_compatible(struct device_node *root)
+{
+	const char *compat = imx6_variants[skov_board_no].dts_compatible;
+	const char *generic = "skov,imx6";
+	size_t size, size_generic;
+	char *buf;
 	int ret;
-	const char *val;
-	uint32_t brightness;
+
+	size = strlen(compat) + strlen(no_switch_suffix) + 1;
+	size_generic = strlen(generic) + strlen(no_switch_suffix) + 1;
+	size = max(size, size_generic);
+	buf = xzalloc(size);
+	if (!buf) {
+		pr_warn("Can't allocate buffer\n");
+		return;
+	}
+
+	/* add generic compatible, so systemd&co can make right decisions */
+	ret = snprintf(buf, size, "%s%s", generic, no_switch_suffix);
+	if (ret >= 0)
+		fixup_machine_compatible(buf, root);
+	else
+		pr_warn("Can't prepare generic compatible string\n");
+
+	/* add specific compatible as fallback, in case this board has new
+	 * challenges.
+	 */
+	ret = snprintf(buf, size, "%s%s", compat, no_switch_suffix);
+	if (ret >= 0)
+		fixup_machine_compatible(buf, root);
+	else
+		pr_warn("Can't prepare specific compatible string\n");
+
+	free(buf);
+}
+
+static void skov_imx6_no_switch(struct device_node *root)
+{
 	struct device_node *node;
-	struct device_node *chosen = of_create_node(root, "/chosen");
+	int ret;
+
+	fixup_noswitch_machine_compatible(root);
 
+	node = of_find_node_by_path_from(root, "/soc/bus at 2100000/ethernet at 2188000");
+	if (!node) {
+		pr_warn("Did not find node to disable it\n");
+	} else {
+		ret = of_device_disable(node);
+		if (ret)
+			pr_warn("Can't disable ethernet node\n");
+	}
+
+	node = of_find_node_by_alias(root, "mdio-gpio0");
+	if (node) {
+		ret = of_device_disable(node);
+		if (ret)
+			pr_warn("Can't disable mdio-gpio0 node\n");
+	} else {
+		pr_warn("Can't find mdio-gpio0 node\n");
+	}
+}
+
+static void skov_imx6_switch(struct device_node *root)
+{
 	eth_of_fixup_node_from_eth_device(root,
 			"/mdio-gpio/ksz8873 at 3/ports/ports at 0", "eth0");
 	eth2_of_fixup_node_individually(root,
 		"/mdio-gpio/ksz8873 at 3/ports/ports at 1", "eth0",
 		"state.ethaddr.eth2", "/state/ethaddr/eth2");
+}
+
+static int skov_imx6_fixup(struct device_node *root, void *unused)
+{
+	struct device_node *chosen = of_create_node(root, "/chosen");
+	struct device_node *node;
+	uint32_t brightness;
+	const char *val;
+	int ret;
+
+	if (skov_no_switch)
+		skov_imx6_no_switch(root);
+	else
+		skov_imx6_switch(root);
 
 	switch (bootsource_get()) {
 	case BOOTSOURCE_MMC:
@@ -432,34 +537,40 @@ static void skov_init_board(const struct board_description *variant)
 	}
 }
 
-static void fixup_machine_compatible(const char *compat,
-				     struct device_node *root)
+static int skov_switch_test(void)
 {
-	const char *curcompat;
-	int cclen = 0, clen = strlen(compat) + 1;
-	void *buf;
+	struct phy_device *phydev;
+	struct mii_bus *mii;
+	int ret;
 
-	if (!root) {
-		root = of_get_root_node();
-		if (!root)
-			return;
-	}
+	if (skov_board_no < 0)
+		return 0;
 
-	curcompat = of_get_property(root, "compatible", &cclen);
+	/* On this boards, we have only one MDIO bus. So, it is enough to take
+	 * the first one.
+	 */
+	mii = mdiobus_get_bus(SKOV_GPIO_MDIO_BUS);
+	/* We can't read the switch ID, but we get get ID of the first PHY,
+	 * which is enough to test if the switch is attached.
+	 */
+	phydev = get_phy_device(mii, SKOV_LAN1_PHY_ADDR);
+	if (IS_ERR(phydev))
+		goto no_switch;
 
-	buf = xzalloc(cclen + clen);
+	if (phydev->phy_id != PHY_ID_KSZ886X)
+		goto no_switch;
 
-	memcpy(buf, compat, clen);
-	memcpy(buf + clen, curcompat, cclen);
+	return 0;
 
-	/*
-	 * Prepend the compatible from board entry to the machine compatible.
-	 * Used to match bootspec entries against it.
-	 */
-	of_set_property(root, "compatible", buf, cclen + clen, true);
+no_switch:
+	skov_no_switch = true;
+	fixup_noswitch_machine_compatible(NULL);
 
-	free(buf);
+	pr_notice("No-switch variant is detected\n");
+
+	return 0;
 }
+late_initcall(skov_switch_test);
 
 static int skov_imx6_probe(struct device_d *dev)
 {
-- 
2.30.2