[PATCH] ARM: dts: stm32: Auto-detect second MAC on STM32MP15xx DH electronics DHCOM

[Marek Vasut]

Test whether this system is compatible with STM32MP15xx DHCOM SoM,
if so, test whether R292 pull up is populated on pin PC3, which is
an indication that the second MAC chip, KS8851-16MLL, is populated.
Use this information to patch 'status' DT property into the second
ethernet MAC DT node and enable/disable the MAC on systems where
the chip is/isn't populated respectively.

Use spl_perform_fixups() to patch the U-Boot proper DT from SPL and
ft_board_setup() to patch Linux DT from U-Boot proper. This way both
software components are configured the same way.

Signed-off-by: Marek Vasut <marex at denx.de>
---
Cc: Patrice Chotard <patrice.chotard at foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Tom Rini <trini at konsulko.com>
Cc: u-boot at dh-electronics.com
Cc: u-boot at lists.denx.de
Cc: uboot-stm32 at st-md-mailman.stormreply.com
---
 arch/arm/dts/stm32mp15xx-dhcom-u-boot.dtsi |  1 +
 board/dhelectronics/dh_stm32mp1/board.c    | 65 ++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/arch/arm/dts/stm32mp15xx-dhcom-u-boot.dtsi b/arch/arm/dts/stm32mp15xx-dhcom-u-boot.dtsi
index 1b445619325..d7b78cdcfa9 100644
--- a/arch/arm/dts/stm32mp15xx-dhcom-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp15xx-dhcom-u-boot.dtsi
@@ -26,6 +26,7 @@
 		u-boot,error-led = "error";
 		dh,som-coding-gpios = <&gpiof 12 0>, <&gpiof 13 0>, <&gpiof 15 0>;
 		dh,ddr3-coding-gpios = <&gpioz 6 0>, <&gpioz 7 0>;
+		dh,mac-coding-gpios = <&gpioc 3 0>;
 	};
 };
 
diff --git a/board/dhelectronics/dh_stm32mp1/board.c b/board/dhelectronics/dh_stm32mp1/board.c
index 20c9d70737e..ebd45f9053f 100644
--- a/board/dhelectronics/dh_stm32mp1/board.c
+++ b/board/dhelectronics/dh_stm32mp1/board.c
@@ -37,6 +37,7 @@
 #include <power/regulator.h>
 #include <remoteproc.h>
 #include <reset.h>
+#include <spl.h>
 #include <syscon.h>
 #include <usb.h>
 #include <usb/dwc2_udc.h>
@@ -672,12 +673,69 @@ void board_quiesce_devices(void)
 #endif
 }
 
+static void dh_stm32_ks8851_fixup(void *blob)
+{
+	struct gpio_desc ks8851intrn;
+	bool compatible = false;
+	int ks8851intrn_value;
+	const char *prop;
+	ofnode node;
+	int idx = 0;
+	int offset;
+	int ret;
+
+	/* Do nothing if not STM32MP15xx DHCOM SoM */
+	while ((prop = fdt_stringlist_get(blob, 0, "compatible", idx++, NULL))) {
+		if (!strstr(prop, "dhcom-som"))
+			continue;
+		compatible = true;
+		break;
+	}
+
+	if (!compatible)
+		return;
+
+	/*
+	 * Read state of INTRN pull up resistor, if this pull up is populated,
+	 * KS8851-16MLL is populated as well and should be enabled, otherwise
+	 * it should be disabled.
+	 */
+	node = ofnode_path("/config");
+	if (!ofnode_valid(node))
+		return;
+
+	ret = gpio_request_by_name_nodev(node, "dh,mac-coding-gpios", 0,
+					 &ks8851intrn, GPIOD_IS_IN);
+	if (ret)
+		return;
+
+	ks8851intrn_value = dm_gpio_get_value(&ks8851intrn);
+
+	dm_gpio_free(NULL, &ks8851intrn);
+
+	/* Set the 'status' property into KS8851-16MLL DT node. */
+	offset = fdt_path_offset(blob, "ethernet1");
+	ret = fdt_node_check_compatible(blob, offset, "micrel,ks8851-mll");
+	if (ret)	/* Not compatible */
+		return;
+
+	/* Add a bit of extra space for new 'status' property */
+	ret = fdt_shrink_to_minimum(blob, 4096);
+	if (!ret)
+		return;
+
+	fdt_setprop_string(blob, offset, "status",
+			   ks8851intrn_value ? "okay" : "disabled");
+}
+
 #if defined(CONFIG_OF_BOARD_SETUP)
 int ft_board_setup(void *blob, struct bd_info *bd)
 {
 	const char *buck3path = "/soc/i2c at 5c002000/stpmic at 33/regulators/buck3";
 	int buck3off, ret, uv;
 
+	dh_stm32_ks8851_fixup(blob);
+
 	ret = board_get_regulator_buck3_nvm_uv_av96(&uv);
 	if (ret)	/* Not Avenger96 board, do not patch Buck3 in DT. */
 		return 0;
@@ -698,6 +756,13 @@ int ft_board_setup(void *blob, struct bd_info *bd)
 }
 #endif
 
+#if defined(CONFIG_SPL_BUILD)
+void spl_perform_fixups(struct spl_image_info *spl_image)
+{
+	dh_stm32_ks8851_fixup(spl_image_fdt_addr(spl_image));
+}
+#endif
+
 static void board_copro_image_process(ulong fw_image, size_t fw_size)
 {
 	int ret, id = 0; /* Copro id fixed to 0 as only one coproc on mp1 */
-- 
2.43.0