ARM: i.MX: Add ZII SCU2 Mezz Board

Add ZII SCU2 Mezz Board. Which is a i.MX51 based board that is similar
enough to RDU1 that they both can be handled by a single
image (type can be detected at runtime).

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

4 files changed, 90 insertions, 5 deletions

diff --git a/arch/arm/boards/zii-imx51-rdu1/board.c b/arch/arm/boards/zii-imx51-rdu1/board.c
index 601c9a236e..5c05134c23 100644
--- a/arch/arm/boards/zii-imx51-rdu1/board.c
+++ b/arch/arm/boards/zii-imx51-rdu1/board.c
@@ -23,12 +23,17 @@
 
 static int zii_rdu1_init(void)
 {
-	if (!of_machine_is_compatible("zii,imx51-rdu1"))
+	const char *hostname;
+
+	if (!of_machine_is_compatible("zii,imx51-rdu1") &&
+	    !of_machine_is_compatible("zii,imx51-scu2-mezz"))
 		return 0;
 
+	hostname = of_get_machine_compatible() + strlen("imx51-");
+
 	imx51_babbage_power_init();
 
-	barebox_set_hostname("rdu1");
+	barebox_set_hostname(hostname);
 
 	imx51_bbu_internal_mmcboot_register_handler("eMMC", "/dev/mmc0", 0);
 	imx51_bbu_internal_spi_i2c_register_handler("SPI",
diff --git a/arch/arm/boards/zii-imx51-rdu1/lowlevel.c b/arch/arm/boards/zii-imx51-rdu1/lowlevel.c
index cca331a9cb..d82597e0bf 100644
--- a/arch/arm/boards/zii-imx51-rdu1/lowlevel.c
+++ b/arch/arm/boards/zii-imx51-rdu1/lowlevel.c
@@ -29,18 +29,85 @@ static inline void setup_uart(void)
 	putc_ll('>');
 }
 
+enum zii_platform_imx51_type {
+	ZII_PLATFORM_IMX51_RDU_REV_B = 0b0000,
+	ZII_PLATFORM_IMX51_SCU2_ESB  = 0b0001,
+	ZII_PLATFORM_IMX51_SCU_MEZZ  = 0b0010,
+	ZII_PLATFORM_IMX51_NIU_REV   = 0b0011,
+	ZII_PLATFORM_IMX51_SCU2_MEZZ = 0b0100,
+	ZII_PLATFORM_IMX51_SCU3_ESB  = 0b0101,
+	ZII_PLATFORM_IMX51_RDU_REV_C = 0b1101,
+};
+
+static unsigned int get_system_type(void)
+{
+#define GPIO_DR		0x000
+#define GPIO_GDIR	0x004
+#define SYSTEM_TYPE	GENMASK(6, 3)
+
+	u32 gdir, dr;
+	void __iomem *gpio4 = IOMEM(MX51_GPIO4_BASE_ADDR);
+	void __iomem *iomuxbase = IOMEM(MX51_IOMUXC_BASE_ADDR);
+
+	/*
+	 * System type is encoded as a 4-bit number specified by the
+	 * following pins (pulled up or down with resistors on the
+	 * board).
+	*/
+	imx_setup_pad(iomuxbase, MX51_PAD_NANDF_D2__GPIO4_6);
+	imx_setup_pad(iomuxbase, MX51_PAD_NANDF_D3__GPIO4_5);
+	imx_setup_pad(iomuxbase, MX51_PAD_NANDF_D4__GPIO4_4);
+	imx_setup_pad(iomuxbase, MX51_PAD_NANDF_D5__GPIO4_3);
+
+	gdir = readl(gpio4 + GPIO_GDIR);
+	gdir &= ~SYSTEM_TYPE;
+	writel(gdir, gpio4 + GPIO_GDIR);
+
+	dr = readl(gpio4 + GPIO_DR);
+
+	return FIELD_GET(SYSTEM_TYPE, dr);
+}
+
 extern char __dtb_imx51_zii_rdu1_start[];
+extern char __dtb_imx51_zii_scu2_mezz_start[];
 
 ENTRY_FUNCTION(start_imx51_zii_rdu1, r0, r1, r2)
 {
 	void *fdt;
+	const unsigned int system_type = get_system_type();
 
 	imx5_cpu_lowlevel_init();
 
 	if (IS_ENABLED(CONFIG_DEBUG_LL))
 		setup_uart();
 
-	fdt = __dtb_imx51_zii_rdu1_start + get_runtime_offset();
+	switch (system_type) {
+	default:
+		/*
+		 * see similar code in
+		 * arch/arm/boards/zii-vf610-dev/lowlevel.c for
+		 * reasoning for placing barrier() below.
+		 */
+		barrier();
+
+		if (IS_ENABLED(CONFIG_DEBUG_LL)) {
+			relocate_to_current_adr();
+			setup_c();
+			puts_ll("\n*********************************\n");
+			puts_ll("* Unknown system type: ");
+			puthex_ll(system_type);
+			puts_ll("\n* Assuming RDU1\n");
+			puts_ll("*********************************\n");
+		}
+		/* FALLTHROUGH */
+	case ZII_PLATFORM_IMX51_RDU_REV_B:
+	case ZII_PLATFORM_IMX51_RDU_REV_C:
+		fdt = __dtb_imx51_zii_rdu1_start;
+		break;
+	case ZII_PLATFORM_IMX51_SCU2_MEZZ:
+		fdt = __dtb_imx51_zii_scu2_mezz_start;
+		break;
+	}
 
-	imx51_barebox_entry(fdt);
+	imx51_barebox_entry(fdt + get_runtime_offset());
 }
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 827fbe10f2..f14c3c0380 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -103,7 +103,9 @@ pbl-dtb-$(CONFIG_MACH_VEXPRESS) += vexpress-v2p-ca15.dtb.o
 pbl-dtb-$(CONFIG_MACH_VSCOM_BALTOS) += am335x-baltos-minimal.dtb.o
 pbl-dtb-$(CONFIG_MACH_WARP7) += imx7s-warp.dtb.o
 pbl-dtb-$(CONFIG_MACH_VF610_TWR) += vf610-twr.dtb.o
-pbl-dtb-$(CONFIG_MACH_ZII_RDU1) += imx51-zii-rdu1.dtb.o
+pbl-dtb-$(CONFIG_MACH_ZII_RDU1) +=	\
+	imx51-zii-rdu1.dtb.o		\
+	imx51-zii-scu2-mezz.dtb.o
 pbl-dtb-$(CONFIG_MACH_ZII_RDU2) += imx6q-zii-rdu2.dtb.o imx6qp-zii-rdu2.dtb.o
 pbl-dtb-$(CONFIG_MACH_ZII_VF610_DEV) += \
 	vf610-zii-dev-rev-b.dtb.o 	\
diff --git a/arch/arm/dts/imx51-zii-scu2-mezz.dts b/arch/arm/dts/imx51-zii-scu2-mezz.dts
new file mode 100644
index 0000000000..68a374bb2b
--- /dev/null
+++ b/arch/arm/dts/imx51-zii-scu2-mezz.dts
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+
+/*
+ * Copyright (C) 2018 Zodiac Inflight Innovations
+ */
+
+#include <arm/imx51-zii-scu2-mezz.dts>
+
+&iim {
+	barebox,provide-mac-address = <&fec 1 9>;
+};