arm: Add support for ST-Ericsson U8500 SoC
The NovaThor U8500 SoC was released by ST-Ericsson in 2011.
It was used for some development boards like the CALAO Systems
Snowball SBC, but mass production was primarily for Android
smartphones like the Samsung Galaxy S III mini.
Previous support for U8500 was removed in
commit 68282f55b846 ("arm: Remove unused ST-Ericsson u8500 arch")
since none of the boards were converted to generic boards
before the deadline.
The new code does not have much in common with the previous code.
I have completely rewritten everything, embracing the Driver Model
and device trees wherever possible.
The U8500 support is a bit more minimal for now - my primary
use case is to use U-Boot as alternative bootloader for some of the
U8500 Samsung smartphones. At the moment U-Boot is chain-loaded from
the original Samsung bootloader. A side effect of this is that we
can (temporarily) get away without implementing some functionality
- e.g. all clocks are already enabled by the original bootloader.
More functionality will be added in future patches.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: John Rigby <john.rigby@linaro.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a623ef5..78cc79a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1009,6 +1009,24 @@
imply SPL_SERIAL_SUPPORT
imply USB_GADGET
+config ARCH_U8500
+ bool "ST-Ericsson U8500 Series"
+ select CPU_V7A
+ select DM
+ select DM_GPIO
+ select DM_MMC if MMC
+ select DM_SERIAL
+ select DM_USB if USB
+ select OF_CONTROL
+ select SYSRESET
+ select TIMER
+ imply ARM_PL180_MMCI
+ imply DM_RTC
+ imply NOMADIK_MTU_TIMER
+ imply PL01X_SERIAL
+ imply RTC_PL031
+ imply SYSRESET_SYSCON
+
config ARCH_VERSAL
bool "Support Xilinx Versal Platform"
select ARM64
@@ -1779,6 +1797,8 @@
source "arch/arm/mach-tegra/Kconfig"
+source "arch/arm/mach-u8500/Kconfig"
+
source "arch/arm/mach-uniphier/Kconfig"
source "arch/arm/cpu/armv7/vf610/Kconfig"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 1e60a9f..e25bb0e 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -79,6 +79,7 @@
machine-$(CONFIG_STM32) += stm32
machine-$(CONFIG_ARCH_STM32MP) += stm32mp
machine-$(CONFIG_TEGRA) += tegra
+machine-$(CONFIG_ARCH_U8500) += u8500
machine-$(CONFIG_ARCH_UNIPHIER) += uniphier
machine-$(CONFIG_ARCH_ZYNQ) += zynq
machine-$(CONFIG_ARCH_ZYNQMP) += zynqmp
diff --git a/arch/arm/dts/ste-dbx5x0-u-boot.dtsi b/arch/arm/dts/ste-dbx5x0-u-boot.dtsi
new file mode 100644
index 0000000..4a99ee5
--- /dev/null
+++ b/arch/arm/dts/ste-dbx5x0-u-boot.dtsi
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "skeleton.dtsi"
+#include "ste-dbx5x0.dtsi"
+
+/ {
+ soc {
+ /* FIXME: Remove this when clk driver is implemented */
+ mtu@a03c6000 {
+ clock-frequency = <133000000>;
+ };
+ uart@80120000 {
+ clock = <38400000>;
+ };
+ uart@80121000 {
+ clock = <38400000>;
+ };
+ uart@80007000 {
+ clock = <38400000>;
+ };
+ };
+
+ reboot {
+ compatible = "syscon-reboot";
+ regmap = <&prcmu>;
+ offset = <0x228>; /* PRCM_APE_SOFTRST */
+ mask = <0x1>;
+ };
+};
diff --git a/arch/arm/include/asm/gpio.h b/arch/arm/include/asm/gpio.h
index 6ff5f42..7203ccb 100644
--- a/arch/arm/include/asm/gpio.h
+++ b/arch/arm/include/asm/gpio.h
@@ -3,7 +3,7 @@
!defined(CONFIG_ARCH_BCM63158) && !defined(CONFIG_ARCH_ROCKCHIP) && \
!defined(CONFIG_ARCH_LX2160A) && !defined(CONFIG_ARCH_LS1028A) && \
!defined(CONFIG_ARCH_LS2080A) && !defined(CONFIG_ARCH_LS1088A) && \
- !defined(CONFIG_ARCH_ASPEED)
+ !defined(CONFIG_ARCH_ASPEED) && !defined(CONFIG_ARCH_U8500)
#include <asm/arch/gpio.h>
#endif
#include <asm-generic/gpio.h>
diff --git a/arch/arm/mach-u8500/Kconfig b/arch/arm/mach-u8500/Kconfig
new file mode 100644
index 0000000..3bc7629
--- /dev/null
+++ b/arch/arm/mach-u8500/Kconfig
@@ -0,0 +1,6 @@
+if ARCH_U8500
+
+config SYS_SOC
+ default "u8500"
+
+endif
diff --git a/arch/arm/mach-u8500/Makefile b/arch/arm/mach-u8500/Makefile
new file mode 100644
index 0000000..0a53cbd
--- /dev/null
+++ b/arch/arm/mach-u8500/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+obj-y += cache.o
+obj-$(CONFIG_DISPLAY_CPUINFO) += cpuinfo.o
diff --git a/arch/arm/mach-u8500/cache.c b/arch/arm/mach-u8500/cache.c
new file mode 100644
index 0000000..3d96d09
--- /dev/null
+++ b/arch/arm/mach-u8500/cache.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2019 Stephan Gerhold <stephan@gerhold.net>
+ */
+
+#include <common.h>
+#include <cpu_func.h>
+#include <asm/armv7.h>
+#include <asm/pl310.h>
+
+#define PL310_WAY_MASK 0xff
+
+#if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
+void enable_caches(void)
+{
+ /* Enable D-cache. I-cache is already enabled in start.S */
+ dcache_enable();
+}
+#endif
+
+#ifdef CONFIG_SYS_L2_PL310
+void v7_outer_cache_disable(void)
+{
+ struct pl310_regs *const pl310 = (struct pl310_regs *)CONFIG_SYS_PL310_BASE;
+
+ /*
+ * Linux expects the L2 cache to be turned off by the bootloader.
+ * Otherwise, it fails very early (shortly after decompressing the kernel).
+ *
+ * On U8500, the L2 cache can be only turned on/off from the secure world.
+ * Instead, prevent usage of the L2 cache by locking all ways.
+ * The kernel needs to unlock them to make the L2 cache work again.
+ */
+ writel(PL310_WAY_MASK, &pl310->pl310_lockdown_dbase);
+ writel(PL310_WAY_MASK, &pl310->pl310_lockdown_ibase);
+}
+#endif
diff --git a/arch/arm/mach-u8500/cpuinfo.c b/arch/arm/mach-u8500/cpuinfo.c
new file mode 100644
index 0000000..20f5ff3
--- /dev/null
+++ b/arch/arm/mach-u8500/cpuinfo.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2019 Stephan Gerhold <stephan@gerhold.net>
+ */
+
+#include <common.h>
+#include <asm/io.h>
+
+#define U8500_BOOTROM_BASE 0x90000000
+#define U8500_ASIC_ID_LOC_V2 (U8500_BOOTROM_BASE + 0x1DBF4)
+
+int print_cpuinfo(void)
+{
+ /* Convert ASIC ID to display string, e.g. 0x8520A0 => DB8520 V1.0 */
+ u32 asicid = readl(U8500_ASIC_ID_LOC_V2);
+ u32 cpu = (asicid >> 8) & 0xffff;
+ u32 rev = asicid & 0xff;
+
+ /* 0xA0 => 0x10 (V1.0) */
+ if (rev >= 0xa0)
+ rev -= 0x90;
+
+ printf("CPU: ST-Ericsson DB%x V%d.%d\n", cpu, rev >> 4, rev & 0xf);
+ return 0;
+}