From 689088f9dae8b823651095a34aff76cc61099ef9 Mon Sep 17 00:00:00 2001 From: Stephan Gerhold Date: Sat, 4 Jan 2020 18:45:17 +0100 Subject: 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 Cc: John Rigby Signed-off-by: Stephan Gerhold Reviewed-by: Linus Walleij --- arch/arm/mach-u8500/Kconfig | 6 ++++++ arch/arm/mach-u8500/Makefile | 4 ++++ arch/arm/mach-u8500/cache.c | 37 +++++++++++++++++++++++++++++++++++++ arch/arm/mach-u8500/cpuinfo.c | 25 +++++++++++++++++++++++++ 4 files changed, 72 insertions(+) create mode 100644 arch/arm/mach-u8500/Kconfig create mode 100644 arch/arm/mach-u8500/Makefile create mode 100644 arch/arm/mach-u8500/cache.c create mode 100644 arch/arm/mach-u8500/cpuinfo.c (limited to 'arch/arm/mach-u8500') diff --git a/arch/arm/mach-u8500/Kconfig b/arch/arm/mach-u8500/Kconfig new file mode 100644 index 0000000000..3bc76295cb --- /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 0000000000..0a53cbd9ac --- /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 0000000000..3d96d09f31 --- /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 + */ + +#include +#include +#include +#include + +#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 0000000000..20f5ff3398 --- /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 + */ + +#include +#include + +#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; +} -- cgit