Add very basic support for taking an lpss device out of reset. Signed-off-by: Simon Glass <s...@chromium.org> ---
Changes in v3: None Changes in v2: None arch/x86/cpu/apollolake/Makefile | 1 + arch/x86/cpu/apollolake/lpss.c | 31 +++++++++++++++++++++++++++++++ arch/x86/include/asm/lpss.h | 11 +++++++++++ 3 files changed, 43 insertions(+) create mode 100644 arch/x86/cpu/apollolake/lpss.c create mode 100644 arch/x86/include/asm/lpss.h diff --git a/arch/x86/cpu/apollolake/Makefile b/arch/x86/cpu/apollolake/Makefile index 5d98a5a6db2..b58ef8e019c 100644 --- a/arch/x86/cpu/apollolake/Makefile +++ b/arch/x86/cpu/apollolake/Makefile @@ -2,4 +2,5 @@ # # Copyright (c) 2016 Google, Inc +obj-y += lpss.o obj-y += pmc.o diff --git a/arch/x86/cpu/apollolake/lpss.c b/arch/x86/cpu/apollolake/lpss.c new file mode 100644 index 00000000000..2f4aea79c07 --- /dev/null +++ b/arch/x86/cpu/apollolake/lpss.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Special driver to handle of-platdata + * + * Copyright 2019 Google LLC + * + * Some code from coreboot lpss.c + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/lpss.h> + +enum { + LPSS_RESET_CTL_REG = 0x204, + + /* + * Bit 1:0 controls LPSS controller reset. + * + * 00 ->LPSS Host Controller is in reset (Reset Asserted) + * 01/10 ->Reserved + * 11 ->LPSS Host Controller is NOT at reset (Reset Released) + */ + LPSS_CNT_RST_RELEASE = 3, +}; + +/* Take controller out of reset */ +void lpss_reset_release(void *regs) +{ + writel(LPSS_CNT_RST_RELEASE, regs + LPSS_RESET_CTL_REG); +} diff --git a/arch/x86/include/asm/lpss.h b/arch/x86/include/asm/lpss.h new file mode 100644 index 00000000000..4bd56a5fa30 --- /dev/null +++ b/arch/x86/include/asm/lpss.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright 2019 Google LLC + */ + +#ifndef __ASM_LPSS_H +#define __ASM_LPSS_H + +void lpss_reset_release(void *regs); + +#endif -- 2.23.0.866.gb869b98d4c-goog _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot