sunxi: Enable non-secure access to RTC on sun6i (A31s)

On the A31s the RTC is by default secured. Thus when u-boot
loads the kernel in non-secure world, the RTC is unavailable. The
SoC has a TrustZone Protection Controller, which can be used to
enable non-secure access to the RTC.

On the A31 the TZPC doesn't seem to do anything, i.e. changes to
its register contents do not affect access to the RTC.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Chen-Yu Tsai 2015-08-25 10:49:19 +08:00 committed by Hans de Goede
parent 3537a0e8ca
commit 92369844ec
4 changed files with 47 additions and 0 deletions

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@ -28,6 +28,7 @@ obj-$(CONFIG_MACH_SUN6I) += clock_sun6i.o
obj-$(CONFIG_MACH_SUN7I) += clock_sun4i.o
obj-$(CONFIG_MACH_SUN8I) += clock_sun6i.o
obj-$(CONFIG_MACH_SUN9I) += clock_sun9i.o
obj-$(CONFIG_MACH_SUN6I) += tzpc.o
obj-$(CONFIG_AXP152_POWER) += pmic_bus.o
obj-$(CONFIG_AXP209_POWER) += pmic_bus.o

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@ -23,6 +23,7 @@
#include <asm/arch/gpio.h>
#include <asm/arch/sys_proto.h>
#include <asm/arch/timer.h>
#include <asm/arch/tzpc.h>
#include <asm/arch/mmc.h>
#include <linux/compiler.h>
@ -115,6 +116,10 @@ void s_init(void)
"orr r0, r0, #1 << 6\n"
"mcr p15, 0, r0, c1, c0, 1\n");
#endif
#if defined CONFIG_MACH_SUN6I
/* Enable non-secure access to the RTC */
tzpc_init();
#endif
clock_init();
timer_init();

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@ -0,0 +1,18 @@
/*
* (C) Copyright 2015 Chen-Yu Tsai <wens@csie.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/tzpc.h>
/* Configure Trust Zone Protection Controller */
void tzpc_init(void)
{
struct sunxi_tzpc *tzpc = (struct sunxi_tzpc *)SUNXI_TZPC_BASE;
/* Enable non-secure access to the RTC */
writel(SUNXI_TZPC_DECPORT0_RTC, &tzpc->decport0_set);
}

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@ -0,0 +1,23 @@
/*
* (C) Copyright 2015 Chen-Yu Tsai <wens@csie.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _SUNXI_TZPC_H
#define _SUNXI_TZPC_H
#ifndef __ASSEMBLY__
struct sunxi_tzpc {
u32 r0size; /* 0x00 Size of secure RAM region */
u32 decport0_status; /* 0x04 Status of decode protection port 0 */
u32 decport0_set; /* 0x08 Set decode protection port 0 */
u32 decport0_clear; /* 0x0c Clear decode protection port 0 */
};
#endif
#define SUNXI_TZPC_DECPORT0_RTC (1 << 1)
void tzpc_init(void);
#endif /* _SUNXI_TZPC_H */