diff options
author | Colin Cross <ccross@android.com> | 2010-04-25 00:29:45 -0700 |
---|---|---|
committer | Dan Willemsen <dwillemsen@nvidia.com> | 2011-11-30 21:34:36 -0800 |
commit | 1ae52cd40073f35c17452abc128b29dbee8bf75c (patch) | |
tree | ca015de0cb9efcc9aae7a7c4fa74003cd723f2e4 | |
parent | ad117211ea3b94a22a8f0e8571403dabd93cfaa6 (diff) |
[ARM] tegra: Add arch-specific udelay using TMRUS
Change-Id: If075117642a725ee2ee24a622068274e588a5bc1
Signed-off-by: Colin Cross <ccross@android.com>
-rw-r--r-- | arch/arm/Kconfig | 1 | ||||
-rw-r--r-- | arch/arm/mach-tegra/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/mach-tegra/delay.S | 50 | ||||
-rw-r--r-- | arch/arm/mach-tegra/include/mach/delay.h | 41 |
4 files changed, 93 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 82c6521d04a7..9c4d71ba4595 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -607,6 +607,7 @@ config ARCH_TEGRA select HAVE_CLK select HAVE_SCHED_CLOCK select ARCH_HAS_CPUFREQ + select ARCH_PROVIDES_UDELAY help This enables support for NVIDIA Tegra based systems (Tegra APX, Tegra 6xx and Tegra 2 series). diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index f0a3f0b728c1..52ec87c5fc48 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -6,6 +6,7 @@ obj-y += clock.o obj-y += timer.o obj-y += pinmux.o obj-y += devices.o +obj-y += delay.o obj-y += powergate.o obj-$(CONFIG_PM_SLEEP) += pm.o obj-$(CONFIG_PM_SLEEP) += pm-irq.o diff --git a/arch/arm/mach-tegra/delay.S b/arch/arm/mach-tegra/delay.S new file mode 100644 index 000000000000..01123bfe6a0c --- /dev/null +++ b/arch/arm/mach-tegra/delay.S @@ -0,0 +1,50 @@ +/* + * arch/arm/mach-tegra/delay.S + * + * Copyright (C) 2010 Google, Inc. + * + * Author: + * Colin Cross <ccross@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <mach/iomap.h> +#include <mach/io.h> + + .text + +ENTRY(__udelay) +ENTRY(__const_udelay) + ldr r3, =(IO_PPSB_VIRT + TEGRA_TMRUS_BASE - IO_PPSB_PHYS) + ldr r1, [r3] + +/* r0 - usecs to wait + * r1 - initial value of the counter + */ +loop: + ldr r2, [r3] + sub r2, r2, r1 + cmp r2, r0 + bls loop + mov pc, lr +ENDPROC(__const_udelay) +ENDPROC(__udelay) + + +@ Delay routine +ENTRY(__delay) + subs r0, r0, #1 + bhi __delay + mov pc, lr +ENDPROC(__delay) diff --git a/arch/arm/mach-tegra/include/mach/delay.h b/arch/arm/mach-tegra/include/mach/delay.h new file mode 100644 index 000000000000..2defb7b9b658 --- /dev/null +++ b/arch/arm/mach-tegra/include/mach/delay.h @@ -0,0 +1,41 @@ +/* + * arch/arm/mach-tegra/include/mach/delay.h + * + * Copyright (C) 2010 Google, Inc. + * + * Author: + * Colin Cross <ccross@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +#ifndef __MACH_TEGRA_DELAY_H +#define __MACH_TEGRA_DELAY_H + +/* needed by loops_per_jiffy calculations */ +extern void __delay(int loops); + +extern void __udelay(unsigned long usecs); +extern void __const_udelay(unsigned long usecs); + +/* we don't have any restrictions on maximum udelay length, but we'll enforce + * the same restriction as the ARM default so we don't introduce any + * incompatibilties in drivers. + */ +extern void __bad_udelay(void); + +#define MAX_UDELAY_MS 2 + +#define udelay(n) \ + ((__builtin_constant_p(n) && (n) > (MAX_UDELAY_MS * 1000)) ? \ + __bad_udelay() : \ + __udelay(n)) + +#endif /* defined(__MACH_TEGRA_DELAY_H) */ |