From 76f3a19c08955e1eef766c3b52f4166fe357457a Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Sun, 25 Apr 2010 00:29:45 -0700 Subject: [PATCH] [ARM] tegra: Add arch-specific udelay using TMRUS Change-Id: If075117642a725ee2ee24a622068274e588a5bc1 Signed-off-by: Colin Cross --- arch/arm/Kconfig | 1 + arch/arm/mach-tegra/Makefile | 1 + arch/arm/mach-tegra/delay.S | 50 ++++++++++++++++++++++++ arch/arm/mach-tegra/include/mach/delay.h | 41 +++++++++++++++++++ 4 files changed, 93 insertions(+) create mode 100644 arch/arm/mach-tegra/delay.S create mode 100644 arch/arm/mach-tegra/include/mach/delay.h diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 00e5955014ab..968c7c812454 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -577,6 +577,7 @@ config ARCH_TEGRA select COMMON_CLKDEV select ARCH_HAS_BARRIERS if CACHE_L2X0 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 288e3369c31d..6b4a94bee566 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -6,6 +6,7 @@ obj-y += timer.o obj-y += gpio.o obj-y += pinmux.o obj-y += devices.o +obj-y += delay.o obj-y += powergate.o obj-y += suspend.o obj-y += fuse.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 + * + * 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 +#include +#include +#include + + .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 + * + * 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) */ -- 2.34.1