From e2f91578b35347341482f6af9e4fcf3174531efd Mon Sep 17 00:00:00 2001 From: Olof Johansson Date: Wed, 12 Oct 2011 23:52:29 -0700 Subject: ARM: tegra: use APB DMA for accessing APB devices Tegra2 hangs if APB registers are accessed from the cpu during an apb dma operation. The workaround is to use apb dma to read/write the registers instead. There is a dependency loop between fuses, clocks, and APBDMA. If dma is enabled, fuse reads must go through APBDMA to avoid corruption due to a hw bug. APBDMA requires a clock to be enabled. Clocks must read a fuse to determine allowable cpu frequencies. Separate out the fuse DMA initialization, and allow the fuse read and write functions to be called without using DMA before the DMA initialization has been completed. Access to the fuses before APBDMA is initialized won't hit the hardware bug because nothing else can be using DMA. Original fuse registar access code from Varun Wadekar , improved by Colin Cross and later moved to separate driver by Jon Mayo . Major refactoring/cleanup by Olof Johansson . Changes since v1: * fix 'return false' on error condition * dequeue dma ops in case of timeout From: Jon Mayo . Signed-off-by: Jon Mayo . Signed-off-by: Olof Johansson Acked-by: Stephen Warren --- arch/arm/mach-tegra/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mach-tegra/Makefile') diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index e120ff54f663..23d15fba3843 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -15,7 +15,7 @@ obj-$(CONFIG_ARCH_TEGRA_3x_SOC) += pinmux-tegra30-tables.o obj-$(CONFIG_ARCH_TEGRA_3x_SOC) += board-dt-tegra30.o obj-$(CONFIG_SMP) += platsmp.o localtimer.o headsmp.o obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o -obj-$(CONFIG_TEGRA_SYSTEM_DMA) += dma.o +obj-$(CONFIG_TEGRA_SYSTEM_DMA) += dma.o apbio.o obj-$(CONFIG_CPU_FREQ) += cpu-tegra.o obj-$(CONFIG_TEGRA_PCI) += pcie.o obj-$(CONFIG_USB_SUPPORT) += usb_phy.o -- cgit v1.2.3-59-g8ed1b From d3b8bdd5f9bc538fb17466cbb7af43209b55cb93 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Wed, 25 Jan 2012 14:43:28 -0700 Subject: ARM: tegra: Add a simple PMC driver This PMC driver is enough to parse the nvidia,invert-interrupt property from device tree, and configure the PMC's to honor that. In the future, this file could expand to centralize all other PMC accesses within the mach-tegra code. Signed-off-by: Stephen Warren Signed-off-by: Olof Johansson --- arch/arm/mach-tegra/Makefile | 1 + arch/arm/mach-tegra/common.c | 3 ++ arch/arm/mach-tegra/pmc.c | 76 ++++++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-tegra/pmc.h | 23 ++++++++++++++ 4 files changed, 103 insertions(+) create mode 100644 arch/arm/mach-tegra/pmc.c create mode 100644 arch/arm/mach-tegra/pmc.h (limited to 'arch/arm/mach-tegra/Makefile') diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index 23d15fba3843..e0b7a4d32599 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -7,6 +7,7 @@ obj-y += clock.o obj-y += timer.o obj-y += pinmux.o obj-y += fuse.o +obj-y += pmc.o obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += powergate.o obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_clocks.o obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_emc.o diff --git a/arch/arm/mach-tegra/common.c b/arch/arm/mach-tegra/common.c index 76210e5df561..43da4284d862 100644 --- a/arch/arm/mach-tegra/common.c +++ b/arch/arm/mach-tegra/common.c @@ -32,6 +32,7 @@ #include "board.h" #include "clock.h" #include "fuse.h" +#include "pmc.h" /* * Storage for debug-macro.S's state. @@ -117,11 +118,13 @@ void __init tegra20_init_early(void) tegra2_init_clocks(); tegra_clk_init_from_table(tegra20_clk_init_table); tegra_init_cache(0x331, 0x441); + tegra_pmc_init(); } #endif #ifdef CONFIG_ARCH_TEGRA_3x_SOC void __init tegra30_init_early(void) { tegra_init_cache(0x441, 0x551); + tegra_pmc_init(); } #endif diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c new file mode 100644 index 000000000000..7af6a54404be --- /dev/null +++ b/arch/arm/mach-tegra/pmc.c @@ -0,0 +1,76 @@ +/* + * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + * + */ + +#include +#include +#include + +#include + +#define PMC_CTRL 0x0 +#define PMC_CTRL_INTR_LOW (1 << 17) + +static inline u32 tegra_pmc_readl(u32 reg) +{ + return readl(IO_ADDRESS(TEGRA_PMC_BASE + reg)); +} + +static inline void tegra_pmc_writel(u32 val, u32 reg) +{ + writel(val, IO_ADDRESS(TEGRA_PMC_BASE + reg)); +} + +#ifdef CONFIG_OF +static const struct of_device_id matches[] __initconst = { + { .compatible = "nvidia,tegra20-pmc" }, + { } +}; +#endif + +void __init tegra_pmc_init(void) +{ + /* + * For now, Harmony is the only board that uses the PMC, and it wants + * the signal inverted. Seaboard would too if it used the PMC. + * Hopefully by the time other boards want to use the PMC, everything + * will be device-tree, or they also want it inverted. + */ + bool invert_interrupt = true; + u32 val; + +#ifdef CONFIG_OF + if (of_have_populated_dt()) { + struct device_node *np; + + invert_interrupt = false; + + np = of_find_matching_node(NULL, matches); + if (np) { + if (of_find_property(np, "nvidia,invert-interrupt", + NULL)) + invert_interrupt = true; + } + } +#endif + + val = tegra_pmc_readl(PMC_CTRL); + if (invert_interrupt) + val |= PMC_CTRL_INTR_LOW; + else + val &= ~PMC_CTRL_INTR_LOW; + tegra_pmc_writel(val, PMC_CTRL); +} diff --git a/arch/arm/mach-tegra/pmc.h b/arch/arm/mach-tegra/pmc.h new file mode 100644 index 000000000000..8995ee4a8768 --- /dev/null +++ b/arch/arm/mach-tegra/pmc.h @@ -0,0 +1,23 @@ +/* + * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + * + */ + +#ifndef __MACH_TEGRA_PMC_H +#define __MACH_TEGRA_PMC_H + +void tegra_pmc_init(void); + +#endif -- cgit v1.2.3-59-g8ed1b