From 6be47ca3bd4465c4e9275c5af3f36ce55da6c216 Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Fri, 12 Apr 2013 12:28:20 +0200 Subject: tegra: add T20 timer driver Replace the ad-hoc clocksource implementation with a proper driver for the Tegra 20 timer. This driver is able to do the required hardware initialisation itself. Signed-off-by: Lucas Stach Tested-by: Antony Pavlov Signed-off-by: Sascha Hauer --- arch/arm/dts/tegra20.dtsi | 9 +++ arch/arm/mach-tegra/Makefile | 2 +- arch/arm/mach-tegra/clock.c | 56 ----------------- arch/arm/mach-tegra/tegra20-car.c | 4 ++ arch/arm/mach-tegra/tegra20-timer.c | 119 ++++++++++++++++++++++++++++++++++++ 5 files changed, 133 insertions(+), 57 deletions(-) delete mode 100644 arch/arm/mach-tegra/clock.c create mode 100644 arch/arm/mach-tegra/tegra20-timer.c diff --git a/arch/arm/dts/tegra20.dtsi b/arch/arm/dts/tegra20.dtsi index 2edfda1916..cc765279f3 100644 --- a/arch/arm/dts/tegra20.dtsi +++ b/arch/arm/dts/tegra20.dtsi @@ -3,6 +3,15 @@ / { compatible = "nvidia,tegra20"; + timer@60005000 { + compatible = "nvidia,tegra20-timer"; + reg = <0x60005000 0x60>; + interrupts = <0 0 0x04 + 0 1 0x04 + 0 41 0x04 + 0 42 0x04>; + }; + tegra_car: clock { compatible = "nvidia,tegra20-car"; reg = <0x60006000 0x1000>; diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile index 9aa7725f28..1112d11680 100644 --- a/arch/arm/mach-tegra/Makefile +++ b/arch/arm/mach-tegra/Makefile @@ -1,3 +1,3 @@ -obj-y += clock.o obj-y += reset.o obj-y += tegra20-car.o +obj-y += tegra20-timer.o diff --git a/arch/arm/mach-tegra/clock.c b/arch/arm/mach-tegra/clock.c deleted file mode 100644 index 82065ee74f..0000000000 --- a/arch/arm/mach-tegra/clock.c +++ /dev/null @@ -1,56 +0,0 @@ -/* - * Copyright (C) 2011 Antony Pavlov - * - * This file is part of barebox. - * See file CREDITS for list of people who contributed to this project. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation. - * - * 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. - * - */ - -/** - * @file - * @brief Clocksource based on Tegra internal timer - */ - -#include -#include -#include -#include -#include -#include -#include - -static void __iomem *timer_reg_base = (void __iomem *) (TEGRA_TMR1_BASE); - -#define timer_writel(value, reg) \ - __raw_writel(value, (u32)timer_reg_base + (reg)) -#define timer_readl(reg) \ - __raw_readl((u32)timer_reg_base + (reg)) - -static uint64_t tegra_clocksource_read(void) -{ - return timer_readl(0x10); -} - -static struct clocksource cs = { - .read = tegra_clocksource_read, - .mask = 0xffffffff, -}; - -/* FIXME: here we have no initialization. All initialization made by U-Boot */ -static int clocksource_init(void) -{ - cs.mult = clocksource_hz2mult(1000000, cs.shift); - init_clock(&cs); - - return 0; -} -core_initcall(clocksource_init); diff --git a/arch/arm/mach-tegra/tegra20-car.c b/arch/arm/mach-tegra/tegra20-car.c index 93616bf98e..3af7bdcc4a 100644 --- a/arch/arm/mach-tegra/tegra20-car.c +++ b/arch/arm/mach-tegra/tegra20-car.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -92,6 +93,9 @@ static int tegra20_car_probe(struct device_d *dev) /* timer is a gate, but as it's enabled by BOOTROM we needn't worry */ clks[timer] = clk_fixed_factor("timer", "clk_m", 1, 1); + /* device to clock links */ + clkdev_add_physbase(clks[timer], TEGRA_TMR1_BASE, NULL); + return 0; } diff --git a/arch/arm/mach-tegra/tegra20-timer.c b/arch/arm/mach-tegra/tegra20-timer.c new file mode 100644 index 0000000000..aafbfd43c7 --- /dev/null +++ b/arch/arm/mach-tegra/tegra20-timer.c @@ -0,0 +1,119 @@ +/* + * Copyright (C) 2013 Lucas Stach + * + * 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 . + */ + +/** + * @file + * @brief Device driver for the Tegra 20 timer, which exposes a clocksource. + */ + +#include +#include +#include +#include +#include + +/* register definitions */ +#define TIMERUS_CNTR_1US 0x10 +#define TIMERUS_USEC_CFG 0x14 + +static void __iomem *timer_base; + +static uint64_t tegra20_timer_cs_read(void) +{ + return readl(timer_base + TIMERUS_CNTR_1US); +} + +static struct clocksource cs = { + .read = tegra20_timer_cs_read, + .mask = CLOCKSOURCE_MASK(32), +}; + +static int tegra20_timer_probe(struct device_d *dev) +{ + struct clk *timer_clk; + unsigned long rate; + u32 reg; + + /* use only one timer */ + if (timer_base) + return -EBUSY; + + timer_base = dev_request_mem_region(dev, 0); + if (!timer_base) { + dev_err(dev, "could not get memory region\n"); + return -ENODEV; + } + + timer_clk = clk_get(dev, NULL); + if (!timer_clk) { + dev_err(dev, "could not get clock\n"); + return -ENODEV; + } + + clk_enable(timer_clk); + + /* + * calibrate timer to run at 1MHz + * TIMERUS_USEC_CFG selects the scale down factor with bits [0:7] + * representing the divisor and bits [8:15] representing the dividend + * each in n+1 form. + */ + rate = clk_get_rate(timer_clk); + switch (rate) { + case 12000000: + reg = 0x000b; + break; + case 13000000: + reg = 0x000c; + break; + case 19200000: + reg = 0x045f; + break; + case 26000000: + reg = 0x0019; + break; + default: + reg = 0; + dev_warn(dev, "unknown timer clock rate\n"); + break; + } + writel(reg, timer_base + TIMERUS_USEC_CFG); + + cs.mult = clocksource_hz2mult(1000000, cs.shift); + init_clock(&cs); + + return 0; +} + +static __maybe_unused struct of_device_id tegra20_timer_dt_ids[] = { + { + .compatible = "nvidia,tegra20-timer", + }, { + /* sentinel */ + } +}; + +static struct driver_d tegra20_timer_driver = { + .probe = tegra20_timer_probe, + .name = "tegra20-timer", + .of_compatible = DRV_OF_COMPAT(tegra20_timer_dt_ids), +}; + +static int tegra20_timer_init(void) +{ + return platform_driver_register(&tegra20_timer_driver); +} +coredevice_initcall(tegra20_timer_init); -- cgit v1.2.3