From 694e33a7f42de7dcc8b43c3990c597b19ef9b438 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 18 Oct 2012 14:01:25 +0200 Subject: ARM: plat-nomadik: move MTU, kill plat-nomadik This moves the MTU timer driver from arch/arm/plat-nomadik to drivers/clocksource and moves the header file to the platform_data directory. As this moves the last file being compiled to an object out of arch/arm/plat-nomadik, we have to "turn off the light" and delete the plat-nomadik directory, because it is not allowed to have an empty Makefile in a plat-* directory. This is probably also a desired side effect of depopulating the arch/arm directory of drivers. Luckily we have just deleted all the include files prior to this so by moving the last one we may delete the directory. After this all the Ux500 and Nomadik device drivers live outside of the arch/arm hierarchy. Cc: Alessandro Rubini Acked-by: Arnd Bergmann Signed-off-by: Linus Walleij --- drivers/clocksource/Kconfig | 17 ++- drivers/clocksource/Makefile | 1 + drivers/clocksource/nomadik-mtu.c | 224 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 241 insertions(+), 1 deletion(-) create mode 100644 drivers/clocksource/nomadik-mtu.c (limited to 'drivers/clocksource') diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 6a78073c3808..c9f67de8b7b4 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -22,6 +22,21 @@ config DW_APB_TIMER_OF config ARMADA_370_XP_TIMER bool +config CLKSRC_NOMADIK_MTU + bool + depends on (ARCH_NOMADIK || ARCH_U8500) + select CLKSRC_MMIO + help + Support for Multi Timer Unit. MTU provides access + to multiple interrupt generating programmable + 32-bit free running decrementing counters. + +config CLKSRC_NOMADIK_MTU_SCHED_CLOCK + bool + depends on CLKSRC_NOMADIK_MTU + help + Use the Multi Timer Unit as the sched_clock. + config CLKSRC_DBX500_PRCMU bool "Clocksource PRCMU Timer" depends on UX500_SOC_DB8500 @@ -31,7 +46,7 @@ config CLKSRC_DBX500_PRCMU config CLKSRC_DBX500_PRCMU_SCHED_CLOCK bool "Clocksource PRCMU Timer sched_clock" - depends on (CLKSRC_DBX500_PRCMU && !NOMADIK_MTU_SCHED_CLOCK) + depends on (CLKSRC_DBX500_PRCMU && !CLKSRC_NOMADIK_MTU_SCHED_CLOCK) default y help Use the always on PRCMU Timer as sched_clock diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 603be366f762..24fb888ee0a2 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_CLKBLD_I8253) += i8253.o obj-$(CONFIG_CLKSRC_MMIO) += mmio.o obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o +obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o diff --git a/drivers/clocksource/nomadik-mtu.c b/drivers/clocksource/nomadik-mtu.c new file mode 100644 index 000000000000..23c780ba0d35 --- /dev/null +++ b/drivers/clocksource/nomadik-mtu.c @@ -0,0 +1,224 @@ +/* + * Copyright (C) 2008 STMicroelectronics + * Copyright (C) 2010 Alessandro Rubini + * Copyright (C) 2010 Linus Walleij for ST-Ericsson + * + * 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * The MTU device hosts four different counters, with 4 set of + * registers. These are register names. + */ + +#define MTU_IMSC 0x00 /* Interrupt mask set/clear */ +#define MTU_RIS 0x04 /* Raw interrupt status */ +#define MTU_MIS 0x08 /* Masked interrupt status */ +#define MTU_ICR 0x0C /* Interrupt clear register */ + +/* per-timer registers take 0..3 as argument */ +#define MTU_LR(x) (0x10 + 0x10 * (x) + 0x00) /* Load value */ +#define MTU_VAL(x) (0x10 + 0x10 * (x) + 0x04) /* Current value */ +#define MTU_CR(x) (0x10 + 0x10 * (x) + 0x08) /* Control reg */ +#define MTU_BGLR(x) (0x10 + 0x10 * (x) + 0x0c) /* At next overflow */ + +/* bits for the control register */ +#define MTU_CRn_ENA 0x80 +#define MTU_CRn_PERIODIC 0x40 /* if 0 = free-running */ +#define MTU_CRn_PRESCALE_MASK 0x0c +#define MTU_CRn_PRESCALE_1 0x00 +#define MTU_CRn_PRESCALE_16 0x04 +#define MTU_CRn_PRESCALE_256 0x08 +#define MTU_CRn_32BITS 0x02 +#define MTU_CRn_ONESHOT 0x01 /* if 0 = wraps reloading from BGLR*/ + +/* Other registers are usual amba/primecell registers, currently not used */ +#define MTU_ITCR 0xff0 +#define MTU_ITOP 0xff4 + +#define MTU_PERIPH_ID0 0xfe0 +#define MTU_PERIPH_ID1 0xfe4 +#define MTU_PERIPH_ID2 0xfe8 +#define MTU_PERIPH_ID3 0xfeC + +#define MTU_PCELL0 0xff0 +#define MTU_PCELL1 0xff4 +#define MTU_PCELL2 0xff8 +#define MTU_PCELL3 0xffC + +static void __iomem *mtu_base; +static bool clkevt_periodic; +static u32 clk_prescale; +static u32 nmdk_cycle; /* write-once */ + +#ifdef CONFIG_NOMADIK_MTU_SCHED_CLOCK +/* + * Override the global weak sched_clock symbol with this + * local implementation which uses the clocksource to get some + * better resolution when scheduling the kernel. + */ +static u32 notrace nomadik_read_sched_clock(void) +{ + if (unlikely(!mtu_base)) + return 0; + + return -readl(mtu_base + MTU_VAL(0)); +} +#endif + +/* Clockevent device: use one-shot mode */ +static int nmdk_clkevt_next(unsigned long evt, struct clock_event_device *ev) +{ + writel(1 << 1, mtu_base + MTU_IMSC); + writel(evt, mtu_base + MTU_LR(1)); + /* Load highest value, enable device, enable interrupts */ + writel(MTU_CRn_ONESHOT | clk_prescale | + MTU_CRn_32BITS | MTU_CRn_ENA, + mtu_base + MTU_CR(1)); + + return 0; +} + +void nmdk_clkevt_reset(void) +{ + if (clkevt_periodic) { + /* Timer: configure load and background-load, and fire it up */ + writel(nmdk_cycle, mtu_base + MTU_LR(1)); + writel(nmdk_cycle, mtu_base + MTU_BGLR(1)); + + writel(MTU_CRn_PERIODIC | clk_prescale | + MTU_CRn_32BITS | MTU_CRn_ENA, + mtu_base + MTU_CR(1)); + writel(1 << 1, mtu_base + MTU_IMSC); + } else { + /* Generate an interrupt to start the clockevent again */ + (void) nmdk_clkevt_next(nmdk_cycle, NULL); + } +} + +static void nmdk_clkevt_mode(enum clock_event_mode mode, + struct clock_event_device *dev) +{ + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + clkevt_periodic = true; + nmdk_clkevt_reset(); + break; + case CLOCK_EVT_MODE_ONESHOT: + clkevt_periodic = false; + break; + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + writel(0, mtu_base + MTU_IMSC); + /* disable timer */ + writel(0, mtu_base + MTU_CR(1)); + /* load some high default value */ + writel(0xffffffff, mtu_base + MTU_LR(1)); + break; + case CLOCK_EVT_MODE_RESUME: + break; + } +} + +static struct clock_event_device nmdk_clkevt = { + .name = "mtu_1", + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, + .rating = 200, + .set_mode = nmdk_clkevt_mode, + .set_next_event = nmdk_clkevt_next, +}; + +/* + * IRQ Handler for timer 1 of the MTU block. + */ +static irqreturn_t nmdk_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evdev = dev_id; + + writel(1 << 1, mtu_base + MTU_ICR); /* Interrupt clear reg */ + evdev->event_handler(evdev); + return IRQ_HANDLED; +} + +static struct irqaction nmdk_timer_irq = { + .name = "Nomadik Timer Tick", + .flags = IRQF_DISABLED | IRQF_TIMER, + .handler = nmdk_timer_interrupt, + .dev_id = &nmdk_clkevt, +}; + +void nmdk_clksrc_reset(void) +{ + /* Disable */ + writel(0, mtu_base + MTU_CR(0)); + + /* ClockSource: configure load and background-load, and fire it up */ + writel(nmdk_cycle, mtu_base + MTU_LR(0)); + writel(nmdk_cycle, mtu_base + MTU_BGLR(0)); + + writel(clk_prescale | MTU_CRn_32BITS | MTU_CRn_ENA, + mtu_base + MTU_CR(0)); +} + +void __init nmdk_timer_init(void __iomem *base, int irq) +{ + unsigned long rate; + struct clk *clk0; + + mtu_base = base; + clk0 = clk_get_sys("mtu0", NULL); + BUG_ON(IS_ERR(clk0)); + BUG_ON(clk_prepare(clk0) < 0); + BUG_ON(clk_enable(clk0) < 0); + + /* + * Tick rate is 2.4MHz for Nomadik and 2.4Mhz, 100MHz or 133 MHz + * for ux500. + * Use a divide-by-16 counter if the tick rate is more than 32MHz. + * At 32 MHz, the timer (with 32 bit counter) can be programmed + * to wake-up at a max 127s a head in time. Dividing a 2.4 MHz timer + * with 16 gives too low timer resolution. + */ + rate = clk_get_rate(clk0); + if (rate > 32000000) { + rate /= 16; + clk_prescale = MTU_CRn_PRESCALE_16; + } else { + clk_prescale = MTU_CRn_PRESCALE_1; + } + + /* Cycles for periodic mode */ + nmdk_cycle = DIV_ROUND_CLOSEST(rate, HZ); + + + /* Timer 0 is the free running clocksource */ + nmdk_clksrc_reset(); + + if (clocksource_mmio_init(mtu_base + MTU_VAL(0), "mtu_0", + rate, 200, 32, clocksource_mmio_readl_down)) + pr_err("timer: failed to initialize clock source %s\n", + "mtu_0"); + +#ifdef CONFIG_NOMADIK_MTU_SCHED_CLOCK + setup_sched_clock(nomadik_read_sched_clock, 32, rate); +#endif + + /* Timer 1 is used for events, register irq and clockevents */ + setup_irq(irq, &nmdk_timer_irq); + nmdk_clkevt.cpumask = cpumask_of(0); + clockevents_config_and_register(&nmdk_clkevt, rate, 2, 0xffffffffU); +} -- cgit v1.2.3