diff options
Diffstat (limited to 'kernel/arch/arm/mach-imx/time.c')
| -rw-r--r-- | kernel/arch/arm/mach-imx/time.c | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-imx/time.c b/kernel/arch/arm/mach-imx/time.c new file mode 100644 index 000000000..15d18e198 --- /dev/null +++ b/kernel/arch/arm/mach-imx/time.c @@ -0,0 +1,385 @@ +/* + * linux/arch/arm/plat-mxc/time.c + * + * Copyright (C) 2000-2001 Deep Blue Solutions + * Copyright (C) 2002 Shane Nay (shane@minirl.com) + * Copyright (C) 2006-2007 Pavel Pisa (ppisa@pikron.com) + * Copyright (C) 2008 Juergen Beisert (kernel@pengutronix.de) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301, USA. + */ + +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/clockchips.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/sched_clock.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include <asm/mach/time.h> + +#include "common.h" +#include "hardware.h" + +/* + * There are 2 versions of the timer hardware on Freescale MXC hardware. + * Version 1: MX1/MXL, MX21, MX27. + * Version 2: MX25, MX31, MX35, MX37, MX51 + */ + +/* defines common for all i.MX */ +#define MXC_TCTL 0x00 +#define MXC_TCTL_TEN (1 << 0) /* Enable module */ +#define MXC_TPRER 0x04 + +/* MX1, MX21, MX27 */ +#define MX1_2_TCTL_CLK_PCLK1 (1 << 1) +#define MX1_2_TCTL_IRQEN (1 << 4) +#define MX1_2_TCTL_FRR (1 << 8) +#define MX1_2_TCMP 0x08 +#define MX1_2_TCN 0x10 +#define MX1_2_TSTAT 0x14 + +/* MX21, MX27 */ +#define MX2_TSTAT_CAPT (1 << 1) +#define MX2_TSTAT_COMP (1 << 0) + +/* MX31, MX35, MX25, MX5, MX6 */ +#define V2_TCTL_WAITEN (1 << 3) /* Wait enable mode */ +#define V2_TCTL_CLK_IPG (1 << 6) +#define V2_TCTL_CLK_PER (2 << 6) +#define V2_TCTL_CLK_OSC_DIV8 (5 << 6) +#define V2_TCTL_FRR (1 << 9) +#define V2_TCTL_24MEN (1 << 10) +#define V2_TPRER_PRE24M 12 +#define V2_IR 0x0c +#define V2_TSTAT 0x08 +#define V2_TSTAT_OF1 (1 << 0) +#define V2_TCN 0x24 +#define V2_TCMP 0x10 + +#define V2_TIMER_RATE_OSC_DIV8 3000000 + +#define timer_is_v1() (cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27()) +#define timer_is_v2() (!timer_is_v1()) + +static struct clock_event_device clockevent_mxc; +static enum clock_event_mode clockevent_mode = CLOCK_EVT_MODE_UNUSED; + +static void __iomem *timer_base; + +static inline void gpt_irq_disable(void) +{ + unsigned int tmp; + + if (timer_is_v2()) + __raw_writel(0, timer_base + V2_IR); + else { + tmp = __raw_readl(timer_base + MXC_TCTL); + __raw_writel(tmp & ~MX1_2_TCTL_IRQEN, timer_base + MXC_TCTL); + } +} + +static inline void gpt_irq_enable(void) +{ + if (timer_is_v2()) + __raw_writel(1<<0, timer_base + V2_IR); + else { + __raw_writel(__raw_readl(timer_base + MXC_TCTL) | MX1_2_TCTL_IRQEN, + timer_base + MXC_TCTL); + } +} + +static void gpt_irq_acknowledge(void) +{ + if (timer_is_v1()) { + if (cpu_is_mx1()) + __raw_writel(0, timer_base + MX1_2_TSTAT); + else + __raw_writel(MX2_TSTAT_CAPT | MX2_TSTAT_COMP, + timer_base + MX1_2_TSTAT); + } else if (timer_is_v2()) + __raw_writel(V2_TSTAT_OF1, timer_base + V2_TSTAT); +} + +static void __iomem *sched_clock_reg; + +static u64 notrace mxc_read_sched_clock(void) +{ + return sched_clock_reg ? __raw_readl(sched_clock_reg) : 0; +} + +static struct delay_timer imx_delay_timer; + +static unsigned long imx_read_current_timer(void) +{ + return __raw_readl(sched_clock_reg); +} + +static int __init mxc_clocksource_init(struct clk *timer_clk) +{ + unsigned int c = clk_get_rate(timer_clk); + void __iomem *reg = timer_base + (timer_is_v2() ? V2_TCN : MX1_2_TCN); + + imx_delay_timer.read_current_timer = &imx_read_current_timer; + imx_delay_timer.freq = c; + register_current_timer_delay(&imx_delay_timer); + + sched_clock_reg = reg; + + sched_clock_register(mxc_read_sched_clock, 32, c); + return clocksource_mmio_init(reg, "mxc_timer1", c, 200, 32, + clocksource_mmio_readl_up); +} + +/* clock event */ + +static int mx1_2_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long tcmp; + + tcmp = __raw_readl(timer_base + MX1_2_TCN) + evt; + + __raw_writel(tcmp, timer_base + MX1_2_TCMP); + + return (int)(tcmp - __raw_readl(timer_base + MX1_2_TCN)) < 0 ? + -ETIME : 0; +} + +static int v2_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long tcmp; + + tcmp = __raw_readl(timer_base + V2_TCN) + evt; + + __raw_writel(tcmp, timer_base + V2_TCMP); + + return evt < 0x7fffffff && + (int)(tcmp - __raw_readl(timer_base + V2_TCN)) < 0 ? + -ETIME : 0; +} + +#ifdef DEBUG +static const char *clock_event_mode_label[] = { + [CLOCK_EVT_MODE_PERIODIC] = "CLOCK_EVT_MODE_PERIODIC", + [CLOCK_EVT_MODE_ONESHOT] = "CLOCK_EVT_MODE_ONESHOT", + [CLOCK_EVT_MODE_SHUTDOWN] = "CLOCK_EVT_MODE_SHUTDOWN", + [CLOCK_EVT_MODE_UNUSED] = "CLOCK_EVT_MODE_UNUSED", + [CLOCK_EVT_MODE_RESUME] = "CLOCK_EVT_MODE_RESUME", +}; +#endif /* DEBUG */ + +static void mxc_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long flags; + + /* + * The timer interrupt generation is disabled at least + * for enough time to call mxc_set_next_event() + */ + local_irq_save(flags); + + /* Disable interrupt in GPT module */ + gpt_irq_disable(); + + if (mode != clockevent_mode) { + /* Set event time into far-far future */ + if (timer_is_v2()) + __raw_writel(__raw_readl(timer_base + V2_TCN) - 3, + timer_base + V2_TCMP); + else + __raw_writel(__raw_readl(timer_base + MX1_2_TCN) - 3, + timer_base + MX1_2_TCMP); + + /* Clear pending interrupt */ + gpt_irq_acknowledge(); + } + +#ifdef DEBUG + printk(KERN_INFO "mxc_set_mode: changing mode from %s to %s\n", + clock_event_mode_label[clockevent_mode], + clock_event_mode_label[mode]); +#endif /* DEBUG */ + + /* Remember timer mode */ + clockevent_mode = mode; + local_irq_restore(flags); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + printk(KERN_ERR"mxc_set_mode: Periodic mode is not " + "supported for i.MX\n"); + break; + case CLOCK_EVT_MODE_ONESHOT: + /* + * Do not put overhead of interrupt enable/disable into + * mxc_set_next_event(), the core has about 4 minutes + * to call mxc_set_next_event() or shutdown clock after + * mode switching + */ + local_irq_save(flags); + gpt_irq_enable(); + local_irq_restore(flags); + break; + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_RESUME: + /* Left event sources disabled, no more interrupts appear */ + break; + } +} + +/* + * IRQ handler for the timer + */ +static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = &clockevent_mxc; + uint32_t tstat; + + if (timer_is_v2()) + tstat = __raw_readl(timer_base + V2_TSTAT); + else + tstat = __raw_readl(timer_base + MX1_2_TSTAT); + + gpt_irq_acknowledge(); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction mxc_timer_irq = { + .name = "i.MX Timer Tick", + .flags = IRQF_TIMER | IRQF_IRQPOLL, + .handler = mxc_timer_interrupt, +}; + +static struct clock_event_device clockevent_mxc = { + .name = "mxc_timer1", + .features = CLOCK_EVT_FEAT_ONESHOT, + .set_mode = mxc_set_mode, + .set_next_event = mx1_2_set_next_event, + .rating = 200, +}; + +static int __init mxc_clockevent_init(struct clk *timer_clk) +{ + if (timer_is_v2()) + clockevent_mxc.set_next_event = v2_set_next_event; + + clockevent_mxc.cpumask = cpumask_of(0); + clockevents_config_and_register(&clockevent_mxc, + clk_get_rate(timer_clk), + 0xff, 0xfffffffe); + + return 0; +} + +static void __init _mxc_timer_init(int irq, + struct clk *clk_per, struct clk *clk_ipg) +{ + uint32_t tctl_val; + + if (IS_ERR(clk_per)) { + pr_err("i.MX timer: unable to get clk\n"); + return; + } + + if (!IS_ERR(clk_ipg)) + clk_prepare_enable(clk_ipg); + + clk_prepare_enable(clk_per); + + /* + * Initialise to a known state (all timers off, and timing reset) + */ + + __raw_writel(0, timer_base + MXC_TCTL); + __raw_writel(0, timer_base + MXC_TPRER); /* see datasheet note */ + + if (timer_is_v2()) { + tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN; + if (clk_get_rate(clk_per) == V2_TIMER_RATE_OSC_DIV8) { + tctl_val |= V2_TCTL_CLK_OSC_DIV8; + if (cpu_is_imx6dl() || cpu_is_imx6sx()) { + /* 24 / 8 = 3 MHz */ + __raw_writel(7 << V2_TPRER_PRE24M, + timer_base + MXC_TPRER); + tctl_val |= V2_TCTL_24MEN; + } + } else { + tctl_val |= V2_TCTL_CLK_PER; + } + } else { + tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN; + } + + __raw_writel(tctl_val, timer_base + MXC_TCTL); + + /* init and register the timer to the framework */ + mxc_clocksource_init(clk_per); + mxc_clockevent_init(clk_per); + + /* Make irqs happen */ + setup_irq(irq, &mxc_timer_irq); +} + +void __init mxc_timer_init(void __iomem *base, int irq) +{ + struct clk *clk_per = clk_get_sys("imx-gpt.0", "per"); + struct clk *clk_ipg = clk_get_sys("imx-gpt.0", "ipg"); + + timer_base = base; + + _mxc_timer_init(irq, clk_per, clk_ipg); +} + +static void __init mxc_timer_init_dt(struct device_node *np) +{ + struct clk *clk_per, *clk_ipg; + int irq; + + if (timer_base) + return; + + timer_base = of_iomap(np, 0); + WARN_ON(!timer_base); + irq = irq_of_parse_and_map(np, 0); + + clk_ipg = of_clk_get_by_name(np, "ipg"); + + /* Try osc_per first, and fall back to per otherwise */ + clk_per = of_clk_get_by_name(np, "osc_per"); + if (IS_ERR(clk_per)) + clk_per = of_clk_get_by_name(np, "per"); + + _mxc_timer_init(irq, clk_per, clk_ipg); +} +CLOCKSOURCE_OF_DECLARE(mx1_timer, "fsl,imx1-gpt", mxc_timer_init_dt); +CLOCKSOURCE_OF_DECLARE(mx25_timer, "fsl,imx25-gpt", mxc_timer_init_dt); +CLOCKSOURCE_OF_DECLARE(mx50_timer, "fsl,imx50-gpt", mxc_timer_init_dt); +CLOCKSOURCE_OF_DECLARE(mx51_timer, "fsl,imx51-gpt", mxc_timer_init_dt); +CLOCKSOURCE_OF_DECLARE(mx53_timer, "fsl,imx53-gpt", mxc_timer_init_dt); +CLOCKSOURCE_OF_DECLARE(mx6q_timer, "fsl,imx6q-gpt", mxc_timer_init_dt); +CLOCKSOURCE_OF_DECLARE(mx6sl_timer, "fsl,imx6sl-gpt", mxc_timer_init_dt); +CLOCKSOURCE_OF_DECLARE(mx6sx_timer, "fsl,imx6sx-gpt", mxc_timer_init_dt); |