/*
* 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);
