linux/drivers/clocksource/timer-imx-gpt.c
Lucas Stach f1c08c9bc8 clocksource/drivers/imx: Allow timer irq affinity change
Allow the timer core to change the smp affinity of the broadcast timer
irq by setting CLOCK_EVT_FEAT_DYNIRQ flag. For this to work the timer
core needs to be told about the used irq.

This reduces interrupt pressure and wakeups on CPU0 as well as vastly
reducing the number of timer broadcast IPIs.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-10-15 17:42:05 +02:00

545 lines
14 KiB
C

/*
* 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/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <soc/imx/timer.h>
/*
* There are 4 versions of the timer hardware on Freescale MXC hardware.
* - MX1/MXL
* - MX21, MX27.
* - MX25, MX31, MX35, MX37, MX51, MX6Q(rev1.0)
* - MX6DL, MX6SX, MX6Q(rev1.1+)
*/
/* 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
struct imx_timer {
enum imx_gpt_type type;
void __iomem *base;
int irq;
struct clk *clk_per;
struct clk *clk_ipg;
const struct imx_gpt_data *gpt;
struct clock_event_device ced;
struct irqaction act;
};
struct imx_gpt_data {
int reg_tstat;
int reg_tcn;
int reg_tcmp;
void (*gpt_setup_tctl)(struct imx_timer *imxtm);
void (*gpt_irq_enable)(struct imx_timer *imxtm);
void (*gpt_irq_disable)(struct imx_timer *imxtm);
void (*gpt_irq_acknowledge)(struct imx_timer *imxtm);
int (*set_next_event)(unsigned long evt,
struct clock_event_device *ced);
};
static inline struct imx_timer *to_imx_timer(struct clock_event_device *ced)
{
return container_of(ced, struct imx_timer, ced);
}
static void imx1_gpt_irq_disable(struct imx_timer *imxtm)
{
unsigned int tmp;
tmp = readl_relaxed(imxtm->base + MXC_TCTL);
writel_relaxed(tmp & ~MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
}
#define imx21_gpt_irq_disable imx1_gpt_irq_disable
static void imx31_gpt_irq_disable(struct imx_timer *imxtm)
{
writel_relaxed(0, imxtm->base + V2_IR);
}
#define imx6dl_gpt_irq_disable imx31_gpt_irq_disable
static void imx1_gpt_irq_enable(struct imx_timer *imxtm)
{
unsigned int tmp;
tmp = readl_relaxed(imxtm->base + MXC_TCTL);
writel_relaxed(tmp | MX1_2_TCTL_IRQEN, imxtm->base + MXC_TCTL);
}
#define imx21_gpt_irq_enable imx1_gpt_irq_enable
static void imx31_gpt_irq_enable(struct imx_timer *imxtm)
{
writel_relaxed(1<<0, imxtm->base + V2_IR);
}
#define imx6dl_gpt_irq_enable imx31_gpt_irq_enable
static void imx1_gpt_irq_acknowledge(struct imx_timer *imxtm)
{
writel_relaxed(0, imxtm->base + MX1_2_TSTAT);
}
static void imx21_gpt_irq_acknowledge(struct imx_timer *imxtm)
{
writel_relaxed(MX2_TSTAT_CAPT | MX2_TSTAT_COMP,
imxtm->base + MX1_2_TSTAT);
}
static void imx31_gpt_irq_acknowledge(struct imx_timer *imxtm)
{
writel_relaxed(V2_TSTAT_OF1, imxtm->base + V2_TSTAT);
}
#define imx6dl_gpt_irq_acknowledge imx31_gpt_irq_acknowledge
static void __iomem *sched_clock_reg;
static u64 notrace mxc_read_sched_clock(void)
{
return sched_clock_reg ? readl_relaxed(sched_clock_reg) : 0;
}
static struct delay_timer imx_delay_timer;
static unsigned long imx_read_current_timer(void)
{
return readl_relaxed(sched_clock_reg);
}
static int __init mxc_clocksource_init(struct imx_timer *imxtm)
{
unsigned int c = clk_get_rate(imxtm->clk_per);
void __iomem *reg = imxtm->base + imxtm->gpt->reg_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 *ced)
{
struct imx_timer *imxtm = to_imx_timer(ced);
unsigned long tcmp;
tcmp = readl_relaxed(imxtm->base + MX1_2_TCN) + evt;
writel_relaxed(tcmp, imxtm->base + MX1_2_TCMP);
return (int)(tcmp - readl_relaxed(imxtm->base + MX1_2_TCN)) < 0 ?
-ETIME : 0;
}
static int v2_set_next_event(unsigned long evt,
struct clock_event_device *ced)
{
struct imx_timer *imxtm = to_imx_timer(ced);
unsigned long tcmp;
tcmp = readl_relaxed(imxtm->base + V2_TCN) + evt;
writel_relaxed(tcmp, imxtm->base + V2_TCMP);
return evt < 0x7fffffff &&
(int)(tcmp - readl_relaxed(imxtm->base + V2_TCN)) < 0 ?
-ETIME : 0;
}
static int mxc_shutdown(struct clock_event_device *ced)
{
struct imx_timer *imxtm = to_imx_timer(ced);
unsigned long flags;
u32 tcn;
/*
* 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 */
imxtm->gpt->gpt_irq_disable(imxtm);
tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
/* Set event time into far-far future */
writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
/* Clear pending interrupt */
imxtm->gpt->gpt_irq_acknowledge(imxtm);
#ifdef DEBUG
printk(KERN_INFO "%s: changing mode\n", __func__);
#endif /* DEBUG */
local_irq_restore(flags);
return 0;
}
static int mxc_set_oneshot(struct clock_event_device *ced)
{
struct imx_timer *imxtm = to_imx_timer(ced);
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 */
imxtm->gpt->gpt_irq_disable(imxtm);
if (!clockevent_state_oneshot(ced)) {
u32 tcn = readl_relaxed(imxtm->base + imxtm->gpt->reg_tcn);
/* Set event time into far-far future */
writel_relaxed(tcn - 3, imxtm->base + imxtm->gpt->reg_tcmp);
/* Clear pending interrupt */
imxtm->gpt->gpt_irq_acknowledge(imxtm);
}
#ifdef DEBUG
printk(KERN_INFO "%s: changing mode\n", __func__);
#endif /* DEBUG */
/*
* 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
*/
imxtm->gpt->gpt_irq_enable(imxtm);
local_irq_restore(flags);
return 0;
}
/*
* IRQ handler for the timer
*/
static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *ced = dev_id;
struct imx_timer *imxtm = to_imx_timer(ced);
uint32_t tstat;
tstat = readl_relaxed(imxtm->base + imxtm->gpt->reg_tstat);
imxtm->gpt->gpt_irq_acknowledge(imxtm);
ced->event_handler(ced);
return IRQ_HANDLED;
}
static int __init mxc_clockevent_init(struct imx_timer *imxtm)
{
struct clock_event_device *ced = &imxtm->ced;
struct irqaction *act = &imxtm->act;
ced->name = "mxc_timer1";
ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ;
ced->set_state_shutdown = mxc_shutdown;
ced->set_state_oneshot = mxc_set_oneshot;
ced->tick_resume = mxc_shutdown;
ced->set_next_event = imxtm->gpt->set_next_event;
ced->rating = 200;
ced->cpumask = cpumask_of(0);
ced->irq = imxtm->irq;
clockevents_config_and_register(ced, clk_get_rate(imxtm->clk_per),
0xff, 0xfffffffe);
act->name = "i.MX Timer Tick";
act->flags = IRQF_TIMER | IRQF_IRQPOLL;
act->handler = mxc_timer_interrupt;
act->dev_id = ced;
return setup_irq(imxtm->irq, act);
}
static void imx1_gpt_setup_tctl(struct imx_timer *imxtm)
{
u32 tctl_val;
tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN;
writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
}
#define imx21_gpt_setup_tctl imx1_gpt_setup_tctl
static void imx31_gpt_setup_tctl(struct imx_timer *imxtm)
{
u32 tctl_val;
tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8)
tctl_val |= V2_TCTL_CLK_OSC_DIV8;
else
tctl_val |= V2_TCTL_CLK_PER;
writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
}
static void imx6dl_gpt_setup_tctl(struct imx_timer *imxtm)
{
u32 tctl_val;
tctl_val = V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN;
if (clk_get_rate(imxtm->clk_per) == V2_TIMER_RATE_OSC_DIV8) {
tctl_val |= V2_TCTL_CLK_OSC_DIV8;
/* 24 / 8 = 3 MHz */
writel_relaxed(7 << V2_TPRER_PRE24M, imxtm->base + MXC_TPRER);
tctl_val |= V2_TCTL_24MEN;
} else {
tctl_val |= V2_TCTL_CLK_PER;
}
writel_relaxed(tctl_val, imxtm->base + MXC_TCTL);
}
static const struct imx_gpt_data imx1_gpt_data = {
.reg_tstat = MX1_2_TSTAT,
.reg_tcn = MX1_2_TCN,
.reg_tcmp = MX1_2_TCMP,
.gpt_irq_enable = imx1_gpt_irq_enable,
.gpt_irq_disable = imx1_gpt_irq_disable,
.gpt_irq_acknowledge = imx1_gpt_irq_acknowledge,
.gpt_setup_tctl = imx1_gpt_setup_tctl,
.set_next_event = mx1_2_set_next_event,
};
static const struct imx_gpt_data imx21_gpt_data = {
.reg_tstat = MX1_2_TSTAT,
.reg_tcn = MX1_2_TCN,
.reg_tcmp = MX1_2_TCMP,
.gpt_irq_enable = imx21_gpt_irq_enable,
.gpt_irq_disable = imx21_gpt_irq_disable,
.gpt_irq_acknowledge = imx21_gpt_irq_acknowledge,
.gpt_setup_tctl = imx21_gpt_setup_tctl,
.set_next_event = mx1_2_set_next_event,
};
static const struct imx_gpt_data imx31_gpt_data = {
.reg_tstat = V2_TSTAT,
.reg_tcn = V2_TCN,
.reg_tcmp = V2_TCMP,
.gpt_irq_enable = imx31_gpt_irq_enable,
.gpt_irq_disable = imx31_gpt_irq_disable,
.gpt_irq_acknowledge = imx31_gpt_irq_acknowledge,
.gpt_setup_tctl = imx31_gpt_setup_tctl,
.set_next_event = v2_set_next_event,
};
static const struct imx_gpt_data imx6dl_gpt_data = {
.reg_tstat = V2_TSTAT,
.reg_tcn = V2_TCN,
.reg_tcmp = V2_TCMP,
.gpt_irq_enable = imx6dl_gpt_irq_enable,
.gpt_irq_disable = imx6dl_gpt_irq_disable,
.gpt_irq_acknowledge = imx6dl_gpt_irq_acknowledge,
.gpt_setup_tctl = imx6dl_gpt_setup_tctl,
.set_next_event = v2_set_next_event,
};
static void __init _mxc_timer_init(struct imx_timer *imxtm)
{
switch (imxtm->type) {
case GPT_TYPE_IMX1:
imxtm->gpt = &imx1_gpt_data;
break;
case GPT_TYPE_IMX21:
imxtm->gpt = &imx21_gpt_data;
break;
case GPT_TYPE_IMX31:
imxtm->gpt = &imx31_gpt_data;
break;
case GPT_TYPE_IMX6DL:
imxtm->gpt = &imx6dl_gpt_data;
break;
default:
BUG();
}
if (IS_ERR(imxtm->clk_per)) {
pr_err("i.MX timer: unable to get clk\n");
return;
}
if (!IS_ERR(imxtm->clk_ipg))
clk_prepare_enable(imxtm->clk_ipg);
clk_prepare_enable(imxtm->clk_per);
/*
* Initialise to a known state (all timers off, and timing reset)
*/
writel_relaxed(0, imxtm->base + MXC_TCTL);
writel_relaxed(0, imxtm->base + MXC_TPRER); /* see datasheet note */
imxtm->gpt->gpt_setup_tctl(imxtm);
/* init and register the timer to the framework */
mxc_clocksource_init(imxtm);
mxc_clockevent_init(imxtm);
}
void __init mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type)
{
struct imx_timer *imxtm;
imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
BUG_ON(!imxtm);
imxtm->clk_per = clk_get_sys("imx-gpt.0", "per");
imxtm->clk_ipg = clk_get_sys("imx-gpt.0", "ipg");
imxtm->base = ioremap(pbase, SZ_4K);
BUG_ON(!imxtm->base);
imxtm->type = type;
imxtm->irq = irq;
_mxc_timer_init(imxtm);
}
static void __init mxc_timer_init_dt(struct device_node *np, enum imx_gpt_type type)
{
struct imx_timer *imxtm;
static int initialized;
/* Support one instance only */
if (initialized)
return;
imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
BUG_ON(!imxtm);
imxtm->base = of_iomap(np, 0);
WARN_ON(!imxtm->base);
imxtm->irq = irq_of_parse_and_map(np, 0);
imxtm->clk_ipg = of_clk_get_by_name(np, "ipg");
/* Try osc_per first, and fall back to per otherwise */
imxtm->clk_per = of_clk_get_by_name(np, "osc_per");
if (IS_ERR(imxtm->clk_per))
imxtm->clk_per = of_clk_get_by_name(np, "per");
imxtm->type = type;
_mxc_timer_init(imxtm);
initialized = 1;
}
static void __init imx1_timer_init_dt(struct device_node *np)
{
mxc_timer_init_dt(np, GPT_TYPE_IMX1);
}
static void __init imx21_timer_init_dt(struct device_node *np)
{
mxc_timer_init_dt(np, GPT_TYPE_IMX21);
}
static void __init imx31_timer_init_dt(struct device_node *np)
{
enum imx_gpt_type type = GPT_TYPE_IMX31;
/*
* We were using the same compatible string for i.MX6Q/D and i.MX6DL/S
* GPT device, while they actually have different programming model.
* This is a workaround to keep the existing i.MX6DL/S DTBs continue
* working with the new kernel.
*/
if (of_machine_is_compatible("fsl,imx6dl"))
type = GPT_TYPE_IMX6DL;
mxc_timer_init_dt(np, type);
}
static void __init imx6dl_timer_init_dt(struct device_node *np)
{
mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
}
CLOCKSOURCE_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
CLOCKSOURCE_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);