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remarkable-linux/drivers/clocksource/mxs_timer.c
Daniel Lezcano 1727339590 clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE 
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the
clocksource at early stage. However, this macro is also used to initialize
the clockevent if any, or the clockevent only.

It was originally suggested to declare another macro to initialize a
clockevent, so in order to separate the two entities even they belong to the
same IP. This was not accepted because of the impact on the DT where splitting
a clocksource/clockevent definition does not make sense as it is a Linux
concept not a hardware description.

On the other side, the clocksource has not interrupt declared while the
clockevent has, so it is easy from the driver to know if the description is
for a clockevent or a clocksource, IOW it could be implemented at the driver
level.

So instead of dealing with a named clocksource macro, let's use a more generic
one: TIMER_OF_DECLARE.

The patch has not functional changes.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 11:58:45 +02:00

297 lines
8.1 KiB
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/*
* 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)
* Copyright (C) 2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* 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/err.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clockchips.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/stmp_device.h>
#include <linux/sched_clock.h>
/*
* There are 2 versions of the timrot on Freescale MXS-based SoCs.
* The v1 on MX23 only gets 16 bits counter, while v2 on MX28
* extends the counter to 32 bits.
*
* The implementation uses two timers, one for clock_event and
* another for clocksource. MX28 uses timrot 0 and 1, while MX23
* uses 0 and 2.
*/
#define MX23_TIMROT_VERSION_OFFSET 0x0a0
#define MX28_TIMROT_VERSION_OFFSET 0x120
#define BP_TIMROT_MAJOR_VERSION 24
#define BV_TIMROT_VERSION_1 0x01
#define BV_TIMROT_VERSION_2 0x02
#define timrot_is_v1() (timrot_major_version == BV_TIMROT_VERSION_1)
/*
* There are 4 registers for each timrotv2 instance, and 2 registers
* for each timrotv1. So address step 0x40 in macros below strides
* one instance of timrotv2 while two instances of timrotv1.
*
* As the result, HW_TIMROT_XXXn(1) defines the address of timrot1
* on MX28 while timrot2 on MX23.
*/
/* common between v1 and v2 */
#define HW_TIMROT_ROTCTRL 0x00
#define HW_TIMROT_TIMCTRLn(n) (0x20 + (n) * 0x40)
/* v1 only */
#define HW_TIMROT_TIMCOUNTn(n) (0x30 + (n) * 0x40)
/* v2 only */
#define HW_TIMROT_RUNNING_COUNTn(n) (0x30 + (n) * 0x40)
#define HW_TIMROT_FIXED_COUNTn(n) (0x40 + (n) * 0x40)
#define BM_TIMROT_TIMCTRLn_RELOAD (1 << 6)
#define BM_TIMROT_TIMCTRLn_UPDATE (1 << 7)
#define BM_TIMROT_TIMCTRLn_IRQ_EN (1 << 14)
#define BM_TIMROT_TIMCTRLn_IRQ (1 << 15)
#define BP_TIMROT_TIMCTRLn_SELECT 0
#define BV_TIMROTv1_TIMCTRLn_SELECT__32KHZ_XTAL 0x8
#define BV_TIMROTv2_TIMCTRLn_SELECT__32KHZ_XTAL 0xb
#define BV_TIMROTv2_TIMCTRLn_SELECT__TICK_ALWAYS 0xf
static struct clock_event_device mxs_clockevent_device;
static void __iomem *mxs_timrot_base;
static u32 timrot_major_version;
static inline void timrot_irq_disable(void)
{
__raw_writel(BM_TIMROT_TIMCTRLn_IRQ_EN, mxs_timrot_base +
HW_TIMROT_TIMCTRLn(0) + STMP_OFFSET_REG_CLR);
}
static inline void timrot_irq_enable(void)
{
__raw_writel(BM_TIMROT_TIMCTRLn_IRQ_EN, mxs_timrot_base +
HW_TIMROT_TIMCTRLn(0) + STMP_OFFSET_REG_SET);
}
static void timrot_irq_acknowledge(void)
{
__raw_writel(BM_TIMROT_TIMCTRLn_IRQ, mxs_timrot_base +
HW_TIMROT_TIMCTRLn(0) + STMP_OFFSET_REG_CLR);
}
static u64 timrotv1_get_cycles(struct clocksource *cs)
{
return ~((__raw_readl(mxs_timrot_base + HW_TIMROT_TIMCOUNTn(1))
& 0xffff0000) >> 16);
}
static int timrotv1_set_next_event(unsigned long evt,
struct clock_event_device *dev)
{
/* timrot decrements the count */
__raw_writel(evt, mxs_timrot_base + HW_TIMROT_TIMCOUNTn(0));
return 0;
}
static int timrotv2_set_next_event(unsigned long evt,
struct clock_event_device *dev)
{
/* timrot decrements the count */
__raw_writel(evt, mxs_timrot_base + HW_TIMROT_FIXED_COUNTn(0));
return 0;
}
static irqreturn_t mxs_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
timrot_irq_acknowledge();
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction mxs_timer_irq = {
.name = "MXS Timer Tick",
.dev_id = &mxs_clockevent_device,
.flags = IRQF_TIMER | IRQF_IRQPOLL,
.handler = mxs_timer_interrupt,
};
static void mxs_irq_clear(char *state)
{
/* Disable interrupt in timer module */
timrot_irq_disable();
/* Set event time into the furthest future */
if (timrot_is_v1())
__raw_writel(0xffff, mxs_timrot_base + HW_TIMROT_TIMCOUNTn(1));
else
__raw_writel(0xffffffff,
mxs_timrot_base + HW_TIMROT_FIXED_COUNTn(1));
/* Clear pending interrupt */
timrot_irq_acknowledge();
#ifdef DEBUG
pr_info("%s: changing mode to %s\n", __func__, state)
#endif /* DEBUG */
}
static int mxs_shutdown(struct clock_event_device *evt)
{
mxs_irq_clear("shutdown");
return 0;
}
static int mxs_set_oneshot(struct clock_event_device *evt)
{
if (clockevent_state_oneshot(evt))
mxs_irq_clear("oneshot");
timrot_irq_enable();
return 0;
}
static struct clock_event_device mxs_clockevent_device = {
.name = "mxs_timrot",
.features = CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = mxs_shutdown,
.set_state_oneshot = mxs_set_oneshot,
.tick_resume = mxs_shutdown,
.set_next_event = timrotv2_set_next_event,
.rating = 200,
};
static int __init mxs_clockevent_init(struct clk *timer_clk)
{
if (timrot_is_v1())
mxs_clockevent_device.set_next_event = timrotv1_set_next_event;
mxs_clockevent_device.cpumask = cpumask_of(0);
clockevents_config_and_register(&mxs_clockevent_device,
clk_get_rate(timer_clk),
timrot_is_v1() ? 0xf : 0x2,
timrot_is_v1() ? 0xfffe : 0xfffffffe);
return 0;
}
static struct clocksource clocksource_mxs = {
.name = "mxs_timer",
.rating = 200,
.read = timrotv1_get_cycles,
.mask = CLOCKSOURCE_MASK(16),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static u64 notrace mxs_read_sched_clock_v2(void)
{
return ~readl_relaxed(mxs_timrot_base + HW_TIMROT_RUNNING_COUNTn(1));
}
static int __init mxs_clocksource_init(struct clk *timer_clk)
{
unsigned int c = clk_get_rate(timer_clk);
if (timrot_is_v1())
clocksource_register_hz(&clocksource_mxs, c);
else {
clocksource_mmio_init(mxs_timrot_base + HW_TIMROT_RUNNING_COUNTn(1),
"mxs_timer", c, 200, 32, clocksource_mmio_readl_down);
sched_clock_register(mxs_read_sched_clock_v2, 32, c);
}
return 0;
}
static int __init mxs_timer_init(struct device_node *np)
{
struct clk *timer_clk;
int irq, ret;
mxs_timrot_base = of_iomap(np, 0);
WARN_ON(!mxs_timrot_base);
timer_clk = of_clk_get(np, 0);
if (IS_ERR(timer_clk)) {
pr_err("%s: failed to get clk\n", __func__);
return PTR_ERR(timer_clk);
}
ret = clk_prepare_enable(timer_clk);
if (ret)
return ret;
/*
* Initialize timers to a known state
*/
stmp_reset_block(mxs_timrot_base + HW_TIMROT_ROTCTRL);
/* get timrot version */
timrot_major_version = __raw_readl(mxs_timrot_base +
(of_device_is_compatible(np, "fsl,imx23-timrot") ?
MX23_TIMROT_VERSION_OFFSET :
MX28_TIMROT_VERSION_OFFSET));
timrot_major_version >>= BP_TIMROT_MAJOR_VERSION;
/* one for clock_event */
__raw_writel((timrot_is_v1() ?
BV_TIMROTv1_TIMCTRLn_SELECT__32KHZ_XTAL :
BV_TIMROTv2_TIMCTRLn_SELECT__TICK_ALWAYS) |
BM_TIMROT_TIMCTRLn_UPDATE |
BM_TIMROT_TIMCTRLn_IRQ_EN,
mxs_timrot_base + HW_TIMROT_TIMCTRLn(0));
/* another for clocksource */
__raw_writel((timrot_is_v1() ?
BV_TIMROTv1_TIMCTRLn_SELECT__32KHZ_XTAL :
BV_TIMROTv2_TIMCTRLn_SELECT__TICK_ALWAYS) |
BM_TIMROT_TIMCTRLn_RELOAD,
mxs_timrot_base + HW_TIMROT_TIMCTRLn(1));
/* set clocksource timer fixed count to the maximum */
if (timrot_is_v1())
__raw_writel(0xffff,
mxs_timrot_base + HW_TIMROT_TIMCOUNTn(1));
else
__raw_writel(0xffffffff,
mxs_timrot_base + HW_TIMROT_FIXED_COUNTn(1));
/* init and register the timer to the framework */
ret = mxs_clocksource_init(timer_clk);
if (ret)
return ret;
ret = mxs_clockevent_init(timer_clk);
if (ret)
return ret;
/* Make irqs happen */
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0)
return -EINVAL;
return setup_irq(irq, &mxs_timer_irq);
}
TIMER_OF_DECLARE(mxs, "fsl,timrot", mxs_timer_init);
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