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linux-stable/drivers/clocksource/timer-fttmr010.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

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/*
* Faraday Technology FTTMR010 timer driver
* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
*
* Based on a rewrite of arch/arm/mach-gemini/timer.c:
* Copyright (C) 2001-2006 Storlink, Corp.
* Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/sched_clock.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/bitops.h>
/*
* Register definitions for the timers
*/
#define TIMER1_COUNT (0x00)
#define TIMER1_LOAD (0x04)
#define TIMER1_MATCH1 (0x08)
#define TIMER1_MATCH2 (0x0c)
#define TIMER2_COUNT (0x10)
#define TIMER2_LOAD (0x14)
#define TIMER2_MATCH1 (0x18)
#define TIMER2_MATCH2 (0x1c)
#define TIMER3_COUNT (0x20)
#define TIMER3_LOAD (0x24)
#define TIMER3_MATCH1 (0x28)
#define TIMER3_MATCH2 (0x2c)
#define TIMER_CR (0x30)
#define TIMER_INTR_STATE (0x34)
#define TIMER_INTR_MASK (0x38)
#define TIMER_1_CR_ENABLE BIT(0)
#define TIMER_1_CR_CLOCK BIT(1)
#define TIMER_1_CR_INT BIT(2)
#define TIMER_2_CR_ENABLE BIT(3)
#define TIMER_2_CR_CLOCK BIT(4)
#define TIMER_2_CR_INT BIT(5)
#define TIMER_3_CR_ENABLE BIT(6)
#define TIMER_3_CR_CLOCK BIT(7)
#define TIMER_3_CR_INT BIT(8)
#define TIMER_1_CR_UPDOWN BIT(9)
#define TIMER_2_CR_UPDOWN BIT(10)
#define TIMER_3_CR_UPDOWN BIT(11)
/*
* The Aspeed AST2400 moves bits around in the control register
* and lacks bits for setting the timer to count upwards.
*/
#define TIMER_1_CR_ASPEED_ENABLE BIT(0)
#define TIMER_1_CR_ASPEED_CLOCK BIT(1)
#define TIMER_1_CR_ASPEED_INT BIT(2)
#define TIMER_2_CR_ASPEED_ENABLE BIT(4)
#define TIMER_2_CR_ASPEED_CLOCK BIT(5)
#define TIMER_2_CR_ASPEED_INT BIT(6)
#define TIMER_3_CR_ASPEED_ENABLE BIT(8)
#define TIMER_3_CR_ASPEED_CLOCK BIT(9)
#define TIMER_3_CR_ASPEED_INT BIT(10)
#define TIMER_1_INT_MATCH1 BIT(0)
#define TIMER_1_INT_MATCH2 BIT(1)
#define TIMER_1_INT_OVERFLOW BIT(2)
#define TIMER_2_INT_MATCH1 BIT(3)
#define TIMER_2_INT_MATCH2 BIT(4)
#define TIMER_2_INT_OVERFLOW BIT(5)
#define TIMER_3_INT_MATCH1 BIT(6)
#define TIMER_3_INT_MATCH2 BIT(7)
#define TIMER_3_INT_OVERFLOW BIT(8)
#define TIMER_INT_ALL_MASK 0x1ff
struct fttmr010 {
void __iomem *base;
unsigned int tick_rate;
bool count_down;
u32 t1_enable_val;
struct clock_event_device clkevt;
};
/* A local singleton used by sched_clock, which is stateless */
static struct fttmr010 *local_fttmr;
static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt)
{
return container_of(evt, struct fttmr010, clkevt);
}
static u64 notrace fttmr010_read_sched_clock(void)
{
if (local_fttmr->count_down)
return ~readl(local_fttmr->base + TIMER2_COUNT);
return readl(local_fttmr->base + TIMER2_COUNT);
}
static int fttmr010_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
struct fttmr010 *fttmr010 = to_fttmr010(evt);
u32 cr;
/* Stop */
cr = readl(fttmr010->base + TIMER_CR);
cr &= ~fttmr010->t1_enable_val;
writel(cr, fttmr010->base + TIMER_CR);
/* Setup the match register forward/backward in time */
cr = readl(fttmr010->base + TIMER1_COUNT);
if (fttmr010->count_down)
cr -= cycles;
else
cr += cycles;
writel(cr, fttmr010->base + TIMER1_MATCH1);
/* Start */
cr = readl(fttmr010->base + TIMER_CR);
cr |= fttmr010->t1_enable_val;
writel(cr, fttmr010->base + TIMER_CR);
return 0;
}
static int fttmr010_timer_shutdown(struct clock_event_device *evt)
{
struct fttmr010 *fttmr010 = to_fttmr010(evt);
u32 cr;
/* Stop */
cr = readl(fttmr010->base + TIMER_CR);
cr &= ~fttmr010->t1_enable_val;
writel(cr, fttmr010->base + TIMER_CR);
return 0;
}
static int fttmr010_timer_set_oneshot(struct clock_event_device *evt)
{
struct fttmr010 *fttmr010 = to_fttmr010(evt);
u32 cr;
/* Stop */
cr = readl(fttmr010->base + TIMER_CR);
cr &= ~fttmr010->t1_enable_val;
writel(cr, fttmr010->base + TIMER_CR);
/* Setup counter start from 0 or ~0 */
writel(0, fttmr010->base + TIMER1_COUNT);
if (fttmr010->count_down)
writel(~0, fttmr010->base + TIMER1_LOAD);
else
writel(0, fttmr010->base + TIMER1_LOAD);
/* Enable interrupt */
cr = readl(fttmr010->base + TIMER_INTR_MASK);
cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2);
cr |= TIMER_1_INT_MATCH1;
writel(cr, fttmr010->base + TIMER_INTR_MASK);
return 0;
}
static int fttmr010_timer_set_periodic(struct clock_event_device *evt)
{
struct fttmr010 *fttmr010 = to_fttmr010(evt);
u32 period = DIV_ROUND_CLOSEST(fttmr010->tick_rate, HZ);
u32 cr;
/* Stop */
cr = readl(fttmr010->base + TIMER_CR);
cr &= ~fttmr010->t1_enable_val;
writel(cr, fttmr010->base + TIMER_CR);
/* Setup timer to fire at 1/HZ intervals. */
if (fttmr010->count_down) {
writel(period, fttmr010->base + TIMER1_LOAD);
writel(0, fttmr010->base + TIMER1_MATCH1);
} else {
cr = 0xffffffff - (period - 1);
writel(cr, fttmr010->base + TIMER1_COUNT);
writel(cr, fttmr010->base + TIMER1_LOAD);
/* Enable interrupt on overflow */
cr = readl(fttmr010->base + TIMER_INTR_MASK);
cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2);
cr |= TIMER_1_INT_OVERFLOW;
writel(cr, fttmr010->base + TIMER_INTR_MASK);
}
/* Start the timer */
cr = readl(fttmr010->base + TIMER_CR);
cr |= fttmr010->t1_enable_val;
writel(cr, fttmr010->base + TIMER_CR);
return 0;
}
/*
* IRQ handler for the timer
*/
static irqreturn_t fttmr010_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed)
{
struct fttmr010 *fttmr010;
int irq;
struct clk *clk;
int ret;
u32 val;
/*
* These implementations require a clock reference.
* FIXME: we currently only support clocking using PCLK
* and using EXTCLK is not supported in the driver.
*/
clk = of_clk_get_by_name(np, "PCLK");
if (IS_ERR(clk)) {
pr_err("could not get PCLK\n");
return PTR_ERR(clk);
}
ret = clk_prepare_enable(clk);
if (ret) {
pr_err("failed to enable PCLK\n");
return ret;
}
fttmr010 = kzalloc(sizeof(*fttmr010), GFP_KERNEL);
if (!fttmr010) {
ret = -ENOMEM;
goto out_disable_clock;
}
fttmr010->tick_rate = clk_get_rate(clk);
fttmr010->base = of_iomap(np, 0);
if (!fttmr010->base) {
pr_err("Can't remap registers");
ret = -ENXIO;
goto out_free;
}
/* IRQ for timer 1 */
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0) {
pr_err("Can't parse IRQ");
ret = -EINVAL;
goto out_unmap;
}
/*
* The Aspeed AST2400 moves bits around in the control register,
* otherwise it works the same.
*/
if (is_aspeed) {
fttmr010->t1_enable_val = TIMER_1_CR_ASPEED_ENABLE |
TIMER_1_CR_ASPEED_INT;
/* Downward not available */
fttmr010->count_down = true;
} else {
fttmr010->t1_enable_val = TIMER_1_CR_ENABLE | TIMER_1_CR_INT;
}
/*
* Reset the interrupt mask and status
*/
writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK);
writel(0, fttmr010->base + TIMER_INTR_STATE);
/*
* Enable timer 1 count up, timer 2 count up, except on Aspeed,
* where everything just counts down.
*/
if (is_aspeed)
val = TIMER_2_CR_ASPEED_ENABLE;
else {
val = TIMER_2_CR_ENABLE;
if (!fttmr010->count_down)
val |= TIMER_1_CR_UPDOWN | TIMER_2_CR_UPDOWN;
}
writel(val, fttmr010->base + TIMER_CR);
/*
* Setup free-running clocksource timer (interrupts
* disabled.)
*/
local_fttmr = fttmr010;
writel(0, fttmr010->base + TIMER2_COUNT);
writel(0, fttmr010->base + TIMER2_MATCH1);
writel(0, fttmr010->base + TIMER2_MATCH2);
if (fttmr010->count_down) {
writel(~0, fttmr010->base + TIMER2_LOAD);
clocksource_mmio_init(fttmr010->base + TIMER2_COUNT,
"FTTMR010-TIMER2",
fttmr010->tick_rate,
300, 32, clocksource_mmio_readl_down);
} else {
writel(0, fttmr010->base + TIMER2_LOAD);
clocksource_mmio_init(fttmr010->base + TIMER2_COUNT,
"FTTMR010-TIMER2",
fttmr010->tick_rate,
300, 32, clocksource_mmio_readl_up);
}
sched_clock_register(fttmr010_read_sched_clock, 32,
fttmr010->tick_rate);
/*
* Setup clockevent timer (interrupt-driven) on timer 1.
*/
writel(0, fttmr010->base + TIMER1_COUNT);
writel(0, fttmr010->base + TIMER1_LOAD);
writel(0, fttmr010->base + TIMER1_MATCH1);
writel(0, fttmr010->base + TIMER1_MATCH2);
ret = request_irq(irq, fttmr010_timer_interrupt, IRQF_TIMER,
"FTTMR010-TIMER1", &fttmr010->clkevt);
if (ret) {
pr_err("FTTMR010-TIMER1 no IRQ\n");
goto out_unmap;
}
fttmr010->clkevt.name = "FTTMR010-TIMER1";
/* Reasonably fast and accurate clock event */
fttmr010->clkevt.rating = 300;
fttmr010->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT;
fttmr010->clkevt.set_next_event = fttmr010_timer_set_next_event;
fttmr010->clkevt.set_state_shutdown = fttmr010_timer_shutdown;
fttmr010->clkevt.set_state_periodic = fttmr010_timer_set_periodic;
fttmr010->clkevt.set_state_oneshot = fttmr010_timer_set_oneshot;
fttmr010->clkevt.tick_resume = fttmr010_timer_shutdown;
fttmr010->clkevt.cpumask = cpumask_of(0);
fttmr010->clkevt.irq = irq;
clockevents_config_and_register(&fttmr010->clkevt,
fttmr010->tick_rate,
1, 0xffffffff);
return 0;
out_unmap:
iounmap(fttmr010->base);
out_free:
kfree(fttmr010);
out_disable_clock:
clk_disable_unprepare(clk);
return ret;
}
static __init int aspeed_timer_init(struct device_node *np)
{
return fttmr010_common_init(np, true);
}
static __init int fttmr010_timer_init(struct device_node *np)
{
return fttmr010_common_init(np, false);
}
TIMER_OF_DECLARE(fttmr010, "faraday,fttmr010", fttmr010_timer_init);
TIMER_OF_DECLARE(gemini, "cortina,gemini-timer", fttmr010_timer_init);
TIMER_OF_DECLARE(moxart, "moxa,moxart-timer", fttmr010_timer_init);
TIMER_OF_DECLARE(ast2400, "aspeed,ast2400-timer", aspeed_timer_init);
TIMER_OF_DECLARE(ast2500, "aspeed,ast2500-timer", aspeed_timer_init);
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