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linux/drivers/clocksource/timer-u300.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

463 lines
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/*
* Copyright (C) 2007-2009 ST-Ericsson AB
* License terms: GNU General Public License (GPL) version 2
* Timer COH 901 328, runs the OS timer interrupt.
* Author: Linus Walleij <linus.walleij@stericsson.com>
*/
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>
/* Generic stuff */
#include <asm/mach/map.h>
#include <asm/mach/time.h>
/*
* APP side special timer registers
* This timer contains four timers which can fire an interrupt each.
* OS (operating system) timer @ 32768 Hz
* DD (device driver) timer @ 1 kHz
* GP1 (general purpose 1) timer @ 1MHz
* GP2 (general purpose 2) timer @ 1MHz
*/
/* Reset OS Timer 32bit (-/W) */
#define U300_TIMER_APP_ROST (0x0000)
#define U300_TIMER_APP_ROST_TIMER_RESET (0x00000000)
/* Enable OS Timer 32bit (-/W) */
#define U300_TIMER_APP_EOST (0x0004)
#define U300_TIMER_APP_EOST_TIMER_ENABLE (0x00000000)
/* Disable OS Timer 32bit (-/W) */
#define U300_TIMER_APP_DOST (0x0008)
#define U300_TIMER_APP_DOST_TIMER_DISABLE (0x00000000)
/* OS Timer Mode Register 32bit (-/W) */
#define U300_TIMER_APP_SOSTM (0x000c)
#define U300_TIMER_APP_SOSTM_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_SOSTM_MODE_ONE_SHOT (0x00000001)
/* OS Timer Status Register 32bit (R/-) */
#define U300_TIMER_APP_OSTS (0x0010)
#define U300_TIMER_APP_OSTS_TIMER_STATE_MASK (0x0000000F)
#define U300_TIMER_APP_OSTS_TIMER_STATE_IDLE (0x00000001)
#define U300_TIMER_APP_OSTS_TIMER_STATE_ACTIVE (0x00000002)
#define U300_TIMER_APP_OSTS_ENABLE_IND (0x00000010)
#define U300_TIMER_APP_OSTS_MODE_MASK (0x00000020)
#define U300_TIMER_APP_OSTS_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_OSTS_MODE_ONE_SHOT (0x00000020)
#define U300_TIMER_APP_OSTS_IRQ_ENABLED_IND (0x00000040)
#define U300_TIMER_APP_OSTS_IRQ_PENDING_IND (0x00000080)
/* OS Timer Current Count Register 32bit (R/-) */
#define U300_TIMER_APP_OSTCC (0x0014)
/* OS Timer Terminal Count Register 32bit (R/W) */
#define U300_TIMER_APP_OSTTC (0x0018)
/* OS Timer Interrupt Enable Register 32bit (-/W) */
#define U300_TIMER_APP_OSTIE (0x001c)
#define U300_TIMER_APP_OSTIE_IRQ_DISABLE (0x00000000)
#define U300_TIMER_APP_OSTIE_IRQ_ENABLE (0x00000001)
/* OS Timer Interrupt Acknowledge Register 32bit (-/W) */
#define U300_TIMER_APP_OSTIA (0x0020)
#define U300_TIMER_APP_OSTIA_IRQ_ACK (0x00000080)
/* Reset DD Timer 32bit (-/W) */
#define U300_TIMER_APP_RDDT (0x0040)
#define U300_TIMER_APP_RDDT_TIMER_RESET (0x00000000)
/* Enable DD Timer 32bit (-/W) */
#define U300_TIMER_APP_EDDT (0x0044)
#define U300_TIMER_APP_EDDT_TIMER_ENABLE (0x00000000)
/* Disable DD Timer 32bit (-/W) */
#define U300_TIMER_APP_DDDT (0x0048)
#define U300_TIMER_APP_DDDT_TIMER_DISABLE (0x00000000)
/* DD Timer Mode Register 32bit (-/W) */
#define U300_TIMER_APP_SDDTM (0x004c)
#define U300_TIMER_APP_SDDTM_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_SDDTM_MODE_ONE_SHOT (0x00000001)
/* DD Timer Status Register 32bit (R/-) */
#define U300_TIMER_APP_DDTS (0x0050)
#define U300_TIMER_APP_DDTS_TIMER_STATE_MASK (0x0000000F)
#define U300_TIMER_APP_DDTS_TIMER_STATE_IDLE (0x00000001)
#define U300_TIMER_APP_DDTS_TIMER_STATE_ACTIVE (0x00000002)
#define U300_TIMER_APP_DDTS_ENABLE_IND (0x00000010)
#define U300_TIMER_APP_DDTS_MODE_MASK (0x00000020)
#define U300_TIMER_APP_DDTS_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_DDTS_MODE_ONE_SHOT (0x00000020)
#define U300_TIMER_APP_DDTS_IRQ_ENABLED_IND (0x00000040)
#define U300_TIMER_APP_DDTS_IRQ_PENDING_IND (0x00000080)
/* DD Timer Current Count Register 32bit (R/-) */
#define U300_TIMER_APP_DDTCC (0x0054)
/* DD Timer Terminal Count Register 32bit (R/W) */
#define U300_TIMER_APP_DDTTC (0x0058)
/* DD Timer Interrupt Enable Register 32bit (-/W) */
#define U300_TIMER_APP_DDTIE (0x005c)
#define U300_TIMER_APP_DDTIE_IRQ_DISABLE (0x00000000)
#define U300_TIMER_APP_DDTIE_IRQ_ENABLE (0x00000001)
/* DD Timer Interrupt Acknowledge Register 32bit (-/W) */
#define U300_TIMER_APP_DDTIA (0x0060)
#define U300_TIMER_APP_DDTIA_IRQ_ACK (0x00000080)
/* Reset GP1 Timer 32bit (-/W) */
#define U300_TIMER_APP_RGPT1 (0x0080)
#define U300_TIMER_APP_RGPT1_TIMER_RESET (0x00000000)
/* Enable GP1 Timer 32bit (-/W) */
#define U300_TIMER_APP_EGPT1 (0x0084)
#define U300_TIMER_APP_EGPT1_TIMER_ENABLE (0x00000000)
/* Disable GP1 Timer 32bit (-/W) */
#define U300_TIMER_APP_DGPT1 (0x0088)
#define U300_TIMER_APP_DGPT1_TIMER_DISABLE (0x00000000)
/* GP1 Timer Mode Register 32bit (-/W) */
#define U300_TIMER_APP_SGPT1M (0x008c)
#define U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT (0x00000001)
/* GP1 Timer Status Register 32bit (R/-) */
#define U300_TIMER_APP_GPT1S (0x0090)
#define U300_TIMER_APP_GPT1S_TIMER_STATE_MASK (0x0000000F)
#define U300_TIMER_APP_GPT1S_TIMER_STATE_IDLE (0x00000001)
#define U300_TIMER_APP_GPT1S_TIMER_STATE_ACTIVE (0x00000002)
#define U300_TIMER_APP_GPT1S_ENABLE_IND (0x00000010)
#define U300_TIMER_APP_GPT1S_MODE_MASK (0x00000020)
#define U300_TIMER_APP_GPT1S_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_GPT1S_MODE_ONE_SHOT (0x00000020)
#define U300_TIMER_APP_GPT1S_IRQ_ENABLED_IND (0x00000040)
#define U300_TIMER_APP_GPT1S_IRQ_PENDING_IND (0x00000080)
/* GP1 Timer Current Count Register 32bit (R/-) */
#define U300_TIMER_APP_GPT1CC (0x0094)
/* GP1 Timer Terminal Count Register 32bit (R/W) */
#define U300_TIMER_APP_GPT1TC (0x0098)
/* GP1 Timer Interrupt Enable Register 32bit (-/W) */
#define U300_TIMER_APP_GPT1IE (0x009c)
#define U300_TIMER_APP_GPT1IE_IRQ_DISABLE (0x00000000)
#define U300_TIMER_APP_GPT1IE_IRQ_ENABLE (0x00000001)
/* GP1 Timer Interrupt Acknowledge Register 32bit (-/W) */
#define U300_TIMER_APP_GPT1IA (0x00a0)
#define U300_TIMER_APP_GPT1IA_IRQ_ACK (0x00000080)
/* Reset GP2 Timer 32bit (-/W) */
#define U300_TIMER_APP_RGPT2 (0x00c0)
#define U300_TIMER_APP_RGPT2_TIMER_RESET (0x00000000)
/* Enable GP2 Timer 32bit (-/W) */
#define U300_TIMER_APP_EGPT2 (0x00c4)
#define U300_TIMER_APP_EGPT2_TIMER_ENABLE (0x00000000)
/* Disable GP2 Timer 32bit (-/W) */
#define U300_TIMER_APP_DGPT2 (0x00c8)
#define U300_TIMER_APP_DGPT2_TIMER_DISABLE (0x00000000)
/* GP2 Timer Mode Register 32bit (-/W) */
#define U300_TIMER_APP_SGPT2M (0x00cc)
#define U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_SGPT2M_MODE_ONE_SHOT (0x00000001)
/* GP2 Timer Status Register 32bit (R/-) */
#define U300_TIMER_APP_GPT2S (0x00d0)
#define U300_TIMER_APP_GPT2S_TIMER_STATE_MASK (0x0000000F)
#define U300_TIMER_APP_GPT2S_TIMER_STATE_IDLE (0x00000001)
#define U300_TIMER_APP_GPT2S_TIMER_STATE_ACTIVE (0x00000002)
#define U300_TIMER_APP_GPT2S_ENABLE_IND (0x00000010)
#define U300_TIMER_APP_GPT2S_MODE_MASK (0x00000020)
#define U300_TIMER_APP_GPT2S_MODE_CONTINUOUS (0x00000000)
#define U300_TIMER_APP_GPT2S_MODE_ONE_SHOT (0x00000020)
#define U300_TIMER_APP_GPT2S_IRQ_ENABLED_IND (0x00000040)
#define U300_TIMER_APP_GPT2S_IRQ_PENDING_IND (0x00000080)
/* GP2 Timer Current Count Register 32bit (R/-) */
#define U300_TIMER_APP_GPT2CC (0x00d4)
/* GP2 Timer Terminal Count Register 32bit (R/W) */
#define U300_TIMER_APP_GPT2TC (0x00d8)
/* GP2 Timer Interrupt Enable Register 32bit (-/W) */
#define U300_TIMER_APP_GPT2IE (0x00dc)
#define U300_TIMER_APP_GPT2IE_IRQ_DISABLE (0x00000000)
#define U300_TIMER_APP_GPT2IE_IRQ_ENABLE (0x00000001)
/* GP2 Timer Interrupt Acknowledge Register 32bit (-/W) */
#define U300_TIMER_APP_GPT2IA (0x00e0)
#define U300_TIMER_APP_GPT2IA_IRQ_ACK (0x00000080)
/* Clock request control register - all four timers */
#define U300_TIMER_APP_CRC (0x100)
#define U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE (0x00000001)
static void __iomem *u300_timer_base;
struct u300_clockevent_data {
struct clock_event_device cevd;
unsigned ticks_per_jiffy;
};
static int u300_shutdown(struct clock_event_device *evt)
{
/* Disable interrupts on GP1 */
writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
u300_timer_base + U300_TIMER_APP_GPT1IE);
/* Disable GP1 */
writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
u300_timer_base + U300_TIMER_APP_DGPT1);
return 0;
}
/*
* If we have oneshot timer active, the oneshot scheduling function
* u300_set_next_event() is called immediately after.
*/
static int u300_set_oneshot(struct clock_event_device *evt)
{
/* Just return; here? */
/*
* The actual event will be programmed by the next event hook,
* so we just set a dummy value somewhere at the end of the
* universe here.
*/
/* Disable interrupts on GPT1 */
writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
u300_timer_base + U300_TIMER_APP_GPT1IE);
/* Disable GP1 while we're reprogramming it. */
writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
u300_timer_base + U300_TIMER_APP_DGPT1);
/*
* Expire far in the future, u300_set_next_event() will be
* called soon...
*/
writel(0xFFFFFFFF, u300_timer_base + U300_TIMER_APP_GPT1TC);
/* We run one shot per tick here! */
writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,
u300_timer_base + U300_TIMER_APP_SGPT1M);
/* Enable interrupts for this timer */
writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
u300_timer_base + U300_TIMER_APP_GPT1IE);
/* Enable timer */
writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
u300_timer_base + U300_TIMER_APP_EGPT1);
return 0;
}
static int u300_set_periodic(struct clock_event_device *evt)
{
struct u300_clockevent_data *cevdata =
container_of(evt, struct u300_clockevent_data, cevd);
/* Disable interrupts on GPT1 */
writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
u300_timer_base + U300_TIMER_APP_GPT1IE);
/* Disable GP1 while we're reprogramming it. */
writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
u300_timer_base + U300_TIMER_APP_DGPT1);
/*
* Set the periodic mode to a certain number of ticks per
* jiffy.
*/
writel(cevdata->ticks_per_jiffy,
u300_timer_base + U300_TIMER_APP_GPT1TC);
/*
* Set continuous mode, so the timer keeps triggering
* interrupts.
*/
writel(U300_TIMER_APP_SGPT1M_MODE_CONTINUOUS,
u300_timer_base + U300_TIMER_APP_SGPT1M);
/* Enable timer interrupts */
writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
u300_timer_base + U300_TIMER_APP_GPT1IE);
/* Then enable the OS timer again */
writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
u300_timer_base + U300_TIMER_APP_EGPT1);
return 0;
}
/*
* The app timer in one shot mode obviously has to be reprogrammed
* in EXACTLY this sequence to work properly. Do NOT try to e.g. replace
* the interrupt disable + timer disable commands with a reset command,
* it will fail miserably. Apparently (and I found this the hard way)
* the timer is very sensitive to the instruction order, though you don't
* get that impression from the data sheet.
*/
static int u300_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
/* Disable interrupts on GPT1 */
writel(U300_TIMER_APP_GPT1IE_IRQ_DISABLE,
u300_timer_base + U300_TIMER_APP_GPT1IE);
/* Disable GP1 while we're reprogramming it. */
writel(U300_TIMER_APP_DGPT1_TIMER_DISABLE,
u300_timer_base + U300_TIMER_APP_DGPT1);
/* Reset the General Purpose timer 1. */
writel(U300_TIMER_APP_RGPT1_TIMER_RESET,
u300_timer_base + U300_TIMER_APP_RGPT1);
/* IRQ in n * cycles */
writel(cycles, u300_timer_base + U300_TIMER_APP_GPT1TC);
/*
* We run one shot per tick here! (This is necessary to reconfigure,
* the timer will tilt if you don't!)
*/
writel(U300_TIMER_APP_SGPT1M_MODE_ONE_SHOT,
u300_timer_base + U300_TIMER_APP_SGPT1M);
/* Enable timer interrupts */
writel(U300_TIMER_APP_GPT1IE_IRQ_ENABLE,
u300_timer_base + U300_TIMER_APP_GPT1IE);
/* Then enable the OS timer again */
writel(U300_TIMER_APP_EGPT1_TIMER_ENABLE,
u300_timer_base + U300_TIMER_APP_EGPT1);
return 0;
}
static struct u300_clockevent_data u300_clockevent_data = {
/* Use general purpose timer 1 as clock event */
.cevd = {
.name = "GPT1",
/* Reasonably fast and accurate clock event */
.rating = 300,
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = u300_set_next_event,
.set_state_shutdown = u300_shutdown,
.set_state_periodic = u300_set_periodic,
.set_state_oneshot = u300_set_oneshot,
},
};
/* Clock event timer interrupt handler */
static irqreturn_t u300_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &u300_clockevent_data.cevd;
/* ACK/Clear timer IRQ for the APP GPT1 Timer */
writel(U300_TIMER_APP_GPT1IA_IRQ_ACK,
u300_timer_base + U300_TIMER_APP_GPT1IA);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction u300_timer_irq = {
.name = "U300 Timer Tick",
.flags = IRQF_TIMER | IRQF_IRQPOLL,
.handler = u300_timer_interrupt,
};
/*
* Override the global weak sched_clock symbol with this
* local implementation which uses the clocksource to get some
* better resolution when scheduling the kernel. We accept that
* this wraps around for now, since it is just a relative time
* stamp. (Inspired by OMAP implementation.)
*/
static u64 notrace u300_read_sched_clock(void)
{
return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);
}
static unsigned long u300_read_current_timer(void)
{
return readl(u300_timer_base + U300_TIMER_APP_GPT2CC);
}
static struct delay_timer u300_delay_timer;
/*
* This sets up the system timers, clock source and clock event.
*/
static int __init u300_timer_init_of(struct device_node *np)
{
unsigned int irq;
struct clk *clk;
unsigned long rate;
int ret;
u300_timer_base = of_iomap(np, 0);
if (!u300_timer_base) {
pr_err("could not ioremap system timer\n");
return -ENXIO;
}
/* Get the IRQ for the GP1 timer */
irq = irq_of_parse_and_map(np, 2);
if (!irq) {
pr_err("no IRQ for system timer\n");
return -EINVAL;
}
pr_info("U300 GP1 timer @ base: %p, IRQ: %u\n", u300_timer_base, irq);
/* Clock the interrupt controller */
clk = of_clk_get(np, 0);
if (IS_ERR(clk))
return PTR_ERR(clk);
ret = clk_prepare_enable(clk);
if (ret)
return ret;
rate = clk_get_rate(clk);
u300_clockevent_data.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
sched_clock_register(u300_read_sched_clock, 32, rate);
u300_delay_timer.read_current_timer = &u300_read_current_timer;
u300_delay_timer.freq = rate;
register_current_timer_delay(&u300_delay_timer);
/*
* Disable the "OS" and "DD" timers - these are designed for Symbian!
* Example usage in cnh1601578 cpu subsystem pd_timer_app.c
*/
writel(U300_TIMER_APP_CRC_CLOCK_REQUEST_ENABLE,
u300_timer_base + U300_TIMER_APP_CRC);
writel(U300_TIMER_APP_ROST_TIMER_RESET,
u300_timer_base + U300_TIMER_APP_ROST);
writel(U300_TIMER_APP_DOST_TIMER_DISABLE,
u300_timer_base + U300_TIMER_APP_DOST);
writel(U300_TIMER_APP_RDDT_TIMER_RESET,
u300_timer_base + U300_TIMER_APP_RDDT);
writel(U300_TIMER_APP_DDDT_TIMER_DISABLE,
u300_timer_base + U300_TIMER_APP_DDDT);
/* Reset the General Purpose timer 1. */
writel(U300_TIMER_APP_RGPT1_TIMER_RESET,
u300_timer_base + U300_TIMER_APP_RGPT1);
/* Set up the IRQ handler */
ret = setup_irq(irq, &u300_timer_irq);
if (ret)
return ret;
/* Reset the General Purpose timer 2 */
writel(U300_TIMER_APP_RGPT2_TIMER_RESET,
u300_timer_base + U300_TIMER_APP_RGPT2);
/* Set this timer to run around forever */
writel(0xFFFFFFFFU, u300_timer_base + U300_TIMER_APP_GPT2TC);
/* Set continuous mode so it wraps around */
writel(U300_TIMER_APP_SGPT2M_MODE_CONTINUOUS,
u300_timer_base + U300_TIMER_APP_SGPT2M);
/* Disable timer interrupts */
writel(U300_TIMER_APP_GPT2IE_IRQ_DISABLE,
u300_timer_base + U300_TIMER_APP_GPT2IE);
/* Then enable the GP2 timer to use as a free running us counter */
writel(U300_TIMER_APP_EGPT2_TIMER_ENABLE,
u300_timer_base + U300_TIMER_APP_EGPT2);
/* Use general purpose timer 2 as clock source */
ret = clocksource_mmio_init(u300_timer_base + U300_TIMER_APP_GPT2CC,
"GPT2", rate, 300, 32, clocksource_mmio_readl_up);
if (ret) {
pr_err("timer: failed to initialize U300 clock source\n");
return ret;
}
/* Configure and register the clockevent */
clockevents_config_and_register(&u300_clockevent_data.cevd, rate,
1, 0xffffffff);
/*
* TODO: init and register the rest of the timers too, they can be
* used by hrtimers!
*/
return 0;
}
TIMER_OF_DECLARE(u300_timer, "stericsson,u300-apptimer",
u300_timer_init_of);
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