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Release 4.14 drivers/clocksource/sh_cmt.c

Directory: drivers/clocksource
/*
 * SuperH Timer Support - CMT
 *
 *  Copyright (C) 2008 Magnus Damm
 *
 * 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
 *
 * 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.
 */

#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/sh_timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

struct sh_cmt_device;

/*
 * The CMT comes in 5 different identified flavours, depending not only on the
 * SoC but also on the particular instance. The following table lists the main
 * characteristics of those flavours.
 *
 *                      16B     32B     32B-F   48B     48B-2
 * -----------------------------------------------------------------------------
 * Channels             2       1/4     1       6       2/8
 * Control Width        16      16      16      16      32
 * Counter Width        16      32      32      32/48   32/48
 * Shared Start/Stop    Y       Y       Y       Y       N
 *
 * The 48-bit gen2 version has a per-channel start/stop register located in the
 * channel registers block. All other versions have a shared start/stop register
 * located in the global space.
 *
 * Channels are indexed from 0 to N-1 in the documentation. The channel index
 * infers the start/stop bit position in the control register and the channel
 * registers block address. Some CMT instances have a subset of channels
 * available, in which case the index in the documentation doesn't match the
 * "real" index as implemented in hardware. This is for instance the case with
 * CMT0 on r8a7740, which is a 32-bit variant with a single channel numbered 0
 * in the documentation but using start/stop bit 5 and having its registers
 * block at 0x60.
 *
 * Similarly CMT0 on r8a73a4, r8a7790 and r8a7791, while implementing 32-bit
 * channels only, is a 48-bit gen2 CMT with the 48-bit channels unavailable.
 */


enum sh_cmt_model {
	
SH_CMT_16BIT,
	
SH_CMT_32BIT,
	
SH_CMT_32BIT_FAST,
	
SH_CMT_48BIT,
	
SH_CMT_48BIT_GEN2,
};


struct sh_cmt_info {
	
enum sh_cmt_model model;

	
unsigned long width; /* 16 or 32 bit version of hardware block */
	
unsigned long overflow_bit;
	
unsigned long clear_bits;

	/* callbacks for CMSTR and CMCSR access */
	
unsigned long (*read_control)(void __iomem *base, unsigned long offs);
	
void (*write_control)(void __iomem *base, unsigned long offs,
			      unsigned long value);

	/* callbacks for CMCNT and CMCOR access */
	
unsigned long (*read_count)(void __iomem *base, unsigned long offs);
	
void (*write_count)(void __iomem *base, unsigned long offs,
			    unsigned long value);
};


struct sh_cmt_channel {
	
struct sh_cmt_device *cmt;

	
unsigned int index;	/* Index in the documentation */
	
unsigned int hwidx;	/* Real hardware index */

	
void __iomem *iostart;
	
void __iomem *ioctrl;

	
unsigned int timer_bit;
	
unsigned long flags;
	
unsigned long match_value;
	
unsigned long next_match_value;
	
unsigned long max_match_value;
	
raw_spinlock_t lock;
	
struct clock_event_device ced;
	
struct clocksource cs;
	
unsigned long total_cycles;
	
bool cs_enabled;
};


struct sh_cmt_device {
	
struct platform_device *pdev;

	
const struct sh_cmt_info *info;

	
void __iomem *mapbase;
	
struct clk *clk;
	
unsigned long rate;

	
raw_spinlock_t lock; /* Protect the shared start/stop register */

	
struct sh_cmt_channel *channels;
	
unsigned int num_channels;
	
unsigned int hw_channels;

	
bool has_clockevent;
	
bool has_clocksource;
};


#define SH_CMT16_CMCSR_CMF		(1 << 7)

#define SH_CMT16_CMCSR_CMIE		(1 << 6)

#define SH_CMT16_CMCSR_CKS8		(0 << 0)

#define SH_CMT16_CMCSR_CKS32		(1 << 0)

#define SH_CMT16_CMCSR_CKS128		(2 << 0)

#define SH_CMT16_CMCSR_CKS512		(3 << 0)

#define SH_CMT16_CMCSR_CKS_MASK		(3 << 0)


#define SH_CMT32_CMCSR_CMF		(1 << 15)

#define SH_CMT32_CMCSR_OVF		(1 << 14)

#define SH_CMT32_CMCSR_WRFLG		(1 << 13)

#define SH_CMT32_CMCSR_STTF		(1 << 12)

#define SH_CMT32_CMCSR_STPF		(1 << 11)

#define SH_CMT32_CMCSR_SSIE		(1 << 10)

#define SH_CMT32_CMCSR_CMS		(1 << 9)

#define SH_CMT32_CMCSR_CMM		(1 << 8)

#define SH_CMT32_CMCSR_CMTOUT_IE	(1 << 7)

#define SH_CMT32_CMCSR_CMR_NONE		(0 << 4)

#define SH_CMT32_CMCSR_CMR_DMA		(1 << 4)

#define SH_CMT32_CMCSR_CMR_IRQ		(2 << 4)

#define SH_CMT32_CMCSR_CMR_MASK		(3 << 4)

#define SH_CMT32_CMCSR_DBGIVD		(1 << 3)

#define SH_CMT32_CMCSR_CKS_RCLK8	(4 << 0)

#define SH_CMT32_CMCSR_CKS_RCLK32	(5 << 0)

#define SH_CMT32_CMCSR_CKS_RCLK128	(6 << 0)

#define SH_CMT32_CMCSR_CKS_RCLK1	(7 << 0)

#define SH_CMT32_CMCSR_CKS_MASK		(7 << 0)




static unsigned long sh_cmt_read16(void __iomem *base, unsigned long offs)
{
	return ioread16(base + (offs << 1));
}


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static unsigned long sh_cmt_read32(void __iomem *base, unsigned long offs)
{
	return ioread32(base + (offs << 2));
}


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static void sh_cmt_write16(void __iomem *base, unsigned long offs,
			   unsigned long value)
{
	iowrite16(value, base + (offs << 1));
}


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static void sh_cmt_write32(void __iomem *base, unsigned long offs,
			   unsigned long value)
{
	iowrite32(value, base + (offs << 2));
}


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static const struct sh_cmt_info sh_cmt_info[] = {
	[SH_CMT_16BIT] = {
		.model = SH_CMT_16BIT,
		.width = 16,
		.overflow_bit = SH_CMT16_CMCSR_CMF,
		.clear_bits = ~SH_CMT16_CMCSR_CMF,
		.read_control = sh_cmt_read16,
		.write_control = sh_cmt_write16,
		.read_count = sh_cmt_read16,
		.write_count = sh_cmt_write16,
        },
	[SH_CMT_32BIT] = {
		.model = SH_CMT_32BIT,
		.width = 32,
		.overflow_bit = SH_CMT32_CMCSR_CMF,
		.clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
		.read_control = sh_cmt_read16,
		.write_control = sh_cmt_write16,
		.read_count = sh_cmt_read32,
		.write_count = sh_cmt_write32,
        },
	[SH_CMT_32BIT_FAST] = {
		.model = SH_CMT_32BIT_FAST,
		.width = 32,
		.overflow_bit = SH_CMT32_CMCSR_CMF,
		.clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
		.read_control = sh_cmt_read16,
		.write_control = sh_cmt_write16,
		.read_count = sh_cmt_read32,
		.write_count = sh_cmt_write32,
        },
	[SH_CMT_48BIT] = {
		.model = SH_CMT_48BIT,
		.width = 32,
		.overflow_bit = SH_CMT32_CMCSR_CMF,
		.clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
		.read_control = sh_cmt_read32,
		.write_control = sh_cmt_write32,
		.read_count = sh_cmt_read32,
		.write_count = sh_cmt_write32,
        },
	[SH_CMT_48BIT_GEN2] = {
		.model = SH_CMT_48BIT_GEN2,
		.width = 32,
		.overflow_bit = SH_CMT32_CMCSR_CMF,
		.clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF),
		.read_control = sh_cmt_read32,
		.write_control = sh_cmt_write32,
		.read_count = sh_cmt_read32,
		.write_count = sh_cmt_write32,
        },
};


#define CMCSR 0 
/* channel register */

#define CMCNT 1 
/* channel register */

#define CMCOR 2 
/* channel register */




static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_channel *ch)
{
	if (ch->iostart)
		return ch->cmt->info->read_control(ch->iostart, 0);
	else
		return ch->cmt->info->read_control(ch->cmt->mapbase, 0);
}


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static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch,
				      unsigned long value)
{
	if (ch->iostart)
		ch->cmt->info->write_control(ch->iostart, 0, value);
	else
		ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
}


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static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_channel *ch)
{
	return ch->cmt->info->read_control(ch->ioctrl, CMCSR);
}


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static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch,
				      unsigned long value)
{
	ch->cmt->info->write_control(ch->ioctrl, CMCSR, value);
}


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static inline unsigned long sh_cmt_read_cmcnt(struct sh_cmt_channel *ch)
{
	return ch->cmt->info->read_count(ch->ioctrl, CMCNT);
}


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static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch,
				      unsigned long value)
{
	ch->cmt->info->write_count(ch->ioctrl, CMCNT, value);
}


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static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch,
				      unsigned long value)
{
	ch->cmt->info->write_count(ch->ioctrl, CMCOR, value);
}


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static unsigned long sh_cmt_get_counter(struct sh_cmt_channel *ch,
					int *has_wrapped)
{
	unsigned long v1, v2, v3;
	int o1, o2;

	o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit;

	/* Make sure the timer value is stable. Stolen from acpi_pm.c */
	do {
		o2 = o1;
		v1 = sh_cmt_read_cmcnt(ch);
		v2 = sh_cmt_read_cmcnt(ch);
		v3 = sh_cmt_read_cmcnt(ch);
		o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit;
	} while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
			  || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));

	*has_wrapped = o1;
	return v2;
}


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static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
{
	unsigned long flags, value;

	/* start stop register shared by multiple timer channels */
	raw_spin_lock_irqsave(&ch->cmt->lock, flags);
	value = sh_cmt_read_cmstr(ch);

	if (start)
		value |= 1 << ch->timer_bit;
	else
		value &= ~(1 << ch->timer_bit);

	sh_cmt_write_cmstr(ch, value);
	raw_spin_unlock_irqrestore(&ch->cmt->lock, flags);
}


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static int sh_cmt_enable(struct sh_cmt_channel *ch)
{
	int k, ret;

	pm_runtime_get_sync(&ch->cmt->pdev->dev);
	dev_pm_syscore_device(&ch->cmt->pdev->dev, true);

	/* enable clock */
	ret = clk_enable(ch->cmt->clk);
	if (ret) {
		dev_err(&ch->cmt->pdev->dev, "ch%u: cannot enable clock\n",
			ch->index);
		goto err0;
	}

	/* make sure channel is disabled */
	sh_cmt_start_stop_ch(ch, 0);

	/* configure channel, periodic mode and maximum timeout */
	if (ch->cmt->info->width == 16) {
		sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE |
				   SH_CMT16_CMCSR_CKS512);
	} else {
		sh_cmt_write_cmcsr(ch, SH_CMT32_CMCSR_CMM |
				   SH_CMT32_CMCSR_CMTOUT_IE |
				   SH_CMT32_CMCSR_CMR_IRQ |
				   SH_CMT32_CMCSR_CKS_RCLK8);
	}

	sh_cmt_write_cmcor(ch, 0xffffffff);
	sh_cmt_write_cmcnt(ch, 0);

	/*
         * According to the sh73a0 user's manual, as CMCNT can be operated
         * only by the RCLK (Pseudo 32 KHz), there's one restriction on
         * modifying CMCNT register; two RCLK cycles are necessary before
         * this register is either read or any modification of the value
         * it holds is reflected in the LSI's actual operation.
         *
         * While at it, we're supposed to clear out the CMCNT as of this
         * moment, so make sure it's processed properly here.  This will
         * take RCLKx2 at maximum.
         */
	for (k = 0; k < 100; k++) {
		if (!sh_cmt_read_cmcnt(ch))
			break;
		udelay(1);
	}

	if (sh_cmt_read_cmcnt(ch)) {
		dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n",
			ch->index);
		ret = -ETIMEDOUT;
		goto err1;
	}

	/* enable channel */
	sh_cmt_start_stop_ch(ch, 1);
	return 0;
 err1:
	/* stop clock */
	clk_disable(ch->cmt->clk);

 err0:
	return ret;
}


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Total236100.00%11100.00%






static void sh_cmt_disable(struct sh_cmt_channel *ch)
{
	/* disable channel */
	sh_cmt_start_stop_ch(ch, 0);

	/* disable interrupts in CMT block */
	sh_cmt_write_cmcsr(ch, 0);

	/* stop clock */
	clk_disable(ch->cmt->clk);

	dev_pm_syscore_device(&ch->cmt->pdev->dev, false);
	pm_runtime_put(&ch->cmt->pdev->dev);
}


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/* private flags */

#define FLAG_CLOCKEVENT (1 << 0)

#define FLAG_CLOCKSOURCE (1 << 1)

#define FLAG_REPROGRAM (1 << 2)

#define FLAG_SKIPEVENT (1 << 3)

#define FLAG_IRQCONTEXT (1 << 4)




static void sh_cmt_clock_event_program_verify(struct sh_cmt_channel *ch,
					      int absolute)
{
	unsigned long new_match;
	unsigned long value = ch->next_match_value;
	unsigned long delay = 0;
	unsigned long now = 0;
	int has_wrapped;

	now = sh_cmt_get_counter(ch, &has_wrapped);
	ch->flags |= FLAG_REPROGRAM; /* force reprogram */

	if (has_wrapped) {
		/* we're competing with the interrupt handler.
                 *  -> let the interrupt handler reprogram the timer.
                 *  -> interrupt number two handles the event.
                 */
		ch->flags |= FLAG_SKIPEVENT;
		return;
	}

	if (absolute)
		now = 0;

	do {
		/* reprogram the timer hardware,
                 * but don't save the new match value yet.
                 */
		new_match = now + value + delay;
		if (new_match > ch->max_match_value)
			new_match = ch->max_match_value;

		sh_cmt_write_cmcor(ch, new_match);

		now = sh_cmt_get_counter(ch, &has_wrapped);
		if (has_wrapped && (new_match > ch->match_value)) {
			/* we are changing to a greater match value,
                         * so this wrap must be caused by the counter
                         * matching the old value.
                         * -> first interrupt reprograms the timer.
                         * -> interrupt number two handles the event.
                         */
			ch->flags |= FLAG_SKIPEVENT;
			break;
		}

		if (has_wrapped) {
			/* we are changing to a smaller match value,
                         * so the wrap must be caused by the counter
                         * matching the new value.
                         * -> save programmed match value.
                         * -> let isr handle the event.
                         */
			ch->match_value = new_match;
			break;
		}

		/* be safe: verify hardware settings */
		if (now < new_match) {
			/* timer value is below match value, all good.
                         * this makes sure we won't miss any match events.
                         * -> save programmed match value.
                         * -> let isr handle the event.
                         */
			ch->match_value = new_match;
			break;
		}

		/* the counter has reached a value greater
                 * than our new match value. and since the
                 * has_wrapped flag isn't set we must have
                 * programmed a too close event.
                 * -> increase delay and retry.
                 */
		if (delay)
			delay <<= 1;
		else
			delay = 1;

		if (!delay)
			dev_warn(&ch->cmt->pdev->dev, "ch%u: too long delay\n",
				 ch->index);

	} while (delay);
}


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static void __sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta)
{
	if (delta > ch->max_match_value)
		dev_warn(&ch->cmt->pdev->dev, "ch%u: delta out of range\n",
			 ch->index);

	ch->next_match_value = delta;
	sh_cmt_clock_event_program_verify(ch, 0);
}


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static void sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&ch->lock, flags);
	__sh_cmt_set_next(ch, delta);
	raw_spin_unlock_irqrestore(&ch->lock, flags);
}


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static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
{
	struct sh_cmt_channel *ch = dev_id;

	/* clear flags */
	sh_cmt_write_cmcsr(ch, sh_cmt_read_cmcsr(ch) &
			   ch->cmt->info->clear_bits);

	/* update clock source counter to begin with if enabled
         * the wrap flag should be cleared by the timer specific
         * isr before we end up here.
         */
	if (ch->flags & FLAG_CLOCKSOURCE)
		ch->total_cycles += ch->match_value + 1;

	if (!(ch->flags & FLAG_REPROGRAM))
		ch->next_match_value = ch->max_match_value;

	ch->flags |= FLAG_IRQCONTEXT;

	if (ch->flags & FLAG_CLOCKEVENT) {
		if (!(ch->flags & FLAG_SKIPEVENT)) {
			if (clockevent_state_oneshot(&ch->ced)) {
				ch->next_match_value = ch->max_match_value;
				ch->flags |= FLAG_REPROGRAM;
			}

			ch->ced.event_handler(&ch->ced);
		}
	}

	ch->flags &= ~FLAG_SKIPEVENT;

	if (ch->flags & FLAG_REPROGRAM) {
		ch->flags &= ~FLAG_REPROGRAM;
		sh_cmt_clock_event_program_verify(ch, 1);

		if (ch->flags & FLAG_CLOCKEVENT)
			if ((clockevent_state_shutdown(&ch->ced))
			    || (ch->match_value == ch->next_match_value))
				ch->flags &= ~FLAG_REPROGRAM;
	}

	ch->flags &= ~FLAG_IRQCONTEXT;

	return IRQ_HANDLED;
}


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static int sh_cmt_start(struct sh_cmt_channel *ch, unsigned long flag)
{
	int ret = 0;
	unsigned long flags;

	raw_spin_lock_irqsave(&ch->lock, flags);

	if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
		ret = sh_cmt_enable(ch);

	if (ret)
		goto out;
	ch->flags |= flag;

	/* setup timeout if no clockevent */
	if ((flag == FLAG_CLOCKSOURCE) && (!(ch->flags & FLAG_CLOCKEVENT)))
		__sh_cmt_set_next(ch, ch->max_match_value);
 out:
	raw_spin_unlock_irqrestore(&ch->lock, flags);

	return ret;
}


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static void sh_cmt_stop(struct sh_cmt_channel *ch, unsigned long flag)
{
	unsigned long flags;
	unsigned long f;

	raw_spin_lock_irqsave(&ch->lock, flags);

	f = ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE);
	ch->flags &= ~flag;

	if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE)))
		sh_cmt_disable(ch);

	/* adjust the timeout to maximum if only clocksource left */
	if ((flag == FLAG_CLOCKEVENT) && (ch->flags & FLAG_CLOCKSOURCE))
		__sh_cmt_set_next(ch, ch->max_match_value);

	raw_spin_unlock_irqrestore(&ch->lock, flags);
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm9687.27%125.00%


Laurent Pinchart1110.00%125.00%


Paul Mundt21.82%125.00%


Takashi Yoshii10.91%125.00%


Total110100.00%4100.00%






static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs)
{
	return container_of(cs, struct sh_cmt_channel, cs);
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm2291.67%150.00%


Laurent Pinchart28.33%150.00%


Total24100.00%2100.00%






static u64 sh_cmt_clocksource_read(struct clocksource *cs)
{
	struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
	unsigned long flags, raw;
	unsigned long value;
	int has_wrapped;

	raw_spin_lock_irqsave(&ch->lock, flags);
	value = ch->total_cycles;
	raw = sh_cmt_get_counter(ch, &has_wrapped);

	if (unlikely(has_wrapped))
		raw += ch->match_value + 1;
	raw_spin_unlock_irqrestore(&ch->lock, flags);

	return value + raw;
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm8088.89%350.00%


Laurent Pinchart77.78%116.67%


Paul Mundt22.22%116.67%


Thomas Gleixner11.11%116.67%


Total90100.00%6100.00%






static int sh_cmt_clocksource_enable(struct clocksource *cs)
{
	int ret;
	struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);

	WARN_ON(ch->cs_enabled);

	ch->total_cycles = 0;

	ret = sh_cmt_start(ch, FLAG_CLOCKSOURCE);
	if (!ret)
		ch->cs_enabled = true;

	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm4371.67%250.00%


Rafael J. Wysocki1118.33%125.00%


Laurent Pinchart610.00%125.00%


Total60100.00%4100.00%






static void sh_cmt_clocksource_disable(struct clocksource *cs)
{
	struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);

	WARN_ON(!ch->cs_enabled);

	sh_cmt_stop(ch, FLAG_CLOCKSOURCE);
	ch->cs_enabled = false;
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm1945.24%133.33%


Rafael J. Wysocki1842.86%133.33%


Laurent Pinchart511.90%133.33%


Total42100.00%3100.00%






static void sh_cmt_clocksource_suspend(struct clocksource *cs)
{
	struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);

	if (!ch->cs_enabled)
		return;

	sh_cmt_stop(ch, FLAG_CLOCKSOURCE);
	pm_genpd_syscore_poweroff(&ch->cmt->pdev->dev);
}


Contributors
PersonTokensPropCommitsCommitProp
Rafael J. Wysocki3470.83%133.33%


Geert Uytterhoeven816.67%133.33%


Laurent Pinchart612.50%133.33%


Total48100.00%3100.00%






static void sh_cmt_clocksource_resume(struct clocksource *cs)
{
	struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);

	if (!ch->cs_enabled)
		return;

	pm_genpd_syscore_poweron(&ch->cmt->pdev->dev);
	sh_cmt_start(ch, FLAG_CLOCKSOURCE);
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm1939.58%125.00%


Rafael J. Wysocki1531.25%125.00%


Geert Uytterhoeven816.67%125.00%


Laurent Pinchart612.50%125.00%


Total48100.00%4100.00%






static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch,
				       const char *name)
{
	struct clocksource *cs = &ch->cs;

	cs->name = name;
	cs->rating = 125;
	cs->read = sh_cmt_clocksource_read;
	cs->enable = sh_cmt_clocksource_enable;
	cs->disable = sh_cmt_clocksource_disable;
	cs->suspend = sh_cmt_clocksource_suspend;
	cs->resume = sh_cmt_clocksource_resume;
	cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;

	dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n",
		 ch->index);

	clocksource_register_hz(cs, ch->cmt->rate);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm9679.34%330.00%


Laurent Pinchart1310.74%440.00%


Paul Mundt64.96%110.00%


Nicolai Stange54.13%110.00%


Rafael J. Wysocki10.83%110.00%


Total121100.00%10100.00%






static struct sh_cmt_channel *ced_to_sh_cmt(struct clock_event_device *ced)
{
	return container_of(ced, struct sh_cmt_channel, ced);
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm2291.67%150.00%


Laurent Pinchart28.33%150.00%


Total24100.00%2100.00%






static void sh_cmt_clock_event_start(struct sh_cmt_channel *ch, int periodic)
{
	sh_cmt_start(ch, FLAG_CLOCKEVENT);

	if (periodic)
		sh_cmt_set_next(ch, ((ch->cmt->rate + HZ/2) / HZ) - 1);
	else
		sh_cmt_set_next(ch, ch->max_match_value);
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm4984.48%250.00%


Laurent Pinchart712.07%125.00%


Nicolai Stange23.45%125.00%


Total58100.00%4100.00%






static int sh_cmt_clock_event_shutdown(struct clock_event_device *ced)
{
	struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);

	sh_cmt_stop(ch, FLAG_CLOCKEVENT);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm2374.19%133.33%


Viresh Kumar516.13%133.33%


Laurent Pinchart39.68%133.33%


Total31100.00%3100.00%






static int sh_cmt_clock_event_set_state(struct clock_event_device *ced,
					int periodic)
{
	struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);

	/* deal with old setting first */
	if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
		sh_cmt_stop(ch, FLAG_CLOCKEVENT);

	dev_info(&ch->cmt->pdev->dev, "ch%u: used for %s clock events\n",
		 ch->index, periodic ? "periodic" : "oneshot");
	sh_cmt_clock_event_start(ch, periodic);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Viresh Kumar4760.26%120.00%


Magnus Damm1519.23%120.00%


Laurent Pinchart1012.82%240.00%


Paul Mundt67.69%120.00%


Total78100.00%5100.00%






static int sh_cmt_clock_event_set_oneshot(struct clock_event_device *ced)
{
	return sh_cmt_clock_event_set_state(ced, 0);
}


Contributors
PersonTokensPropCommitsCommitProp
Viresh Kumar1578.95%150.00%


Magnus Damm421.05%150.00%


Total19100.00%2100.00%






static int sh_cmt_clock_event_set_periodic(struct clock_event_device *ced)
{
	return sh_cmt_clock_event_set_state(ced, 1);
}


Contributors
PersonTokensPropCommitsCommitProp
Viresh Kumar1894.74%150.00%


Magnus Damm15.26%150.00%


Total19100.00%2100.00%






static int sh_cmt_clock_event_next(unsigned long delta,
				   struct clock_event_device *ced)
{
	struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);

	BUG_ON(!clockevent_state_oneshot(ced));
	if (likely(ch->flags & FLAG_IRQCONTEXT))
		ch->next_match_value = delta - 1;
	else
		sh_cmt_set_next(ch, delta - 1);

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm5786.36%250.00%


Laurent Pinchart57.58%125.00%


Viresh Kumar46.06%125.00%


Total66100.00%4100.00%






static void sh_cmt_clock_event_suspend(struct clock_event_device *ced)
{
	struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);

	pm_genpd_syscore_poweroff(&ch->cmt->pdev->dev);
	clk_unprepare(ch->cmt->clk);
}


Contributors
PersonTokensPropCommitsCommitProp
Rafael J. Wysocki2150.00%133.33%


Laurent Pinchart2150.00%266.67%


Total42100.00%3100.00%






static void sh_cmt_clock_event_resume(struct clock_event_device *ced)
{
	struct sh_cmt_channel *ch = ced_to_sh_cmt(ced);

	clk_prepare(ch->cmt->clk);
	pm_genpd_syscore_poweron(&ch->cmt->pdev->dev);
}


Contributors
PersonTokensPropCommitsCommitProp
Laurent Pinchart2150.00%266.67%


Rafael J. Wysocki2150.00%133.33%


Total42100.00%3100.00%






static int sh_cmt_register_clockevent(struct sh_cmt_channel *ch,
				      const char *name)
{
	struct clock_event_device *ced = &ch->ced;
	int irq;
	int ret;

	irq = platform_get_irq(ch->cmt->pdev, ch->index);
	if (irq < 0) {
		dev_err(&ch->cmt->pdev->dev, "ch%u: failed to get irq\n",
			ch->index);
		return irq;
	}

	ret = request_irq(irq, sh_cmt_interrupt,
			  IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
			  dev_name(&ch->cmt->pdev->dev), ch);
	if (ret) {
		dev_err(&ch->cmt->pdev->dev, "ch%u: failed to request irq %d\n",
			ch->index, irq);
		return ret;
	}

	ced->name = name;
	ced->features = CLOCK_EVT_FEAT_PERIODIC;
	ced->features |= CLOCK_EVT_FEAT_ONESHOT;
	ced->rating = 125;
	ced->cpumask = cpu_possible_mask;
	ced->set_next_event = sh_cmt_clock_event_next;
	ced->set_state_shutdown = sh_cmt_clock_event_shutdown;
	ced->set_state_periodic = sh_cmt_clock_event_set_periodic;
	ced->set_state_oneshot = sh_cmt_clock_event_set_oneshot;
	ced->suspend = sh_cmt_clock_event_suspend;
	ced->resume = sh_cmt_clock_event_resume;

	/* TODO: calculate good shift from rate and counter bit width */
	ced->shift = 32;
	ced->mult = div_sc(ch->cmt->rate, NSEC_PER_SEC, ced->shift);
	ced->max_delta_ns = clockevent_delta2ns(ch->max_match_value, ced);
	ced->max_delta_ticks = ch->max_match_value;
	ced->min_delta_ns = clockevent_delta2ns(0x1f, ced);
	ced->min_delta_ticks = 0x1f;

	dev_info(&ch->cmt->pdev->dev, "ch%u: used for clock events\n",
		 ch->index);
	clockevents_register_device(ced);

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Laurent Pinchart12643.45%650.00%


Magnus Damm6823.45%18.33%


Nicolai Stange6422.07%216.67%


Viresh Kumar144.83%18.33%


Rafael J. Wysocki124.14%18.33%


Paul Mundt62.07%18.33%


Total290100.00%12100.00%






static int sh_cmt_register(struct sh_cmt_channel *ch, const char *name,
			   bool clockevent, bool clocksource)
{
	int ret;

	if (clockevent) {
		ch->cmt->has_clockevent = true;
		ret = sh_cmt_register_clockevent(ch, name);
		if (ret < 0)
			return ret;
	}

	if (clocksource) {
		ch->cmt->has_clocksource = true;
		sh_cmt_register_clocksource(ch, name);
	}

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Laurent Pinchart4555.56%666.67%


Magnus Damm3543.21%222.22%


Paul Mundt11.23%111.11%


Total81100.00%9100.00%






static int sh_cmt_setup_channel(struct sh_cmt_channel *ch, unsigned int index,
				unsigned int hwidx, bool clockevent,
				bool clocksource, struct sh_cmt_device *cmt)
{
	int ret;

	/* Skip unused channels. */
	if (!clockevent && !clocksource)
		return 0;

	ch->cmt = cmt;
	ch->index = index;
	ch->hwidx = hwidx;

	/*
         * Compute the address of the channel control register block. For the
         * timers with a per-channel start/stop register, compute its address
         * as well.
         */
	switch (cmt->info->model) {
	case SH_CMT_16BIT:
		ch->ioctrl = cmt->mapbase + 2 + ch->hwidx * 6;
		break;
	case SH_CMT_32BIT:
	case SH_CMT_48BIT:
		ch->ioctrl = cmt->mapbase + 0x10 + ch->hwidx * 0x10;
		break;
	case SH_CMT_32BIT_FAST:
		/*
                 * The 32-bit "fast" timer has a single channel at hwidx 5 but
                 * is located at offset 0x40 instead of 0x60 for some reason.
                 */
		ch->ioctrl = cmt->mapbase + 0x40;
		break;
	case SH_CMT_48BIT_GEN2:
		ch->iostart = cmt->mapbase + ch->hwidx * 0x100;
		ch->ioctrl = ch->iostart + 0x10;
		break;
	}

	if (cmt->info->width == (sizeof(ch->max_match_value) * 8))
		ch->max_match_value = ~0;
	else
		ch->max_match_value = (1 << cmt->info->width) - 1;

	ch->match_value = ch->max_match_value;
	raw_spin_lock_init(&ch->lock);

	ch->timer_bit = cmt->info->model == SH_CMT_48BIT_GEN2 ? 0 : ch->hwidx;

	ret = sh_cmt_register(ch, dev_name(&cmt->pdev->dev),
			      clockevent, clocksource);
	if (ret) {
		dev_err(&cmt->pdev->dev, "ch%u: registration failed\n",
			ch->index);
		return ret;
	}
	ch->cs_enabled = false;

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Laurent Pinchart292100.00%6100.00%


Total292100.00%6100.00%






static int sh_cmt_map_memory(struct sh_cmt_device *cmt)
{
	struct resource *mem;

	mem = platform_get_resource(cmt->pdev, IORESOURCE_MEM, 0);
	if (!mem) {
		dev_err(&cmt->pdev->dev, "failed to get I/O memory\n");
		return -ENXIO;
	}

	cmt->mapbase = ioremap_nocache(mem->start, resource_size(mem));
	if (cmt->mapbase == NULL) {
		dev_err(&cmt->pdev->dev, "failed to remap I/O memory\n");
		return -ENXIO;
	}

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm5253.61%133.33%


Laurent Pinchart4546.39%266.67%


Total97100.00%3100.00%




static const struct platform_device_id sh_cmt_id_table[] = {
	{ "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] },
	{ "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] },
	{ }
};
MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);


static const struct of_device_id sh_cmt_of_table[] __maybe_unused = {
	{ .compatible = "renesas,cmt-32", .data = &sh_cmt_info[SH_CMT_32BIT] },
	{ .compatible = "renesas,cmt-32-fast", .data = &sh_cmt_info[SH_CMT_32BIT_FAST] },
	{ .compatible = "renesas,cmt-48", .data = &sh_cmt_info[SH_CMT_48BIT] },
	{ .compatible = "renesas,cmt-48-gen2", .data = &sh_cmt_info[SH_CMT_48BIT_GEN2] },
	{ }
};
MODULE_DEVICE_TABLE(of, sh_cmt_of_table);




static int sh_cmt_parse_dt(struct sh_cmt_device *cmt)
{
	struct device_node *np = cmt->pdev->dev.of_node;

	return of_property_read_u32(np, "renesas,channels-mask",
				    &cmt->hw_channels);
}


Contributors
PersonTokensPropCommitsCommitProp
Laurent Pinchart37100.00%2100.00%


Total37100.00%2100.00%






static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
{
	unsigned int mask;
	unsigned int i;
	int ret;

	cmt->pdev = pdev;
	raw_spin_lock_init(&cmt->lock);

	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
		const struct of_device_id *id;

		id = of_match_node(sh_cmt_of_table, pdev->dev.of_node);
		cmt->info = id->data;

		ret = sh_cmt_parse_dt(cmt);
		if (ret < 0)
			return ret;
	} else if (pdev->dev.platform_data) {
		struct sh_timer_config *cfg = pdev->dev.platform_data;
		const struct platform_device_id *id = pdev->id_entry;

		cmt->info = (const struct sh_cmt_info *)id->driver_data;
		cmt->hw_channels = cfg->channels_mask;
	} else {
		dev_err(&cmt->pdev->dev, "missing platform data\n");
		return -ENXIO;
	}

	/* Get hold of clock. */
	cmt->clk = clk_get(&cmt->pdev->dev, "fck");
	if (IS_ERR(cmt->clk)) {
		dev_err(&cmt->pdev->dev, "cannot get clock\n");
		return PTR_ERR(cmt->clk);
	}

	ret = clk_prepare(cmt->clk);
	if (ret < 0)
		goto err_clk_put;

	/* Determine clock rate. */
	ret = clk_enable(cmt->clk);
	if (ret < 0)
		goto err_clk_unprepare;

	if (cmt->info->width == 16)
		cmt->rate = clk_get_rate(cmt->clk) / 512;
	else
		cmt->rate = clk_get_rate(cmt->clk) / 8;

	clk_disable(cmt->clk);

	/* Map the memory resource(s). */
	ret = sh_cmt_map_memory(cmt);
	if (ret < 0)
		goto err_clk_unprepare;

	/* Allocate and setup the channels. */
	cmt->num_channels = hweight8(cmt->hw_channels);
	cmt->channels = kzalloc(cmt->num_channels * sizeof(*cmt->channels),
				GFP_KERNEL);
	if (cmt->channels == NULL) {
		ret = -ENOMEM;
		goto err_unmap;
	}

	/*
         * Use the first channel as a clock event device and the second channel
         * as a clock source. If only one channel is available use it for both.
         */
	for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) {
		unsigned int hwidx = ffs(mask) - 1;
		bool clocksource = i == 1 || cmt->num_channels == 1;
		bool clockevent = i == 0;

		ret = sh_cmt_setup_channel(&cmt->channels[i], i, hwidx,
					   clockevent, clocksource, cmt);
		if (ret < 0)
			goto err_unmap;

		mask &= ~(1 << hwidx);
	}

	platform_set_drvdata(pdev, cmt);

	return 0;

err_unmap:
	kfree(cmt->channels);
	iounmap(cmt->mapbase);
err_clk_unprepare:
	clk_unprepare(cmt->clk);
err_clk_put:
	clk_put(cmt->clk);
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Laurent Pinchart37372.85%956.25%


Nicolai Stange6312.30%16.25%


Magnus Damm499.57%318.75%


Paul Mundt275.27%318.75%


Total512100.00%16100.00%






static int sh_cmt_probe(struct platform_device *pdev)
{
	struct sh_cmt_device *cmt = platform_get_drvdata(pdev);
	int ret;

	if (!is_early_platform_device(pdev)) {
		pm_runtime_set_active(&pdev->dev);
		pm_runtime_enable(&pdev->dev);
	}

	if (cmt) {
		dev_info(&pdev->dev, "kept as earlytimer\n");
		goto out;
	}

	cmt = kzalloc(sizeof(*cmt), GFP_KERNEL);
	if (cmt == NULL)
		return -ENOMEM;

	ret = sh_cmt_setup(cmt, pdev);
	if (ret) {
		kfree(cmt);
		pm_runtime_idle(&pdev->dev);
		return ret;
	}
	if (is_early_platform_device(pdev))
		return 0;

 out:
	if (cmt->has_clockevent || cmt->has_clocksource)
		pm_runtime_irq_safe(&pdev->dev);
	else
		pm_runtime_idle(&pdev->dev);

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Rafael J. Wysocki7646.06%333.33%


Magnus Damm7042.42%222.22%


Laurent Pinchart137.88%333.33%


Paul Mundt63.64%111.11%


Total165100.00%9100.00%






static int sh_cmt_remove(struct platform_device *pdev)
{
	return -EBUSY; /* cannot unregister clockevent and clocksource */
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm16100.00%1100.00%


Total16100.00%1100.00%




static struct platform_driver sh_cmt_device_driver = {
	.probe		= sh_cmt_probe,
	.remove		= sh_cmt_remove,
	.driver		= {
		.name	= "sh_cmt",
		.of_match_table = of_match_ptr(sh_cmt_of_table),
        },
	.id_table	= sh_cmt_id_table,
};




static int __init sh_cmt_init(void)
{
	return platform_driver_register(&sh_cmt_device_driver);
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm16100.00%1100.00%


Total16100.00%1100.00%






static void __exit sh_cmt_exit(void)
{
	platform_driver_unregister(&sh_cmt_device_driver);
}


Contributors
PersonTokensPropCommitsCommitProp
Magnus Damm15100.00%1100.00%


Total15100.00%1100.00%



early_platform_init("earlytimer", &sh_cmt_device_driver);

subsys_initcall(sh_cmt_init);

module_exit(sh_cmt_exit);

MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("SuperH CMT Timer Driver");
MODULE_LICENSE("GPL v2");

Overall Contributors
PersonTokensPropCommitsCommitProp
Laurent Pinchart214443.77%2340.35%


Magnus Damm210943.06%1628.07%


Rafael J. Wysocki2565.23%35.26%


Nicolai Stange1382.82%23.51%


Viresh Kumar1112.27%11.75%


Paul Mundt851.74%610.53%


Takashi Yoshii330.67%11.75%


Geert Uytterhoeven160.33%11.75%


Tejun Heo20.04%11.75%


Paul Gortmaker20.04%11.75%


Thomas Gleixner10.02%11.75%


Simon Horman10.02%11.75%


Total4898100.00%57100.00%


Directory: drivers/clocksource



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