drivers/clocksource/timer-imx-gpt.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 //
 //  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)

 #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>

 /*
  * 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+)
  */
 enum imx_gpt_type {
 	GPT_TYPE_IMX1,		/* i.MX1 */
 	GPT_TYPE_IMX21,		/* i.MX21/27 */
 	GPT_TYPE_IMX31,		/* i.MX31/35/25/37/51/6Q */
 	GPT_TYPE_IMX6DL,	/* i.MX6DL/SX/SL */
 };

 /* 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 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);
 }

 static void imx31_gpt_irq_disable(struct imx_timer *imxtm)
 {
 	writel_relaxed(0, imxtm->base + V2_IR);
 }

 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);
 }

 static void imx31_gpt_irq_enable(struct imx_timer *imxtm)
 {
 	writel_relaxed(1<<0, imxtm->base + V2_IR);
 }

 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);
 }

 static void __iomem *sched_clock_reg;

 static u64 notrace mxc_read_sched_clock(void)
 {
 	return sched_clock_reg ? readl_relaxed(sched_clock_reg) : 0;
 }

 #if defined(CONFIG_ARM)
 static struct delay_timer imx_delay_timer;

 static unsigned long imx_read_current_timer(void)
 {
 	return readl_relaxed(sched_clock_reg);
 }
 #endif

 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;

 #if defined(CONFIG_ARM)
 	imx_delay_timer.read_current_timer = &imx_read_current_timer;
 	imx_delay_timer.freq = c;
 	register_current_timer_delay(&imx_delay_timer);
 #endif

 	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);
 	u32 tcn;

 	/* 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 */

 	return 0;
 }

 static int mxc_set_oneshot(struct clock_event_device *ced)
 {
 	struct imx_timer *imxtm = to_imx_timer(ced);

 	/* 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);

 	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;

 	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);

 	return request_irq(imxtm->irq, mxc_timer_interrupt,
 			   IRQF_TIMER | IRQF_IRQPOLL, "i.MX Timer Tick", ced);
 }

 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);
 }

 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 = imx1_gpt_irq_enable,
 	.gpt_irq_disable = imx1_gpt_irq_disable,
 	.gpt_irq_acknowledge = imx21_gpt_irq_acknowledge,
 	.gpt_setup_tctl = imx1_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 = imx31_gpt_irq_enable,
 	.gpt_irq_disable = imx31_gpt_irq_disable,
 	.gpt_irq_acknowledge = imx31_gpt_irq_acknowledge,
 	.gpt_setup_tctl = imx6dl_gpt_setup_tctl,
 	.set_next_event = v2_set_next_event,
 };

 static int __init _mxc_timer_init(struct imx_timer *imxtm)
 {
 	int ret;

 	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:
 		return -EINVAL;
 	}

 	if (IS_ERR(imxtm->clk_per)) {
 		pr_err("i.MX timer: unable to get clk\n");
 		return PTR_ERR(imxtm->clk_per);
 	}

 	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 */
 	ret = mxc_clocksource_init(imxtm);
 	if (ret)
 		return ret;

 	return mxc_clockevent_init(imxtm);
 }

 static int __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
 {
 	struct imx_timer *imxtm;
 	static int initialized;
 	int ret;

 	/* Support one instance only */
 	if (initialized)
 		return 0;

 	imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
 	if (!imxtm)
 		return -ENOMEM;

 	imxtm->base = of_iomap(np, 0);
 	if (!imxtm->base)
 		return -ENXIO;

 	imxtm->irq = irq_of_parse_and_map(np, 0);
 	if (imxtm->irq <= 0)
 		return -EINVAL;

 	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;

 	ret = _mxc_timer_init(imxtm);
 	if (ret)
 		return ret;

 	initialized = 1;

 	return 0;
 }

 static int __init imx1_timer_init_dt(struct device_node *np)
 {
 	return mxc_timer_init_dt(np, GPT_TYPE_IMX1);
 }

 static int __init imx21_timer_init_dt(struct device_node *np)
 {
 	return mxc_timer_init_dt(np, GPT_TYPE_IMX21);
 }

 static int __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;

 	return mxc_timer_init_dt(np, type);
 }

 static int __init imx6dl_timer_init_dt(struct device_node *np)
 {
 	return mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
 }

 TIMER_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
 TIMER_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
 TIMER_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
 TIMER_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
 TIMER_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
 TIMER_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
 TIMER_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
 TIMER_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
 TIMER_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
 TIMER_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
 TIMER_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
 TIMER_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);
	// SPDX-License-Identifier: GPL-2.0+
	//
	// 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)

	#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>

	/*
	* 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+)
	*/
	enum imx_gpt_type {
	GPT_TYPE_IMX1, /* i.MX1 */
	GPT_TYPE_IMX21, /* i.MX21/27 */
	GPT_TYPE_IMX31, /* i.MX31/35/25/37/51/6Q */
	GPT_TYPE_IMX6DL, /* i.MX6DL/SX/SL */
	};

	/* 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 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);
	}

	static void imx31_gpt_irq_disable(struct imx_timer *imxtm)
	{
	writel_relaxed(0, imxtm->base + V2_IR);
	}

	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);
	}

	static void imx31_gpt_irq_enable(struct imx_timer *imxtm)
	{
	writel_relaxed(1<<0, imxtm->base + V2_IR);
	}

	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);
	}

	static void __iomem *sched_clock_reg;

	static u64 notrace mxc_read_sched_clock(void)
	{
	return sched_clock_reg ? readl_relaxed(sched_clock_reg) : 0;
	}

	#if defined(CONFIG_ARM)
	static struct delay_timer imx_delay_timer;

	static unsigned long imx_read_current_timer(void)
	{
	return readl_relaxed(sched_clock_reg);
	}
	#endif

	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;

	#if defined(CONFIG_ARM)
	imx_delay_timer.read_current_timer = &imx_read_current_timer;
	imx_delay_timer.freq = c;
	register_current_timer_delay(&imx_delay_timer);
	#endif

	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);
	u32 tcn;

	/* 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 */

	return 0;
	}

	static int mxc_set_oneshot(struct clock_event_device *ced)
	{
	struct imx_timer *imxtm = to_imx_timer(ced);

	/* 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);

	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;

	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);

	return request_irq(imxtm->irq, mxc_timer_interrupt,
	IRQF_TIMER \| IRQF_IRQPOLL, "i.MX Timer Tick", ced);
	}

	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);
	}

	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 = imx1_gpt_irq_enable,
	.gpt_irq_disable = imx1_gpt_irq_disable,
	.gpt_irq_acknowledge = imx21_gpt_irq_acknowledge,
	.gpt_setup_tctl = imx1_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 = imx31_gpt_irq_enable,
	.gpt_irq_disable = imx31_gpt_irq_disable,
	.gpt_irq_acknowledge = imx31_gpt_irq_acknowledge,
	.gpt_setup_tctl = imx6dl_gpt_setup_tctl,
	.set_next_event = v2_set_next_event,
	};

	static int __init _mxc_timer_init(struct imx_timer *imxtm)
	{
	int ret;

	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:
	return -EINVAL;
	}

	if (IS_ERR(imxtm->clk_per)) {
	pr_err("i.MX timer: unable to get clk\n");
	return PTR_ERR(imxtm->clk_per);
	}

	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 */
	ret = mxc_clocksource_init(imxtm);
	if (ret)
	return ret;

	return mxc_clockevent_init(imxtm);
	}

	static int __init mxc_timer_init_dt(struct device_node *np, enum imx_gpt_type type)
	{
	struct imx_timer *imxtm;
	static int initialized;
	int ret;

	/* Support one instance only */
	if (initialized)
	return 0;

	imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
	if (!imxtm)
	return -ENOMEM;

	imxtm->base = of_iomap(np, 0);
	if (!imxtm->base)
	return -ENXIO;

	imxtm->irq = irq_of_parse_and_map(np, 0);
	if (imxtm->irq <= 0)
	return -EINVAL;

	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;

	ret = _mxc_timer_init(imxtm);
	if (ret)
	return ret;

	initialized = 1;

	return 0;
	}

	static int __init imx1_timer_init_dt(struct device_node *np)
	{
	return mxc_timer_init_dt(np, GPT_TYPE_IMX1);
	}

	static int __init imx21_timer_init_dt(struct device_node *np)
	{
	return mxc_timer_init_dt(np, GPT_TYPE_IMX21);
	}

	static int __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;

	return mxc_timer_init_dt(np, type);
	}

	static int __init imx6dl_timer_init_dt(struct device_node *np)
	{
	return mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
	}

	TIMER_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
	TIMER_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
	TIMER_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
	TIMER_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
	TIMER_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
	TIMER_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
	TIMER_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
	TIMER_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
	TIMER_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
	TIMER_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
	TIMER_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
	TIMER_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);