[deliverable/linux.git] / arch / powerpc / sysdev / fsl_gtm.c

/*
 * Freescale General-purpose Timers Module
 *
 * Copyright (c) Freescale Semiconductor, Inc. 2006.
 *               Shlomi Gridish <gridish@freescale.com>
 *               Jerry Huang <Chang-Ming.Huang@freescale.com>
 * Copyright (c) MontaVista Software, Inc. 2008.
 *               Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <asm/fsl_gtm.h>

#define GTCFR_STP(x)		((x) & 1 ? 1 << 5 : 1 << 1)
#define GTCFR_RST(x)		((x) & 1 ? 1 << 4 : 1 << 0)

#define GTMDR_ICLK_MASK		(3 << 1)
#define GTMDR_ICLK_ICAS		(0 << 1)
#define GTMDR_ICLK_ICLK		(1 << 1)
#define GTMDR_ICLK_SLGO		(2 << 1)
#define GTMDR_FRR		(1 << 3)
#define GTMDR_ORI		(1 << 4)
#define GTMDR_SPS(x)		((x) << 8)

struct gtm_timers_regs {
	u8	gtcfr1;		/* Timer 1, Timer 2 global config register */
	u8	res0[0x3];
	u8	gtcfr2;		/* Timer 3, timer 4 global config register */
	u8	res1[0xB];
	__be16	gtmdr1;		/* Timer 1 mode register */
	__be16	gtmdr2;		/* Timer 2 mode register */
	__be16	gtrfr1;		/* Timer 1 reference register */
	__be16	gtrfr2;		/* Timer 2 reference register */
	__be16	gtcpr1;		/* Timer 1 capture register */
	__be16	gtcpr2;		/* Timer 2 capture register */
	__be16	gtcnr1;		/* Timer 1 counter */
	__be16	gtcnr2;		/* Timer 2 counter */
	__be16	gtmdr3;		/* Timer 3 mode register */
	__be16	gtmdr4;		/* Timer 4 mode register */
	__be16	gtrfr3;		/* Timer 3 reference register */
	__be16	gtrfr4;		/* Timer 4 reference register */
	__be16	gtcpr3;		/* Timer 3 capture register */
	__be16	gtcpr4;		/* Timer 4 capture register */
	__be16	gtcnr3;		/* Timer 3 counter */
	__be16	gtcnr4;		/* Timer 4 counter */
	__be16	gtevr1;		/* Timer 1 event register */
	__be16	gtevr2;		/* Timer 2 event register */
	__be16	gtevr3;		/* Timer 3 event register */
	__be16	gtevr4;		/* Timer 4 event register */
	__be16	gtpsr1;		/* Timer 1 prescale register */
	__be16	gtpsr2;		/* Timer 2 prescale register */
	__be16	gtpsr3;		/* Timer 3 prescale register */
	__be16	gtpsr4;		/* Timer 4 prescale register */
	u8 res2[0x40];
} __attribute__ ((packed));

struct gtm {
	unsigned int clock;
	struct gtm_timers_regs __iomem *regs;
	struct gtm_timer timers[4];
	spinlock_t lock;
	struct list_head list_node;
};

static LIST_HEAD(gtms);

/**
 * gtm_get_timer - request GTM timer to use it with the rest of GTM API
 * Context:	non-IRQ
 *
 * This function reserves GTM timer for later use. It returns gtm_timer
 * structure to use with the rest of GTM API, you should use timer->irq
 * to manage timer interrupt.
 */
struct gtm_timer *gtm_get_timer16(void)
{
	struct gtm *gtm = NULL;
	int i;

	list_for_each_entry(gtm, &gtms, list_node) {
		spin_lock_irq(&gtm->lock);

		for (i = 0; i < ARRAY_SIZE(gtm->timers); i++) {
			if (!gtm->timers[i].requested) {
				gtm->timers[i].requested = true;
				spin_unlock_irq(&gtm->lock);
				return &gtm->timers[i];
			}
		}

		spin_unlock_irq(&gtm->lock);
	}

	if (gtm)
		return ERR_PTR(-EBUSY);
	return ERR_PTR(-ENODEV);
}
EXPORT_SYMBOL(gtm_get_timer16);

/**
 * gtm_get_specific_timer - request specific GTM timer
 * @gtm:	specific GTM, pass here GTM's device_node->data
 * @timer:	specific timer number, Timer1 is 0.
 * Context:	non-IRQ
 *
 * This function reserves GTM timer for later use. It returns gtm_timer
 * structure to use with the rest of GTM API, you should use timer->irq
 * to manage timer interrupt.
 */
struct gtm_timer *gtm_get_specific_timer16(struct gtm *gtm,
					   unsigned int timer)
{
	struct gtm_timer *ret = ERR_PTR(-EBUSY);

	if (timer > 3)
		return ERR_PTR(-EINVAL);

	spin_lock_irq(&gtm->lock);

	if (gtm->timers[timer].requested)
		goto out;

	ret = &gtm->timers[timer];
	ret->requested = true;

out:
	spin_unlock_irq(&gtm->lock);
	return ret;
}
EXPORT_SYMBOL(gtm_get_specific_timer16);

/**
 * gtm_put_timer16 - release 16 bits GTM timer
 * @tmr:	pointer to the gtm_timer structure obtained from gtm_get_timer
 * Context:	any
 *
 * This function releases GTM timer so others may request it.
 */
void gtm_put_timer16(struct gtm_timer *tmr)
{
	gtm_stop_timer16(tmr);

	spin_lock_irq(&tmr->gtm->lock);
	tmr->requested = false;
	spin_unlock_irq(&tmr->gtm->lock);
}
EXPORT_SYMBOL(gtm_put_timer16);

/*
 * This is back-end for the exported functions, it's used to reset single
 * timer in reference mode.
 */
static int gtm_set_ref_timer16(struct gtm_timer *tmr, int frequency,
			       int reference_value, bool free_run)
{
	struct gtm *gtm = tmr->gtm;
	int num = tmr - &gtm->timers[0];
	unsigned int prescaler;
	u8 iclk = GTMDR_ICLK_ICLK;
	u8 psr;
	u8 sps;
	unsigned long flags;
	int max_prescaler = 256 * 256 * 16;

	/* CPM2 doesn't have primary prescaler */
	if (!tmr->gtpsr)
		max_prescaler /= 256;

	prescaler = gtm->clock / frequency;
	/*
	 * We have two 8 bit prescalers -- primary and secondary (psr, sps),
	 * plus "slow go" mode (clk / 16). So, total prescale value is
	 * 16 * (psr + 1) * (sps + 1). Though, for CPM2 GTMs we losing psr.
	 */
	if (prescaler > max_prescaler)
		return -EINVAL;

	if (prescaler > max_prescaler / 16) {
		iclk = GTMDR_ICLK_SLGO;
		prescaler /= 16;
	}

	if (prescaler <= 256) {
		psr = 0;
		sps = prescaler - 1;
	} else {
		psr = 256 - 1;
		sps = prescaler / 256 - 1;
	}

	spin_lock_irqsave(&gtm->lock, flags);

	/*
	 * Properly reset timers: stop, reset, set up prescalers, reference
	 * value and clear event register.
	 */
	clrsetbits_8(tmr->gtcfr, ~(GTCFR_STP(num) | GTCFR_RST(num)),
				 GTCFR_STP(num) | GTCFR_RST(num));

	setbits8(tmr->gtcfr, GTCFR_STP(num));

	if (tmr->gtpsr)
		out_be16(tmr->gtpsr, psr);
	clrsetbits_be16(tmr->gtmdr, 0xFFFF, iclk | GTMDR_SPS(sps) |
			GTMDR_ORI | (free_run ? GTMDR_FRR : 0));
	out_be16(tmr->gtcnr, 0);
	out_be16(tmr->gtrfr, reference_value);
	out_be16(tmr->gtevr, 0xFFFF);

	/* Let it be. */
	clrbits8(tmr->gtcfr, GTCFR_STP(num));

	spin_unlock_irqrestore(&gtm->lock, flags);

	return 0;
}

/**
 * gtm_set_timer16 - (re)set 16 bit timer with arbitrary precision
 * @tmr:	pointer to the gtm_timer structure obtained from gtm_get_timer
 * @usec:	timer interval in microseconds
 * @reload:	if set, the timer will reset upon expiry rather than
 *         	continue running free.
 * Context:	any
 *
 * This function (re)sets the GTM timer so that it counts up to the requested
 * interval value, and fires the interrupt when the value is reached. This
 * function will reduce the precision of the timer as needed in order for the
 * requested timeout to fit in a 16-bit register.
 */
int gtm_set_timer16(struct gtm_timer *tmr, unsigned long usec, bool reload)
{
	/* quite obvious, frequency which is enough for µSec precision */
	int freq = 1000000;
	unsigned int bit;

	bit = fls_long(usec);
	if (bit > 15) {
		freq >>= bit - 15;
		usec >>= bit - 15;
	}

	if (!freq)
		return -EINVAL;

	return gtm_set_ref_timer16(tmr, freq, usec, reload);
}
EXPORT_SYMBOL(gtm_set_timer16);

/**
 * gtm_set_exact_utimer16 - (re)set 16 bits timer
 * @tmr:	pointer to the gtm_timer structure obtained from gtm_get_timer
 * @usec:	timer interval in microseconds
 * @reload:	if set, the timer will reset upon expiry rather than
 *         	continue running free.
 * Context:	any
 *
 * This function (re)sets GTM timer so that it counts up to the requested
 * interval value, and fires the interrupt when the value is reached. If reload
 * flag was set, timer will also reset itself upon reference value, otherwise
 * it continues to increment.
 *
 * The _exact_ bit in the function name states that this function will not
 * crop precision of the "usec" argument, thus usec is limited to 16 bits
 * (single timer width).
 */
int gtm_set_exact_timer16(struct gtm_timer *tmr, u16 usec, bool reload)
{
	/* quite obvious, frequency which is enough for µSec precision */
	const int freq = 1000000;

	/*
	 * We can lower the frequency (and probably power consumption) by
	 * dividing both frequency and usec by 2 until there is no remainder.
	 * But we won't bother with this unless savings are measured, so just
	 * run the timer as is.
	 */

	return gtm_set_ref_timer16(tmr, freq, usec, reload);
}
EXPORT_SYMBOL(gtm_set_exact_timer16);

/**
 * gtm_stop_timer16 - stop single timer
 * @tmr:	pointer to the gtm_timer structure obtained from gtm_get_timer
 * Context:	any
 *
 * This function simply stops the GTM timer.
 */
void gtm_stop_timer16(struct gtm_timer *tmr)
{
	struct gtm *gtm = tmr->gtm;
	int num = tmr - &gtm->timers[0];
	unsigned long flags;

	spin_lock_irqsave(&gtm->lock, flags);

	setbits8(tmr->gtcfr, GTCFR_STP(num));
	out_be16(tmr->gtevr, 0xFFFF);

	spin_unlock_irqrestore(&gtm->lock, flags);
}
EXPORT_SYMBOL(gtm_stop_timer16);

/**
 * gtm_ack_timer16 - acknowledge timer event (free-run timers only)
 * @tmr:	pointer to the gtm_timer structure obtained from gtm_get_timer
 * @events:	events mask to ack
 * Context:	any
 *
 * Thus function used to acknowledge timer interrupt event, use it inside the
 * interrupt handler.
 */
void gtm_ack_timer16(struct gtm_timer *tmr, u16 events)
{
	out_be16(tmr->gtevr, events);
}
EXPORT_SYMBOL(gtm_ack_timer16);

static void __init gtm_set_shortcuts(struct device_node *np,
				     struct gtm_timer *timers,
				     struct gtm_timers_regs __iomem *regs)
{
	/*
	 * Yeah, I don't like this either, but timers' registers a bit messed,
	 * so we have to provide shortcuts to write timer independent code.
	 * Alternative option is to create gt*() accessors, but that will be
	 * even uglier and cryptic.
	 */
	timers[0].gtcfr = &regs->gtcfr1;
	timers[0].gtmdr = &regs->gtmdr1;
	timers[0].gtcnr = &regs->gtcnr1;
	timers[0].gtrfr = &regs->gtrfr1;
	timers[0].gtevr = &regs->gtevr1;

	timers[1].gtcfr = &regs->gtcfr1;
	timers[1].gtmdr = &regs->gtmdr2;
	timers[1].gtcnr = &regs->gtcnr2;
	timers[1].gtrfr = &regs->gtrfr2;
	timers[1].gtevr = &regs->gtevr2;

	timers[2].gtcfr = &regs->gtcfr2;
	timers[2].gtmdr = &regs->gtmdr3;
	timers[2].gtcnr = &regs->gtcnr3;
	timers[2].gtrfr = &regs->gtrfr3;
	timers[2].gtevr = &regs->gtevr3;

	timers[3].gtcfr = &regs->gtcfr2;
	timers[3].gtmdr = &regs->gtmdr4;
	timers[3].gtcnr = &regs->gtcnr4;
	timers[3].gtrfr = &regs->gtrfr4;
	timers[3].gtevr = &regs->gtevr4;

	/* CPM2 doesn't have primary prescaler */
	if (!of_device_is_compatible(np, "fsl,cpm2-gtm")) {
		timers[0].gtpsr = &regs->gtpsr1;
		timers[1].gtpsr = &regs->gtpsr2;
		timers[2].gtpsr = &regs->gtpsr3;
		timers[3].gtpsr = &regs->gtpsr4;
	}
}

static int __init fsl_gtm_init(void)
{
	struct device_node *np;

	for_each_compatible_node(np, NULL, "fsl,gtm") {
		int i;
		struct gtm *gtm;
		const u32 *clock;
		int size;

		gtm = kzalloc(sizeof(*gtm), GFP_KERNEL);
		if (!gtm) {
			pr_err("%s: unable to allocate memory\n",
				np->full_name);
			continue;
		}

		spin_lock_init(&gtm->lock);

		clock = of_get_property(np, "clock-frequency", &size);
		if (!clock || size != sizeof(*clock)) {
			pr_err("%s: no clock-frequency\n", np->full_name);
			goto err;
		}
		gtm->clock = *clock;

		for (i = 0; i < ARRAY_SIZE(gtm->timers); i++) {
			unsigned int irq;

			irq = irq_of_parse_and_map(np, i);
			if (irq == NO_IRQ) {
				pr_err("%s: not enough interrupts specified\n",
				       np->full_name);
				goto err;
			}
			gtm->timers[i].irq = irq;
			gtm->timers[i].gtm = gtm;
		}

		gtm->regs = of_iomap(np, 0);
		if (!gtm->regs) {
			pr_err("%s: unable to iomap registers\n",
			       np->full_name);
			goto err;
		}

		gtm_set_shortcuts(np, gtm->timers, gtm->regs);
		list_add(&gtm->list_node, &gtms);

		/* We don't want to lose the node and its ->data */
		np->data = gtm;
		of_node_get(np);

		continue;
err:
		kfree(gtm);
	}
	return 0;
}
arch_initcall(fsl_gtm_init);
Commit	Line	Data
83ff9dcf AV	1	/*
	2	* Freescale General-purpose Timers Module
	3	*
8a56e1ee	4	* Copyright (c) Freescale Semiconductor, Inc. 2006.
83ff9dcf AV	5	* Shlomi Gridish <gridish@freescale.com>
	6	* Jerry Huang <Chang-Ming.Huang@freescale.com>
	7	* Copyright (c) MontaVista Software, Inc. 2008.
	8	* Anton Vorontsov <avorontsov@ru.mvista.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License as published by the
	12	* Free Software Foundation; either version 2 of the License, or (at your
	13	* option) any later version.
	14	*/
	15
	16	#include <linux/kernel.h>
22ae782f	17	#include <linux/err.h>
83ff9dcf AV	18	#include <linux/errno.h>
	19	#include <linux/list.h>
	20	#include <linux/io.h>
	21	#include <linux/of.h>
26a2056e RH	22	#include <linux/of_address.h>
26a2056e RH	23	#include <linux/of_irq.h>
83ff9dcf AV	24	#include <linux/spinlock.h>
83ff9dcf AV	25	#include <linux/bitops.h>
5a0e3ad6	26	#include <linux/slab.h>
66b15db6	27	#include <linux/export.h>
83ff9dcf AV	28	#include <asm/fsl_gtm.h>
	29
	30	#define GTCFR_STP(x) ((x) & 1 ? 1 << 5 : 1 << 1)
	31	#define GTCFR_RST(x) ((x) & 1 ? 1 << 4 : 1 << 0)
	32
	33	#define GTMDR_ICLK_MASK (3 << 1)
	34	#define GTMDR_ICLK_ICAS (0 << 1)
	35	#define GTMDR_ICLK_ICLK (1 << 1)
	36	#define GTMDR_ICLK_SLGO (2 << 1)
	37	#define GTMDR_FRR (1 << 3)
	38	#define GTMDR_ORI (1 << 4)
	39	#define GTMDR_SPS(x) ((x) << 8)
	40
	41	struct gtm_timers_regs {
	42	u8 gtcfr1; /* Timer 1, Timer 2 global config register */
	43	u8 res0[0x3];
	44	u8 gtcfr2; /* Timer 3, timer 4 global config register */
	45	u8 res1[0xB];
	46	__be16 gtmdr1; /* Timer 1 mode register */
	47	__be16 gtmdr2; /* Timer 2 mode register */
	48	__be16 gtrfr1; /* Timer 1 reference register */
	49	__be16 gtrfr2; /* Timer 2 reference register */
	50	__be16 gtcpr1; /* Timer 1 capture register */
	51	__be16 gtcpr2; /* Timer 2 capture register */
	52	__be16 gtcnr1; /* Timer 1 counter */
	53	__be16 gtcnr2; /* Timer 2 counter */
	54	__be16 gtmdr3; /* Timer 3 mode register */
	55	__be16 gtmdr4; /* Timer 4 mode register */
	56	__be16 gtrfr3; /* Timer 3 reference register */
	57	__be16 gtrfr4; /* Timer 4 reference register */
	58	__be16 gtcpr3; /* Timer 3 capture register */
	59	__be16 gtcpr4; /* Timer 4 capture register */
	60	__be16 gtcnr3; /* Timer 3 counter */
	61	__be16 gtcnr4; /* Timer 4 counter */
	62	__be16 gtevr1; /* Timer 1 event register */
	63	__be16 gtevr2; /* Timer 2 event register */
	64	__be16 gtevr3; /* Timer 3 event register */
	65	__be16 gtevr4; /* Timer 4 event register */
	66	__be16 gtpsr1; /* Timer 1 prescale register */
	67	__be16 gtpsr2; /* Timer 2 prescale register */
	68	__be16 gtpsr3; /* Timer 3 prescale register */
	69	__be16 gtpsr4; /* Timer 4 prescale register */
	70	u8 res2[0x40];
	71	} __attribute__ ((packed));
	72
	73	struct gtm {
	74	unsigned int clock;
	75	struct gtm_timers_regs __iomem *regs;
	76	struct gtm_timer timers[4];
	77	spinlock_t lock;
	78	struct list_head list_node;
	79	};
	80
	81	static LIST_HEAD(gtms);
	82
	83	/**
	84	* gtm_get_timer - request GTM timer to use it with the rest of GTM API
	85	* Context: non-IRQ
	86	*
	87	* This function reserves GTM timer for later use. It returns gtm_timer
	88	* structure to use with the rest of GTM API, you should use timer->irq
	89	* to manage timer interrupt.
	90	*/
	91	struct gtm_timer *gtm_get_timer16(void)
92	{
93	struct gtm *gtm = NULL;
94	int i;
95
96	list_for_each_entry(gtm, &gtms, list_node) {
97	spin_lock_irq(&gtm->lock);
98
99	for (i = 0; i < ARRAY_SIZE(gtm->timers); i++) {
100	if (!gtm->timers[i].requested) {
101	gtm->timers[i].requested = true;
102	spin_unlock_irq(&gtm->lock);
103	return &gtm->timers[i];
104	}
105	}
106
107	spin_unlock_irq(&gtm->lock);
108	}
109
110	if (gtm)
111	return ERR_PTR(-EBUSY);
112	return ERR_PTR(-ENODEV);
113	}
114	EXPORT_SYMBOL(gtm_get_timer16);
115
116	/**
117	* gtm_get_specific_timer - request specific GTM timer
118	* @gtm: specific GTM, pass here GTM's device_node->data
119	* @timer: specific timer number, Timer1 is 0.
120	* Context: non-IRQ
121	*
122	* This function reserves GTM timer for later use. It returns gtm_timer
123	* structure to use with the rest of GTM API, you should use timer->irq
124	* to manage timer interrupt.
125	*/
126	struct gtm_timer gtm_get_specific_timer16(struct gtm gtm,
127	unsigned int timer)
128	{
129	struct gtm_timer *ret = ERR_PTR(-EBUSY);
130
131	if (timer > 3)
132	return ERR_PTR(-EINVAL);
133
134	spin_lock_irq(&gtm->lock);
135
136	if (gtm->timers[timer].requested)
137	goto out;
138
139	ret = &gtm->timers[timer];
140	ret->requested = true;
141
142	out:
143	spin_unlock_irq(&gtm->lock);
144	return ret;
145	}
146	EXPORT_SYMBOL(gtm_get_specific_timer16);
147
148	/**
149	* gtm_put_timer16 - release 16 bits GTM timer
150	* @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
151	* Context: any
152	*
153	* This function releases GTM timer so others may request it.
154	*/
155	void gtm_put_timer16(struct gtm_timer *tmr)
156	{
157	gtm_stop_timer16(tmr);
158
159	spin_lock_irq(&tmr->gtm->lock);
160	tmr->requested = false;
161	spin_unlock_irq(&tmr->gtm->lock);
162	}
163	EXPORT_SYMBOL(gtm_put_timer16);
164
165	/*
166	* This is back-end for the exported functions, it's used to reset single
167	* timer in reference mode.
168	*/
169	static int gtm_set_ref_timer16(struct gtm_timer *tmr, int frequency,
170	int reference_value, bool free_run)
171	{
172	struct gtm *gtm = tmr->gtm;
173	int num = tmr - &gtm->timers[0];
174	unsigned int prescaler;
175	u8 iclk = GTMDR_ICLK_ICLK;
176	u8 psr;
177	u8 sps;
178	unsigned long flags;
179	int max_prescaler = 256 * 256 * 16;
180
181	/* CPM2 doesn't have primary prescaler */
182	if (!tmr->gtpsr)
183	max_prescaler /= 256;
184
185	prescaler = gtm->clock / frequency;
186	/*
187	* We have two 8 bit prescalers -- primary and secondary (psr, sps),
188	* plus "slow go" mode (clk / 16). So, total prescale value is
189	* 16 * (psr + 1) * (sps + 1). Though, for CPM2 GTMs we losing psr.
190	*/
191	if (prescaler > max_prescaler)
192	return -EINVAL;
193
194	if (prescaler > max_prescaler / 16) {
195	iclk = GTMDR_ICLK_SLGO;
196	prescaler /= 16;
197	}
198
199	if (prescaler <= 256) {
200	psr = 0;
201	sps = prescaler - 1;
202	} else {
203	psr = 256 - 1;
204	sps = prescaler / 256 - 1;
205	}
206
207	spin_lock_irqsave(&gtm->lock, flags);
208
209	/*
210	* Properly reset timers: stop, reset, set up prescalers, reference
211	* value and clear event register.
212	*/
213	clrsetbits_8(tmr->gtcfr, ~(GTCFR_STP(num) \| GTCFR_RST(num)),
214	GTCFR_STP(num) \| GTCFR_RST(num));
215
216	setbits8(tmr->gtcfr, GTCFR_STP(num));
217
218	if (tmr->gtpsr)
219	out_be16(tmr->gtpsr, psr);
220	clrsetbits_be16(tmr->gtmdr, 0xFFFF, iclk \| GTMDR_SPS(sps) \|
221	GTMDR_ORI \| (free_run ? GTMDR_FRR : 0));
222	out_be16(tmr->gtcnr, 0);
223	out_be16(tmr->gtrfr, reference_value);
224	out_be16(tmr->gtevr, 0xFFFF);
225
226	/* Let it be. */
227	clrbits8(tmr->gtcfr, GTCFR_STP(num));
228
229	spin_unlock_irqrestore(&gtm->lock, flags);
230
231	return 0;
232	}
233
234	/**
235	* gtm_set_timer16 - (re)set 16 bit timer with arbitrary precision
236	* @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
237	* @usec: timer interval in microseconds
238	* @reload: if set, the timer will reset upon expiry rather than
239	* continue running free.
240	* Context: any
241	*
242	* This function (re)sets the GTM timer so that it counts up to the requested
243	* interval value, and fires the interrupt when the value is reached. This
244	* function will reduce the precision of the timer as needed in order for the
245	* requested timeout to fit in a 16-bit register.
246	*/
247	int gtm_set_timer16(struct gtm_timer *tmr, unsigned long usec, bool reload)
248	{
249	/* quite obvious, frequency which is enough for µSec precision */
250	int freq = 1000000;
251	unsigned int bit;
252
253	bit = fls_long(usec);
254	if (bit > 15) {
255	freq >>= bit - 15;
256	usec >>= bit - 15;
257	}
258
259	if (!freq)
260	return -EINVAL;
261
262	return gtm_set_ref_timer16(tmr, freq, usec, reload);
263	}
264	EXPORT_SYMBOL(gtm_set_timer16);
265
266	/**
267	* gtm_set_exact_utimer16 - (re)set 16 bits timer
268	* @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
269	* @usec: timer interval in microseconds
270	* @reload: if set, the timer will reset upon expiry rather than
271	* continue running free.
272	* Context: any
273	*
274	* This function (re)sets GTM timer so that it counts up to the requested
275	* interval value, and fires the interrupt when the value is reached. If reload
276	* flag was set, timer will also reset itself upon reference value, otherwise
277	* it continues to increment.
278	*
279	* The _exact_ bit in the function name states that this function will not
280	* crop precision of the "usec" argument, thus usec is limited to 16 bits
281	* (single timer width).
282	*/
283	int gtm_set_exact_timer16(struct gtm_timer *tmr, u16 usec, bool reload)
284	{
285	/* quite obvious, frequency which is enough for µSec precision */
286	const int freq = 1000000;
287
288	/*
289	* We can lower the frequency (and probably power consumption) by
290	* dividing both frequency and usec by 2 until there is no remainder.
291	* But we won't bother with this unless savings are measured, so just
292	* run the timer as is.
293	*/
294
295	return gtm_set_ref_timer16(tmr, freq, usec, reload);
296	}
297	EXPORT_SYMBOL(gtm_set_exact_timer16);
298
299	/**
300	* gtm_stop_timer16 - stop single timer
301	* @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
302	* Context: any
303	*
304	* This function simply stops the GTM timer.
305	*/
306	void gtm_stop_timer16(struct gtm_timer *tmr)
307	{
308	struct gtm *gtm = tmr->gtm;
309	int num = tmr - &gtm->timers[0];
310	unsigned long flags;
311
312	spin_lock_irqsave(&gtm->lock, flags);
313
314	setbits8(tmr->gtcfr, GTCFR_STP(num));
315	out_be16(tmr->gtevr, 0xFFFF);
316
317	spin_unlock_irqrestore(&gtm->lock, flags);
318	}
319	EXPORT_SYMBOL(gtm_stop_timer16);
320
321	/**
322	* gtm_ack_timer16 - acknowledge timer event (free-run timers only)
323	* @tmr: pointer to the gtm_timer structure obtained from gtm_get_timer
324	* @events: events mask to ack
325	* Context: any
326	*
327	* Thus function used to acknowledge timer interrupt event, use it inside the
328	* interrupt handler.
329	*/
330	void gtm_ack_timer16(struct gtm_timer *tmr, u16 events)
331	{
332	out_be16(tmr->gtevr, events);
333	}
334	EXPORT_SYMBOL(gtm_ack_timer16);
335
336	static void __init gtm_set_shortcuts(struct device_node *np,
337	struct gtm_timer *timers,
338	struct gtm_timers_regs __iomem *regs)
339	{
340	/*
341	* Yeah, I don't like this either, but timers' registers a bit messed,
342	* so we have to provide shortcuts to write timer independent code.
343	* Alternative option is to create gt*() accessors, but that will be
344	* even uglier and cryptic.
345	*/
346	timers[0].gtcfr = &regs->gtcfr1;
347	timers[0].gtmdr = &regs->gtmdr1;
348	timers[0].gtcnr = &regs->gtcnr1;
349	timers[0].gtrfr = &regs->gtrfr1;
350	timers[0].gtevr = &regs->gtevr1;
351
352	timers[1].gtcfr = &regs->gtcfr1;
353	timers[1].gtmdr = &regs->gtmdr2;
354	timers[1].gtcnr = &regs->gtcnr2;
355	timers[1].gtrfr = &regs->gtrfr2;
356	timers[1].gtevr = &regs->gtevr2;
357
358	timers[2].gtcfr = &regs->gtcfr2;
359	timers[2].gtmdr = &regs->gtmdr3;
360	timers[2].gtcnr = &regs->gtcnr3;
361	timers[2].gtrfr = &regs->gtrfr3;
362	timers[2].gtevr = &regs->gtevr3;
363
364	timers[3].gtcfr = &regs->gtcfr2;
365	timers[3].gtmdr = &regs->gtmdr4;
366	timers[3].gtcnr = &regs->gtcnr4;
367	timers[3].gtrfr = &regs->gtrfr4;
368	timers[3].gtevr = &regs->gtevr4;
369
370	/* CPM2 doesn't have primary prescaler */
371	if (!of_device_is_compatible(np, "fsl,cpm2-gtm")) {
372	timers[0].gtpsr = &regs->gtpsr1;
373	timers[1].gtpsr = &regs->gtpsr2;
374	timers[2].gtpsr = &regs->gtpsr3;
375	timers[3].gtpsr = &regs->gtpsr4;
376	}
377	}
378
379	static int __init fsl_gtm_init(void)
380	{
381	struct device_node *np;
382
383	for_each_compatible_node(np, NULL, "fsl,gtm") {
384	int i;
385	struct gtm *gtm;
386	const u32 *clock;
387	int size;
388
389	gtm = kzalloc(sizeof(*gtm), GFP_KERNEL);
390	if (!gtm) {
391	pr_err("%s: unable to allocate memory\n",
392	np->full_name);
393	continue;
394	}
395
396	spin_lock_init(&gtm->lock);
397
398	clock = of_get_property(np, "clock-frequency", &size);
399	if (!clock \|\| size != sizeof(*clock)) {
400	pr_err("%s: no clock-frequency\n", np->full_name);
401	goto err;
402	}
403	gtm->clock = *clock;
404
405	for (i = 0; i < ARRAY_SIZE(gtm->timers); i++) {
f7578496	406	unsigned int irq;
83ff9dcf	407
f7578496 TR	408	irq = irq_of_parse_and_map(np, i);
f7578496 TR	409	if (irq == NO_IRQ) {
83ff9dcf AV	410	pr_err("%s: not enough interrupts specified\n",
	411	np->full_name);
	412	goto err;
	413	}
f7578496	414	gtm->timers[i].irq = irq;
83ff9dcf AV	415	gtm->timers[i].gtm = gtm;
	416	}
	417
	418	gtm->regs = of_iomap(np, 0);
	419	if (!gtm->regs) {
	420	pr_err("%s: unable to iomap registers\n",
	421	np->full_name);
	422	goto err;
	423	}
	424
	425	gtm_set_shortcuts(np, gtm->timers, gtm->regs);
	426	list_add(&gtm->list_node, &gtms);
	427
	428	/* We don't want to lose the node and its ->data */
	429	np->data = gtm;
	430	of_node_get(np);
	431
	432	continue;
	433	err:
	434	kfree(gtm);
	435	}
	436	return 0;
	437	}
	438	arch_initcall(fsl_gtm_init);