[linux-2.6-block.git] / drivers / clocksource / timer-imx-tpm.c

// SPDX-License-Identifier: GPL-2.0+
//
// Copyright 2016 Freescale Semiconductor, Inc.
// Copyright 2017 NXP

#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>

#define TPM_PARAM			0x4
#define TPM_PARAM_WIDTH_SHIFT		16
#define TPM_PARAM_WIDTH_MASK		(0xff << 16)
#define TPM_SC				0x10
#define TPM_SC_CMOD_INC_PER_CNT		(0x1 << 3)
#define TPM_SC_CMOD_DIV_DEFAULT		0x3
#define TPM_SC_CMOD_DIV_MAX		0x7
#define TPM_SC_TOF_MASK			(0x1 << 7)
#define TPM_CNT				0x14
#define TPM_MOD				0x18
#define TPM_STATUS			0x1c
#define TPM_STATUS_CH0F			BIT(0)
#define TPM_C0SC			0x20
#define TPM_C0SC_CHIE			BIT(6)
#define TPM_C0SC_MODE_SHIFT		2
#define TPM_C0SC_MODE_MASK		0x3c
#define TPM_C0SC_MODE_SW_COMPARE	0x4
#define TPM_C0SC_CHF_MASK		(0x1 << 7)
#define TPM_C0V				0x24

static int counter_width;
static int rating;
static void __iomem *timer_base;
static struct clock_event_device clockevent_tpm;

static inline void tpm_timer_disable(void)
{
	unsigned int val;

	/* channel disable */
	val = readl(timer_base + TPM_C0SC);
	val &= ~(TPM_C0SC_MODE_MASK | TPM_C0SC_CHIE);
	writel(val, timer_base + TPM_C0SC);
}

static inline void tpm_timer_enable(void)
{
	unsigned int val;

	/* channel enabled in sw compare mode */
	val = readl(timer_base + TPM_C0SC);
	val |= (TPM_C0SC_MODE_SW_COMPARE << TPM_C0SC_MODE_SHIFT) |
	       TPM_C0SC_CHIE;
	writel(val, timer_base + TPM_C0SC);
}

static inline void tpm_irq_acknowledge(void)
{
	writel(TPM_STATUS_CH0F, timer_base + TPM_STATUS);
}

static struct delay_timer tpm_delay_timer;

static inline unsigned long tpm_read_counter(void)
{
	return readl(timer_base + TPM_CNT);
}

static unsigned long tpm_read_current_timer(void)
{
	return tpm_read_counter();
}

static u64 notrace tpm_read_sched_clock(void)
{
	return tpm_read_counter();
}

static int __init tpm_clocksource_init(unsigned long rate)
{
	tpm_delay_timer.read_current_timer = &tpm_read_current_timer;
	tpm_delay_timer.freq = rate;
	register_current_timer_delay(&tpm_delay_timer);

	sched_clock_register(tpm_read_sched_clock, counter_width, rate);

	return clocksource_mmio_init(timer_base + TPM_CNT, "imx-tpm",
				     rate, rating, counter_width,
				     clocksource_mmio_readl_up);
}

static int tpm_set_next_event(unsigned long delta,
				struct clock_event_device *evt)
{
	unsigned long next, now;

	next = tpm_read_counter();
	next += delta;
	writel(next, timer_base + TPM_C0V);
	now = tpm_read_counter();

	/*
	 * NOTE: We observed in a very small probability, the bus fabric
	 * contention between GPU and A7 may results a few cycles delay
	 * of writing CNT registers which may cause the min_delta event got
	 * missed, so we need add a ETIME check here in case it happened.
	 */
	return (int)(next - now) <= 0 ? -ETIME : 0;
}

static int tpm_set_state_oneshot(struct clock_event_device *evt)
{
	tpm_timer_enable();

	return 0;
}

static int tpm_set_state_shutdown(struct clock_event_device *evt)
{
	tpm_timer_disable();

	return 0;
}

static irqreturn_t tpm_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = dev_id;

	tpm_irq_acknowledge();

	evt->event_handler(evt);

	return IRQ_HANDLED;
}

static struct clock_event_device clockevent_tpm = {
	.name			= "i.MX7ULP TPM Timer",
	.features		= CLOCK_EVT_FEAT_ONESHOT,
	.set_state_oneshot	= tpm_set_state_oneshot,
	.set_next_event		= tpm_set_next_event,
	.set_state_shutdown	= tpm_set_state_shutdown,
};

static int __init tpm_clockevent_init(unsigned long rate, int irq)
{
	int ret;

	ret = request_irq(irq, tpm_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL,
			  "i.MX7ULP TPM Timer", &clockevent_tpm);

	clockevent_tpm.rating = rating;
	clockevent_tpm.cpumask = cpumask_of(0);
	clockevent_tpm.irq = irq;
	clockevents_config_and_register(&clockevent_tpm, rate, 300,
					GENMASK(counter_width - 1, 1));

	return ret;
}

static int __init tpm_timer_init(struct device_node *np)
{
	struct clk *ipg, *per;
	int irq, ret;
	u32 rate;

	timer_base = of_iomap(np, 0);
	if (!timer_base) {
		pr_err("tpm: failed to get base address\n");
		return -ENXIO;
	}

	irq = irq_of_parse_and_map(np, 0);
	if (!irq) {
		pr_err("tpm: failed to get irq\n");
		ret = -ENOENT;
		goto err_iomap;
	}

	ipg = of_clk_get_by_name(np, "ipg");
	per = of_clk_get_by_name(np, "per");
	if (IS_ERR(ipg) || IS_ERR(per)) {
		pr_err("tpm: failed to get ipg or per clk\n");
		ret = -ENODEV;
		goto err_clk_get;
	}

	/* enable clk before accessing registers */
	ret = clk_prepare_enable(ipg);
	if (ret) {
		pr_err("tpm: ipg clock enable failed (%d)\n", ret);
		goto err_clk_get;
	}

	ret = clk_prepare_enable(per);
	if (ret) {
		pr_err("tpm: per clock enable failed (%d)\n", ret);
		goto err_per_clk_enable;
	}

	counter_width = (readl(timer_base + TPM_PARAM) & TPM_PARAM_WIDTH_MASK)
		>> TPM_PARAM_WIDTH_SHIFT;
	/* use rating 200 for 32-bit counter and 150 for 16-bit counter */
	rating = counter_width == 0x20 ? 200 : 150;

	/*
	 * Initialize tpm module to a known state
	 * 1) Counter disabled
	 * 2) TPM counter operates in up counting mode
	 * 3) Timer Overflow Interrupt disabled
	 * 4) Channel0 disabled
	 * 5) DMA transfers disabled
	 */
	/* make sure counter is disabled */
	writel(0, timer_base + TPM_SC);
	/* TOF is W1C */
	writel(TPM_SC_TOF_MASK, timer_base + TPM_SC);
	writel(0, timer_base + TPM_CNT);
	/* CHF is W1C */
	writel(TPM_C0SC_CHF_MASK, timer_base + TPM_C0SC);

	/*
	 * increase per cnt,
	 * div 8 for 32-bit counter and div 128 for 16-bit counter
	 */
	writel(TPM_SC_CMOD_INC_PER_CNT |
		(counter_width == 0x20 ?
		TPM_SC_CMOD_DIV_DEFAULT : TPM_SC_CMOD_DIV_MAX),
		     timer_base + TPM_SC);

	/* set MOD register to maximum for free running mode */
	writel(GENMASK(counter_width - 1, 0), timer_base + TPM_MOD);

	rate = clk_get_rate(per) >> 3;
	ret = tpm_clocksource_init(rate);
	if (ret)
		goto err_per_clk_enable;

	ret = tpm_clockevent_init(rate, irq);
	if (ret)
		goto err_per_clk_enable;

	return 0;

err_per_clk_enable:
	clk_disable_unprepare(ipg);
err_clk_get:
	clk_put(per);
	clk_put(ipg);
err_iomap:
	iounmap(timer_base);
	return ret;
}
TIMER_OF_DECLARE(imx7ulp, "fsl,imx7ulp-tpm", tpm_timer_init);
Commit	Line	Data
c8437a6c FE	1	// SPDX-License-Identifier: GPL-2.0+
	2	//
	3	// Copyright 2016 Freescale Semiconductor, Inc.
	4	// Copyright 2017 NXP
059ab7b8 DA	5
	6	#include <linux/clk.h>
	7	#include <linux/clockchips.h>
	8	#include <linux/clocksource.h>
	9	#include <linux/delay.h>
	10	#include <linux/interrupt.h>
	11	#include <linux/of_address.h>
	12	#include <linux/of_irq.h>
	13	#include <linux/sched_clock.h>
	14
0136c741 AH	15	#define TPM_PARAM 0x4
	16	#define TPM_PARAM_WIDTH_SHIFT 16
	17	#define TPM_PARAM_WIDTH_MASK (0xff << 16)
059ab7b8 DA	18	#define TPM_SC 0x10
	19	#define TPM_SC_CMOD_INC_PER_CNT (0x1 << 3)
	20	#define TPM_SC_CMOD_DIV_DEFAULT 0x3
0136c741	21	#define TPM_SC_CMOD_DIV_MAX 0x7
506a7be9	22	#define TPM_SC_TOF_MASK (0x1 << 7)
059ab7b8 DA	23	#define TPM_CNT 0x14
	24	#define TPM_MOD 0x18
	25	#define TPM_STATUS 0x1c
	26	#define TPM_STATUS_CH0F BIT(0)
	27	#define TPM_C0SC 0x20
	28	#define TPM_C0SC_CHIE BIT(6)
	29	#define TPM_C0SC_MODE_SHIFT 2
	30	#define TPM_C0SC_MODE_MASK 0x3c
	31	#define TPM_C0SC_MODE_SW_COMPARE 0x4
506a7be9	32	#define TPM_C0SC_CHF_MASK (0x1 << 7)
059ab7b8 DA	33	#define TPM_C0V 0x24
059ab7b8 DA	34
0136c741 AH	35	static int counter_width;
0136c741 AH	36	static int rating;
059ab7b8 DA	37	static void __iomem *timer_base;
	38	static struct clock_event_device clockevent_tpm;
	39
	40	static inline void tpm_timer_disable(void)
	41	{
	42	unsigned int val;
	43
	44	/* channel disable */
	45	val = readl(timer_base + TPM_C0SC);
	46	val &= ~(TPM_C0SC_MODE_MASK \| TPM_C0SC_CHIE);
	47	writel(val, timer_base + TPM_C0SC);
	48	}
	49
	50	static inline void tpm_timer_enable(void)
	51	{
	52	unsigned int val;
	53
	54	/* channel enabled in sw compare mode */
	55	val = readl(timer_base + TPM_C0SC);
	56	val \|= (TPM_C0SC_MODE_SW_COMPARE << TPM_C0SC_MODE_SHIFT) \|
	57	TPM_C0SC_CHIE;
	58	writel(val, timer_base + TPM_C0SC);
	59	}
	60
	61	static inline void tpm_irq_acknowledge(void)
	62	{
	63	writel(TPM_STATUS_CH0F, timer_base + TPM_STATUS);
	64	}
	65
	66	static struct delay_timer tpm_delay_timer;
	67
	68	static inline unsigned long tpm_read_counter(void)
	69	{
	70	return readl(timer_base + TPM_CNT);
	71	}
	72
	73	static unsigned long tpm_read_current_timer(void)
	74	{
	75	return tpm_read_counter();
	76	}
	77
	78	static u64 notrace tpm_read_sched_clock(void)
	79	{
	80	return tpm_read_counter();
	81	}
	82
	83	static int __init tpm_clocksource_init(unsigned long rate)
	84	{
	85	tpm_delay_timer.read_current_timer = &tpm_read_current_timer;
	86	tpm_delay_timer.freq = rate;
	87	register_current_timer_delay(&tpm_delay_timer);
	88
0136c741	89	sched_clock_register(tpm_read_sched_clock, counter_width, rate);
059ab7b8 DA	90
059ab7b8 DA	91	return clocksource_mmio_init(timer_base + TPM_CNT, "imx-tpm",
0136c741 AH	92	rate, rating, counter_width,
0136c741 AH	93	clocksource_mmio_readl_up);
059ab7b8 DA	94	}
	95
	96	static int tpm_set_next_event(unsigned long delta,
	97	struct clock_event_device *evt)
	98	{
	99	unsigned long next, now;
	100
	101	next = tpm_read_counter();
	102	next += delta;
	103	writel(next, timer_base + TPM_C0V);
	104	now = tpm_read_counter();
	105
	106	/*
	107	* NOTE: We observed in a very small probability, the bus fabric
	108	* contention between GPU and A7 may results a few cycles delay
	109	* of writing CNT registers which may cause the min_delta event got
	110	* missed, so we need add a ETIME check here in case it happened.
	111	*/
74071884	112	return (int)(next - now) <= 0 ? -ETIME : 0;
059ab7b8 DA	113	}
	114
	115	static int tpm_set_state_oneshot(struct clock_event_device *evt)
	116	{
	117	tpm_timer_enable();
	118
	119	return 0;
	120	}
	121
	122	static int tpm_set_state_shutdown(struct clock_event_device *evt)
	123	{
	124	tpm_timer_disable();
	125
	126	return 0;
	127	}
	128
	129	static irqreturn_t tpm_timer_interrupt(int irq, void *dev_id)
	130	{
	131	struct clock_event_device *evt = dev_id;
	132
	133	tpm_irq_acknowledge();
	134
	135	evt->event_handler(evt);
	136
	137	return IRQ_HANDLED;
	138	}
	139
	140	static struct clock_event_device clockevent_tpm = {
	141	.name = "i.MX7ULP TPM Timer",
	142	.features = CLOCK_EVT_FEAT_ONESHOT,
	143	.set_state_oneshot = tpm_set_state_oneshot,
	144	.set_next_event = tpm_set_next_event,
	145	.set_state_shutdown = tpm_set_state_shutdown,
059ab7b8 DA	146	};
	147
	148	static int __init tpm_clockevent_init(unsigned long rate, int irq)
	149	{
	150	int ret;
	151
	152	ret = request_irq(irq, tpm_timer_interrupt, IRQF_TIMER \| IRQF_IRQPOLL,
	153	"i.MX7ULP TPM Timer", &clockevent_tpm);
	154
0136c741	155	clockevent_tpm.rating = rating;
059ab7b8 DA	156	clockevent_tpm.cpumask = cpumask_of(0);
059ab7b8 DA	157	clockevent_tpm.irq = irq;
0136c741 AH	158	clockevents_config_and_register(&clockevent_tpm, rate, 300,
0136c741 AH	159	GENMASK(counter_width - 1, 1));
059ab7b8 DA	160
	161	return ret;
	162	}
	163
	164	static int __init tpm_timer_init(struct device_node *np)
	165	{
	166	struct clk ipg, per;
	167	int irq, ret;
	168	u32 rate;
	169
	170	timer_base = of_iomap(np, 0);
	171	if (!timer_base) {
	172	pr_err("tpm: failed to get base address\n");
	173	return -ENXIO;
	174	}
	175
	176	irq = irq_of_parse_and_map(np, 0);
	177	if (!irq) {
	178	pr_err("tpm: failed to get irq\n");
	179	ret = -ENOENT;
	180	goto err_iomap;
	181	}
	182
	183	ipg = of_clk_get_by_name(np, "ipg");
	184	per = of_clk_get_by_name(np, "per");
	185	if (IS_ERR(ipg) \|\| IS_ERR(per)) {
16328e7b	186	pr_err("tpm: failed to get ipg or per clk\n");
059ab7b8 DA	187	ret = -ENODEV;
	188	goto err_clk_get;
	189	}
	190
	191	/* enable clk before accessing registers */
	192	ret = clk_prepare_enable(ipg);
	193	if (ret) {
	194	pr_err("tpm: ipg clock enable failed (%d)\n", ret);
	195	goto err_clk_get;
	196	}
	197
	198	ret = clk_prepare_enable(per);
	199	if (ret) {
	200	pr_err("tpm: per clock enable failed (%d)\n", ret);
	201	goto err_per_clk_enable;
	202	}
	203
0136c741 AH	204	counter_width = (readl(timer_base + TPM_PARAM) & TPM_PARAM_WIDTH_MASK)
	205	>> TPM_PARAM_WIDTH_SHIFT;
	206	/* use rating 200 for 32-bit counter and 150 for 16-bit counter */
	207	rating = counter_width == 0x20 ? 200 : 150;
	208
059ab7b8 DA	209	/*
	210	* Initialize tpm module to a known state
	211	* 1) Counter disabled
	212	* 2) TPM counter operates in up counting mode
	213	* 3) Timer Overflow Interrupt disabled
	214	* 4) Channel0 disabled
	215	* 5) DMA transfers disabled
	216	*/
506a7be9	217	/* make sure counter is disabled */
059ab7b8	218	writel(0, timer_base + TPM_SC);
506a7be9 AH	219	/* TOF is W1C */
506a7be9 AH	220	writel(TPM_SC_TOF_MASK, timer_base + TPM_SC);
059ab7b8	221	writel(0, timer_base + TPM_CNT);
506a7be9 AH	222	/* CHF is W1C */
506a7be9 AH	223	writel(TPM_C0SC_CHF_MASK, timer_base + TPM_C0SC);
059ab7b8	224
0136c741 AH	225	/*
	226	* increase per cnt,
	227	* div 8 for 32-bit counter and div 128 for 16-bit counter
	228	*/
	229	writel(TPM_SC_CMOD_INC_PER_CNT \|
	230	(counter_width == 0x20 ?
	231	TPM_SC_CMOD_DIV_DEFAULT : TPM_SC_CMOD_DIV_MAX),
059ab7b8 DA	232	timer_base + TPM_SC);
	233
	234	/* set MOD register to maximum for free running mode */
0136c741	235	writel(GENMASK(counter_width - 1, 0), timer_base + TPM_MOD);
059ab7b8 DA	236
	237	rate = clk_get_rate(per) >> 3;
	238	ret = tpm_clocksource_init(rate);
	239	if (ret)
	240	goto err_per_clk_enable;
	241
	242	ret = tpm_clockevent_init(rate, irq);
	243	if (ret)
	244	goto err_per_clk_enable;
	245
	246	return 0;
	247
	248	err_per_clk_enable:
	249	clk_disable_unprepare(ipg);
	250	err_clk_get:
	251	clk_put(per);
	252	clk_put(ipg);
	253	err_iomap:
	254	iounmap(timer_base);
	255	return ret;
	256	}
	257	TIMER_OF_DECLARE(imx7ulp, "fsl,imx7ulp-tpm", tpm_timer_init);