aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/kernel/cevt-txx9.c
blob: e5c30b1d0860f5e1e669070619833f4605cfef1c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Based on linux/arch/mips/kernel/cevt-r4k.c,
 *          linux/arch/mips/jmr3927/rbhma3100/setup.c
 *
 * Copyright 2001 MontaVista Software Inc.
 * Copyright (C) 2000-2001 Toshiba Corporation
 * Copyright (C) 2007 MIPS Technologies, Inc.
 * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
 */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/time.h>
#include <asm/txx9tmr.h>

#define TCR_BASE (TXx9_TMTCR_CCDE | TXx9_TMTCR_CRE | TXx9_TMTCR_TMODE_ITVL)
#define TIMER_CCD	0	/* 1/2 */
#define TIMER_CLK(imclk)	((imclk) / (2 << TIMER_CCD))

struct txx9_clocksource {
	struct clocksource cs;
	struct txx9_tmr_reg __iomem *tmrptr;
};

static cycle_t txx9_cs_read(struct clocksource *cs)
{
	struct txx9_clocksource *txx9_cs =
		container_of(cs, struct txx9_clocksource, cs);
	return __raw_readl(&txx9_cs->tmrptr->trr);
}

/* Use 1 bit smaller width to use full bits in that width */
#define TXX9_CLOCKSOURCE_BITS (TXX9_TIMER_BITS - 1)

static struct txx9_clocksource txx9_clocksource = {
	.cs = {
		.name		= "TXx9",
		.rating		= 200,
		.read		= txx9_cs_read,
		.mask		= CLOCKSOURCE_MASK(TXX9_CLOCKSOURCE_BITS),
		.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
	},
};

void __init txx9_clocksource_init(unsigned long baseaddr,
				  unsigned int imbusclk)
{
	struct txx9_tmr_reg __iomem *tmrptr;

	clocksource_register_hz(&txx9_clocksource.cs, TIMER_CLK(imbusclk));

	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
	__raw_writel(TCR_BASE, &tmrptr->tcr);
	__raw_writel(0, &tmrptr->tisr);
	__raw_writel(TIMER_CCD, &tmrptr->ccdr);
	__raw_writel(TXx9_TMITMR_TZCE, &tmrptr->itmr);
	__raw_writel(1 << TXX9_CLOCKSOURCE_BITS, &tmrptr->cpra);
	__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
	txx9_clocksource.tmrptr = tmrptr;
}

struct txx9_clock_event_device {
	struct clock_event_device cd;
	struct txx9_tmr_reg __iomem *tmrptr;
};

static void txx9tmr_stop_and_clear(struct txx9_tmr_reg __iomem *tmrptr)
{
	/* stop and reset counter */
	__raw_writel(TCR_BASE, &tmrptr->tcr);
	/* clear pending interrupt */
	__raw_writel(0, &tmrptr->tisr);
}

static void txx9tmr_set_mode(enum clock_event_mode mode,
			     struct clock_event_device *evt)
{
	struct txx9_clock_event_device *txx9_cd =
		container_of(evt, struct txx9_clock_event_device, cd);
	struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;

	txx9tmr_stop_and_clear(tmrptr);
	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
		__raw_writel(TXx9_TMITMR_TIIE | TXx9_TMITMR_TZCE,
			     &tmrptr->itmr);
		/* start timer */
		__raw_writel(((u64)(NSEC_PER_SEC / HZ) * evt->mult) >>
			     evt->shift,
			     &tmrptr->cpra);
		__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
		break;
	case CLOCK_EVT_MODE_SHUTDOWN:
	case CLOCK_EVT_MODE_UNUSED:
		__raw_writel(0, &tmrptr->itmr);
		break;
	case CLOCK_EVT_MODE_ONESHOT:
		__raw_writel(TXx9_TMITMR_TIIE, &tmrptr->itmr);
		break;
	case CLOCK_EVT_MODE_RESUME:
		__raw_writel(TIMER_CCD, &tmrptr->ccdr);
		__raw_writel(0, &tmrptr->itmr);
		break;
	}
}

static int txx9tmr_set_next_event(unsigned long delta,
				  struct clock_event_device *evt)
{
	struct txx9_clock_event_device *txx9_cd =
		container_of(evt, struct txx9_clock_event_device, cd);
	struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;

	txx9tmr_stop_and_clear(tmrptr);
	/* start timer */
	__raw_writel(delta, &tmrptr->cpra);
	__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
	return 0;
}

static struct txx9_clock_event_device txx9_clock_event_device = {
	.cd = {
		.name		= "TXx9",
		.features	= CLOCK_EVT_FEAT_PERIODIC |
				  CLOCK_EVT_FEAT_ONESHOT,
		.rating		= 200,
		.set_mode	= txx9tmr_set_mode,
		.set_next_event	= txx9tmr_set_next_event,
	},
};

static irqreturn_t txx9tmr_interrupt(int irq, void *dev_id)
{
	struct txx9_clock_event_device *txx9_cd = dev_id;
	struct clock_event_device *cd = &txx9_cd->cd;
	struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;

	__raw_writel(0, &tmrptr->tisr);	/* ack interrupt */
	cd->event_handler(cd);
	return IRQ_HANDLED;
}

static struct irqaction txx9tmr_irq = {
	.handler	= txx9tmr_interrupt,
	.flags		= IRQF_PERCPU | IRQF_TIMER,
	.name		= "txx9tmr",
	.dev_id		= &txx9_clock_event_device,
};

void __init txx9_clockevent_init(unsigned long baseaddr, int irq,
				 unsigned int imbusclk)
{
	struct clock_event_device *cd = &txx9_clock_event_device.cd;
	struct txx9_tmr_reg __iomem *tmrptr;

	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
	txx9tmr_stop_and_clear(tmrptr);
	__raw_writel(TIMER_CCD, &tmrptr->ccdr);
	__raw_writel(0, &tmrptr->itmr);
	txx9_clock_event_device.tmrptr = tmrptr;

	clockevent_set_clock(cd, TIMER_CLK(imbusclk));
	cd->max_delta_ns =
		clockevent_delta2ns(0xffffffff >> (32 - TXX9_TIMER_BITS), cd);
	cd->min_delta_ns = clockevent_delta2ns(0xf, cd);
	cd->irq = irq;
	cd->cpumask = cpumask_of(0),
	clockevents_register_device(cd);
	setup_irq(irq, &txx9tmr_irq);
	printk(KERN_INFO "TXx9: clockevent device at 0x%lx, irq %d\n",
	       baseaddr, irq);
}

void __init txx9_tmr_init(unsigned long baseaddr)
{
	struct txx9_tmr_reg __iomem *tmrptr;

	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
	/* Start once to make CounterResetEnable effective */
	__raw_writel(TXx9_TMTCR_CRE | TXx9_TMTCR_TCE, &tmrptr->tcr);
	/* Stop and reset the counter */
	__raw_writel(TXx9_TMTCR_CRE, &tmrptr->tcr);
	__raw_writel(0, &tmrptr->tisr);
	__raw_writel(0xffffffff, &tmrptr->cpra);
	__raw_writel(0, &tmrptr->itmr);
	__raw_writel(0, &tmrptr->ccdr);
	__raw_writel(0, &tmrptr->pgmr);
	iounmap(tmrptr);
}