xref: /openbmc/linux/arch/mips/kernel/cevt-txx9.c (revision 54525552)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Based on linux/arch/mips/kernel/cevt-r4k.c,
7  *          linux/arch/mips/jmr3927/rbhma3100/setup.c
8  *
9  * Copyright 2001 MontaVista Software Inc.
10  * Copyright (C) 2000-2001 Toshiba Corporation
11  * Copyright (C) 2007 MIPS Technologies, Inc.
12  * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
13  */
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <asm/time.h>
18 #include <asm/txx9tmr.h>
19 
20 #define TCR_BASE (TXx9_TMTCR_CCDE | TXx9_TMTCR_CRE | TXx9_TMTCR_TMODE_ITVL)
21 #define TIMER_CCD	0	/* 1/2 */
22 #define TIMER_CLK(imclk)	((imclk) / (2 << TIMER_CCD))
23 
24 struct txx9_clocksource {
25 	struct clocksource cs;
26 	struct txx9_tmr_reg __iomem *tmrptr;
27 };
28 
29 static cycle_t txx9_cs_read(struct clocksource *cs)
30 {
31 	struct txx9_clocksource *txx9_cs =
32 		container_of(cs, struct txx9_clocksource, cs);
33 	return __raw_readl(&txx9_cs->tmrptr->trr);
34 }
35 
36 /* Use 1 bit smaller width to use full bits in that width */
37 #define TXX9_CLOCKSOURCE_BITS (TXX9_TIMER_BITS - 1)
38 
39 static struct txx9_clocksource txx9_clocksource = {
40 	.cs = {
41 		.name		= "TXx9",
42 		.rating		= 200,
43 		.read		= txx9_cs_read,
44 		.mask		= CLOCKSOURCE_MASK(TXX9_CLOCKSOURCE_BITS),
45 		.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
46 	},
47 };
48 
49 void __init txx9_clocksource_init(unsigned long baseaddr,
50 				  unsigned int imbusclk)
51 {
52 	struct txx9_tmr_reg __iomem *tmrptr;
53 
54 	clocksource_register_hz(&txx9_clocksource.cs, TIMER_CLK(imbusclk));
55 
56 	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
57 	__raw_writel(TCR_BASE, &tmrptr->tcr);
58 	__raw_writel(0, &tmrptr->tisr);
59 	__raw_writel(TIMER_CCD, &tmrptr->ccdr);
60 	__raw_writel(TXx9_TMITMR_TZCE, &tmrptr->itmr);
61 	__raw_writel(1 << TXX9_CLOCKSOURCE_BITS, &tmrptr->cpra);
62 	__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
63 	txx9_clocksource.tmrptr = tmrptr;
64 }
65 
66 struct txx9_clock_event_device {
67 	struct clock_event_device cd;
68 	struct txx9_tmr_reg __iomem *tmrptr;
69 };
70 
71 static void txx9tmr_stop_and_clear(struct txx9_tmr_reg __iomem *tmrptr)
72 {
73 	/* stop and reset counter */
74 	__raw_writel(TCR_BASE, &tmrptr->tcr);
75 	/* clear pending interrupt */
76 	__raw_writel(0, &tmrptr->tisr);
77 }
78 
79 static void txx9tmr_set_mode(enum clock_event_mode mode,
80 			     struct clock_event_device *evt)
81 {
82 	struct txx9_clock_event_device *txx9_cd =
83 		container_of(evt, struct txx9_clock_event_device, cd);
84 	struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
85 
86 	txx9tmr_stop_and_clear(tmrptr);
87 	switch (mode) {
88 	case CLOCK_EVT_MODE_PERIODIC:
89 		__raw_writel(TXx9_TMITMR_TIIE | TXx9_TMITMR_TZCE,
90 			     &tmrptr->itmr);
91 		/* start timer */
92 		__raw_writel(((u64)(NSEC_PER_SEC / HZ) * evt->mult) >>
93 			     evt->shift,
94 			     &tmrptr->cpra);
95 		__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
96 		break;
97 	case CLOCK_EVT_MODE_SHUTDOWN:
98 	case CLOCK_EVT_MODE_UNUSED:
99 		__raw_writel(0, &tmrptr->itmr);
100 		break;
101 	case CLOCK_EVT_MODE_ONESHOT:
102 		__raw_writel(TXx9_TMITMR_TIIE, &tmrptr->itmr);
103 		break;
104 	case CLOCK_EVT_MODE_RESUME:
105 		__raw_writel(TIMER_CCD, &tmrptr->ccdr);
106 		__raw_writel(0, &tmrptr->itmr);
107 		break;
108 	}
109 }
110 
111 static int txx9tmr_set_next_event(unsigned long delta,
112 				  struct clock_event_device *evt)
113 {
114 	struct txx9_clock_event_device *txx9_cd =
115 		container_of(evt, struct txx9_clock_event_device, cd);
116 	struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
117 
118 	txx9tmr_stop_and_clear(tmrptr);
119 	/* start timer */
120 	__raw_writel(delta, &tmrptr->cpra);
121 	__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
122 	return 0;
123 }
124 
125 static struct txx9_clock_event_device txx9_clock_event_device = {
126 	.cd = {
127 		.name		= "TXx9",
128 		.features	= CLOCK_EVT_FEAT_PERIODIC |
129 				  CLOCK_EVT_FEAT_ONESHOT,
130 		.rating		= 200,
131 		.set_mode	= txx9tmr_set_mode,
132 		.set_next_event	= txx9tmr_set_next_event,
133 	},
134 };
135 
136 static irqreturn_t txx9tmr_interrupt(int irq, void *dev_id)
137 {
138 	struct txx9_clock_event_device *txx9_cd = dev_id;
139 	struct clock_event_device *cd = &txx9_cd->cd;
140 	struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
141 
142 	__raw_writel(0, &tmrptr->tisr);	/* ack interrupt */
143 	cd->event_handler(cd);
144 	return IRQ_HANDLED;
145 }
146 
147 static struct irqaction txx9tmr_irq = {
148 	.handler	= txx9tmr_interrupt,
149 	.flags		= IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER,
150 	.name		= "txx9tmr",
151 	.dev_id		= &txx9_clock_event_device,
152 };
153 
154 void __init txx9_clockevent_init(unsigned long baseaddr, int irq,
155 				 unsigned int imbusclk)
156 {
157 	struct clock_event_device *cd = &txx9_clock_event_device.cd;
158 	struct txx9_tmr_reg __iomem *tmrptr;
159 
160 	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
161 	txx9tmr_stop_and_clear(tmrptr);
162 	__raw_writel(TIMER_CCD, &tmrptr->ccdr);
163 	__raw_writel(0, &tmrptr->itmr);
164 	txx9_clock_event_device.tmrptr = tmrptr;
165 
166 	clockevent_set_clock(cd, TIMER_CLK(imbusclk));
167 	cd->max_delta_ns =
168 		clockevent_delta2ns(0xffffffff >> (32 - TXX9_TIMER_BITS), cd);
169 	cd->min_delta_ns = clockevent_delta2ns(0xf, cd);
170 	cd->irq = irq;
171 	cd->cpumask = cpumask_of(0),
172 	clockevents_register_device(cd);
173 	setup_irq(irq, &txx9tmr_irq);
174 	printk(KERN_INFO "TXx9: clockevent device at 0x%lx, irq %d\n",
175 	       baseaddr, irq);
176 }
177 
178 void __init txx9_tmr_init(unsigned long baseaddr)
179 {
180 	struct txx9_tmr_reg __iomem *tmrptr;
181 
182 	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
183 	/* Start once to make CounterResetEnable effective */
184 	__raw_writel(TXx9_TMTCR_CRE | TXx9_TMTCR_TCE, &tmrptr->tcr);
185 	/* Stop and reset the counter */
186 	__raw_writel(TXx9_TMTCR_CRE, &tmrptr->tcr);
187 	__raw_writel(0, &tmrptr->tisr);
188 	__raw_writel(0xffffffff, &tmrptr->cpra);
189 	__raw_writel(0, &tmrptr->itmr);
190 	__raw_writel(0, &tmrptr->ccdr);
191 	__raw_writel(0, &tmrptr->pgmr);
192 	iounmap(tmrptr);
193 }
194