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 <linux/sched_clock.h>
18 #include <asm/time.h>
19 #include <asm/txx9tmr.h>
20
21 #define TCR_BASE (TXx9_TMTCR_CCDE | TXx9_TMTCR_CRE | TXx9_TMTCR_TMODE_ITVL)
22 #define TIMER_CCD 0 /* 1/2 */
23 #define TIMER_CLK(imclk) ((imclk) / (2 << TIMER_CCD))
24
25 struct txx9_clocksource {
26 struct clocksource cs;
27 struct txx9_tmr_reg __iomem *tmrptr;
28 };
29
30 static u64 txx9_cs_read(struct clocksource *cs)
31 {
32 struct txx9_clocksource *txx9_cs =
33 container_of(cs, struct txx9_clocksource, cs);
34 return __raw_readl(&txx9_cs->tmrptr->trr);
35 }
36
37 /* Use 1 bit smaller width to use full bits in that width */
38 #define TXX9_CLOCKSOURCE_BITS (TXX9_TIMER_BITS - 1)
39
40 static struct txx9_clocksource txx9_clocksource = {
41 .cs = {
42 .name = "TXx9",
43 .rating = 200,
44 .read = txx9_cs_read,
45 .mask = CLOCKSOURCE_MASK(TXX9_CLOCKSOURCE_BITS),
46 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
47 },
48 };
49
50 static u64 notrace txx9_read_sched_clock(void)
51 {
52 return __raw_readl(&txx9_clocksource.tmrptr->trr);
53 }
54
55 void __init txx9_clocksource_init(unsigned long baseaddr,
56 unsigned int imbusclk)
57 {
58 struct txx9_tmr_reg __iomem *tmrptr;
59
60 clocksource_register_hz(&txx9_clocksource.cs, TIMER_CLK(imbusclk));
61
62 tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
63 __raw_writel(TCR_BASE, &tmrptr->tcr);
64 __raw_writel(0, &tmrptr->tisr);
65 __raw_writel(TIMER_CCD, &tmrptr->ccdr);
66 __raw_writel(TXx9_TMITMR_TZCE, &tmrptr->itmr);
67 __raw_writel(1 << TXX9_CLOCKSOURCE_BITS, &tmrptr->cpra);
68 __raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
69 txx9_clocksource.tmrptr = tmrptr;
70
71 sched_clock_register(txx9_read_sched_clock, TXX9_CLOCKSOURCE_BITS,
72 TIMER_CLK(imbusclk));
73 }
74
75 struct txx9_clock_event_device {
76 struct clock_event_device cd;
77 struct txx9_tmr_reg __iomem *tmrptr;
78 };
79
80 static void txx9tmr_stop_and_clear(struct txx9_tmr_reg __iomem *tmrptr)
81 {
82 /* stop and reset counter */
83 __raw_writel(TCR_BASE, &tmrptr->tcr);
84 /* clear pending interrupt */
85 __raw_writel(0, &tmrptr->tisr);
86 }
87
88 static int txx9tmr_set_state_periodic(struct clock_event_device *evt)
89 {
90 struct txx9_clock_event_device *txx9_cd =
91 container_of(evt, struct txx9_clock_event_device, cd);
92 struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
93
94 txx9tmr_stop_and_clear(tmrptr);
95
96 __raw_writel(TXx9_TMITMR_TIIE | TXx9_TMITMR_TZCE, &tmrptr->itmr);
97 /* start timer */
98 __raw_writel(((u64)(NSEC_PER_SEC / HZ) * evt->mult) >> evt->shift,
99 &tmrptr->cpra);
100 __raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
101 return 0;
102 }
103
104 static int txx9tmr_set_state_oneshot(struct clock_event_device *evt)
105 {
106 struct txx9_clock_event_device *txx9_cd =
107 container_of(evt, struct txx9_clock_event_device, cd);
108 struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
109
110 txx9tmr_stop_and_clear(tmrptr);
111 __raw_writel(TXx9_TMITMR_TIIE, &tmrptr->itmr);
112 return 0;
113 }
114
115 static int txx9tmr_set_state_shutdown(struct clock_event_device *evt)
116 {
117 struct txx9_clock_event_device *txx9_cd =
118 container_of(evt, struct txx9_clock_event_device, cd);
119 struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
120
121 txx9tmr_stop_and_clear(tmrptr);
122 __raw_writel(0, &tmrptr->itmr);
123 return 0;
124 }
125
126 static int txx9tmr_tick_resume(struct clock_event_device *evt)
127 {
128 struct txx9_clock_event_device *txx9_cd =
129 container_of(evt, struct txx9_clock_event_device, cd);
130 struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
131
132 txx9tmr_stop_and_clear(tmrptr);
133 __raw_writel(TIMER_CCD, &tmrptr->ccdr);
134 __raw_writel(0, &tmrptr->itmr);
135 return 0;
136 }
137
138 static int txx9tmr_set_next_event(unsigned long delta,
139 struct clock_event_device *evt)
140 {
141 struct txx9_clock_event_device *txx9_cd =
142 container_of(evt, struct txx9_clock_event_device, cd);
143 struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
144
145 txx9tmr_stop_and_clear(tmrptr);
146 /* start timer */
147 __raw_writel(delta, &tmrptr->cpra);
148 __raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
149 return 0;
150 }
151
152 static struct txx9_clock_event_device txx9_clock_event_device = {
153 .cd = {
154 .name = "TXx9",
155 .features = CLOCK_EVT_FEAT_PERIODIC |
156 CLOCK_EVT_FEAT_ONESHOT,
157 .rating = 200,
158 .set_state_shutdown = txx9tmr_set_state_shutdown,
159 .set_state_periodic = txx9tmr_set_state_periodic,
160 .set_state_oneshot = txx9tmr_set_state_oneshot,
161 .tick_resume = txx9tmr_tick_resume,
162 .set_next_event = txx9tmr_set_next_event,
163 },
164 };
165
166 static irqreturn_t txx9tmr_interrupt(int irq, void *dev_id)
167 {
168 struct txx9_clock_event_device *txx9_cd = dev_id;
169 struct clock_event_device *cd = &txx9_cd->cd;
170 struct txx9_tmr_reg __iomem *tmrptr = txx9_cd->tmrptr;
171
172 __raw_writel(0, &tmrptr->tisr); /* ack interrupt */
173 cd->event_handler(cd);
174 return IRQ_HANDLED;
175 }
176
177 void __init txx9_clockevent_init(unsigned long baseaddr, int irq,
178 unsigned int imbusclk)
179 {
180 struct clock_event_device *cd = &txx9_clock_event_device.cd;
181 struct txx9_tmr_reg __iomem *tmrptr;
182
183 tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
184 txx9tmr_stop_and_clear(tmrptr);
185 __raw_writel(TIMER_CCD, &tmrptr->ccdr);
186 __raw_writel(0, &tmrptr->itmr);
187 txx9_clock_event_device.tmrptr = tmrptr;
188
189 clockevent_set_clock(cd, TIMER_CLK(imbusclk));
190 cd->max_delta_ns =
191 clockevent_delta2ns(0xffffffff >> (32 - TXX9_TIMER_BITS), cd);
192 cd->max_delta_ticks = 0xffffffff >> (32 - TXX9_TIMER_BITS);
193 cd->min_delta_ns = clockevent_delta2ns(0xf, cd);
194 cd->min_delta_ticks = 0xf;
195 cd->irq = irq;
196 cd->cpumask = cpumask_of(0);
197 clockevents_register_device(cd);
198 if (request_irq(irq, txx9tmr_interrupt, IRQF_PERCPU | IRQF_TIMER,
199 "txx9tmr", &txx9_clock_event_device))
200 pr_err("Failed to request irq %d (txx9tmr)\n", irq);
201 printk(KERN_INFO "TXx9: clockevent device at 0x%lx, irq %d\n",
202 baseaddr, irq);
203 }
204
205 void __init txx9_tmr_init(unsigned long baseaddr)
206 {
207 struct txx9_tmr_reg __iomem *tmrptr;
208
209 tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
210 /* Start once to make CounterResetEnable effective */
211 __raw_writel(TXx9_TMTCR_CRE | TXx9_TMTCR_TCE, &tmrptr->tcr);
212 /* Stop and reset the counter */
213 __raw_writel(TXx9_TMTCR_CRE, &tmrptr->tcr);
214 __raw_writel(0, &tmrptr->tisr);
215 __raw_writel(0xffffffff, &tmrptr->cpra);
216 __raw_writel(0, &tmrptr->itmr);
217 __raw_writel(0, &tmrptr->ccdr);
218 __raw_writel(0, &tmrptr->pgmr);
219 iounmap(tmrptr);
220 }
221
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