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Barry Song4898de32012-12-20 19:37:32 +08001/*
2 * System timer for CSR SiRFprimaII
3 *
4 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
5 *
6 * Licensed under GPLv2 or later.
7 */
8
9#include <linux/kernel.h>
10#include <linux/interrupt.h>
11#include <linux/clockchips.h>
12#include <linux/clocksource.h>
Stephen Boyd05a65482013-02-15 17:02:16 -080013#include <linux/cpu.h>
Barry Song4898de32012-12-20 19:37:32 +080014#include <linux/bitops.h>
15#include <linux/irq.h>
16#include <linux/clk.h>
17#include <linux/slab.h>
18#include <linux/of.h>
19#include <linux/of_irq.h>
20#include <linux/of_address.h>
Stephen Boyd38ff87f2013-06-01 23:39:40 -070021#include <linux/sched_clock.h>
Uwe Kleine-König980c51a2013-11-11 21:06:11 +010022
Barry Song4898de32012-12-20 19:37:32 +080023#define SIRFSOC_TIMER_32COUNTER_0_CTRL 0x0000
24#define SIRFSOC_TIMER_32COUNTER_1_CTRL 0x0004
25#define SIRFSOC_TIMER_MATCH_0 0x0018
26#define SIRFSOC_TIMER_MATCH_1 0x001c
27#define SIRFSOC_TIMER_COUNTER_0 0x0048
28#define SIRFSOC_TIMER_COUNTER_1 0x004c
29#define SIRFSOC_TIMER_INTR_STATUS 0x0060
30#define SIRFSOC_TIMER_WATCHDOG_EN 0x0064
31#define SIRFSOC_TIMER_64COUNTER_CTRL 0x0068
32#define SIRFSOC_TIMER_64COUNTER_LO 0x006c
33#define SIRFSOC_TIMER_64COUNTER_HI 0x0070
34#define SIRFSOC_TIMER_64COUNTER_LOAD_LO 0x0074
35#define SIRFSOC_TIMER_64COUNTER_LOAD_HI 0x0078
36#define SIRFSOC_TIMER_64COUNTER_RLATCHED_LO 0x007c
37#define SIRFSOC_TIMER_64COUNTER_RLATCHED_HI 0x0080
38
39#define SIRFSOC_TIMER_REG_CNT 6
40
Barry Song5833ac92015-01-12 00:04:43 +080041static unsigned long atlas7_timer_rate;
Yanchang Lief89af12014-11-11 20:42:52 +080042
Barry Song4898de32012-12-20 19:37:32 +080043static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = {
44 SIRFSOC_TIMER_WATCHDOG_EN,
45 SIRFSOC_TIMER_32COUNTER_0_CTRL,
46 SIRFSOC_TIMER_32COUNTER_1_CTRL,
47 SIRFSOC_TIMER_64COUNTER_CTRL,
48 SIRFSOC_TIMER_64COUNTER_RLATCHED_LO,
49 SIRFSOC_TIMER_64COUNTER_RLATCHED_HI,
50};
51
52static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT];
53
54static void __iomem *sirfsoc_timer_base;
Barry Song4898de32012-12-20 19:37:32 +080055
56/* disable count and interrupt */
57static inline void sirfsoc_timer_count_disable(int idx)
58{
59 writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) & ~0x7,
60 sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx);
61}
62
63/* enable count and interrupt */
64static inline void sirfsoc_timer_count_enable(int idx)
65{
Hao Liu28cf3562014-09-29 01:50:06 +020066 writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) | 0x3,
Barry Song4898de32012-12-20 19:37:32 +080067 sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx);
68}
69
70/* timer interrupt handler */
71static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
72{
73 struct clock_event_device *ce = dev_id;
74 int cpu = smp_processor_id();
75
76 /* clear timer interrupt */
77 writel_relaxed(BIT(cpu), sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
78
79 if (ce->mode == CLOCK_EVT_MODE_ONESHOT)
80 sirfsoc_timer_count_disable(cpu);
81
82 ce->event_handler(ce);
83
84 return IRQ_HANDLED;
85}
86
87/* read 64-bit timer counter */
88static cycle_t sirfsoc_timer_read(struct clocksource *cs)
89{
90 u64 cycles;
91
92 writel_relaxed((readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
93 BIT(0)) & ~BIT(1), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
94
95 cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_HI);
96 cycles = (cycles << 32) | readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_LO);
97
98 return cycles;
99}
100
101static int sirfsoc_timer_set_next_event(unsigned long delta,
102 struct clock_event_device *ce)
103{
104 int cpu = smp_processor_id();
105
Hao Liu28cf3562014-09-29 01:50:06 +0200106 /* disable timer first, then modify the related registers */
107 sirfsoc_timer_count_disable(cpu);
108
Barry Song4898de32012-12-20 19:37:32 +0800109 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0 +
110 4 * cpu);
111 writel_relaxed(delta, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0 +
112 4 * cpu);
113
114 /* enable the tick */
115 sirfsoc_timer_count_enable(cpu);
116
117 return 0;
118}
119
120static void sirfsoc_timer_set_mode(enum clock_event_mode mode,
121 struct clock_event_device *ce)
122{
123 switch (mode) {
124 case CLOCK_EVT_MODE_ONESHOT:
125 /* enable in set_next_event */
126 break;
127 default:
128 break;
129 }
130
131 sirfsoc_timer_count_disable(smp_processor_id());
132}
133
134static void sirfsoc_clocksource_suspend(struct clocksource *cs)
135{
136 int i;
137
138 for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
139 sirfsoc_timer_reg_val[i] = readl_relaxed(sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
140}
141
142static void sirfsoc_clocksource_resume(struct clocksource *cs)
143{
144 int i;
145
146 for (i = 0; i < SIRFSOC_TIMER_REG_CNT - 2; i++)
147 writel_relaxed(sirfsoc_timer_reg_val[i], sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
148
149 writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 2],
150 sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO);
151 writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 1],
152 sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI);
153
154 writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
155 BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
156}
157
Stephen Boyd05a65482013-02-15 17:02:16 -0800158static struct clock_event_device __percpu *sirfsoc_clockevent;
Barry Song4898de32012-12-20 19:37:32 +0800159
160static struct clocksource sirfsoc_clocksource = {
161 .name = "sirfsoc_clocksource",
162 .rating = 200,
163 .mask = CLOCKSOURCE_MASK(64),
164 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
165 .read = sirfsoc_timer_read,
166 .suspend = sirfsoc_clocksource_suspend,
167 .resume = sirfsoc_clocksource_resume,
168};
169
170static struct irqaction sirfsoc_timer_irq = {
171 .name = "sirfsoc_timer0",
172 .flags = IRQF_TIMER | IRQF_NOBALANCING,
173 .handler = sirfsoc_timer_interrupt,
Barry Song4898de32012-12-20 19:37:32 +0800174};
175
Barry Song4898de32012-12-20 19:37:32 +0800176static struct irqaction sirfsoc_timer1_irq = {
177 .name = "sirfsoc_timer1",
178 .flags = IRQF_TIMER | IRQF_NOBALANCING,
179 .handler = sirfsoc_timer_interrupt,
180};
181
Paul Gortmaker8c37bb32013-06-19 11:32:08 -0400182static int sirfsoc_local_timer_setup(struct clock_event_device *ce)
Barry Song4898de32012-12-20 19:37:32 +0800183{
Stephen Boyd05a65482013-02-15 17:02:16 -0800184 int cpu = smp_processor_id();
185 struct irqaction *action;
Barry Song4898de32012-12-20 19:37:32 +0800186
Stephen Boyd05a65482013-02-15 17:02:16 -0800187 if (cpu == 0)
188 action = &sirfsoc_timer_irq;
189 else
190 action = &sirfsoc_timer1_irq;
191
192 ce->irq = action->irq;
Barry Song4898de32012-12-20 19:37:32 +0800193 ce->name = "local_timer";
Stephen Boyd05a65482013-02-15 17:02:16 -0800194 ce->features = CLOCK_EVT_FEAT_ONESHOT;
195 ce->rating = 200;
Barry Song4898de32012-12-20 19:37:32 +0800196 ce->set_mode = sirfsoc_timer_set_mode;
197 ce->set_next_event = sirfsoc_timer_set_next_event;
Barry Song5833ac92015-01-12 00:04:43 +0800198 clockevents_calc_mult_shift(ce, atlas7_timer_rate, 60);
Stephen Boyd05a65482013-02-15 17:02:16 -0800199 ce->max_delta_ns = clockevent_delta2ns(-2, ce);
200 ce->min_delta_ns = clockevent_delta2ns(2, ce);
201 ce->cpumask = cpumask_of(cpu);
Barry Song4898de32012-12-20 19:37:32 +0800202
Stephen Boyd05a65482013-02-15 17:02:16 -0800203 action->dev_id = ce;
204 BUG_ON(setup_irq(ce->irq, action));
Zhiwu Songf214be52014-05-07 14:46:44 +0800205 irq_force_affinity(action->irq, cpumask_of(cpu));
Barry Song4898de32012-12-20 19:37:32 +0800206
207 clockevents_register_device(ce);
208 return 0;
209}
210
211static void sirfsoc_local_timer_stop(struct clock_event_device *ce)
212{
Stephen Boyd05a65482013-02-15 17:02:16 -0800213 int cpu = smp_processor_id();
214
Barry Song4898de32012-12-20 19:37:32 +0800215 sirfsoc_timer_count_disable(1);
216
Stephen Boyd05a65482013-02-15 17:02:16 -0800217 if (cpu == 0)
218 remove_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq);
219 else
220 remove_irq(sirfsoc_timer1_irq.irq, &sirfsoc_timer1_irq);
Barry Song4898de32012-12-20 19:37:32 +0800221}
222
Olof Johansson47dcd352013-07-23 14:51:34 -0700223static int sirfsoc_cpu_notify(struct notifier_block *self,
224 unsigned long action, void *hcpu)
Stephen Boyd05a65482013-02-15 17:02:16 -0800225{
226 /*
227 * Grab cpu pointer in each case to avoid spurious
228 * preemptible warnings
229 */
230 switch (action & ~CPU_TASKS_FROZEN) {
231 case CPU_STARTING:
232 sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent));
233 break;
234 case CPU_DYING:
235 sirfsoc_local_timer_stop(this_cpu_ptr(sirfsoc_clockevent));
236 break;
237 }
238
239 return NOTIFY_OK;
240}
241
Olof Johansson47dcd352013-07-23 14:51:34 -0700242static struct notifier_block sirfsoc_cpu_nb = {
Stephen Boyd05a65482013-02-15 17:02:16 -0800243 .notifier_call = sirfsoc_cpu_notify,
Barry Song4898de32012-12-20 19:37:32 +0800244};
Barry Song4898de32012-12-20 19:37:32 +0800245
246static void __init sirfsoc_clockevent_init(void)
247{
Stephen Boyd05a65482013-02-15 17:02:16 -0800248 sirfsoc_clockevent = alloc_percpu(struct clock_event_device);
249 BUG_ON(!sirfsoc_clockevent);
Barry Song4898de32012-12-20 19:37:32 +0800250
Stephen Boyd05a65482013-02-15 17:02:16 -0800251 BUG_ON(register_cpu_notifier(&sirfsoc_cpu_nb));
Barry Song4898de32012-12-20 19:37:32 +0800252
Stephen Boyd05a65482013-02-15 17:02:16 -0800253 /* Immediately configure the timer on the boot CPU */
254 sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent));
Barry Song4898de32012-12-20 19:37:32 +0800255}
256
257/* initialize the kernel jiffy timer source */
Barry Song5833ac92015-01-12 00:04:43 +0800258static void __init sirfsoc_atlas7_timer_init(struct device_node *np)
Barry Song4898de32012-12-20 19:37:32 +0800259{
Barry Song4898de32012-12-20 19:37:32 +0800260 struct clk *clk;
261
Zhiwu Songc7cff542014-05-05 19:30:04 +0800262 clk = of_clk_get(np, 0);
Barry Song4898de32012-12-20 19:37:32 +0800263 BUG_ON(IS_ERR(clk));
Zhiwu Song38941522014-07-03 20:52:51 +0800264
265 BUG_ON(clk_prepare_enable(clk));
266
Barry Song5833ac92015-01-12 00:04:43 +0800267 atlas7_timer_rate = clk_get_rate(clk);
Barry Song4898de32012-12-20 19:37:32 +0800268
Yanchang Lief89af12014-11-11 20:42:52 +0800269 /* timer dividers: 0, not divided */
270 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
271 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL);
272 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_1_CTRL);
Barry Song4898de32012-12-20 19:37:32 +0800273
274 /* Initialize timer counters to 0 */
275 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO);
276 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI);
277 writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
278 BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
279 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0);
280 writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_1);
281
282 /* Clear all interrupts */
283 writel_relaxed(0xFFFF, sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
284
Barry Song5833ac92015-01-12 00:04:43 +0800285 BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, atlas7_timer_rate));
Barry Song4898de32012-12-20 19:37:32 +0800286
Barry Song4898de32012-12-20 19:37:32 +0800287 sirfsoc_clockevent_init();
288}
289
Arnd Bergmann275786b2013-03-19 15:27:22 +0100290static void __init sirfsoc_of_timer_init(struct device_node *np)
Barry Song4898de32012-12-20 19:37:32 +0800291{
Barry Song4898de32012-12-20 19:37:32 +0800292 sirfsoc_timer_base = of_iomap(np, 0);
293 if (!sirfsoc_timer_base)
294 panic("unable to map timer cpu registers\n");
295
296 sirfsoc_timer_irq.irq = irq_of_parse_and_map(np, 0);
297 if (!sirfsoc_timer_irq.irq)
298 panic("No irq passed for timer0 via DT\n");
299
Barry Song4898de32012-12-20 19:37:32 +0800300 sirfsoc_timer1_irq.irq = irq_of_parse_and_map(np, 1);
301 if (!sirfsoc_timer1_irq.irq)
302 panic("No irq passed for timer1 via DT\n");
Barry Song4898de32012-12-20 19:37:32 +0800303
Barry Song5833ac92015-01-12 00:04:43 +0800304 sirfsoc_atlas7_timer_init(np);
Barry Song4898de32012-12-20 19:37:32 +0800305}
Barry Song5833ac92015-01-12 00:04:43 +0800306CLOCKSOURCE_OF_DECLARE(sirfsoc_atlas7_timer, "sirf,atlas7-tick", sirfsoc_of_timer_init);