Merge tag 'iommu-updates-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro...
[deliverable/linux.git] / drivers / clocksource / time-armada-370-xp.c
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1/*
2 * Marvell Armada 370/XP SoC timer handling.
3 *
4 * Copyright (C) 2012 Marvell
5 *
6 * Lior Amsalem <alior@marvell.com>
7 * Gregory CLEMENT <gregory.clement@free-electrons.com>
8 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
9 *
10 * This file is licensed under the terms of the GNU General Public
11 * License version 2. This program is licensed "as is" without any
12 * warranty of any kind, whether express or implied.
13 *
14 * Timer 0 is used as free-running clocksource, while timer 1 is
15 * used as clock_event_device.
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16 *
17 * ---
18 * Clocksource driver for Armada 370 and Armada XP SoC.
19 * This driver implements one compatible string for each SoC, given
20 * each has its own characteristics:
21 *
22 * * Armada 370 has no 25 MHz fixed timer.
23 *
24 * * Armada XP cannot work properly without such 25 MHz fixed timer as
25 * doing otherwise leads to using a clocksource whose frequency varies
26 * when doing cpufreq frequency changes.
27 *
28 * See Documentation/devicetree/bindings/timer/marvell,armada-370-xp-timer.txt
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29 */
30
31#include <linux/init.h>
32#include <linux/platform_device.h>
33#include <linux/kernel.h>
307c2bf4 34#include <linux/clk.h>
5ddb6d21 35#include <linux/cpu.h>
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36#include <linux/timer.h>
37#include <linux/clockchips.h>
38#include <linux/interrupt.h>
39#include <linux/of.h>
40#include <linux/of_irq.h>
41#include <linux/of_address.h>
42#include <linux/irq.h>
43#include <linux/module.h>
38ff87f7 44#include <linux/sched_clock.h>
ddd3f69f 45#include <linux/percpu.h>
f9a49ab5 46#include <linux/syscore_ops.h>
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47
48/*
49 * Timer block registers.
50 */
51#define TIMER_CTRL_OFF 0x0000
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52#define TIMER0_EN BIT(0)
53#define TIMER0_RELOAD_EN BIT(1)
54#define TIMER0_25MHZ BIT(11)
6fe9cbd1 55#define TIMER0_DIV(div) ((div) << 19)
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56#define TIMER1_EN BIT(2)
57#define TIMER1_RELOAD_EN BIT(3)
58#define TIMER1_25MHZ BIT(12)
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59#define TIMER1_DIV(div) ((div) << 22)
60#define TIMER_EVENTS_STATUS 0x0004
61#define TIMER0_CLR_MASK (~0x1)
62#define TIMER1_CLR_MASK (~0x100)
63#define TIMER0_RELOAD_OFF 0x0010
64#define TIMER0_VAL_OFF 0x0014
65#define TIMER1_RELOAD_OFF 0x0018
66#define TIMER1_VAL_OFF 0x001c
67
ddd3f69f 68#define LCL_TIMER_EVENTS_STATUS 0x0028
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69/* Global timers are connected to the coherency fabric clock, and the
70 below divider reduces their incrementing frequency. */
71#define TIMER_DIVIDER_SHIFT 5
72#define TIMER_DIVIDER (1 << TIMER_DIVIDER_SHIFT)
73
74/*
75 * SoC-specific data.
76 */
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77static void __iomem *timer_base, *local_base;
78static unsigned int timer_clk;
79static bool timer25Mhz = true;
08cb8e46 80static u32 enable_mask;
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81
82/*
83 * Number of timer ticks per jiffy.
84 */
85static u32 ticks_per_jiffy;
86
5ddb6d21 87static struct clock_event_device __percpu *armada_370_xp_evt;
ddd3f69f 88
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89static void local_timer_ctrl_clrset(u32 clr, u32 set)
90{
91 writel((readl(local_base + TIMER_CTRL_OFF) & ~clr) | set,
92 local_base + TIMER_CTRL_OFF);
93}
ddd3f69f 94
d9dbcbe0 95static u64 notrace armada_370_xp_read_sched_clock(void)
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96{
97 return ~readl(timer_base + TIMER0_VAL_OFF);
98}
99
100/*
101 * Clockevent handling.
102 */
103static int
104armada_370_xp_clkevt_next_event(unsigned long delta,
105 struct clock_event_device *dev)
106{
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107 /*
108 * Clear clockevent timer interrupt.
109 */
ddd3f69f 110 writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
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111
112 /*
113 * Setup new clockevent timer value.
114 */
ddd3f69f 115 writel(delta, local_base + TIMER0_VAL_OFF);
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116
117 /*
118 * Enable the timer.
119 */
08cb8e46 120 local_timer_ctrl_clrset(TIMER0_RELOAD_EN, enable_mask);
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121 return 0;
122}
123
d96f4412 124static int armada_370_xp_clkevt_shutdown(struct clock_event_device *evt)
6fe9cbd1 125{
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126 /*
127 * Disable timer.
128 */
129 local_timer_ctrl_clrset(TIMER0_EN, 0);
130
131 /*
132 * ACK pending timer interrupt.
133 */
134 writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
135 return 0;
136}
137
138static int armada_370_xp_clkevt_set_periodic(struct clock_event_device *evt)
139{
140 /*
141 * Setup timer to fire at 1/HZ intervals.
142 */
143 writel(ticks_per_jiffy - 1, local_base + TIMER0_RELOAD_OFF);
144 writel(ticks_per_jiffy - 1, local_base + TIMER0_VAL_OFF);
145
146 /*
147 * Enable timer.
148 */
149 local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | enable_mask);
150 return 0;
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151}
152
5ddb6d21 153static int armada_370_xp_clkevt_irq;
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154
155static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
156{
157 /*
158 * ACK timer interrupt and call event handler.
159 */
5ddb6d21 160 struct clock_event_device *evt = dev_id;
6fe9cbd1 161
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162 writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
163 evt->event_handler(evt);
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164
165 return IRQ_HANDLED;
166}
167
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168/*
169 * Setup the local clock events for a CPU.
170 */
8c37bb3a 171static int armada_370_xp_timer_setup(struct clock_event_device *evt)
ddd3f69f 172{
3579698e 173 u32 clr = 0, set = 0;
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174 int cpu = smp_processor_id();
175
ddd3f69f 176 if (timer25Mhz)
3579698e 177 set = TIMER0_25MHZ;
ddd3f69f 178 else
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179 clr = TIMER0_25MHZ;
180 local_timer_ctrl_clrset(clr, set);
ddd3f69f 181
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182 evt->name = "armada_370_xp_per_cpu_tick",
183 evt->features = CLOCK_EVT_FEAT_ONESHOT |
184 CLOCK_EVT_FEAT_PERIODIC;
185 evt->shift = 32,
186 evt->rating = 300,
ddd3f69f 187 evt->set_next_event = armada_370_xp_clkevt_next_event,
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188 evt->set_state_shutdown = armada_370_xp_clkevt_shutdown;
189 evt->set_state_periodic = armada_370_xp_clkevt_set_periodic;
190 evt->set_state_oneshot = armada_370_xp_clkevt_shutdown;
191 evt->tick_resume = armada_370_xp_clkevt_shutdown;
5ddb6d21 192 evt->irq = armada_370_xp_clkevt_irq;
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193 evt->cpumask = cpumask_of(cpu);
194
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195 clockevents_config_and_register(evt, timer_clk, 1, 0xfffffffe);
196 enable_percpu_irq(evt->irq, 0);
197
198 return 0;
199}
200
47dcd356 201static void armada_370_xp_timer_stop(struct clock_event_device *evt)
ddd3f69f 202{
d96f4412 203 evt->set_state_shutdown(evt);
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204 disable_percpu_irq(evt->irq);
205}
206
47dcd356 207static int armada_370_xp_timer_cpu_notify(struct notifier_block *self,
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208 unsigned long action, void *hcpu)
209{
210 /*
211 * Grab cpu pointer in each case to avoid spurious
212 * preemptible warnings
213 */
214 switch (action & ~CPU_TASKS_FROZEN) {
215 case CPU_STARTING:
216 armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
217 break;
218 case CPU_DYING:
219 armada_370_xp_timer_stop(this_cpu_ptr(armada_370_xp_evt));
220 break;
221 }
222
223 return NOTIFY_OK;
224}
225
47dcd356 226static struct notifier_block armada_370_xp_timer_cpu_nb = {
5ddb6d21 227 .notifier_call = armada_370_xp_timer_cpu_notify,
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228};
229
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230static u32 timer0_ctrl_reg, timer0_local_ctrl_reg;
231
232static int armada_370_xp_timer_suspend(void)
233{
234 timer0_ctrl_reg = readl(timer_base + TIMER_CTRL_OFF);
235 timer0_local_ctrl_reg = readl(local_base + TIMER_CTRL_OFF);
236 return 0;
237}
238
239static void armada_370_xp_timer_resume(void)
240{
241 writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
242 writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
243 writel(timer0_ctrl_reg, timer_base + TIMER_CTRL_OFF);
244 writel(timer0_local_ctrl_reg, local_base + TIMER_CTRL_OFF);
245}
246
247struct syscore_ops armada_370_xp_timer_syscore_ops = {
248 .suspend = armada_370_xp_timer_suspend,
249 .resume = armada_370_xp_timer_resume,
250};
251
7cd6392c 252static void __init armada_370_xp_timer_common_init(struct device_node *np)
6fe9cbd1 253{
3579698e 254 u32 clr = 0, set = 0;
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255 int res;
256
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257 timer_base = of_iomap(np, 0);
258 WARN_ON(!timer_base);
ddd3f69f 259 local_base = of_iomap(np, 1);
6fe9cbd1 260
08cb8e46 261 if (timer25Mhz) {
a4ae54f9 262 set = TIMER0_25MHZ;
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263 enable_mask = TIMER0_EN;
264 } else {
3579698e 265 clr = TIMER0_25MHZ;
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266 enable_mask = TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT);
267 }
c8af34b4 268 atomic_io_modify(timer_base + TIMER_CTRL_OFF, clr | set, set);
3579698e 269 local_timer_ctrl_clrset(clr, set);
6fe9cbd1 270
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271 /*
272 * We use timer 0 as clocksource, and private(local) timer 0
273 * for clockevents
274 */
5ddb6d21 275 armada_370_xp_clkevt_irq = irq_of_parse_and_map(np, 4);
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276
277 ticks_per_jiffy = (timer_clk + HZ / 2) / HZ;
278
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279 /*
280 * Setup free-running clocksource timer (interrupts
281 * disabled).
282 */
283 writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
284 writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
285
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286 atomic_io_modify(timer_base + TIMER_CTRL_OFF,
287 TIMER0_RELOAD_EN | enable_mask,
288 TIMER0_RELOAD_EN | enable_mask);
6fe9cbd1 289
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290 /*
291 * Set scale and timer for sched_clock.
292 */
293 sched_clock_register(armada_370_xp_read_sched_clock, 32, timer_clk);
294
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295 clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
296 "armada_370_xp_clocksource",
297 timer_clk, 300, 32, clocksource_mmio_readl_down);
298
5ddb6d21 299 register_cpu_notifier(&armada_370_xp_timer_cpu_nb);
6fe9cbd1 300
5ddb6d21 301 armada_370_xp_evt = alloc_percpu(struct clock_event_device);
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302
303
304 /*
305 * Setup clockevent timer (interrupt-driven).
306 */
5ddb6d21 307 res = request_percpu_irq(armada_370_xp_clkevt_irq,
ddd3f69f 308 armada_370_xp_timer_interrupt,
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309 "armada_370_xp_per_cpu_tick",
310 armada_370_xp_evt);
311 /* Immediately configure the timer on the boot CPU */
312 if (!res)
313 armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
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314
315 register_syscore_ops(&armada_370_xp_timer_syscore_ops);
ddd3f69f 316}
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317
318static void __init armada_xp_timer_init(struct device_node *np)
319{
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320 struct clk *clk = of_clk_get_by_name(np, "fixed");
321
322 /* The 25Mhz fixed clock is mandatory, and must always be available */
323 BUG_ON(IS_ERR(clk));
551f2fd5 324 clk_prepare_enable(clk);
5e9fe6cb 325 timer_clk = clk_get_rate(clk);
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326
327 armada_370_xp_timer_common_init(np);
328}
329CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer",
330 armada_xp_timer_init);
331
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332static void __init armada_375_timer_init(struct device_node *np)
333{
334 struct clk *clk;
335
336 clk = of_clk_get_by_name(np, "fixed");
337 if (!IS_ERR(clk)) {
338 clk_prepare_enable(clk);
339 timer_clk = clk_get_rate(clk);
340 } else {
341
342 /*
343 * This fallback is required in order to retain proper
344 * devicetree backwards compatibility.
345 */
346 clk = of_clk_get(np, 0);
347
348 /* Must have at least a clock */
349 BUG_ON(IS_ERR(clk));
350 clk_prepare_enable(clk);
351 timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
352 timer25Mhz = false;
353 }
354
355 armada_370_xp_timer_common_init(np);
356}
357CLOCKSOURCE_OF_DECLARE(armada_375, "marvell,armada-375-timer",
358 armada_375_timer_init);
359
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360static void __init armada_370_timer_init(struct device_node *np)
361{
362 struct clk *clk = of_clk_get(np, 0);
363
ec8e5112 364 BUG_ON(IS_ERR(clk));
551f2fd5 365 clk_prepare_enable(clk);
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366 timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
367 timer25Mhz = false;
368
369 armada_370_xp_timer_common_init(np);
ddd3f69f 370}
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371CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer",
372 armada_370_timer_init);
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