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1 | /* |
2 | * arch/arch/mach-tegra/timer.c | |
3 | * | |
4 | * Copyright (C) 2010 Google, Inc. | |
5 | * | |
6 | * Author: | |
7 | * Colin Cross <ccross@google.com> | |
8 | * | |
9 | * This software is licensed under the terms of the GNU General Public | |
10 | * License version 2, as published by the Free Software Foundation, and | |
11 | * may be copied, distributed, and modified under those terms. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | */ | |
19 | ||
20 | #include <linux/init.h> | |
62248ae8 | 21 | #include <linux/err.h> |
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22 | #include <linux/time.h> |
23 | #include <linux/interrupt.h> | |
24 | #include <linux/irq.h> | |
25 | #include <linux/clockchips.h> | |
26 | #include <linux/clocksource.h> | |
27 | #include <linux/clk.h> | |
28 | #include <linux/io.h> | |
2d5cd9a3 | 29 | |
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30 | #include <asm/mach/time.h> |
31 | #include <asm/localtimer.h> | |
e3f4c0ab | 32 | #include <asm/sched_clock.h> |
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33 | |
34 | #include <mach/iomap.h> | |
35 | #include <mach/irqs.h> | |
2ea67fd1 | 36 | #include <mach/suspend.h> |
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37 | |
38 | #include "board.h" | |
39 | #include "clock.h" | |
40 | ||
09361785 CC |
41 | #define RTC_SECONDS 0x08 |
42 | #define RTC_SHADOW_SECONDS 0x0c | |
43 | #define RTC_MILLISECONDS 0x10 | |
44 | ||
2d5cd9a3 CC |
45 | #define TIMERUS_CNTR_1US 0x10 |
46 | #define TIMERUS_USEC_CFG 0x14 | |
47 | #define TIMERUS_CNTR_FREEZE 0x4c | |
48 | ||
49 | #define TIMER1_BASE 0x0 | |
50 | #define TIMER2_BASE 0x8 | |
51 | #define TIMER3_BASE 0x50 | |
52 | #define TIMER4_BASE 0x58 | |
53 | ||
54 | #define TIMER_PTV 0x0 | |
55 | #define TIMER_PCR 0x4 | |
56 | ||
2d5cd9a3 | 57 | static void __iomem *timer_reg_base = IO_ADDRESS(TEGRA_TMR1_BASE); |
09361785 CC |
58 | static void __iomem *rtc_base = IO_ADDRESS(TEGRA_RTC_BASE); |
59 | ||
60 | static struct timespec persistent_ts; | |
61 | static u64 persistent_ms, last_persistent_ms; | |
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62 | |
63 | #define timer_writel(value, reg) \ | |
75d71166 | 64 | __raw_writel(value, timer_reg_base + (reg)) |
2d5cd9a3 | 65 | #define timer_readl(reg) \ |
75d71166 | 66 | __raw_readl(timer_reg_base + (reg)) |
2d5cd9a3 CC |
67 | |
68 | static int tegra_timer_set_next_event(unsigned long cycles, | |
69 | struct clock_event_device *evt) | |
70 | { | |
71 | u32 reg; | |
72 | ||
73 | reg = 0x80000000 | ((cycles > 1) ? (cycles-1) : 0); | |
74 | timer_writel(reg, TIMER3_BASE + TIMER_PTV); | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | static void tegra_timer_set_mode(enum clock_event_mode mode, | |
80 | struct clock_event_device *evt) | |
81 | { | |
82 | u32 reg; | |
83 | ||
84 | timer_writel(0, TIMER3_BASE + TIMER_PTV); | |
85 | ||
86 | switch (mode) { | |
87 | case CLOCK_EVT_MODE_PERIODIC: | |
88 | reg = 0xC0000000 | ((1000000/HZ)-1); | |
89 | timer_writel(reg, TIMER3_BASE + TIMER_PTV); | |
90 | break; | |
91 | case CLOCK_EVT_MODE_ONESHOT: | |
92 | break; | |
93 | case CLOCK_EVT_MODE_UNUSED: | |
94 | case CLOCK_EVT_MODE_SHUTDOWN: | |
95 | case CLOCK_EVT_MODE_RESUME: | |
96 | break; | |
97 | } | |
98 | } | |
99 | ||
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100 | static struct clock_event_device tegra_clockevent = { |
101 | .name = "timer0", | |
102 | .rating = 300, | |
103 | .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, | |
104 | .set_next_event = tegra_timer_set_next_event, | |
105 | .set_mode = tegra_timer_set_mode, | |
106 | }; | |
107 | ||
2f0778af | 108 | static u32 notrace tegra_read_sched_clock(void) |
e3f4c0ab | 109 | { |
2f0778af | 110 | return timer_readl(TIMERUS_CNTR_1US); |
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111 | } |
112 | ||
09361785 CC |
113 | /* |
114 | * tegra_rtc_read - Reads the Tegra RTC registers | |
115 | * Care must be taken that this funciton is not called while the | |
116 | * tegra_rtc driver could be executing to avoid race conditions | |
117 | * on the RTC shadow register | |
118 | */ | |
b28fba2a | 119 | static u64 tegra_rtc_read_ms(void) |
09361785 CC |
120 | { |
121 | u32 ms = readl(rtc_base + RTC_MILLISECONDS); | |
122 | u32 s = readl(rtc_base + RTC_SHADOW_SECONDS); | |
123 | return (u64)s * MSEC_PER_SEC + ms; | |
124 | } | |
125 | ||
126 | /* | |
127 | * read_persistent_clock - Return time from a persistent clock. | |
128 | * | |
129 | * Reads the time from a source which isn't disabled during PM, the | |
130 | * 32k sync timer. Convert the cycles elapsed since last read into | |
131 | * nsecs and adds to a monotonically increasing timespec. | |
132 | * Care must be taken that this funciton is not called while the | |
133 | * tegra_rtc driver could be executing to avoid race conditions | |
134 | * on the RTC shadow register | |
135 | */ | |
136 | void read_persistent_clock(struct timespec *ts) | |
137 | { | |
138 | u64 delta; | |
139 | struct timespec *tsp = &persistent_ts; | |
140 | ||
141 | last_persistent_ms = persistent_ms; | |
142 | persistent_ms = tegra_rtc_read_ms(); | |
143 | delta = persistent_ms - last_persistent_ms; | |
144 | ||
145 | timespec_add_ns(tsp, delta * NSEC_PER_MSEC); | |
146 | *ts = *tsp; | |
147 | } | |
148 | ||
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149 | static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id) |
150 | { | |
151 | struct clock_event_device *evt = (struct clock_event_device *)dev_id; | |
152 | timer_writel(1<<30, TIMER3_BASE + TIMER_PCR); | |
153 | evt->event_handler(evt); | |
154 | return IRQ_HANDLED; | |
155 | } | |
156 | ||
157 | static struct irqaction tegra_timer_irq = { | |
158 | .name = "timer0", | |
159 | .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_HIGH, | |
160 | .handler = tegra_timer_interrupt, | |
161 | .dev_id = &tegra_clockevent, | |
162 | .irq = INT_TMR3, | |
163 | }; | |
164 | ||
165 | static void __init tegra_init_timer(void) | |
166 | { | |
62248ae8 | 167 | struct clk *clk; |
8e4fab2c | 168 | unsigned long rate; |
2d5cd9a3 CC |
169 | int ret; |
170 | ||
62248ae8 | 171 | clk = clk_get_sys("timer", NULL); |
8e4fab2c PDS |
172 | if (IS_ERR(clk)) { |
173 | pr_warn("Unable to get timer clock." | |
174 | " Assuming 12Mhz input clock.\n"); | |
175 | rate = 12000000; | |
176 | } else { | |
2d85b5d8 | 177 | clk_enable(clk); |
8e4fab2c PDS |
178 | rate = clk_get_rate(clk); |
179 | } | |
62248ae8 CC |
180 | |
181 | /* | |
182 | * rtc registers are used by read_persistent_clock, keep the rtc clock | |
183 | * enabled | |
184 | */ | |
185 | clk = clk_get_sys("rtc-tegra", NULL); | |
2d85b5d8 PDS |
186 | if (IS_ERR(clk)) |
187 | pr_warn("Unable to get rtc-tegra clock\n"); | |
188 | else | |
189 | clk_enable(clk); | |
62248ae8 | 190 | |
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191 | #ifdef CONFIG_HAVE_ARM_TWD |
192 | twd_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE + 0x600); | |
193 | #endif | |
194 | ||
195 | switch (rate) { | |
196 | case 12000000: | |
197 | timer_writel(0x000b, TIMERUS_USEC_CFG); | |
198 | break; | |
199 | case 13000000: | |
200 | timer_writel(0x000c, TIMERUS_USEC_CFG); | |
201 | break; | |
202 | case 19200000: | |
203 | timer_writel(0x045f, TIMERUS_USEC_CFG); | |
204 | break; | |
205 | case 26000000: | |
206 | timer_writel(0x0019, TIMERUS_USEC_CFG); | |
207 | break; | |
208 | default: | |
209 | WARN(1, "Unknown clock rate"); | |
210 | } | |
211 | ||
2f0778af | 212 | setup_sched_clock(tegra_read_sched_clock, 32, 1000000); |
e3f4c0ab | 213 | |
234b6ced RK |
214 | if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US, |
215 | "timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) { | |
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216 | printk(KERN_ERR "Failed to register clocksource\n"); |
217 | BUG(); | |
218 | } | |
219 | ||
220 | ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq); | |
221 | if (ret) { | |
222 | printk(KERN_ERR "Failed to register timer IRQ: %d\n", ret); | |
223 | BUG(); | |
224 | } | |
225 | ||
226 | clockevents_calc_mult_shift(&tegra_clockevent, 1000000, 5); | |
227 | tegra_clockevent.max_delta_ns = | |
228 | clockevent_delta2ns(0x1fffffff, &tegra_clockevent); | |
229 | tegra_clockevent.min_delta_ns = | |
230 | clockevent_delta2ns(0x1, &tegra_clockevent); | |
231 | tegra_clockevent.cpumask = cpu_all_mask; | |
232 | tegra_clockevent.irq = tegra_timer_irq.irq; | |
233 | clockevents_register_device(&tegra_clockevent); | |
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234 | } |
235 | ||
236 | struct sys_timer tegra_timer = { | |
237 | .init = tegra_init_timer, | |
238 | }; | |
09361785 CC |
239 | |
240 | #ifdef CONFIG_PM | |
241 | static u32 usec_config; | |
242 | ||
243 | void tegra_timer_suspend(void) | |
244 | { | |
245 | usec_config = timer_readl(TIMERUS_USEC_CFG); | |
246 | } | |
247 | ||
248 | void tegra_timer_resume(void) | |
249 | { | |
250 | timer_writel(usec_config, TIMERUS_USEC_CFG); | |
251 | } | |
252 | #endif |