diff options
author | Ingo Molnar <mingo@kernel.org> | 2013-01-24 06:47:48 -0500 |
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committer | Ingo Molnar <mingo@kernel.org> | 2013-01-24 06:47:48 -0500 |
commit | befddb21c845f8fb49e637997891ef97c6a869dc (patch) | |
tree | 0e7629123184f2dd50291ad6d477b894175f0f26 /drivers/clocksource/sunxi_timer.c | |
parent | e716efde75267eab919cdb2bef5b2cb77f305326 (diff) | |
parent | 7d1f9aeff1ee4a20b1aeb377dd0f579fe9647619 (diff) |
Merge tag 'v3.8-rc4' into irq/core
Merge Linux 3.8-rc4 before pulling in new commits - we were on an old v3.7 base.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/clocksource/sunxi_timer.c')
-rw-r--r-- | drivers/clocksource/sunxi_timer.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/drivers/clocksource/sunxi_timer.c b/drivers/clocksource/sunxi_timer.c new file mode 100644 index 000000000000..3cd1bd3d7aee --- /dev/null +++ b/drivers/clocksource/sunxi_timer.c | |||
@@ -0,0 +1,171 @@ | |||
1 | /* | ||
2 | * Allwinner A1X SoCs timer handling. | ||
3 | * | ||
4 | * Copyright (C) 2012 Maxime Ripard | ||
5 | * | ||
6 | * Maxime Ripard <maxime.ripard@free-electrons.com> | ||
7 | * | ||
8 | * Based on code from | ||
9 | * Allwinner Technology Co., Ltd. <www.allwinnertech.com> | ||
10 | * Benn Huang <benn@allwinnertech.com> | ||
11 | * | ||
12 | * This file is licensed under the terms of the GNU General Public | ||
13 | * License version 2. This program is licensed "as is" without any | ||
14 | * warranty of any kind, whether express or implied. | ||
15 | */ | ||
16 | |||
17 | #include <linux/clk.h> | ||
18 | #include <linux/clockchips.h> | ||
19 | #include <linux/interrupt.h> | ||
20 | #include <linux/irq.h> | ||
21 | #include <linux/irqreturn.h> | ||
22 | #include <linux/of.h> | ||
23 | #include <linux/of_address.h> | ||
24 | #include <linux/of_irq.h> | ||
25 | #include <linux/sunxi_timer.h> | ||
26 | #include <linux/clk/sunxi.h> | ||
27 | |||
28 | #define TIMER_CTL_REG 0x00 | ||
29 | #define TIMER_CTL_ENABLE (1 << 0) | ||
30 | #define TIMER_IRQ_ST_REG 0x04 | ||
31 | #define TIMER0_CTL_REG 0x10 | ||
32 | #define TIMER0_CTL_ENABLE (1 << 0) | ||
33 | #define TIMER0_CTL_AUTORELOAD (1 << 1) | ||
34 | #define TIMER0_CTL_ONESHOT (1 << 7) | ||
35 | #define TIMER0_INTVAL_REG 0x14 | ||
36 | #define TIMER0_CNTVAL_REG 0x18 | ||
37 | |||
38 | #define TIMER_SCAL 16 | ||
39 | |||
40 | static void __iomem *timer_base; | ||
41 | |||
42 | static void sunxi_clkevt_mode(enum clock_event_mode mode, | ||
43 | struct clock_event_device *clk) | ||
44 | { | ||
45 | u32 u = readl(timer_base + TIMER0_CTL_REG); | ||
46 | |||
47 | switch (mode) { | ||
48 | case CLOCK_EVT_MODE_PERIODIC: | ||
49 | u &= ~(TIMER0_CTL_ONESHOT); | ||
50 | writel(u | TIMER0_CTL_ENABLE, timer_base + TIMER0_CTL_REG); | ||
51 | break; | ||
52 | |||
53 | case CLOCK_EVT_MODE_ONESHOT: | ||
54 | writel(u | TIMER0_CTL_ONESHOT, timer_base + TIMER0_CTL_REG); | ||
55 | break; | ||
56 | case CLOCK_EVT_MODE_UNUSED: | ||
57 | case CLOCK_EVT_MODE_SHUTDOWN: | ||
58 | default: | ||
59 | writel(u & ~(TIMER0_CTL_ENABLE), timer_base + TIMER0_CTL_REG); | ||
60 | break; | ||
61 | } | ||
62 | } | ||
63 | |||
64 | static int sunxi_clkevt_next_event(unsigned long evt, | ||
65 | struct clock_event_device *unused) | ||
66 | { | ||
67 | u32 u = readl(timer_base + TIMER0_CTL_REG); | ||
68 | writel(evt, timer_base + TIMER0_CNTVAL_REG); | ||
69 | writel(u | TIMER0_CTL_ENABLE | TIMER0_CTL_AUTORELOAD, | ||
70 | timer_base + TIMER0_CTL_REG); | ||
71 | |||
72 | return 0; | ||
73 | } | ||
74 | |||
75 | static struct clock_event_device sunxi_clockevent = { | ||
76 | .name = "sunxi_tick", | ||
77 | .shift = 32, | ||
78 | .rating = 300, | ||
79 | .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, | ||
80 | .set_mode = sunxi_clkevt_mode, | ||
81 | .set_next_event = sunxi_clkevt_next_event, | ||
82 | }; | ||
83 | |||
84 | |||
85 | static irqreturn_t sunxi_timer_interrupt(int irq, void *dev_id) | ||
86 | { | ||
87 | struct clock_event_device *evt = (struct clock_event_device *)dev_id; | ||
88 | |||
89 | writel(0x1, timer_base + TIMER_IRQ_ST_REG); | ||
90 | evt->event_handler(evt); | ||
91 | |||
92 | return IRQ_HANDLED; | ||
93 | } | ||
94 | |||
95 | static struct irqaction sunxi_timer_irq = { | ||
96 | .name = "sunxi_timer0", | ||
97 | .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, | ||
98 | .handler = sunxi_timer_interrupt, | ||
99 | .dev_id = &sunxi_clockevent, | ||
100 | }; | ||
101 | |||
102 | static struct of_device_id sunxi_timer_dt_ids[] = { | ||
103 | { .compatible = "allwinner,sunxi-timer" }, | ||
104 | { } | ||
105 | }; | ||
106 | |||
107 | static void __init sunxi_timer_init(void) | ||
108 | { | ||
109 | struct device_node *node; | ||
110 | unsigned long rate = 0; | ||
111 | struct clk *clk; | ||
112 | int ret, irq; | ||
113 | u32 val; | ||
114 | |||
115 | node = of_find_matching_node(NULL, sunxi_timer_dt_ids); | ||
116 | if (!node) | ||
117 | panic("No sunxi timer node"); | ||
118 | |||
119 | timer_base = of_iomap(node, 0); | ||
120 | if (!timer_base) | ||
121 | panic("Can't map registers"); | ||
122 | |||
123 | irq = irq_of_parse_and_map(node, 0); | ||
124 | if (irq <= 0) | ||
125 | panic("Can't parse IRQ"); | ||
126 | |||
127 | sunxi_init_clocks(); | ||
128 | |||
129 | clk = of_clk_get(node, 0); | ||
130 | if (IS_ERR(clk)) | ||
131 | panic("Can't get timer clock"); | ||
132 | |||
133 | rate = clk_get_rate(clk); | ||
134 | |||
135 | writel(rate / (TIMER_SCAL * HZ), | ||
136 | timer_base + TIMER0_INTVAL_REG); | ||
137 | |||
138 | /* set clock source to HOSC, 16 pre-division */ | ||
139 | val = readl(timer_base + TIMER0_CTL_REG); | ||
140 | val &= ~(0x07 << 4); | ||
141 | val &= ~(0x03 << 2); | ||
142 | val |= (4 << 4) | (1 << 2); | ||
143 | writel(val, timer_base + TIMER0_CTL_REG); | ||
144 | |||
145 | /* set mode to auto reload */ | ||
146 | val = readl(timer_base + TIMER0_CTL_REG); | ||
147 | writel(val | TIMER0_CTL_AUTORELOAD, timer_base + TIMER0_CTL_REG); | ||
148 | |||
149 | ret = setup_irq(irq, &sunxi_timer_irq); | ||
150 | if (ret) | ||
151 | pr_warn("failed to setup irq %d\n", irq); | ||
152 | |||
153 | /* Enable timer0 interrupt */ | ||
154 | val = readl(timer_base + TIMER_CTL_REG); | ||
155 | writel(val | TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG); | ||
156 | |||
157 | sunxi_clockevent.mult = div_sc(rate / TIMER_SCAL, | ||
158 | NSEC_PER_SEC, | ||
159 | sunxi_clockevent.shift); | ||
160 | sunxi_clockevent.max_delta_ns = clockevent_delta2ns(0xff, | ||
161 | &sunxi_clockevent); | ||
162 | sunxi_clockevent.min_delta_ns = clockevent_delta2ns(0x1, | ||
163 | &sunxi_clockevent); | ||
164 | sunxi_clockevent.cpumask = cpumask_of(0); | ||
165 | |||
166 | clockevents_register_device(&sunxi_clockevent); | ||
167 | } | ||
168 | |||
169 | struct sys_timer sunxi_timer = { | ||
170 | .init = sunxi_timer_init, | ||
171 | }; | ||