2 * Allwinner A1X SoCs timer handling.
4 * Copyright (C) 2012 Maxime Ripard
6 * Maxime Ripard <maxime.ripard@free-electrons.com>
9 * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
10 * Benn Huang <benn@allwinnertech.com>
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.
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/sched_clock.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
27 #define TIMER_IRQ_EN_REG 0x00
28 #define TIMER_IRQ_EN(val) BIT(val)
29 #define TIMER_IRQ_ST_REG 0x04
30 #define TIMER_CTL_REG(val) (0x10 * val + 0x10)
31 #define TIMER_CTL_ENABLE BIT(0)
32 #define TIMER_CTL_RELOAD BIT(1)
33 #define TIMER_CTL_ONESHOT BIT(7)
34 #define TIMER_INTVAL_REG(val) (0x10 * (val) + 0x14)
35 #define TIMER_CNTVAL_REG(val) (0x10 * (val) + 0x18)
39 static void __iomem
*timer_base
;
41 static void sun4i_clkevt_mode(enum clock_event_mode mode
,
42 struct clock_event_device
*clk
)
44 u32 u
= readl(timer_base
+ TIMER_CTL_REG(0));
47 case CLOCK_EVT_MODE_PERIODIC
:
48 u
&= ~(TIMER_CTL_ONESHOT
);
49 writel(u
| TIMER_CTL_ENABLE
, timer_base
+ TIMER_CTL_REG(0));
52 case CLOCK_EVT_MODE_ONESHOT
:
53 writel(u
| TIMER_CTL_ONESHOT
, timer_base
+ TIMER_CTL_REG(0));
55 case CLOCK_EVT_MODE_UNUSED
:
56 case CLOCK_EVT_MODE_SHUTDOWN
:
58 writel(u
& ~(TIMER_CTL_ENABLE
), timer_base
+ TIMER_CTL_REG(0));
63 static int sun4i_clkevt_next_event(unsigned long evt
,
64 struct clock_event_device
*unused
)
66 u32 u
= readl(timer_base
+ TIMER_CTL_REG(0));
67 writel(evt
, timer_base
+ TIMER_CNTVAL_REG(0));
68 writel(u
| TIMER_CTL_ENABLE
| TIMER_CTL_AUTORELOAD
,
69 timer_base
+ TIMER_CTL_REG(0));
74 static struct clock_event_device sun4i_clockevent
= {
77 .features
= CLOCK_EVT_FEAT_PERIODIC
| CLOCK_EVT_FEAT_ONESHOT
,
78 .set_mode
= sun4i_clkevt_mode
,
79 .set_next_event
= sun4i_clkevt_next_event
,
83 static irqreturn_t
sun4i_timer_interrupt(int irq
, void *dev_id
)
85 struct clock_event_device
*evt
= (struct clock_event_device
*)dev_id
;
87 writel(0x1, timer_base
+ TIMER_IRQ_ST_REG
);
88 evt
->event_handler(evt
);
93 static struct irqaction sun4i_timer_irq
= {
94 .name
= "sun4i_timer0",
95 .flags
= IRQF_DISABLED
| IRQF_TIMER
| IRQF_IRQPOLL
,
96 .handler
= sun4i_timer_interrupt
,
97 .dev_id
= &sun4i_clockevent
,
100 static u32
sun4i_timer_sched_read(void)
102 return ~readl(timer_base
+ TIMER_CNTVAL_REG(1));
105 static void __init
sun4i_timer_init(struct device_node
*node
)
107 unsigned long rate
= 0;
112 timer_base
= of_iomap(node
, 0);
114 panic("Can't map registers");
116 irq
= irq_of_parse_and_map(node
, 0);
118 panic("Can't parse IRQ");
120 clk
= of_clk_get(node
, 0);
122 panic("Can't get timer clock");
124 rate
= clk_get_rate(clk
);
126 writel(~0, timer_base
+ TIMER_INTVAL_REG(1));
127 writel(TIMER_CTL_ENABLE
| TIMER_CTL_RELOAD
|
128 TIMER_CTL_CLK_SRC(TIMER_CTL_CLK_SRC_OSC24M
),
129 timer_base
+ TIMER_CTL_REG(1));
131 setup_sched_clock(sun4i_timer_sched_read
, 32, rate
);
132 clocksource_mmio_init(timer_base
+ TIMER_CNTVAL_REG(1), node
->name
,
133 rate
, 300, 32, clocksource_mmio_readl_down
);
135 writel(rate
/ (TIMER_SCAL
* HZ
),
136 timer_base
+ TIMER_INTVAL_REG(0));
138 /* set clock source to HOSC, 16 pre-division */
139 val
= readl(timer_base
+ TIMER_CTL_REG(0));
142 val
|= (4 << 4) | (1 << 2);
143 writel(val
, timer_base
+ TIMER_CTL_REG(0));
145 /* set mode to auto reload */
146 val
= readl(timer_base
+ TIMER_CTL_REG(0));
147 writel(val
| TIMER_CTL_RELOAD
, timer_base
+ TIMER_CTL_REG(0));
149 ret
= setup_irq(irq
, &sun4i_timer_irq
);
151 pr_warn("failed to setup irq %d\n", irq
);
153 /* Enable timer0 interrupt */
154 val
= readl(timer_base
+ TIMER_IRQ_EN_REG
);
155 writel(val
| TIMER_IRQ_EN(0), timer_base
+ TIMER_IRQ_EN_REG
);
157 sun4i_clockevent
.cpumask
= cpumask_of(0);
159 clockevents_config_and_register(&sun4i_clockevent
, rate
/ TIMER_SCAL
,
162 CLOCKSOURCE_OF_DECLARE(sun4i
, "allwinner,sun4i-timer",