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",