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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
77ba83bb DT |
2 | /* |
3 | * linux/drivers/clocksource/zevio-timer.c | |
4 | * | |
5 | * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au> | |
77ba83bb DT |
6 | */ |
7 | ||
8 | #include <linux/io.h> | |
9 | #include <linux/irq.h> | |
10 | #include <linux/of.h> | |
11 | #include <linux/of_address.h> | |
12 | #include <linux/of_irq.h> | |
13 | #include <linux/clk.h> | |
14 | #include <linux/clockchips.h> | |
15 | #include <linux/cpumask.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/slab.h> | |
18 | ||
19 | #define IO_CURRENT_VAL 0x00 | |
20 | #define IO_DIVIDER 0x04 | |
21 | #define IO_CONTROL 0x08 | |
22 | ||
23 | #define IO_TIMER1 0x00 | |
24 | #define IO_TIMER2 0x0C | |
25 | ||
26 | #define IO_MATCH_BEGIN 0x18 | |
27 | #define IO_MATCH(x) (IO_MATCH_BEGIN + ((x) << 2)) | |
28 | ||
29 | #define IO_INTR_STS 0x00 | |
30 | #define IO_INTR_ACK 0x00 | |
31 | #define IO_INTR_MSK 0x04 | |
32 | ||
33 | #define CNTL_STOP_TIMER (1 << 4) | |
34 | #define CNTL_RUN_TIMER (0 << 4) | |
35 | ||
36 | #define CNTL_INC (1 << 3) | |
37 | #define CNTL_DEC (0 << 3) | |
38 | ||
39 | #define CNTL_TOZERO 0 | |
40 | #define CNTL_MATCH(x) ((x) + 1) | |
41 | #define CNTL_FOREVER 7 | |
42 | ||
43 | /* There are 6 match registers but we only use one. */ | |
44 | #define TIMER_MATCH 0 | |
45 | ||
46 | #define TIMER_INTR_MSK (1 << (TIMER_MATCH)) | |
47 | #define TIMER_INTR_ALL 0x3F | |
48 | ||
49 | struct zevio_timer { | |
50 | void __iomem *base; | |
51 | void __iomem *timer1, *timer2; | |
52 | void __iomem *interrupt_regs; | |
53 | ||
54 | struct clk *clk; | |
55 | struct clock_event_device clkevt; | |
56 | struct irqaction clkevt_irq; | |
57 | ||
58 | char clocksource_name[64]; | |
59 | char clockevent_name[64]; | |
60 | }; | |
61 | ||
62 | static int zevio_timer_set_event(unsigned long delta, | |
63 | struct clock_event_device *dev) | |
64 | { | |
65 | struct zevio_timer *timer = container_of(dev, struct zevio_timer, | |
66 | clkevt); | |
67 | ||
68 | writel(delta, timer->timer1 + IO_CURRENT_VAL); | |
69 | writel(CNTL_RUN_TIMER | CNTL_DEC | CNTL_MATCH(TIMER_MATCH), | |
70 | timer->timer1 + IO_CONTROL); | |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
f0753793 | 75 | static int zevio_timer_shutdown(struct clock_event_device *dev) |
77ba83bb DT |
76 | { |
77 | struct zevio_timer *timer = container_of(dev, struct zevio_timer, | |
78 | clkevt); | |
79 | ||
f0753793 VK |
80 | /* Disable timer interrupts */ |
81 | writel(0, timer->interrupt_regs + IO_INTR_MSK); | |
82 | writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); | |
83 | /* Stop timer */ | |
84 | writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); | |
85 | return 0; | |
86 | } | |
87 | ||
88 | static int zevio_timer_set_oneshot(struct clock_event_device *dev) | |
89 | { | |
90 | struct zevio_timer *timer = container_of(dev, struct zevio_timer, | |
91 | clkevt); | |
92 | ||
93 | /* Enable timer interrupts */ | |
94 | writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_MSK); | |
95 | writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); | |
96 | return 0; | |
77ba83bb DT |
97 | } |
98 | ||
99 | static irqreturn_t zevio_timer_interrupt(int irq, void *dev_id) | |
100 | { | |
101 | struct zevio_timer *timer = dev_id; | |
102 | u32 intr; | |
103 | ||
104 | intr = readl(timer->interrupt_regs + IO_INTR_ACK); | |
105 | if (!(intr & TIMER_INTR_MSK)) | |
106 | return IRQ_NONE; | |
107 | ||
108 | writel(TIMER_INTR_MSK, timer->interrupt_regs + IO_INTR_ACK); | |
109 | writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); | |
110 | ||
111 | if (timer->clkevt.event_handler) | |
112 | timer->clkevt.event_handler(&timer->clkevt); | |
113 | ||
114 | return IRQ_HANDLED; | |
115 | } | |
116 | ||
117 | static int __init zevio_timer_add(struct device_node *node) | |
118 | { | |
119 | struct zevio_timer *timer; | |
120 | struct resource res; | |
121 | int irqnr, ret; | |
122 | ||
123 | timer = kzalloc(sizeof(*timer), GFP_KERNEL); | |
124 | if (!timer) | |
125 | return -ENOMEM; | |
126 | ||
127 | timer->base = of_iomap(node, 0); | |
128 | if (!timer->base) { | |
129 | ret = -EINVAL; | |
130 | goto error_free; | |
131 | } | |
132 | timer->timer1 = timer->base + IO_TIMER1; | |
133 | timer->timer2 = timer->base + IO_TIMER2; | |
134 | ||
135 | timer->clk = of_clk_get(node, 0); | |
136 | if (IS_ERR(timer->clk)) { | |
137 | ret = PTR_ERR(timer->clk); | |
138 | pr_err("Timer clock not found! (error %d)\n", ret); | |
139 | goto error_unmap; | |
140 | } | |
141 | ||
142 | timer->interrupt_regs = of_iomap(node, 1); | |
143 | irqnr = irq_of_parse_and_map(node, 0); | |
144 | ||
145 | of_address_to_resource(node, 0, &res); | |
146 | scnprintf(timer->clocksource_name, sizeof(timer->clocksource_name), | |
2a4849d2 RH |
147 | "%llx.%pOFn_clocksource", |
148 | (unsigned long long)res.start, node); | |
77ba83bb DT |
149 | |
150 | scnprintf(timer->clockevent_name, sizeof(timer->clockevent_name), | |
2a4849d2 RH |
151 | "%llx.%pOFn_clockevent", |
152 | (unsigned long long)res.start, node); | |
77ba83bb DT |
153 | |
154 | if (timer->interrupt_regs && irqnr) { | |
155 | timer->clkevt.name = timer->clockevent_name; | |
156 | timer->clkevt.set_next_event = zevio_timer_set_event; | |
f0753793 VK |
157 | timer->clkevt.set_state_shutdown = zevio_timer_shutdown; |
158 | timer->clkevt.set_state_oneshot = zevio_timer_set_oneshot; | |
159 | timer->clkevt.tick_resume = zevio_timer_set_oneshot; | |
77ba83bb | 160 | timer->clkevt.rating = 200; |
f8f5fe86 | 161 | timer->clkevt.cpumask = cpu_possible_mask; |
77ba83bb DT |
162 | timer->clkevt.features = CLOCK_EVT_FEAT_ONESHOT; |
163 | timer->clkevt.irq = irqnr; | |
164 | ||
165 | writel(CNTL_STOP_TIMER, timer->timer1 + IO_CONTROL); | |
166 | writel(0, timer->timer1 + IO_DIVIDER); | |
167 | ||
168 | /* Start with timer interrupts disabled */ | |
169 | writel(0, timer->interrupt_regs + IO_INTR_MSK); | |
170 | writel(TIMER_INTR_ALL, timer->interrupt_regs + IO_INTR_ACK); | |
171 | ||
172 | /* Interrupt to occur when timer value matches 0 */ | |
173 | writel(0, timer->base + IO_MATCH(TIMER_MATCH)); | |
174 | ||
175 | timer->clkevt_irq.name = timer->clockevent_name; | |
176 | timer->clkevt_irq.handler = zevio_timer_interrupt; | |
177 | timer->clkevt_irq.dev_id = timer; | |
178 | timer->clkevt_irq.flags = IRQF_TIMER | IRQF_IRQPOLL; | |
179 | ||
180 | setup_irq(irqnr, &timer->clkevt_irq); | |
181 | ||
182 | clockevents_config_and_register(&timer->clkevt, | |
183 | clk_get_rate(timer->clk), 0x0001, 0xffff); | |
184 | pr_info("Added %s as clockevent\n", timer->clockevent_name); | |
185 | } | |
186 | ||
187 | writel(CNTL_STOP_TIMER, timer->timer2 + IO_CONTROL); | |
188 | writel(0, timer->timer2 + IO_CURRENT_VAL); | |
189 | writel(0, timer->timer2 + IO_DIVIDER); | |
190 | writel(CNTL_RUN_TIMER | CNTL_FOREVER | CNTL_INC, | |
191 | timer->timer2 + IO_CONTROL); | |
192 | ||
193 | clocksource_mmio_init(timer->timer2 + IO_CURRENT_VAL, | |
194 | timer->clocksource_name, | |
195 | clk_get_rate(timer->clk), | |
196 | 200, 16, | |
197 | clocksource_mmio_readw_up); | |
198 | ||
199 | pr_info("Added %s as clocksource\n", timer->clocksource_name); | |
200 | ||
201 | return 0; | |
202 | error_unmap: | |
203 | iounmap(timer->base); | |
204 | error_free: | |
205 | kfree(timer); | |
206 | return ret; | |
207 | } | |
208 | ||
42452508 | 209 | static int __init zevio_timer_init(struct device_node *node) |
9afa27ce | 210 | { |
42452508 | 211 | return zevio_timer_add(node); |
9afa27ce AS |
212 | } |
213 | ||
17273395 | 214 | TIMER_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_init); |