Commit | Line | Data |
---|---|---|
618b902d YS |
1 | /* |
2 | * linux/arch/h8300/kernel/cpu/timer/timer8.c | |
3 | * | |
4 | * Yoshinori Sato <ysato@users.sourcefoge.jp> | |
5 | * | |
6 | * 8bit Timer driver | |
7 | * | |
8 | */ | |
9 | ||
10 | #include <linux/errno.h> | |
618b902d YS |
11 | #include <linux/kernel.h> |
12 | #include <linux/interrupt.h> | |
13 | #include <linux/init.h> | |
618b902d | 14 | #include <linux/clockchips.h> |
618b902d YS |
15 | #include <linux/clk.h> |
16 | #include <linux/io.h> | |
17 | #include <linux/of.h> | |
4633f4ca YS |
18 | #include <linux/of_address.h> |
19 | #include <linux/of_irq.h> | |
618b902d | 20 | |
618b902d YS |
21 | #define _8TCR 0 |
22 | #define _8TCSR 2 | |
23 | #define TCORA 4 | |
24 | #define TCORB 6 | |
25 | #define _8TCNT 8 | |
26 | ||
618b902d YS |
27 | #define FLAG_STARTED (1 << 3) |
28 | ||
4633f4ca YS |
29 | #define SCALE 64 |
30 | ||
618b902d | 31 | struct timer8_priv { |
618b902d | 32 | struct clock_event_device ced; |
75160515 | 33 | void __iomem *mapbase; |
618b902d YS |
34 | unsigned long flags; |
35 | unsigned int rate; | |
36 | unsigned int tcora; | |
618b902d YS |
37 | }; |
38 | ||
618b902d YS |
39 | static irqreturn_t timer8_interrupt(int irq, void *dev_id) |
40 | { | |
41 | struct timer8_priv *p = dev_id; | |
42 | ||
7053fdac | 43 | if (clockevent_state_oneshot(&p->ced)) |
75160515 | 44 | writew(0x0000, p->mapbase + _8TCR); |
7053fdac DL |
45 | |
46 | p->ced.event_handler(&p->ced); | |
618b902d | 47 | |
f37632d1 YS |
48 | writeb(readb(p->mapbase + _8TCSR) & ~0x40, |
49 | p->mapbase + _8TCSR); | |
50 | ||
618b902d YS |
51 | return IRQ_HANDLED; |
52 | } | |
53 | ||
54 | static void timer8_set_next(struct timer8_priv *p, unsigned long delta) | |
55 | { | |
618b902d | 56 | if (delta >= 0x10000) |
8c09b7d6 | 57 | pr_warn("delta out of range\n"); |
f37632d1 YS |
58 | writeb(readb(p->mapbase + _8TCR) & ~0x40, p->mapbase + _8TCR); |
59 | writew(0, p->mapbase + _8TCNT); | |
60 | writew(delta, p->mapbase + TCORA); | |
75160515 | 61 | writeb(readb(p->mapbase + _8TCR) | 0x40, p->mapbase + _8TCR); |
618b902d YS |
62 | } |
63 | ||
64 | static int timer8_enable(struct timer8_priv *p) | |
65 | { | |
75160515 DL |
66 | writew(0xffff, p->mapbase + TCORA); |
67 | writew(0x0000, p->mapbase + _8TCNT); | |
68 | writew(0x0c02, p->mapbase + _8TCR); | |
618b902d YS |
69 | |
70 | return 0; | |
71 | } | |
72 | ||
73 | static int timer8_start(struct timer8_priv *p) | |
74 | { | |
cce483e0 | 75 | int ret; |
618b902d | 76 | |
cce483e0 DL |
77 | if ((p->flags & FLAG_STARTED)) |
78 | return 0; | |
618b902d | 79 | |
cce483e0 DL |
80 | ret = timer8_enable(p); |
81 | if (!ret) | |
82 | p->flags |= FLAG_STARTED; | |
618b902d | 83 | |
618b902d YS |
84 | return ret; |
85 | } | |
86 | ||
87 | static void timer8_stop(struct timer8_priv *p) | |
88 | { | |
75160515 | 89 | writew(0x0000, p->mapbase + _8TCR); |
618b902d YS |
90 | } |
91 | ||
92 | static inline struct timer8_priv *ced_to_priv(struct clock_event_device *ced) | |
93 | { | |
94 | return container_of(ced, struct timer8_priv, ced); | |
95 | } | |
96 | ||
1f058d52 | 97 | static void timer8_clock_event_start(struct timer8_priv *p, unsigned long delta) |
618b902d YS |
98 | { |
99 | struct clock_event_device *ced = &p->ced; | |
100 | ||
101 | timer8_start(p); | |
102 | ||
103 | ced->shift = 32; | |
104 | ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift); | |
105 | ced->max_delta_ns = clockevent_delta2ns(0xffff, ced); | |
106 | ced->min_delta_ns = clockevent_delta2ns(0x0001, ced); | |
107 | ||
1f058d52 | 108 | timer8_set_next(p, delta); |
618b902d YS |
109 | } |
110 | ||
fc2b2f5d VK |
111 | static int timer8_clock_event_shutdown(struct clock_event_device *ced) |
112 | { | |
113 | timer8_stop(ced_to_priv(ced)); | |
114 | return 0; | |
115 | } | |
116 | ||
117 | static int timer8_clock_event_periodic(struct clock_event_device *ced) | |
618b902d YS |
118 | { |
119 | struct timer8_priv *p = ced_to_priv(ced); | |
120 | ||
4633f4ca | 121 | pr_info("%s: used for periodic clock events\n", ced->name); |
fc2b2f5d | 122 | timer8_stop(p); |
1f058d52 | 123 | timer8_clock_event_start(p, (p->rate + HZ/2) / HZ); |
fc2b2f5d VK |
124 | |
125 | return 0; | |
126 | } | |
127 | ||
128 | static int timer8_clock_event_oneshot(struct clock_event_device *ced) | |
129 | { | |
130 | struct timer8_priv *p = ced_to_priv(ced); | |
131 | ||
4633f4ca | 132 | pr_info("%s: used for oneshot clock events\n", ced->name); |
fc2b2f5d | 133 | timer8_stop(p); |
1f058d52 | 134 | timer8_clock_event_start(p, 0x10000); |
fc2b2f5d VK |
135 | |
136 | return 0; | |
618b902d YS |
137 | } |
138 | ||
139 | static int timer8_clock_event_next(unsigned long delta, | |
140 | struct clock_event_device *ced) | |
141 | { | |
142 | struct timer8_priv *p = ced_to_priv(ced); | |
143 | ||
fc2b2f5d | 144 | BUG_ON(!clockevent_state_oneshot(ced)); |
618b902d YS |
145 | timer8_set_next(p, delta - 1); |
146 | ||
147 | return 0; | |
148 | } | |
149 | ||
4633f4ca YS |
150 | static struct timer8_priv timer8_priv = { |
151 | .ced = { | |
152 | .name = "h8300_8timer", | |
153 | .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, | |
154 | .rating = 200, | |
155 | .set_next_event = timer8_clock_event_next, | |
156 | .set_state_shutdown = timer8_clock_event_shutdown, | |
157 | .set_state_periodic = timer8_clock_event_periodic, | |
158 | .set_state_oneshot = timer8_clock_event_oneshot, | |
159 | }, | |
160 | }; | |
161 | ||
162 | static void __init h8300_8timer_init(struct device_node *node) | |
618b902d | 163 | { |
4633f4ca | 164 | void __iomem *base; |
618b902d | 165 | int irq; |
4633f4ca YS |
166 | int ret = 0; |
167 | int rate; | |
168 | struct clk *clk; | |
618b902d | 169 | |
4633f4ca YS |
170 | clk = of_clk_get(node, 0); |
171 | if (IS_ERR(clk)) { | |
172 | pr_err("failed to get clock for clockevent\n"); | |
173 | return; | |
174 | } | |
618b902d | 175 | |
4633f4ca YS |
176 | base = of_iomap(node, 0); |
177 | if (!base) { | |
178 | pr_err("failed to map registers for clockevent\n"); | |
179 | goto free_clk; | |
618b902d YS |
180 | } |
181 | ||
4633f4ca | 182 | irq = irq_of_parse_and_map(node, 0); |
54a0cd5a | 183 | if (!irq) { |
4633f4ca YS |
184 | pr_err("failed to get irq for clockevent\n"); |
185 | goto unmap_reg; | |
618b902d YS |
186 | } |
187 | ||
75160515 | 188 | timer8_priv.mapbase = base; |
cce483e0 DL |
189 | |
190 | rate = clk_get_rate(clk) / SCALE; | |
191 | if (!rate) { | |
192 | pr_err("Failed to get rate for the clocksource\n"); | |
193 | goto unmap_reg; | |
194 | } | |
618b902d | 195 | |
4633f4ca YS |
196 | ret = request_irq(irq, timer8_interrupt, |
197 | IRQF_TIMER, timer8_priv.ced.name, &timer8_priv); | |
618b902d | 198 | if (ret < 0) { |
4633f4ca YS |
199 | pr_err("failed to request irq %d for clockevent\n", irq); |
200 | goto unmap_reg; | |
618b902d | 201 | } |
cce483e0 | 202 | |
4633f4ca | 203 | clockevents_config_and_register(&timer8_priv.ced, rate, 1, 0x0000ffff); |
4633f4ca | 204 | |
cce483e0 | 205 | return; |
4633f4ca YS |
206 | unmap_reg: |
207 | iounmap(base); | |
208 | free_clk: | |
209 | clk_put(clk); | |
618b902d YS |
210 | } |
211 | ||
4633f4ca | 212 | CLOCKSOURCE_OF_DECLARE(h8300_8bit, "renesas,8bit-timer", h8300_8timer_init); |