Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
618b902d YS |
2 | /* |
3 | * H8/300 16bit Timer driver | |
4 | * | |
5 | * Copyright 2015 Yoshinori Sato <ysato@users.sourcefoge.jp> | |
6 | */ | |
7 | ||
618b902d YS |
8 | #include <linux/interrupt.h> |
9 | #include <linux/init.h> | |
618b902d | 10 | #include <linux/clocksource.h> |
618b902d YS |
11 | #include <linux/clk.h> |
12 | #include <linux/io.h> | |
13 | #include <linux/of.h> | |
4633f4ca YS |
14 | #include <linux/of_address.h> |
15 | #include <linux/of_irq.h> | |
618b902d | 16 | |
618b902d | 17 | #define TSTR 0 |
618b902d YS |
18 | #define TISRC 6 |
19 | ||
20 | #define TCR 0 | |
618b902d | 21 | #define TCNT 2 |
618b902d | 22 | |
d33f250a YS |
23 | #define bset(b, a) iowrite8(ioread8(a) | (1 << (b)), (a)) |
24 | #define bclr(b, a) iowrite8(ioread8(a) & ~(1 << (b)), (a)) | |
25 | ||
618b902d | 26 | struct timer16_priv { |
618b902d | 27 | struct clocksource cs; |
618b902d | 28 | unsigned long total_cycles; |
75160515 DL |
29 | void __iomem *mapbase; |
30 | void __iomem *mapcommon; | |
618b902d YS |
31 | unsigned short cs_enabled; |
32 | unsigned char enb; | |
618b902d | 33 | unsigned char ovf; |
2a0ff877 | 34 | unsigned char ovie; |
618b902d YS |
35 | }; |
36 | ||
37 | static unsigned long timer16_get_counter(struct timer16_priv *p) | |
38 | { | |
d33f250a YS |
39 | unsigned short v1, v2, v3; |
40 | unsigned char o1, o2; | |
618b902d | 41 | |
d33f250a | 42 | o1 = ioread8(p->mapcommon + TISRC) & p->ovf; |
618b902d YS |
43 | |
44 | /* Make sure the timer value is stable. Stolen from acpi_pm.c */ | |
45 | do { | |
46 | o2 = o1; | |
d33f250a YS |
47 | v1 = ioread16be(p->mapbase + TCNT); |
48 | v2 = ioread16be(p->mapbase + TCNT); | |
49 | v3 = ioread16be(p->mapbase + TCNT); | |
50 | o1 = ioread8(p->mapcommon + TISRC) & p->ovf; | |
618b902d YS |
51 | } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3) |
52 | || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2))); | |
53 | ||
2f445e0a YS |
54 | if (likely(!o1)) |
55 | return v2; | |
56 | else | |
57 | return v2 + 0x10000; | |
618b902d YS |
58 | } |
59 | ||
60 | ||
61 | static irqreturn_t timer16_interrupt(int irq, void *dev_id) | |
62 | { | |
63 | struct timer16_priv *p = (struct timer16_priv *)dev_id; | |
64 | ||
d33f250a | 65 | bclr(p->ovf, p->mapcommon + TISRC); |
618b902d YS |
66 | p->total_cycles += 0x10000; |
67 | ||
68 | return IRQ_HANDLED; | |
69 | } | |
70 | ||
71 | static inline struct timer16_priv *cs_to_priv(struct clocksource *cs) | |
72 | { | |
73 | return container_of(cs, struct timer16_priv, cs); | |
74 | } | |
75 | ||
a5a1d1c2 | 76 | static u64 timer16_clocksource_read(struct clocksource *cs) |
618b902d YS |
77 | { |
78 | struct timer16_priv *p = cs_to_priv(cs); | |
05de7ed6 | 79 | unsigned long raw, value; |
618b902d | 80 | |
618b902d YS |
81 | value = p->total_cycles; |
82 | raw = timer16_get_counter(p); | |
618b902d YS |
83 | |
84 | return value + raw; | |
85 | } | |
86 | ||
87 | static int timer16_enable(struct clocksource *cs) | |
88 | { | |
89 | struct timer16_priv *p = cs_to_priv(cs); | |
90 | ||
91 | WARN_ON(p->cs_enabled); | |
92 | ||
93 | p->total_cycles = 0; | |
d33f250a YS |
94 | iowrite16be(0x0000, p->mapbase + TCNT); |
95 | iowrite8(0x83, p->mapbase + TCR); | |
96 | bset(p->ovie, p->mapcommon + TISRC); | |
97 | bset(p->enb, p->mapcommon + TSTR); | |
618b902d YS |
98 | |
99 | p->cs_enabled = true; | |
100 | return 0; | |
101 | } | |
102 | ||
103 | static void timer16_disable(struct clocksource *cs) | |
104 | { | |
105 | struct timer16_priv *p = cs_to_priv(cs); | |
106 | ||
107 | WARN_ON(!p->cs_enabled); | |
108 | ||
d33f250a YS |
109 | bclr(p->ovie, p->mapcommon + TISRC); |
110 | bclr(p->enb, p->mapcommon + TSTR); | |
618b902d YS |
111 | |
112 | p->cs_enabled = false; | |
113 | } | |
114 | ||
4633f4ca YS |
115 | static struct timer16_priv timer16_priv = { |
116 | .cs = { | |
117 | .name = "h8300_16timer", | |
118 | .rating = 200, | |
119 | .read = timer16_clocksource_read, | |
120 | .enable = timer16_enable, | |
121 | .disable = timer16_disable, | |
122 | .mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8), | |
123 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
124 | }, | |
125 | }; | |
126 | ||
618b902d YS |
127 | #define REG_CH 0 |
128 | #define REG_COMM 1 | |
129 | ||
eacf2091 | 130 | static int __init h8300_16timer_init(struct device_node *node) |
618b902d | 131 | { |
4633f4ca | 132 | void __iomem *base[2]; |
618b902d YS |
133 | int ret, irq; |
134 | unsigned int ch; | |
4633f4ca | 135 | struct clk *clk; |
618b902d | 136 | |
4633f4ca YS |
137 | clk = of_clk_get(node, 0); |
138 | if (IS_ERR(clk)) { | |
139 | pr_err("failed to get clock for clocksource\n"); | |
eacf2091 | 140 | return PTR_ERR(clk); |
618b902d YS |
141 | } |
142 | ||
eacf2091 | 143 | ret = -ENXIO; |
4633f4ca YS |
144 | base[REG_CH] = of_iomap(node, 0); |
145 | if (!base[REG_CH]) { | |
146 | pr_err("failed to map registers for clocksource\n"); | |
147 | goto free_clk; | |
618b902d | 148 | } |
618b902d | 149 | |
4633f4ca YS |
150 | base[REG_COMM] = of_iomap(node, 1); |
151 | if (!base[REG_COMM]) { | |
152 | pr_err("failed to map registers for clocksource\n"); | |
153 | goto unmap_ch; | |
618b902d YS |
154 | } |
155 | ||
eacf2091 | 156 | ret = -EINVAL; |
4633f4ca | 157 | irq = irq_of_parse_and_map(node, 0); |
5019c902 | 158 | if (!irq) { |
4633f4ca YS |
159 | pr_err("failed to get irq for clockevent\n"); |
160 | goto unmap_comm; | |
618b902d YS |
161 | } |
162 | ||
4633f4ca | 163 | of_property_read_u32(node, "renesas,channel", &ch); |
618b902d | 164 | |
75160515 DL |
165 | timer16_priv.mapbase = base[REG_CH]; |
166 | timer16_priv.mapcommon = base[REG_COMM]; | |
d33f250a YS |
167 | timer16_priv.enb = ch; |
168 | timer16_priv.ovf = ch; | |
169 | timer16_priv.ovie = 4 + ch; | |
618b902d | 170 | |
4633f4ca YS |
171 | ret = request_irq(irq, timer16_interrupt, |
172 | IRQF_TIMER, timer16_priv.cs.name, &timer16_priv); | |
173 | if (ret < 0) { | |
174 | pr_err("failed to request irq %d of clocksource\n", irq); | |
175 | goto unmap_comm; | |
618b902d | 176 | } |
618b902d | 177 | |
4633f4ca | 178 | clocksource_register_hz(&timer16_priv.cs, |
d33f250a | 179 | clk_get_rate(clk) / 8); |
eacf2091 | 180 | return 0; |
618b902d | 181 | |
4633f4ca YS |
182 | unmap_comm: |
183 | iounmap(base[REG_COMM]); | |
184 | unmap_ch: | |
185 | iounmap(base[REG_CH]); | |
186 | free_clk: | |
187 | clk_put(clk); | |
eacf2091 | 188 | return ret; |
618b902d YS |
189 | } |
190 | ||
17273395 | 191 | TIMER_OF_DECLARE(h8300_16bit, "renesas,16bit-timer", |
eacf2091 | 192 | h8300_16timer_init); |