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Yoshinori Sato618b9022015-01-28 02:52:42 +09001/*
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>
Yoshinori Sato618b9022015-01-28 02:52:42 +090011#include <linux/kernel.h>
12#include <linux/interrupt.h>
13#include <linux/init.h>
Yoshinori Sato618b9022015-01-28 02:52:42 +090014#include <linux/clockchips.h>
Yoshinori Sato618b9022015-01-28 02:52:42 +090015#include <linux/clk.h>
16#include <linux/io.h>
17#include <linux/of.h>
Yoshinori Sato4633f4c2015-11-07 01:31:44 +090018#include <linux/of_address.h>
19#include <linux/of_irq.h>
Yoshinori Sato618b9022015-01-28 02:52:42 +090020
Yoshinori Sato618b9022015-01-28 02:52:42 +090021#define _8TCR 0
22#define _8TCSR 2
23#define TCORA 4
24#define TCORB 6
25#define _8TCNT 8
26
Yoshinori Satod33f2502015-12-05 02:48:18 +090027#define CMIEA 6
28#define CMFA 6
29
Yoshinori Sato618b9022015-01-28 02:52:42 +090030#define FLAG_STARTED (1 << 3)
31
Yoshinori Sato4633f4c2015-11-07 01:31:44 +090032#define SCALE 64
33
Yoshinori Satod33f2502015-12-05 02:48:18 +090034#define bset(b, a) iowrite8(ioread8(a) | (1 << (b)), (a))
35#define bclr(b, a) iowrite8(ioread8(a) & ~(1 << (b)), (a))
36
Yoshinori Sato618b9022015-01-28 02:52:42 +090037struct timer8_priv {
Yoshinori Sato618b9022015-01-28 02:52:42 +090038 struct clock_event_device ced;
Daniel Lezcano75160512015-11-08 22:55:12 +010039 void __iomem *mapbase;
Yoshinori Sato618b9022015-01-28 02:52:42 +090040 unsigned long flags;
41 unsigned int rate;
Yoshinori Sato618b9022015-01-28 02:52:42 +090042};
43
Yoshinori Sato618b9022015-01-28 02:52:42 +090044static irqreturn_t timer8_interrupt(int irq, void *dev_id)
45{
46 struct timer8_priv *p = dev_id;
47
Daniel Lezcano7053fda2015-11-08 18:07:38 +010048 if (clockevent_state_oneshot(&p->ced))
Yoshinori Satod33f2502015-12-05 02:48:18 +090049 iowrite16be(0x0000, p->mapbase + _8TCR);
Daniel Lezcano7053fda2015-11-08 18:07:38 +010050
51 p->ced.event_handler(&p->ced);
Yoshinori Sato618b9022015-01-28 02:52:42 +090052
Yoshinori Satod33f2502015-12-05 02:48:18 +090053 bclr(CMFA, p->mapbase + _8TCSR);
Yoshinori Satof37632d2015-12-05 02:48:16 +090054
Yoshinori Sato618b9022015-01-28 02:52:42 +090055 return IRQ_HANDLED;
56}
57
58static void timer8_set_next(struct timer8_priv *p, unsigned long delta)
59{
Yoshinori Sato618b9022015-01-28 02:52:42 +090060 if (delta >= 0x10000)
Daniel Lezcano8c09b7d2015-11-09 09:02:38 +010061 pr_warn("delta out of range\n");
Yoshinori Satod33f2502015-12-05 02:48:18 +090062 bclr(CMIEA, p->mapbase + _8TCR);
63 iowrite16be(delta, p->mapbase + TCORA);
64 iowrite16be(0x0000, p->mapbase + _8TCNT);
65 bclr(CMFA, p->mapbase + _8TCSR);
66 bset(CMIEA, p->mapbase + _8TCR);
Yoshinori Sato618b9022015-01-28 02:52:42 +090067}
68
69static int timer8_enable(struct timer8_priv *p)
70{
Yoshinori Satod33f2502015-12-05 02:48:18 +090071 iowrite16be(0xffff, p->mapbase + TCORA);
72 iowrite16be(0x0000, p->mapbase + _8TCNT);
73 iowrite16be(0x0c02, p->mapbase + _8TCR);
Yoshinori Sato618b9022015-01-28 02:52:42 +090074
75 return 0;
76}
77
78static int timer8_start(struct timer8_priv *p)
79{
Daniel Lezcanocce483e2015-11-08 23:24:28 +010080 int ret;
Yoshinori Sato618b9022015-01-28 02:52:42 +090081
Daniel Lezcanocce483e2015-11-08 23:24:28 +010082 if ((p->flags & FLAG_STARTED))
83 return 0;
Yoshinori Sato618b9022015-01-28 02:52:42 +090084
Daniel Lezcanocce483e2015-11-08 23:24:28 +010085 ret = timer8_enable(p);
86 if (!ret)
87 p->flags |= FLAG_STARTED;
Yoshinori Sato618b9022015-01-28 02:52:42 +090088
Yoshinori Sato618b9022015-01-28 02:52:42 +090089 return ret;
90}
91
92static void timer8_stop(struct timer8_priv *p)
93{
Yoshinori Satod33f2502015-12-05 02:48:18 +090094 iowrite16be(0x0000, p->mapbase + _8TCR);
Yoshinori Sato618b9022015-01-28 02:52:42 +090095}
96
97static inline struct timer8_priv *ced_to_priv(struct clock_event_device *ced)
98{
99 return container_of(ced, struct timer8_priv, ced);
100}
101
Daniel Lezcano1f058d52015-11-08 17:46:54 +0100102static void timer8_clock_event_start(struct timer8_priv *p, unsigned long delta)
Yoshinori Sato618b9022015-01-28 02:52:42 +0900103{
104 struct clock_event_device *ced = &p->ced;
105
106 timer8_start(p);
107
108 ced->shift = 32;
109 ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
110 ced->max_delta_ns = clockevent_delta2ns(0xffff, ced);
111 ced->min_delta_ns = clockevent_delta2ns(0x0001, ced);
112
Daniel Lezcano1f058d52015-11-08 17:46:54 +0100113 timer8_set_next(p, delta);
Yoshinori Sato618b9022015-01-28 02:52:42 +0900114}
115
Viresh Kumarfc2b2f52015-07-27 15:02:00 +0530116static int timer8_clock_event_shutdown(struct clock_event_device *ced)
117{
118 timer8_stop(ced_to_priv(ced));
119 return 0;
120}
121
122static int timer8_clock_event_periodic(struct clock_event_device *ced)
Yoshinori Sato618b9022015-01-28 02:52:42 +0900123{
124 struct timer8_priv *p = ced_to_priv(ced);
125
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900126 pr_info("%s: used for periodic clock events\n", ced->name);
Viresh Kumarfc2b2f52015-07-27 15:02:00 +0530127 timer8_stop(p);
Daniel Lezcano1f058d52015-11-08 17:46:54 +0100128 timer8_clock_event_start(p, (p->rate + HZ/2) / HZ);
Viresh Kumarfc2b2f52015-07-27 15:02:00 +0530129
130 return 0;
131}
132
133static int timer8_clock_event_oneshot(struct clock_event_device *ced)
134{
135 struct timer8_priv *p = ced_to_priv(ced);
136
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900137 pr_info("%s: used for oneshot clock events\n", ced->name);
Viresh Kumarfc2b2f52015-07-27 15:02:00 +0530138 timer8_stop(p);
Daniel Lezcano1f058d52015-11-08 17:46:54 +0100139 timer8_clock_event_start(p, 0x10000);
Viresh Kumarfc2b2f52015-07-27 15:02:00 +0530140
141 return 0;
Yoshinori Sato618b9022015-01-28 02:52:42 +0900142}
143
144static int timer8_clock_event_next(unsigned long delta,
145 struct clock_event_device *ced)
146{
147 struct timer8_priv *p = ced_to_priv(ced);
148
Viresh Kumarfc2b2f52015-07-27 15:02:00 +0530149 BUG_ON(!clockevent_state_oneshot(ced));
Yoshinori Sato618b9022015-01-28 02:52:42 +0900150 timer8_set_next(p, delta - 1);
151
152 return 0;
153}
154
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900155static struct timer8_priv timer8_priv = {
156 .ced = {
157 .name = "h8300_8timer",
158 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
159 .rating = 200,
160 .set_next_event = timer8_clock_event_next,
161 .set_state_shutdown = timer8_clock_event_shutdown,
162 .set_state_periodic = timer8_clock_event_periodic,
163 .set_state_oneshot = timer8_clock_event_oneshot,
164 },
165};
166
167static void __init h8300_8timer_init(struct device_node *node)
Yoshinori Sato618b9022015-01-28 02:52:42 +0900168{
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900169 void __iomem *base;
Yoshinori Sato618b9022015-01-28 02:52:42 +0900170 int irq;
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900171 struct clk *clk;
Yoshinori Sato618b9022015-01-28 02:52:42 +0900172
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900173 clk = of_clk_get(node, 0);
174 if (IS_ERR(clk)) {
175 pr_err("failed to get clock for clockevent\n");
176 return;
Yoshinori Sato618b9022015-01-28 02:52:42 +0900177 }
178
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900179 base = of_iomap(node, 0);
180 if (!base) {
181 pr_err("failed to map registers for clockevent\n");
182 goto free_clk;
183 }
184
185 irq = irq_of_parse_and_map(node, 0);
Daniel Lezcano54a0cd52015-11-08 17:56:18 +0100186 if (!irq) {
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900187 pr_err("failed to get irq for clockevent\n");
188 goto unmap_reg;
Yoshinori Sato618b9022015-01-28 02:52:42 +0900189 }
190
Daniel Lezcano75160512015-11-08 22:55:12 +0100191 timer8_priv.mapbase = base;
Daniel Lezcanocce483e2015-11-08 23:24:28 +0100192
Yoshinori Sato6f2b6112015-12-05 02:48:17 +0900193 timer8_priv.rate = clk_get_rate(clk) / SCALE;
194 if (!timer8_priv.rate) {
Daniel Lezcanocce483e2015-11-08 23:24:28 +0100195 pr_err("Failed to get rate for the clocksource\n");
196 goto unmap_reg;
197 }
Yoshinori Sato618b9022015-01-28 02:52:42 +0900198
Yoshinori Sato6f2b6112015-12-05 02:48:17 +0900199 if (request_irq(irq, timer8_interrupt, IRQF_TIMER,
200 timer8_priv.ced.name, &timer8_priv) < 0) {
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900201 pr_err("failed to request irq %d for clockevent\n", irq);
202 goto unmap_reg;
Yoshinori Sato618b9022015-01-28 02:52:42 +0900203 }
Yoshinori Sato618b9022015-01-28 02:52:42 +0900204
Yoshinori Sato6f2b6112015-12-05 02:48:17 +0900205 clockevents_config_and_register(&timer8_priv.ced,
206 timer8_priv.rate, 1, 0x0000ffff);
Daniel Lezcanocce483e2015-11-08 23:24:28 +0100207
208 return;
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900209unmap_reg:
210 iounmap(base);
211free_clk:
212 clk_put(clk);
Yoshinori Sato618b9022015-01-28 02:52:42 +0900213}
214
Yoshinori Sato4633f4c2015-11-07 01:31:44 +0900215CLOCKSOURCE_OF_DECLARE(h8300_8bit, "renesas,8bit-timer", h8300_8timer_init);