1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
From bd30f19a006fb52bac80c6463c49dd2f4159f4ac Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sun, 28 Jul 2013 16:26:41 +0200
Subject: [PATCH 06/53] MIPS: ralink: add cpu frequency scaling
This feature will break udelay() and cause the delay loop to have longer delays
when the frequency is scaled causing a performance hit.
Signed-off-by: John Crispin <blogic@openwrt.org>
---
arch/mips/ralink/cevt-rt3352.c | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
--- a/arch/mips/ralink/cevt-rt3352.c
+++ b/arch/mips/ralink/cevt-rt3352.c
@@ -29,6 +29,10 @@
/* enable the counter */
#define CFG_CNT_EN 0x1
+/* mt7620 frequency scaling defines */
+#define CLK_LUT_CFG 0x40
+#define SLEEP_EN BIT(31)
+
struct systick_device {
void __iomem *membase;
struct clock_event_device dev;
@@ -36,21 +40,53 @@ struct systick_device {
int freq_scale;
};
+static void (*systick_freq_scaling)(struct systick_device *sdev, int status);
+
static int systick_set_oneshot(struct clock_event_device *evt);
static int systick_shutdown(struct clock_event_device *evt);
+static inline void mt7620_freq_scaling(struct systick_device *sdev, int status)
+{
+ if (sdev->freq_scale == status)
+ return;
+
+ sdev->freq_scale = status;
+
+ pr_info("%s: %s autosleep mode\n", sdev->dev.name,
+ (status) ? ("enable") : ("disable"));
+ if (status)
+ rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) | SLEEP_EN, CLK_LUT_CFG);
+ else
+ rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) & ~SLEEP_EN, CLK_LUT_CFG);
+}
+
+static inline unsigned int read_count(struct systick_device *sdev)
+{
+ return ioread32(sdev->membase + SYSTICK_COUNT);
+}
+
+static inline unsigned int read_compare(struct systick_device *sdev)
+{
+ return ioread32(sdev->membase + SYSTICK_COMPARE);
+}
+
+static inline void write_compare(struct systick_device *sdev, unsigned int val)
+{
+ iowrite32(val, sdev->membase + SYSTICK_COMPARE);
+}
+
static int systick_next_event(unsigned long delta,
struct clock_event_device *evt)
{
struct systick_device *sdev;
- u32 count;
+ int res;
sdev = container_of(evt, struct systick_device, dev);
- count = ioread32(sdev->membase + SYSTICK_COUNT);
- count = (count + delta) % SYSTICK_FREQ;
- iowrite32(count, sdev->membase + SYSTICK_COMPARE);
+ delta += read_count(sdev);
+ write_compare(sdev, delta);
+ res = ((int)(read_count(sdev) - delta) >= 0) ? -ETIME : 0;
- return 0;
+ return res;
}
static void systick_event_handler(struct clock_event_device *dev)
@@ -60,20 +96,25 @@ static void systick_event_handler(struct
static irqreturn_t systick_interrupt(int irq, void *dev_id)
{
- struct clock_event_device *dev = (struct clock_event_device *) dev_id;
+ int ret = 0;
+ struct clock_event_device *cdev;
+ struct systick_device *sdev;
- dev->event_handler(dev);
+ if (read_c0_cause() & STATUSF_IP7) {
+ cdev = (struct clock_event_device *) dev_id;
+ sdev = container_of(cdev, struct systick_device, dev);
+
+ /* Clear Count/Compare Interrupt */
+ write_compare(sdev, read_compare(sdev));
+ cdev->event_handler(cdev);
+ ret = 1;
+ }
- return IRQ_HANDLED;
+ return IRQ_RETVAL(ret);
}
static struct systick_device systick = {
.dev = {
- /*
- * cevt-r4k uses 300, make sure systick
- * gets used if available
- */
- .rating = 310,
.features = CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = systick_next_event,
.set_state_shutdown = systick_shutdown,
@@ -95,9 +136,15 @@ static int systick_shutdown(struct clock
sdev = container_of(evt, struct systick_device, dev);
if (sdev->irq_requested)
- free_irq(systick.dev.irq, &systick_irqaction);
+ remove_irq(systick.dev.irq, &systick_irqaction);
sdev->irq_requested = 0;
- iowrite32(0, systick.membase + SYSTICK_CONFIG);
+ iowrite32(CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
+
+ if (systick_freq_scaling)
+ systick_freq_scaling(sdev, 0);
+
+ if (systick_freq_scaling)
+ systick_freq_scaling(sdev, 1);
return 0;
}
@@ -117,34 +164,48 @@ static int systick_set_oneshot(struct cl
return 0;
}
+static const struct of_device_id systick_match[] = {
+ { .compatible = "ralink,mt7620a-systick", .data = mt7620_freq_scaling},
+ {},
+};
+
static int __init ralink_systick_init(struct device_node *np)
{
+ const struct of_device_id *match;
+ int rating = 200;
int ret;
systick.membase = of_iomap(np, 0);
if (!systick.membase)
return -ENXIO;
- systick_irqaction.name = np->name;
- systick.dev.name = np->name;
- clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);
- systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
- systick.dev.max_delta_ticks = 0x7fff;
- systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
- systick.dev.min_delta_ticks = 0x3;
+ match = of_match_node(systick_match, np);
+ if (match) {
+ systick_freq_scaling = match->data;
+ /*
+ * cevt-r4k uses 300, make sure systick
+ * gets used if available
+ */
+ rating = 310;
+ }
+
+ /* enable counter than register clock source */
+ iowrite32(CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
+ clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
+ SYSTICK_FREQ, rating, 16, clocksource_mmio_readl_up);
+
+ /* register clock event */
systick.dev.irq = irq_of_parse_and_map(np, 0);
if (!systick.dev.irq) {
pr_err("%s: request_irq failed", np->name);
return -EINVAL;
}
- ret = clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
- SYSTICK_FREQ, 301, 16,
- clocksource_mmio_readl_up);
- if (ret)
- return ret;
-
- clockevents_register_device(&systick.dev);
+ systick_irqaction.name = np->name;
+ systick.dev.name = np->name;
+ systick.dev.rating = rating;
+ systick.dev.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&systick.dev, SYSTICK_FREQ, 0x3, 0x7fff);
pr_info("%s: running - mult: %d, shift: %d\n",
np->name, systick.dev.mult, systick.dev.shift);
|
