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
|
/*
* Copyright (C) 2011 Samsung Electronics
*
* Donghwa Lee <dh09.lee@samsung.com>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <arch/io.h>
#include <cpu/samsung/exynos5250/clk.h>
#include <cpu/samsung/exynos5250/cpu.h>
#include <cpu/samsung/exynos5250/periph.h>
#include <cpu/samsung/exynos5250/pwm.h>
int pwm_enable(int pwm_id)
{
const struct s5p_timer *pwm =
samsung_get_base_timer();
unsigned long tcon;
tcon = readl(&pwm->tcon);
tcon |= TCON_START(pwm_id);
writel(tcon, &pwm->tcon);
return 0;
}
int pwm_check_enabled(int pwm_id)
{
const struct s5p_timer *pwm =
samsung_get_base_timer();
const unsigned long tcon = readl(&pwm->tcon);
return tcon & TCON_START(pwm_id);
}
void pwm_disable(int pwm_id)
{
const struct s5p_timer *pwm =
samsung_get_base_timer();
unsigned long tcon;
tcon = readl(&pwm->tcon);
tcon &= ~TCON_START(pwm_id);
writel(tcon, &pwm->tcon);
}
static unsigned long pwm_calc_tin(int pwm_id, unsigned long freq)
{
unsigned long tin_parent_rate;
unsigned int div;
tin_parent_rate = clock_get_periph_rate(PERIPH_ID_PWM0);
for (div = 2; div <= 16; div *= 2) {
if ((tin_parent_rate / (div << 16)) < freq)
return tin_parent_rate / div;
}
return tin_parent_rate / 16;
}
#define NS_IN_SEC 1000000000UL
int pwm_config(int pwm_id, int duty_ns, int period_ns)
{
const struct s5p_timer *pwm =
samsung_get_base_timer();
unsigned int offset;
unsigned long tin_rate;
unsigned long tin_ns;
unsigned long frequency;
unsigned long tcon;
unsigned long tcnt;
unsigned long tcmp;
/*
* We currently avoid using 64bit arithmetic by using the
* fact that anything faster than 1GHz is easily representable
* by 32bits.
*/
if (period_ns > NS_IN_SEC || duty_ns > NS_IN_SEC || period_ns == 0)
return -1;
// return -ERANGE;
if (duty_ns > period_ns)
return -1;
// return -EINVAL;
frequency = NS_IN_SEC / period_ns;
/* Check to see if we are changing the clock rate of the PWM */
tin_rate = pwm_calc_tin(pwm_id, frequency);
tin_ns = NS_IN_SEC / tin_rate;
tcnt = period_ns / tin_ns;
/* Note, counters count down */
tcmp = duty_ns / tin_ns;
tcmp = tcnt - tcmp;
/* Update the PWM register block. */
offset = pwm_id * 3;
if (pwm_id < 4) {
writel(tcnt, &pwm->tcntb0 + offset);
writel(tcmp, &pwm->tcmpb0 + offset);
}
tcon = readl(&pwm->tcon);
tcon |= TCON_UPDATE(pwm_id);
if (pwm_id < 4)
tcon |= TCON_AUTO_RELOAD(pwm_id);
else
tcon |= TCON4_AUTO_RELOAD;
writel(tcon, &pwm->tcon);
tcon &= ~TCON_UPDATE(pwm_id);
writel(tcon, &pwm->tcon);
return 0;
}
int pwm_init(int pwm_id, int div, int invert)
{
u32 val;
const struct s5p_timer *pwm =
samsung_get_base_timer();
unsigned long ticks_per_period;
unsigned int offset, prescaler;
/*
* Timer Freq(HZ) =
* PWM_CLK / { (prescaler_value + 1) * (divider_value) }
*/
val = readl(&pwm->tcfg0);
if (pwm_id < 2) {
prescaler = PRESCALER_0;
val &= ~0xff;
val |= (prescaler & 0xff);
} else {
prescaler = PRESCALER_1;
val &= ~(0xff << 8);
val |= (prescaler & 0xff) << 8;
}
writel(val, &pwm->tcfg0);
val = readl(&pwm->tcfg1);
val &= ~(0xf << MUX_DIV_SHIFT(pwm_id));
val |= (div & 0xf) << MUX_DIV_SHIFT(pwm_id);
writel(val, &pwm->tcfg1);
if (pwm_id == 4) {
/*
* TODO(sjg): Use this as a countdown timer for now. We count
* down from the maximum value to 0, then reset.
*/
ticks_per_period = -1UL;
} else {
const unsigned long pwm_hz = 1000;
unsigned long timer_rate_hz = clock_get_periph_rate(
PERIPH_ID_PWM0) / ((prescaler + 1) * (1 << div));
ticks_per_period = timer_rate_hz / pwm_hz;
}
/* set count value */
offset = pwm_id * 3;
writel(ticks_per_period, &pwm->tcntb0 + offset);
val = readl(&pwm->tcon) & ~(0xf << TCON_OFFSET(pwm_id));
if (invert && (pwm_id < 4))
val |= TCON_INVERTER(pwm_id);
writel(val, &pwm->tcon);
pwm_enable(pwm_id);
return 0;
}
|
