6b13f685e
 김민수
BSP 최초 추가
|
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
|
/*
* linux/arch/unicore32/kernel/pwm.c
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
* Copyright (C) 2001-2010 Guan Xuetao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/pwm.h>
#include <asm/div64.h>
#include <mach/hardware.h>
struct puv3_pwm_chip {
struct pwm_chip chip;
void __iomem *base;
struct clk *clk;
};
static inline struct puv3_pwm_chip *to_puv3(struct pwm_chip *chip)
{
return container_of(chip, struct puv3_pwm_chip, chip);
}
/*
* period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
* duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
*/
static int puv3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
unsigned long period_cycles, prescale, pv, dc;
struct puv3_pwm_chip *puv3 = to_puv3(chip);
unsigned long long c;
c = clk_get_rate(puv3->clk);
c = c * period_ns;
do_div(c, 1000000000);
period_cycles = c;
if (period_cycles < 1)
period_cycles = 1;
prescale = (period_cycles - 1) / 1024;
pv = period_cycles / (prescale + 1) - 1;
if (prescale > 63)
return -EINVAL;
if (duty_ns == period_ns)
dc = OST_PWMDCCR_FDCYCLE;
else
dc = (pv + 1) * duty_ns / period_ns;
/*
* NOTE: the clock to PWM has to be enabled first
* before writing to the registers
*/
clk_prepare_enable(puv3->clk);
writel(prescale, puv3->base + OST_PWM_PWCR);
writel(pv - dc, puv3->base + OST_PWM_DCCR);
writel(pv, puv3->base + OST_PWM_PCR);
clk_disable_unprepare(puv3->clk);
return 0;
}
static int puv3_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct puv3_pwm_chip *puv3 = to_puv3(chip);
return clk_prepare_enable(puv3->clk);
}
static void puv3_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct puv3_pwm_chip *puv3 = to_puv3(chip);
clk_disable_unprepare(puv3->clk);
}
static const struct pwm_ops puv3_pwm_ops = {
.config = puv3_pwm_config,
.enable = puv3_pwm_enable,
.disable = puv3_pwm_disable,
.owner = THIS_MODULE,
};
static int pwm_probe(struct platform_device *pdev)
{
struct puv3_pwm_chip *puv3;
struct resource *r;
int ret;
puv3 = devm_kzalloc(&pdev->dev, sizeof(*puv3), GFP_KERNEL);
if (puv3 == NULL) {
dev_err(&pdev->dev, "failed to allocate memory
");
return -ENOMEM;
}
puv3->clk = devm_clk_get(&pdev->dev, "OST_CLK");
if (IS_ERR(puv3->clk))
return PTR_ERR(puv3->clk);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
puv3->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(puv3->base))
return PTR_ERR(puv3->base);
puv3->chip.dev = &pdev->dev;
puv3->chip.ops = &puv3_pwm_ops;
puv3->chip.base = -1;
puv3->chip.npwm = 1;
ret = pwmchip_add(&puv3->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d
", ret);
return ret;
}
platform_set_drvdata(pdev, puv3);
return 0;
}
static int pwm_remove(struct platform_device *pdev)
{
struct puv3_pwm_chip *puv3 = platform_get_drvdata(pdev);
return pwmchip_remove(&puv3->chip);
}
static struct platform_driver puv3_pwm_driver = {
.driver = {
.name = "PKUnity-v3-PWM",
.owner = THIS_MODULE,
},
.probe = pwm_probe,
.remove = pwm_remove,
};
module_platform_driver(puv3_pwm_driver);
MODULE_LICENSE("GPL v2");
|