pwm-clps711x.c
4.29 KB
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
/*
* Cirrus Logic CLPS711X PWM driver
*
* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
*
* 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.
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
struct clps711x_chip {
struct pwm_chip chip;
void __iomem *pmpcon;
struct clk *clk;
spinlock_t lock;
};
static inline struct clps711x_chip *to_clps711x_chip(struct pwm_chip *chip)
{
return container_of(chip, struct clps711x_chip, chip);
}
static void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v)
{
/* PWM0 - bits 4..7, PWM1 - bits 8..11 */
u32 shift = (n + 1) * 4;
unsigned long flags;
u32 tmp;
spin_lock_irqsave(&priv->lock, flags);
tmp = readl(priv->pmpcon);
tmp &= ~(0xf << shift);
tmp |= v << shift;
writel(tmp, priv->pmpcon);
spin_unlock_irqrestore(&priv->lock, flags);
}
static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v)
{
/* Duty cycle 0..15 max */
return DIV_ROUND_CLOSEST(v * 0xf, pwm_get_period(pwm));
}
static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct clps711x_chip *priv = to_clps711x_chip(chip);
unsigned int freq = clk_get_rate(priv->clk);
if (!freq)
return -EINVAL;
/* Store constant period value */
pwm_set_period(pwm, DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq));
return 0;
}
static int clps711x_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct clps711x_chip *priv = to_clps711x_chip(chip);
unsigned int duty;
if (period_ns != pwm_get_period(pwm))
return -EINVAL;
duty = clps711x_get_duty(pwm, duty_ns);
clps711x_pwm_update_val(priv, pwm->hwpwm, duty);
return 0;
}
static int clps711x_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct clps711x_chip *priv = to_clps711x_chip(chip);
unsigned int duty;
duty = clps711x_get_duty(pwm, pwm_get_duty_cycle(pwm));
clps711x_pwm_update_val(priv, pwm->hwpwm, duty);
return 0;
}
static void clps711x_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct clps711x_chip *priv = to_clps711x_chip(chip);
clps711x_pwm_update_val(priv, pwm->hwpwm, 0);
}
static const struct pwm_ops clps711x_pwm_ops = {
.request = clps711x_pwm_request,
.config = clps711x_pwm_config,
.enable = clps711x_pwm_enable,
.disable = clps711x_pwm_disable,
.owner = THIS_MODULE,
};
static struct pwm_device *clps711x_pwm_xlate(struct pwm_chip *chip,
const struct of_phandle_args *args)
{
if (args->args[0] >= chip->npwm)
return ERR_PTR(-EINVAL);
return pwm_request_from_chip(chip, args->args[0], NULL);
}
static int clps711x_pwm_probe(struct platform_device *pdev)
{
struct clps711x_chip *priv;
struct resource *res;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->pmpcon = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->pmpcon))
return PTR_ERR(priv->pmpcon);
priv->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
priv->chip.ops = &clps711x_pwm_ops;
priv->chip.dev = &pdev->dev;
priv->chip.base = -1;
priv->chip.npwm = 2;
priv->chip.of_xlate = clps711x_pwm_xlate;
priv->chip.of_pwm_n_cells = 1;
spin_lock_init(&priv->lock);
platform_set_drvdata(pdev, priv);
return pwmchip_add(&priv->chip);
}
static int clps711x_pwm_remove(struct platform_device *pdev)
{
struct clps711x_chip *priv = platform_get_drvdata(pdev);
return pwmchip_remove(&priv->chip);
}
static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
{ .compatible = "cirrus,clps711x-pwm", },
{ }
};
MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
static struct platform_driver clps711x_pwm_driver = {
.driver = {
.name = "clps711x-pwm",
.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
},
.probe = clps711x_pwm_probe,
.remove = clps711x_pwm_remove,
};
module_platform_driver(clps711x_pwm_driver);
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("Cirrus Logic CLPS711X PWM driver");
MODULE_LICENSE("GPL");