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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 platform PWM support
*
* 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.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <asm/mach-jz4740/gpio.h>
#include <asm/mach-jz4740/timer.h>
#define NUM_PWM 8
static const unsigned int jz4740_pwm_gpio_list[NUM_PWM] = {
JZ_GPIO_PWM0,
JZ_GPIO_PWM1,
JZ_GPIO_PWM2,
JZ_GPIO_PWM3,
JZ_GPIO_PWM4,
JZ_GPIO_PWM5,
JZ_GPIO_PWM6,
JZ_GPIO_PWM7,
};
struct jz4740_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
};
static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
{
return container_of(chip, struct jz4740_pwm_chip, chip);
}
static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
unsigned int gpio = jz4740_pwm_gpio_list[pwm->hwpwm];
int ret;
/*
* Timers 0 and 1 are used for system tasks, so they are unavailable
* for use as PWMs.
*/
if (pwm->hwpwm < 2)
return -EBUSY;
ret = gpio_request(gpio, pwm->label);
if (ret) {
dev_err(chip->dev, "Failed to request GPIO#%u for PWM: %d\n",
gpio, ret);
return ret;
}
jz_gpio_set_function(gpio, JZ_GPIO_FUNC_PWM);
jz4740_timer_start(pwm->hwpwm);
return 0;
}
static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
unsigned int gpio = jz4740_pwm_gpio_list[pwm->hwpwm];
jz4740_timer_set_ctrl(pwm->hwpwm, 0);
jz_gpio_set_function(gpio, JZ_GPIO_FUNC_NONE);
gpio_free(gpio);
jz4740_timer_stop(pwm->hwpwm);
}
static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
jz4740_timer_enable(pwm->hwpwm);
return 0;
}
static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
uint32_t ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);
ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
jz4740_timer_disable(pwm->hwpwm);
jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
}
static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
unsigned long long tmp;
unsigned long period, duty;
unsigned int prescaler = 0;
uint16_t ctrl;
bool is_enabled;
tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns;
do_div(tmp, 1000000000);
period = tmp;
while (period > 0xffff && prescaler < 6) {
period >>= 2;
++prescaler;
}
if (prescaler == 6)
return -EINVAL;
tmp = (unsigned long long)period * duty_ns;
do_div(tmp, period_ns);
duty = period - tmp;
if (duty >= period)
duty = period - 1;
is_enabled = jz4740_timer_is_enabled(pwm->hwpwm);
if (is_enabled)
jz4740_pwm_disable(chip, pwm);
jz4740_timer_set_count(pwm->hwpwm, 0);
jz4740_timer_set_duty(pwm->hwpwm, duty);
jz4740_timer_set_period(pwm->hwpwm, period);
ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT |
JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
if (is_enabled)
jz4740_pwm_enable(chip, pwm);
return 0;
}
static const struct pwm_ops jz4740_pwm_ops = {
.request = jz4740_pwm_request,
.free = jz4740_pwm_free,
.config = jz4740_pwm_config,
.enable = jz4740_pwm_enable,
.disable = jz4740_pwm_disable,
.owner = THIS_MODULE,
};
static int jz4740_pwm_probe(struct platform_device *pdev)
{
struct jz4740_pwm_chip *jz4740;
int ret;
jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
if (!jz4740)
return -ENOMEM;
jz4740->clk = clk_get(&pdev->dev, "ext");
if (IS_ERR(jz4740->clk))
return PTR_ERR(jz4740->clk);
jz4740->chip.dev = &pdev->dev;
jz4740->chip.ops = &jz4740_pwm_ops;
jz4740->chip.npwm = NUM_PWM;
jz4740->chip.base = -1;
ret = pwmchip_add(&jz4740->chip);
if (ret < 0) {
clk_put(jz4740->clk);
return ret;
}
platform_set_drvdata(pdev, jz4740);
return 0;
}
static int jz4740_pwm_remove(struct platform_device *pdev)
{
struct jz4740_pwm_chip *jz4740 = platform_get_drvdata(pdev);
int ret;
ret = pwmchip_remove(&jz4740->chip);
if (ret < 0)
return ret;
clk_put(jz4740->clk);
return 0;
}
static struct platform_driver jz4740_pwm_driver = {
.driver = {
.name = "jz4740-pwm",
.owner = THIS_MODULE,
},
.probe = jz4740_pwm_probe,
.remove = jz4740_pwm_remove,
};
module_platform_driver(jz4740_pwm_driver);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Ingenic JZ4740 PWM driver");
MODULE_ALIAS("platform:jz4740-pwm");
MODULE_LICENSE("GPL");
|
