/
0005-leds-leds-pwm-Defer-led_pwm_set-if-PWM-can-sleep.patch
122 lines (109 loc) · 3.53 KB
/
0005-leds-leds-pwm-Defer-led_pwm_set-if-PWM-can-sleep.patch
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
From 7ce1c44504c01773397d5258e705dd284edd86db Mon Sep 17 00:00:00 2001
From: Florian Vaussard <florian.vaussard@epfl.ch>
Date: Mon, 28 Jan 2013 06:00:59 -0800
Subject: [PATCH 5/6] leds: leds-pwm: Defer led_pwm_set() if PWM can sleep
Call to led_pwm_set() can happen inside atomic context, like triggers.
If the PWM call can sleep, defer using a worker.
Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
---
drivers/leds/leds-pwm.c | 50 +++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 42 insertions(+), 8 deletions(-)
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index a1ea5f6..faf52c0 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -23,12 +23,16 @@
#include <linux/pwm.h>
#include <linux/leds_pwm.h>
#include <linux/slab.h>
+#include <linux/workqueue.h>
struct led_pwm_data {
struct led_classdev cdev;
struct pwm_device *pwm;
+ struct work_struct work;
unsigned int active_low;
unsigned int period;
+ int duty;
+ bool can_sleep;
};
struct led_pwm_priv {
@@ -36,6 +40,26 @@ struct led_pwm_priv {
struct led_pwm_data leds[0];
};
+static void __led_pwm_set(struct led_pwm_data *led_dat)
+{
+ int new_duty = led_dat->duty;
+
+ pwm_config(led_dat->pwm, new_duty, led_dat->period);
+
+ if (new_duty == 0)
+ pwm_disable(led_dat->pwm);
+ else
+ pwm_enable(led_dat->pwm);
+}
+
+static void led_pwm_work(struct work_struct *work)
+{
+ struct led_pwm_data *led_dat =
+ container_of(work, struct led_pwm_data, work);
+
+ __led_pwm_set(led_dat);
+}
+
static void led_pwm_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
@@ -44,13 +68,12 @@ static void led_pwm_set(struct led_classdev *led_cdev,
unsigned int max = led_dat->cdev.max_brightness;
unsigned int period = led_dat->period;
- if (brightness == 0) {
- pwm_config(led_dat->pwm, 0, period);
- pwm_disable(led_dat->pwm);
- } else {
- pwm_config(led_dat->pwm, brightness * period / max, period);
- pwm_enable(led_dat->pwm);
- }
+ led_dat->duty = brightness * period / max;
+
+ if (led_dat->can_sleep)
+ schedule_work(&led_dat->work);
+ else
+ __led_pwm_set(led_dat);
}
static inline size_t sizeof_pwm_leds_priv(int num_leds)
@@ -100,6 +123,10 @@ static struct led_pwm_priv *led_pwm_create_of(struct platform_device *pdev)
led_dat->cdev.brightness = LED_OFF;
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
+ led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
+ if (led_dat->can_sleep)
+ INIT_WORK(&led_dat->work, led_pwm_work);
+
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
if (ret < 0) {
dev_err(&pdev->dev, "failed to register for %s\n",
@@ -153,6 +180,10 @@ static int led_pwm_probe(struct platform_device *pdev)
led_dat->cdev.max_brightness = cur_led->max_brightness;
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
+ led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
+ if (led_dat->can_sleep)
+ INIT_WORK(&led_dat->work, led_pwm_work);
+
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
if (ret < 0)
goto err;
@@ -180,8 +211,11 @@ static int led_pwm_remove(struct platform_device *pdev)
struct led_pwm_priv *priv = platform_get_drvdata(pdev);
int i;
- for (i = 0; i < priv->num_leds; i++)
+ for (i = 0; i < priv->num_leds; i++) {
led_classdev_unregister(&priv->leds[i].cdev);
+ if (priv->leds[i].can_sleep)
+ cancel_work_sync(&priv->leds[i].work);
+ }
return 0;
}
--
1.8.2.1