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authorDavid Brownell <david-b@pacbell.net>2007-05-10 05:51:41 -0400
committerRichard Purdie <rpurdie@rpsys.net>2007-07-15 20:15:50 -0400
commit00852279af5ad26956bc7f4d0e86fdb40192e542 (patch)
tree8d8ef74de734d94c59ae2d83f19b446d4ef2ef73 /drivers
parent22e03f3b58dfcca30f0c8de185022132459638d1 (diff)
leds: Teach leds-gpio to handle timer-unsafe GPIOs
Teach the new leds-gpio driver that some GPIOs can't be accessed from timer callbacks ... which is how all today's standard triggers use them. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/leds/leds-gpio.c27
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
index 431dcb61902c..47d90db280ce 100644
--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c
@@ -13,14 +13,26 @@
13#include <linux/init.h> 13#include <linux/init.h>
14#include <linux/platform_device.h> 14#include <linux/platform_device.h>
15#include <linux/leds.h> 15#include <linux/leds.h>
16#include <linux/workqueue.h>
17
16#include <asm/gpio.h> 18#include <asm/gpio.h>
17 19
18struct gpio_led_data { 20struct gpio_led_data {
19 struct led_classdev cdev; 21 struct led_classdev cdev;
20 unsigned gpio; 22 unsigned gpio;
23 struct work_struct work;
24 u8 new_level;
25 u8 can_sleep;
21 u8 active_low; 26 u8 active_low;
22}; 27};
23 28
29static void gpio_led_work(struct work_struct *work)
30{
31 struct gpio_led_data *led_dat =
32 container_of(work, struct gpio_led_data, work);
33
34 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
35}
24 36
25static void gpio_led_set(struct led_classdev *led_cdev, 37static void gpio_led_set(struct led_classdev *led_cdev,
26 enum led_brightness value) 38 enum led_brightness value)
@@ -37,7 +49,15 @@ static void gpio_led_set(struct led_classdev *led_cdev,
37 if (led_dat->active_low) 49 if (led_dat->active_low)
38 level = !level; 50 level = !level;
39 51
40 gpio_set_value(led_dat->gpio, level); 52 /* setting GPIOs with I2C/etc requires a preemptible task context */
53 if (led_dat->can_sleep) {
54 if (preempt_count()) {
55 led_dat->new_level = level;
56 schedule_work(&led_dat->work);
57 } else
58 gpio_set_value_cansleep(led_dat->gpio, level);
59 } else
60 gpio_set_value(led_dat->gpio, level);
41} 61}
42 62
43static int __init gpio_led_probe(struct platform_device *pdev) 63static int __init gpio_led_probe(struct platform_device *pdev)
@@ -62,6 +82,7 @@ static int __init gpio_led_probe(struct platform_device *pdev)
62 led_dat->cdev.name = cur_led->name; 82 led_dat->cdev.name = cur_led->name;
63 led_dat->cdev.default_trigger = cur_led->default_trigger; 83 led_dat->cdev.default_trigger = cur_led->default_trigger;
64 led_dat->gpio = cur_led->gpio; 84 led_dat->gpio = cur_led->gpio;
85 led_dat->can_sleep = gpio_cansleep(cur_led->gpio);
65 led_dat->active_low = cur_led->active_low; 86 led_dat->active_low = cur_led->active_low;
66 led_dat->cdev.brightness_set = gpio_led_set; 87 led_dat->cdev.brightness_set = gpio_led_set;
67 led_dat->cdev.brightness = cur_led->active_low ? LED_FULL : LED_OFF; 88 led_dat->cdev.brightness = cur_led->active_low ? LED_FULL : LED_OFF;
@@ -77,6 +98,8 @@ static int __init gpio_led_probe(struct platform_device *pdev)
77 gpio_free(led_dat->gpio); 98 gpio_free(led_dat->gpio);
78 goto err; 99 goto err;
79 } 100 }
101
102 INIT_WORK(&led_dat->work, gpio_led_work);
80 } 103 }
81 104
82 platform_set_drvdata(pdev, leds_data); 105 platform_set_drvdata(pdev, leds_data);
@@ -90,6 +113,8 @@ err:
90 gpio_free(leds_data[i].gpio); 113 gpio_free(leds_data[i].gpio);
91 } 114 }
92 } 115 }
116
117 flush_scheduled_work();
93 kfree(leds_data); 118 kfree(leds_data);
94 119
95 return ret; 120 return ret;