arch/arm/mach-integrator/leds.c

   1 /*
   2  * Driver for the 4 user LEDs found on the Integrator AP/CP baseboard
   3  * Based on Versatile and RealView machine LED code
   4  *
   5  * License terms: GNU General Public License (GPL) version 2
   6  * Author: Bryan Wu <bryan.wu@canonical.com>
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/io.h>
  11 #include <linux/slab.h>
  12 #include <linux/leds.h>
  13
  14 #include "hardware.h"
  15 #include "cm.h"
  16
  17 #if defined(CONFIG_NEW_LEDS) && defined(CONFIG_LEDS_CLASS)
  18
  19 #define ALPHA_REG __io_address(INTEGRATOR_DBG_BASE)
  20 #define LEDREG  (__io_address(INTEGRATOR_DBG_BASE) + INTEGRATOR_DBG_LEDS_OFFSET)
  21
  22 struct integrator_led {
  23         struct led_classdev     cdev;
  24         u8                      mask;
  25 };
  26
  27 /*
  28  * The triggers lines up below will only be used if the
  29  * LED triggers are compiled in.
  30  */
  31 static const struct {
  32         const char *name;
  33         const char *trigger;
  34 } integrator_leds[] = {
  35         { "integrator:green0", "heartbeat", },
  36         { "integrator:yellow", },
  37         { "integrator:red", },
  38         { "integrator:green1", },
  39         { "integrator:core_module", "cpu0", },
  40 };
  41
  42 static void integrator_led_set(struct led_classdev *cdev,
  43                               enum led_brightness b)
  44 {
  45         struct integrator_led *led = container_of(cdev,
  46                                                  struct integrator_led, cdev);
  47         u32 reg = __raw_readl(LEDREG);
  48
  49         if (b != LED_OFF)
  50                 reg |= led->mask;
  51         else
  52                 reg &= ~led->mask;
  53
  54         while (__raw_readl(ALPHA_REG) & 1)
  55                 cpu_relax();
  56
  57         __raw_writel(reg, LEDREG);
  58 }
  59
  60 static enum led_brightness integrator_led_get(struct led_classdev *cdev)
  61 {
  62         struct integrator_led *led = container_of(cdev,
  63                                                  struct integrator_led, cdev);
  64         u32 reg = __raw_readl(LEDREG);
  65
  66         return (reg & led->mask) ? LED_FULL : LED_OFF;
  67 }
  68
  69 static void cm_led_set(struct led_classdev *cdev,
  70                               enum led_brightness b)
  71 {
  72         if (b != LED_OFF)
  73                 cm_control(CM_CTRL_LED, CM_CTRL_LED);
  74         else
  75                 cm_control(CM_CTRL_LED, 0);
  76 }
  77
  78 static enum led_brightness cm_led_get(struct led_classdev *cdev)
  79 {
  80         u32 reg = cm_get();
  81
  82         return (reg & CM_CTRL_LED) ? LED_FULL : LED_OFF;
  83 }
  84
  85 static int __init integrator_leds_init(void)
  86 {
  87         int i;
  88
  89         for (i = 0; i < ARRAY_SIZE(integrator_leds); i++) {
  90                 struct integrator_led *led;
  91
  92                 led = kzalloc(sizeof(*led), GFP_KERNEL);
  93                 if (!led)
  94                         break;
  95
  96
  97                 led->cdev.name = integrator_leds[i].name;
  98
  99                 if (i == 4) { /* Setting for LED in core module */
 100                         led->cdev.brightness_set = cm_led_set;
 101                         led->cdev.brightness_get = cm_led_get;
 102                 } else {
 103                         led->cdev.brightness_set = integrator_led_set;
 104                         led->cdev.brightness_get = integrator_led_get;
 105                 }
 106
 107                 led->cdev.default_trigger = integrator_leds[i].trigger;
 108                 led->mask = BIT(i);
 109
 110                 if (led_classdev_register(NULL, &led->cdev) < 0) {
 111                         kfree(led);
 112                         break;
 113                 }
 114         }
 115
 116         return 0;
 117 }
 118
 119 /*
 120  * Since we may have triggers on any subsystem, defer registration
 121  * until after subsystem_init.
 122  */
 123 fs_initcall(integrator_leds_init);
 124 #endif