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