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