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debug-leds.c

/*
 * linux/arch/arm/plat-omap/debug-leds.c
 *
 * Copyright 2003 by Texas Instruments Incorporated
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/io.h>

#include <mach/hardware.h>
#include <asm/leds.h>
#include <asm/system.h>
#include <asm/mach-types.h>

#include <plat/fpga.h>
#include <mach/gpio.h>


/* Many OMAP development platforms reuse the same "debug board"; these
 * platforms include H2, H3, H4, and Perseus2.  There are 16 LEDs on the
 * debug board (all green), accessed through FPGA registers.
 *
 * The "surfer" expansion board and H2 sample board also have two-color
 * green+red LEDs (in parallel), used here for timer and idle indicators
 * in preference to the ones on the debug board, for a "Disco LED" effect.
 *
 * This driver exports either the original ARM LED API, the new generic
 * one, or both.
 */

static spinlock_t             lock;
static struct h2p2_dbg_fpga __iomem *fpga;
static u16                    led_state, hw_led_state;


#ifdef      CONFIG_OMAP_DEBUG_LEDS
#define new_led_api()   1
#else
#define new_led_api()   0
#endif


/*-------------------------------------------------------------------------*/

/* original ARM debug LED API:
 *  - timer and idle leds (some boards use non-FPGA leds here);
 *  - up to 4 generic leds, easily accessed in-kernel (any context)
 */

#define GPIO_LED_RED          3
#define GPIO_LED_GREEN        OMAP_MPUIO(4)

#define LED_STATE_ENABLED     0x01
#define LED_STATE_CLAIMED     0x02
#define LED_TIMER_ON          0x04

#define GPIO_IDLE       GPIO_LED_GREEN
#define GPIO_TIMER            GPIO_LED_RED

static void h2p2_dbg_leds_event(led_event_t evt)
{
      unsigned long flags;

      spin_lock_irqsave(&lock, flags);

      if (!(led_state & LED_STATE_ENABLED) && evt != led_start)
            goto done;

      switch (evt) {
      case led_start:
            if (fpga)
                  led_state |= LED_STATE_ENABLED;
            break;

      case led_stop:
      case led_halted:
            /* all leds off during suspend or shutdown */

            if (!(machine_is_omap_perseus2() || machine_is_omap_h4())) {
                  gpio_set_value(GPIO_TIMER, 0);
                  gpio_set_value(GPIO_IDLE, 0);
            }

            __raw_writew(~0, &fpga->leds);
            led_state &= ~LED_STATE_ENABLED;
            goto done;

      case led_claim:
            led_state |= LED_STATE_CLAIMED;
            hw_led_state = 0;
            break;

      case led_release:
            led_state &= ~LED_STATE_CLAIMED;
            break;

#ifdef CONFIG_LEDS_TIMER
      case led_timer:
            led_state ^= LED_TIMER_ON;

            if (machine_is_omap_perseus2() || machine_is_omap_h4())
                  hw_led_state ^= H2P2_DBG_FPGA_P2_LED_TIMER;
            else {
                  gpio_set_value(GPIO_TIMER,
                              led_state & LED_TIMER_ON);
                  goto done;
            }

            break;
#endif

#ifdef CONFIG_LEDS_CPU
      /* LED lit iff busy */
      case led_idle_start:
            if (machine_is_omap_perseus2() || machine_is_omap_h4())
                  hw_led_state &= ~H2P2_DBG_FPGA_P2_LED_IDLE;
            else {
                  gpio_set_value(GPIO_IDLE, 1);
                  goto done;
            }

            break;

      case led_idle_end:
            if (machine_is_omap_perseus2() || machine_is_omap_h4())
                  hw_led_state |= H2P2_DBG_FPGA_P2_LED_IDLE;
            else {
                  gpio_set_value(GPIO_IDLE, 0);
                  goto done;
            }

            break;
#endif

      case led_green_on:
            hw_led_state |= H2P2_DBG_FPGA_LED_GREEN;
            break;
      case led_green_off:
            hw_led_state &= ~H2P2_DBG_FPGA_LED_GREEN;
            break;

      case led_amber_on:
            hw_led_state |= H2P2_DBG_FPGA_LED_AMBER;
            break;
      case led_amber_off:
            hw_led_state &= ~H2P2_DBG_FPGA_LED_AMBER;
            break;

      case led_red_on:
            hw_led_state |= H2P2_DBG_FPGA_LED_RED;
            break;
      case led_red_off:
            hw_led_state &= ~H2P2_DBG_FPGA_LED_RED;
            break;

      case led_blue_on:
            hw_led_state |= H2P2_DBG_FPGA_LED_BLUE;
            break;
      case led_blue_off:
            hw_led_state &= ~H2P2_DBG_FPGA_LED_BLUE;
            break;

      default:
            break;
      }


      /*
       *  Actually burn the LEDs
       */
      if (led_state & LED_STATE_ENABLED)
            __raw_writew(~hw_led_state, &fpga->leds);

done:
      spin_unlock_irqrestore(&lock, flags);
}

/*-------------------------------------------------------------------------*/

/* "new" LED API
 *  - with syfs access and generic triggering
 *  - not readily accessible to in-kernel drivers
 */

00191 struct dbg_led {
      struct led_classdev     cdev;
      u16               mask;
};

static struct dbg_led dbg_leds[] = {
      /* REVISIT at least H2 uses different timer & cpu leds... */
#ifndef CONFIG_LEDS_TIMER
      { .mask = 1 << 0,  .cdev.name =  "d4:green",
            .cdev.default_trigger = "heartbeat", },
#endif
#ifndef CONFIG_LEDS_CPU
      { .mask = 1 << 1,  .cdev.name =  "d5:green", },       /* !idle */
#endif
      { .mask = 1 << 2,  .cdev.name =  "d6:green", },
      { .mask = 1 << 3,  .cdev.name =  "d7:green", },

      { .mask = 1 << 4,  .cdev.name =  "d8:green", },
      { .mask = 1 << 5,  .cdev.name =  "d9:green", },
      { .mask = 1 << 6,  .cdev.name = "d10:green", },
      { .mask = 1 << 7,  .cdev.name = "d11:green", },

      { .mask = 1 << 8,  .cdev.name = "d12:green", },
      { .mask = 1 << 9,  .cdev.name = "d13:green", },
      { .mask = 1 << 10, .cdev.name = "d14:green", },
      { .mask = 1 << 11, .cdev.name = "d15:green", },

#ifndef     CONFIG_LEDS
      { .mask = 1 << 12, .cdev.name = "d16:green", },
      { .mask = 1 << 13, .cdev.name = "d17:green", },
      { .mask = 1 << 14, .cdev.name = "d18:green", },
      { .mask = 1 << 15, .cdev.name = "d19:green", },
#endif
};

static void
fpga_led_set(struct led_classdev *cdev, enum led_brightness value)
{
      struct dbg_led    *led = container_of(cdev, struct dbg_led, cdev);
      unsigned long     flags;

      spin_lock_irqsave(&lock, flags);
      if (value == LED_OFF)
            hw_led_state &= ~led->mask;
      else
            hw_led_state |= led->mask;
      __raw_writew(~hw_led_state, &fpga->leds);
      spin_unlock_irqrestore(&lock, flags);
}

static void __init newled_init(struct device *dev)
{
      unsigned    i;
      struct dbg_led    *led;
      int         status;

      for (i = 0, led = dbg_leds; i < ARRAY_SIZE(dbg_leds); i++, led++) {
            led->cdev.brightness_set = fpga_led_set;
            status = led_classdev_register(dev, &led->cdev);
            if (status < 0)
                  break;
      }
      return;
}


/*-------------------------------------------------------------------------*/

static int /* __init */ fpga_probe(struct platform_device *pdev)
{
      struct resource   *iomem;

      spin_lock_init(&lock);

      iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
      if (!iomem)
            return -ENODEV;

      fpga = ioremap(iomem->start, H2P2_DBG_FPGA_SIZE);
      __raw_writew(~0, &fpga->leds);

#ifdef      CONFIG_LEDS
      leds_event = h2p2_dbg_leds_event;
      leds_event(led_start);
#endif

      if (new_led_api()) {
            newled_init(&pdev->dev);
      }

      return 0;
}

static int fpga_suspend_noirq(struct device *dev)
{
      __raw_writew(~0, &fpga->leds);
      return 0;
}

static int fpga_resume_noirq(struct device *dev)
{
      __raw_writew(~hw_led_state, &fpga->leds);
      return 0;
}

static const struct dev_pm_ops fpga_dev_pm_ops = {
      .suspend_noirq = fpga_suspend_noirq,
      .resume_noirq = fpga_resume_noirq,
};

static struct platform_driver led_driver = {
      .driver.name      = "omap_dbg_led",
      .driver.pm  = &fpga_dev_pm_ops,
      .probe            = fpga_probe,
};

static int __init fpga_init(void)
{
      if (machine_is_omap_h4()
                  || machine_is_omap_h3()
                  || machine_is_omap_h2()
                  || machine_is_omap_perseus2()
                  )
            return platform_driver_register(&led_driver);
      return 0;
}
fs_initcall(fpga_init);

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