arch/arm/plat-omap/debug-leds.c

   1 /*
   2  * linux/arch/arm/plat-omap/debug-leds.c
   3  *
   4  * Copyright 2011 by Bryan Wu <bryan.wu@canonical.com>
   5  * Copyright 2003 by Texas Instruments Incorporated
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/leds.h>
  16 #include <linux/io.h>
  17 #include <linux/platform_data/gpio-omap.h>
  18 #include <linux/slab.h>
  19
  20 #include <mach/hardware.h>
  21 #include <asm/mach-types.h>
  22
  23 #include <plat/fpga.h>
  24
  25 /* Many OMAP development platforms reuse the same "debug board"; these
  26  * platforms include H2, H3, H4, and Perseus2.  There are 16 LEDs on the
  27  * debug board (all green), accessed through FPGA registers.
  28  */
  29
  30 static struct h2p2_dbg_fpga __iomem *fpga;
  31
  32 static u16 fpga_led_state;
  33
  34 struct dbg_led {
  35         struct led_classdev     cdev;
  36         u16                     mask;
  37 };
  38
  39 static const struct {
  40         const char *name;
  41         const char *trigger;
  42 } dbg_leds[] = {
  43         { "dbg:d4", "heartbeat", },
  44         { "dbg:d5", "cpu0", },
  45         { "dbg:d6", "default-on", },
  46         { "dbg:d7", },
  47         { "dbg:d8", },
  48         { "dbg:d9", },
  49         { "dbg:d10", },
  50         { "dbg:d11", },
  51         { "dbg:d12", },
  52         { "dbg:d13", },
  53         { "dbg:d14", },
  54         { "dbg:d15", },
  55         { "dbg:d16", },
  56         { "dbg:d17", },
  57         { "dbg:d18", },
  58         { "dbg:d19", },
  59 };
  60
  61 /*
  62  * The triggers lines up below will only be used if the
  63  * LED triggers are compiled in.
  64  */
  65 static void dbg_led_set(struct led_classdev *cdev,
  66                               enum led_brightness b)
  67 {
  68         struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
  69         u16 reg;
  70
  71         reg = __raw_readw(&fpga->leds);
  72         if (b != LED_OFF)
  73                 reg |= led->mask;
  74         else
  75                 reg &= ~led->mask;
  76         __raw_writew(reg, &fpga->leds);
  77 }
  78
  79 static enum led_brightness dbg_led_get(struct led_classdev *cdev)
  80 {
  81         struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
  82         u16 reg;
  83
  84         reg = __raw_readw(&fpga->leds);
  85         return (reg & led->mask) ? LED_FULL : LED_OFF;
  86 }
  87
  88 static int fpga_probe(struct platform_device *pdev)
  89 {
  90         struct resource *iomem;
  91         int i;
  92
  93         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  94         if (!iomem)
  95                 return -ENODEV;
  96
  97         fpga = ioremap(iomem->start, H2P2_DBG_FPGA_SIZE);
  98         __raw_writew(0xff, &fpga->leds);
  99
 100         for (i = 0; i < ARRAY_SIZE(dbg_leds); i++) {
 101                 struct dbg_led *led;
 102
 103                 led = kzalloc(sizeof(*led), GFP_KERNEL);
 104                 if (!led)
 105                         break;
 106
 107                 led->cdev.name = dbg_leds[i].name;
 108                 led->cdev.brightness_set = dbg_led_set;
 109                 led->cdev.brightness_get = dbg_led_get;
 110                 led->cdev.default_trigger = dbg_leds[i].trigger;
 111                 led->mask = BIT(i);
 112
 113                 if (led_classdev_register(NULL, &led->cdev) < 0) {
 114                         kfree(led);
 115                         break;
 116                 }
 117         }
 118
 119         return 0;
 120 }
 121
 122 static int fpga_suspend_noirq(struct device *dev)
 123 {
 124         fpga_led_state = __raw_readw(&fpga->leds);
 125         __raw_writew(0xff, &fpga->leds);
 126
 127         return 0;
 128 }
 129
 130 static int fpga_resume_noirq(struct device *dev)
 131 {
 132         __raw_writew(~fpga_led_state, &fpga->leds);
 133         return 0;
 134 }
 135
 136 static const struct dev_pm_ops fpga_dev_pm_ops = {
 137         .suspend_noirq = fpga_suspend_noirq,
 138         .resume_noirq = fpga_resume_noirq,
 139 };
 140
 141 static struct platform_driver led_driver = {
 142         .driver.name    = "omap_dbg_led",
 143         .driver.pm      = &fpga_dev_pm_ops,
 144         .probe          = fpga_probe,
 145 };
 146
 147 static int __init fpga_init(void)
 148 {
 149         if (machine_is_omap_h4()
 150                         || machine_is_omap_h3()
 151                         || machine_is_omap_h2()
 152                         || machine_is_omap_perseus2()
 153                         )
 154                 return platform_driver_register(&led_driver);
 155         return 0;
 156 }
 157 fs_initcall(fpga_init);