kernel/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 <asm/mach-types.h>
  21
  22 /* Many OMAP development platforms reuse the same "debug board"; these
  23  * platforms include H2, H3, H4, and Perseus2.  There are 16 LEDs on the
  24  * debug board (all green), accessed through FPGA registers.
  25  */
  26
  27 /* NOTE:  most boards don't have a static mapping for the FPGA ... */
  28 struct h2p2_dbg_fpga {
  29         /* offset 0x00 */
  30         u16             smc91x[8];
  31         /* offset 0x10 */
  32         u16             fpga_rev;
  33         u16             board_rev;
  34         u16             gpio_outputs;
  35         u16             leds;
  36         /* offset 0x18 */
  37         u16             misc_inputs;
  38         u16             lan_status;
  39         u16             lan_reset;
  40         u16             reserved0;
  41         /* offset 0x20 */
  42         u16             ps2_data;
  43         u16             ps2_ctrl;
  44         /* plus also 4 rs232 ports ... */
  45 };
  46
  47 static struct h2p2_dbg_fpga __iomem *fpga;
  48
  49 static u16 fpga_led_state;
  50
  51 struct dbg_led {
  52         struct led_classdev     cdev;
  53         u16                     mask;
  54 };
  55
  56 static const struct {
  57         const char *name;
  58         const char *trigger;
  59 } dbg_leds[] = {
  60         { "dbg:d4", "heartbeat", },
  61         { "dbg:d5", "cpu0", },
  62         { "dbg:d6", "default-on", },
  63         { "dbg:d7", },
  64         { "dbg:d8", },
  65         { "dbg:d9", },
  66         { "dbg:d10", },
  67         { "dbg:d11", },
  68         { "dbg:d12", },
  69         { "dbg:d13", },
  70         { "dbg:d14", },
  71         { "dbg:d15", },
  72         { "dbg:d16", },
  73         { "dbg:d17", },
  74         { "dbg:d18", },
  75         { "dbg:d19", },
  76 };
  77
  78 /*
  79  * The triggers lines up below will only be used if the
  80  * LED triggers are compiled in.
  81  */
  82 static void dbg_led_set(struct led_classdev *cdev,
  83                               enum led_brightness b)
  84 {
  85         struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
  86         u16 reg;
  87
  88         reg = readw_relaxed(&fpga->leds);
  89         if (b != LED_OFF)
  90                 reg |= led->mask;
  91         else
  92                 reg &= ~led->mask;
  93         writew_relaxed(reg, &fpga->leds);
  94 }
  95
  96 static enum led_brightness dbg_led_get(struct led_classdev *cdev)
  97 {
  98         struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
  99         u16 reg;
 100
 101         reg = readw_relaxed(&fpga->leds);
 102         return (reg & led->mask) ? LED_FULL : LED_OFF;
 103 }
 104
 105 static int fpga_probe(struct platform_device *pdev)
 106 {
 107         struct resource *iomem;
 108         int i;
 109
 110         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 111         if (!iomem)
 112                 return -ENODEV;
 113
 114         fpga = ioremap(iomem->start, resource_size(iomem));
 115         writew_relaxed(0xff, &fpga->leds);
 116
 117         for (i = 0; i < ARRAY_SIZE(dbg_leds); i++) {
 118                 struct dbg_led *led;
 119
 120                 led = kzalloc(sizeof(*led), GFP_KERNEL);
 121                 if (!led)
 122                         break;
 123
 124                 led->cdev.name = dbg_leds[i].name;
 125                 led->cdev.brightness_set = dbg_led_set;
 126                 led->cdev.brightness_get = dbg_led_get;
 127                 led->cdev.default_trigger = dbg_leds[i].trigger;
 128                 led->mask = BIT(i);
 129
 130                 if (led_classdev_register(NULL, &led->cdev) < 0) {
 131                         kfree(led);
 132                         break;
 133                 }
 134         }
 135
 136         return 0;
 137 }
 138
 139 static int fpga_suspend_noirq(struct device *dev)
 140 {
 141         fpga_led_state = readw_relaxed(&fpga->leds);
 142         writew_relaxed(0xff, &fpga->leds);
 143
 144         return 0;
 145 }
 146
 147 static int fpga_resume_noirq(struct device *dev)
 148 {
 149         writew_relaxed(~fpga_led_state, &fpga->leds);
 150         return 0;
 151 }
 152
 153 static const struct dev_pm_ops fpga_dev_pm_ops = {
 154         .suspend_noirq = fpga_suspend_noirq,
 155         .resume_noirq = fpga_resume_noirq,
 156 };
 157
 158 static struct platform_driver led_driver = {
 159         .driver.name    = "omap_dbg_led",
 160         .driver.pm      = &fpga_dev_pm_ops,
 161         .probe          = fpga_probe,
 162 };
 163
 164 static int __init fpga_init(void)
 165 {
 166         if (machine_is_omap_h4()
 167                         || machine_is_omap_h3()
 168                         || machine_is_omap_h2()
 169                         || machine_is_omap_perseus2()
 170                         )
 171                 return platform_driver_register(&led_driver);
 172         return 0;
 173 }
 174 fs_initcall(fpga_init);