LXR linux/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 ... */
  28struct 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
  47static struct h2p2_dbg_fpga __iomem *fpga;
  48
  49static u16 fpga_led_state;
  50
  51struct dbg_led {
  52        struct led_classdev     cdev;
  53        u16                     mask;
  54};
  55
  56static 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 */
  82static 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 = __raw_readw(&fpga->leds);
  89        if (b != LED_OFF)
  90                reg |= led->mask;
  91        else
  92                reg &= ~led->mask;
  93        __raw_writew(reg, &fpga->leds);
  94}
  95
  96static 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 = __raw_readw(&fpga->leds);
 102        return (reg & led->mask) ? LED_FULL : LED_OFF;
 103}
 104
 105static 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        __raw_writew(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
 139static int fpga_suspend_noirq(struct device *dev)
 140{
 141        fpga_led_state = __raw_readw(&fpga->leds);
 142        __raw_writew(0xff, &fpga->leds);
 143
 144        return 0;
 145}
 146
 147static int fpga_resume_noirq(struct device *dev)
 148{
 149        __raw_writew(~fpga_led_state, &fpga->leds);
 150        return 0;
 151}
 152
 153static const struct dev_pm_ops fpga_dev_pm_ops = {
 154        .suspend_noirq = fpga_suspend_noirq,
 155        .resume_noirq = fpga_resume_noirq,
 156};
 157
 158static struct platform_driver led_driver = {
 159        .driver.name    = "omap_dbg_led",
 160        .driver.pm      = &fpga_dev_pm_ops,
 161        .probe          = fpga_probe,
 162};
 163
 164static 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}
 174fs_initcall(fpga_init);
 175