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

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/*
* linux/arch/arm/plat-omap/debug-leds.c
*
* Copyright 2011 by Bryan Wu <bryan.wu@canonical.com>
* 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/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/io.h>
#include <linux/platform_data/gpio-omap.h>
#include <linux/slab.h>
#include <asm/mach-types.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.
*/
/* NOTE: most boards don't have a static mapping for the FPGA ... */
struct h2p2_dbg_fpga {
/* offset 0x00 */
u16 smc91x[8];
/* offset 0x10 */
u16 fpga_rev;
u16 board_rev;
u16 gpio_outputs;
u16 leds;
/* offset 0x18 */
u16 misc_inputs;
u16 lan_status;
u16 lan_reset;
u16 reserved0;
/* offset 0x20 */
u16 ps2_data;
u16 ps2_ctrl;
/* plus also 4 rs232 ports ... */
};
static struct h2p2_dbg_fpga __iomem *fpga;
static u16 fpga_led_state;
struct dbg_led {
struct led_classdev cdev;
u16 mask;
};
static const struct {
const char *name;
const char *trigger;
} dbg_leds[] = {
{ "dbg:d4", "heartbeat", },
{ "dbg:d5", "cpu0", },
{ "dbg:d6", "default-on", },
{ "dbg:d7", },
{ "dbg:d8", },
{ "dbg:d9", },
{ "dbg:d10", },
{ "dbg:d11", },
{ "dbg:d12", },
{ "dbg:d13", },
{ "dbg:d14", },
{ "dbg:d15", },
{ "dbg:d16", },
{ "dbg:d17", },
{ "dbg:d18", },
{ "dbg:d19", },
};
/*
* The triggers lines up below will only be used if the
* LED triggers are compiled in.
*/
static void dbg_led_set(struct led_classdev *cdev,
enum led_brightness b)
{
struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
u16 reg;
reg = readw_relaxed(&fpga->leds);
if (b != LED_OFF)
reg |= led->mask;
else
reg &= ~led->mask;
writew_relaxed(reg, &fpga->leds);
}
static enum led_brightness dbg_led_get(struct led_classdev *cdev)
{
struct dbg_led *led = container_of(cdev, struct dbg_led, cdev);
u16 reg;
reg = readw_relaxed(&fpga->leds);
return (reg & led->mask) ? LED_FULL : LED_OFF;
}
static int fpga_probe(struct platform_device *pdev)
{
struct resource *iomem;
int i;
iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!iomem)
return -ENODEV;
fpga = ioremap(iomem->start, resource_size(iomem));
writew_relaxed(0xff, &fpga->leds);
for (i = 0; i < ARRAY_SIZE(dbg_leds); i++) {
struct dbg_led *led;
led = kzalloc(sizeof(*led), GFP_KERNEL);
if (!led)
break;
led->cdev.name = dbg_leds[i].name;
led->cdev.brightness_set = dbg_led_set;
led->cdev.brightness_get = dbg_led_get;
led->cdev.default_trigger = dbg_leds[i].trigger;
led->mask = BIT(i);
if (led_classdev_register(NULL, &led->cdev) < 0) {
kfree(led);
break;
}
}
return 0;
}
static int fpga_suspend_noirq(struct device *dev)
{
fpga_led_state = readw_relaxed(&fpga->leds);
writew_relaxed(0xff, &fpga->leds);
return 0;
}
static int fpga_resume_noirq(struct device *dev)
{
writew_relaxed(~fpga_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);