LED Class support for Soekris net48xx

Hi all,

After many years using Linux and hanging about on LKML without having done much actual kernel hacking, I've decided to have a go! The module below adds LED Class device support for the Soekris net48xx Error LED. Tested only on a net4801, but should work on a net4826 as well. I'd love to find a way of detecting a Soekris net48xx device but there is no DMI or any Soekris-specific PCI devices.

The patch is attached because Thunderbird kills tabs.

Quoted 6 lines · Chris Boot

Hi all,

After many years using Linux and hanging about on LKML without having done much actual kernel hacking, I've decided to have a go! The module below adds LED Class device support for the Soekris net48xx Error LED. Tested only on a net4801, but should work on a net4826 as well. I'd love to find a way of detecting a Soekris net48xx device but there is no DMI or any Soekris-specific PCI devices.

The patch is attached because Thunderbird kills tabs.

FWIW, the vintage scx200_gpio driver manipulates the LED just fine.

# cat /etc/modprobe.d/gpio
# assign last 2 dynamic devnums to gpio (255..240)
options scx200_gpio major=240
options pc8736x_gpio major=241

soekris:~# ll /dev/led
crw-r--r-- 1 root root 240, 20 Jun 24  2005 /dev/led

echo 1 > /dev/led

Is this insufficient ?

Hi all,

After many years using Linux and hanging about on LKML without having done much actual kernel hacking, I've decided to have a go! The module below adds LED Class device support for the Soekris net48xx Error LED. Tested only on a net4801, but should work on a net4826 as well. I'd love to find a way of detecting a Soekris net48xx device but there is no DMI or any Soekris-specific PCI devices.

The patch is attached because Thunderbird kills tabs.

------------------------------------------------------------------------

MAINTAINERS +5 -0

index 196a31c..c55f690 100644
@@ -2666,6 +2666,11 @@ M:	[email protected]
 L:	[email protected]
 S:	Maintained
 
+SOEKRIS NET48XX LED SUPPORT
+P:	Chris Boot
+M:	[email protected]
+S:	Maintained
+
 SPARC (sparc32):
 P:	William L. Irwin
 M:	[email protected]

drivers/leds/Kconfig +7 -0

index 9650998..9c39b98 100644
@@ -69,6 +69,13 @@ config LEDS_AMS_DELTA
 	help
 	  This option enables support for the LEDs on Amstrad Delta (E3).
 
+config LEDS_NET48XX
+	tristate "LED Support for Soekris net48xx series Error LED"
+	depends on LEDS_CLASS && SCx200_GPIO
+	help
+	  This option enables support for the Soekris net4801 and net4826 error
+	  LED.
+
 comment "LED Triggers"
 
 config LEDS_TRIGGERS

drivers/leds/Makefile +1 -0

index 88d3b6e..6aa2aed 100644
@@ -12,6 +12,7 @@ obj-$(CONFIG_LEDS_IXP4XX)		+= leds-ixp4x
 obj-$(CONFIG_LEDS_TOSA)			+= leds-tosa.o
 obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o
 obj-$(CONFIG_LEDS_AMS_DELTA)		+= leds-ams-delta.o
+obj-$(CONFIG_LEDS_NET48XX)		+= leds-net48xx.o
 
 # LED Triggers
 obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o

drivers/leds/leds-net48xx.c new file +116 -0

new file mode 100644
index 0000000..157b561
@@ -0,0 +1,116 @@
+/*
+ * LEDs driver for Soekris net48xx
+ *
+ * Copyright (C) 2006 Chris Boot <[email protected]>
+ *
+ * Based on leds-ams-delta.c
+ *
+ * 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/err.h>
+#include <asm/io.h>
+#include <linux/scx200_gpio.h>
+
+#define NET48XX_ERROR_LED_GPIO	20
+
+static struct platform_device *pdev;
+
+static void net48xx_error_led_set(struct led_classdev *led_cdev,
+		enum led_brightness value)
+{
+	if (value)
+		scx200_gpio_set_high(NET48XX_ERROR_LED_GPIO);
+	else
+		scx200_gpio_set_low(NET48XX_ERROR_LED_GPIO);
+}
+
+static struct led_classdev net48xx_error_led = {
+	.name		= "net48xx:error",
+	.brightness_set	= net48xx_error_led_set,
+};
+
+#ifdef CONFIG_PM
+static int net48xx_led_suspend(struct platform_device *dev,
+		pm_message_t state)
+{
+	return led_classdev_suspend(&net48xx_error_led);
+}
+
+static int net48xx_led_resume(struct platform_device *dev)
+{
+	return led_classdev_resume(&net48xx_error_led);
+}
+#else
+#define net48xx_led_suspend NULL
+#define net48xx_led_resume NULL
+#endif
+
+static int net48xx_led_probe(struct platform_device *pdev)
+{
+	if (!scx200_gpio_present())
+		return ENODEV;
+	
+	return led_classdev_register(&pdev->dev,
+		&net48xx_error_led);
+}
+
+static int net48xx_led_remove(struct platform_device *pdev)
+{
+	led_classdev_unregister(&net48xx_error_led);
+	return 0;
+}
+
+static struct platform_driver net48xx_led_driver = {
+	.probe		= net48xx_led_probe,
+	.remove		= net48xx_led_remove,
+	.suspend	= net48xx_led_suspend,
+	.resume		= net48xx_led_resume,
+	.driver		= {
+		.name = "net48xx-led",
+	},
+};
+
+static int __init net48xx_led_init(void)
+{
+	int ret;
+	
+	if (!scx200_gpio_present()) {
+		ret = ENODEV;
+		goto out;
+	}
+	
+	ret = platform_driver_register(&net48xx_led_driver);
+	if (ret < 0)
+		goto out;
+	
+	pdev = platform_device_register_simple("net48xx-led", -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		ret = PTR_ERR(pdev);
+		platform_driver_unregister(&net48xx_led_driver);
+		goto out;
+	}
+	
+out:
+	return ret;
+}
+
+static void __exit net48xx_led_exit(void)
+{
+	platform_device_unregister(pdev);
+	platform_driver_unregister(&net48xx_led_driver);
+}
+
+module_init(net48xx_led_init);
+module_exit(net48xx_led_exit);
+
+MODULE_AUTHOR("Chris Boot <[email protected]>");
+MODULE_DESCRIPTION("Soekris net48xx LED driver");
+MODULE_LICENSE("GPL");
+

I'd love to find a way of detecting a Soekris net48xx device but there is no DMI or any Soekris-specific PCI devices.

Quoted 2 lines · Chris Boot

I'd love to find a way of detecting a Soekris net48xx device but there is no DMI or any Soekris-specific PCI devices.

You could do ugly things like this:

        int i;
        char *bios = __va(0xf0000);

        for(i = 0; i < 0x10000 - 19; i++) {
                if(memcmp(bios + i, "Soekris Engineering", 19) == 0) {
                        printk("soekris string found at 0x%x\n", i);
                }
        }

The string "net4801" is also in there (although I'm using a 4826).

If anyone knows a better way, I'd like to know it too.

Quoted 3 lines · Eric Lammerts

        char *bios = __va(0xf0000);

        for(i = 0; i < 0x10000 - 19; i++) {

Hmm, very ugly indeed! Where did you dig those offsets up from? Are they likely to work properly in non-Soekris devices?