MIPS: ath79: add common GPIO LEDs device

Almost all boards have one or more LEDs connected to GPIO lines. This
patch adds common code to register a platform_device for them.

The patch also adds support for the LEDs on the PB44 board.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Cc: Cliff Holden <Cliff.Holden@Atheros.com>
Cc: Kathy Giori <Kathy.Giori@Atheros.com>
Patchwork: https://patchwork.linux-mips.org/patch/1953/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/ath79/dev-leds-gpio.c

@@ -0,0 +1,56 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X common GPIO LEDs support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ *  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/init.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+#include "dev-leds-gpio.h"
+
+void __init ath79_register_leds_gpio(int id,
+				     unsigned num_leds,
+				     struct gpio_led *leds)
+{
+	struct platform_device *pdev;
+	struct gpio_led_platform_data pdata;
+	struct gpio_led *p;
+	int err;
+
+	p = kmalloc(num_leds * sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return;
+
+	memcpy(p, leds, num_leds * sizeof(*p));
+
+	pdev = platform_device_alloc("leds-gpio", id);
+	if (!pdev)
+		goto err_free_leds;
+
+	memset(&pdata, 0, sizeof(pdata));
+	pdata.num_leds = num_leds;
+	pdata.leds = p;
+
+	err = platform_device_add_data(pdev, &pdata, sizeof(pdata));
+	if (err)
+		goto err_put_pdev;
+
+	err = platform_device_add(pdev);
+	if (err)
+		goto err_put_pdev;
+
+	return;
+
+err_put_pdev:
+	platform_device_put(pdev);
+
+err_free_leds:
+	kfree(p);
+}