MIPS: BCM47XX: Prepare support for GPIO buttons

So far this adds support for one Netgear model only, but it's designed
and ready to add many more device. We could hopefully import database
from OpenWrt.
Support for SSB is currently disabled, because SSB doesn't implement IRQ
domain yet.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6300/

arch/mips/bcm47xx/Makefile

@@ -4,5 +4,5 @@
 #
 
 obj-y				+= irq.o nvram.o prom.o serial.o setup.o time.o sprom.o
-obj-y				+= board.o leds.o
+obj-y				+= board.o buttons.o leds.o
 obj-$(CONFIG_BCM47XX_SSB)	+= wgt634u.o

arch/mips/bcm47xx/bcm47xx_private.h

@@ -3,6 +3,9 @@
 
 #include <linux/kernel.h>
 
+/* buttons.c */
+int __init bcm47xx_buttons_register(void);
+
 /* leds.c */
 void __init bcm47xx_leds_register(void);
 

arch/mips/bcm47xx/buttons.c

@@ -0,0 +1,95 @@
+#include "bcm47xx_private.h"
+
+#include <linux/input.h>
+#include <linux/gpio_keys.h>
+#include <linux/interrupt.h>
+#include <linux/ssb/ssb_embedded.h>
+#include <bcm47xx_board.h>
+#include <bcm47xx.h>
+
+/**************************************************
+ * Database
+ **************************************************/
+
+static const struct gpio_keys_button
+bcm47xx_buttons_netgear_wndr4500_v1[] __initconst = {
+	{
+		.code		= KEY_WPS_BUTTON,
+		.gpio		= 4,
+		.active_low	= 1,
+	},
+	{
+		.code		= KEY_RFKILL,
+		.gpio		= 5,
+		.active_low	= 1,
+	},
+	{
+		.code		= KEY_RESTART,
+		.gpio		= 6,
+		.active_low	= 1,
+	},
+};
+
+/**************************************************
+ * Init
+ **************************************************/
+
+static struct gpio_keys_platform_data bcm47xx_button_pdata;
+
+static struct platform_device bcm47xx_buttons_gpio_keys = {
+	.name = "gpio-keys",
+	.dev = {
+		.platform_data = &bcm47xx_button_pdata,
+	}
+};
+
+/* Copy data from __initconst */
+static int __init bcm47xx_buttons_copy(const struct gpio_keys_button *buttons,
+				       size_t nbuttons)
+{
+	size_t size = nbuttons * sizeof(*buttons);
+
+	bcm47xx_button_pdata.buttons = kmalloc(size, GFP_KERNEL);
+	if (!bcm47xx_button_pdata.buttons)
+		return -ENOMEM;
+	memcpy(bcm47xx_button_pdata.buttons, buttons, size);
+	bcm47xx_button_pdata.nbuttons = nbuttons;
+
+	return 0;
+}
+
+#define bcm47xx_copy_bdata(dev_buttons)					\
+	bcm47xx_buttons_copy(dev_buttons, ARRAY_SIZE(dev_buttons));
+
+int __init bcm47xx_buttons_register(void)
+{
+	enum bcm47xx_board board = bcm47xx_board_get();
+	int err;
+
+#ifdef CONFIG_BCM47XX_SSB
+	if (bcm47xx_bus_type == BCM47XX_BUS_TYPE_SSB) {
+		pr_debug("Buttons on SSB are not supported yet.\n");
+		return -ENOTSUPP;
+	}
+#endif
+
+	switch (board) {
+	case BCM47XX_BOARD_NETGEAR_WNDR4500V1:
+		err = bcm47xx_copy_bdata(bcm47xx_buttons_netgear_wndr4500_v1);
+		break;
+	default:
+		pr_debug("No buttons configuration found for this device\n");
+		return -ENOTSUPP;
+	}
+
+	if (err)
+		return -ENOMEM;
+
+	err = platform_device_register(&bcm47xx_buttons_gpio_keys);
+	if (err) {
+		pr_err("Failed to register platform device: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}

arch/mips/bcm47xx/setup.c

@@ -255,6 +255,7 @@ static int __init bcm47xx_register_bus_complete(void)
 		break;
 #endif
 	}
+	bcm47xx_buttons_register();
 	bcm47xx_leds_register();
 
 	return 0;