[PATCH V4] MIPS: BCM47XX: Prepare support for GPIO buttons

[Rafał Miłecki <zajec5@xxxxxxxxx>]

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@xxxxxxxxx>
Acked-by: Hauke Mehrtens <hauke@xxxxxxxxxx>
---
V3: Use __initconst and copy data for detected device. This will allow
    us to free some memory after init.
V4: Use const for bcm47xx_buttons_netgear_wndr4500_v1
    Rebase on top of linux-john.git mips-next-3.14
---
 arch/mips/bcm47xx/Makefile          |    2 +-
 arch/mips/bcm47xx/bcm47xx_private.h |    3 ++
 arch/mips/bcm47xx/buttons.c         |   95 +++++++++++++++++++++++++++++++++++
 arch/mips/bcm47xx/setup.c           |    1 +
 4 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 arch/mips/bcm47xx/buttons.c

diff --git a/arch/mips/bcm47xx/Makefile b/arch/mips/bcm47xx/Makefile
index 84e9aed..006a05e 100644
--- a/arch/mips/bcm47xx/Makefile
+++ b/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
diff --git a/arch/mips/bcm47xx/bcm47xx_private.h b/arch/mips/bcm47xx/bcm47xx_private.h
index 1a1e600..5c94ace 100644
--- a/arch/mips/bcm47xx/bcm47xx_private.h
+++ b/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);
 
diff --git a/arch/mips/bcm47xx/buttons.c b/arch/mips/bcm47xx/buttons.c
new file mode 100644
index 0000000..d93711b
--- /dev/null
+++ b/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;
+}
diff --git a/arch/mips/bcm47xx/setup.c b/arch/mips/bcm47xx/setup.c
index bd84473..0bd4702 100644
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -265,6 +265,7 @@ static int __init bcm47xx_register_bus_complete(void)
 #endif
 	}
 
+	bcm47xx_buttons_register();
 	bcm47xx_leds_register();
 
 	fixed_phy_add(PHY_POLL, 0, &bcm47xx_fixed_phy_status);
-- 
1.7.10.4