MIPS: ath79: add common GPIO buttons device

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

The patch also adds support for the buttons 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/1954/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/arch/mips/ath79/dev-gpio-buttons.c b/arch/mips/ath79/dev-gpio-buttons.c
new file mode 100644
index 000000000000..4b0168a11c01
--- /dev/null
+++ b/arch/mips/ath79/dev-gpio-buttons.c
@@ -0,0 +1,58 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X GPIO button 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-gpio-buttons.h"
+
+void __init ath79_register_gpio_keys_polled(int id,
+                                            unsigned poll_interval,
+                                            unsigned nbuttons,
+                                            struct gpio_keys_button *buttons)
+{
+        struct platform_device *pdev;
+        struct gpio_keys_platform_data pdata;
+        struct gpio_keys_button *p;
+        int err;
+
+        p = kmalloc(nbuttons * sizeof(*p), GFP_KERNEL);
+        if (!p)
+                return;
+
+        memcpy(p, buttons, nbuttons * sizeof(*p));
+
+        pdev = platform_device_alloc("gpio-keys-polled", id);
+        if (!pdev)
+                goto err_free_buttons;
+
+        memset(&pdata, 0, sizeof(pdata));
+        pdata.poll_interval = poll_interval;
+        pdata.nbuttons = nbuttons;
+        pdata.buttons = 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_buttons:
+        kfree(p);
+}