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 <[e-mail]>
Signed-off-by: Imre Kaloz <[e-mail]>
Cc: [e-mail]
Cc: Luis R. Rodriguez <[e-mail]>
Cc: Cliff Holden <[e-mail]>
Cc: Kathy Giori <[e-mail]>
Patchwork: https://patchwork.linux-mips.org/patch/1954/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/ath79/Kconfig

···
 config ATH79_MACH_PB44
 	bool "Atheros PB44 reference board"
 	select SOC_AR71XX
+	select ATH79_DEV_GPIO_BUTTONS
 	select ATH79_DEV_LEDS_GPIO
 	help
 	  Say 'Y' here if you want your kernel to support the
···
 	def_bool n
 
 config SOC_AR913X
+	def_bool n
+
+config ATH79_DEV_GPIO_BUTTONS
 	def_bool n
 
 config ATH79_DEV_LEDS_GPIO

arch/mips/ath79/Makefile

···
 # Devices
 #
 obj-y					+= dev-common.o
+obj-$(CONFIG_ATH79_DEV_GPIO_BUTTONS)	+= dev-gpio-buttons.o
 obj-$(CONFIG_ATH79_DEV_LEDS_GPIO)	+= dev-leds-gpio.o
 
 #

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

···
+/*
+ *  Atheros AR71XX/AR724X/AR913X GPIO button support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <[e-mail]>
+ *  Copyright (C) 2008 Imre Kaloz <[e-mail]>
+ *
+ *  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);
+}

arch/mips/ath79/dev-gpio-buttons.h

···
+/*
+ *  Atheros AR71XX/AR724X/AR913X GPIO button support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <[e-mail]>
+ *  Copyright (C) 2008 Imre Kaloz <[e-mail]>
+ *
+ *  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.
+ */
+
+#ifndef _ATH79_DEV_GPIO_BUTTONS_H
+#define _ATH79_DEV_GPIO_BUTTONS_H
+
+#include <linux/input.h>
+#include <linux/gpio_keys.h>
+
+void ath79_register_gpio_keys_polled(int id,
+				     unsigned poll_interval,
+				     unsigned nbuttons,
+				     struct gpio_keys_button *buttons);
+
+#endif /* _ATH79_DEV_GPIO_BUTTONS_H */

arch/mips/ath79/mach-pb44.c

···
 #include <linux/i2c/pcf857x.h>
 
 #include "machtypes.h"
+#include "dev-gpio-buttons.h"
 #include "dev-leds-gpio.h"
 
 #define PB44_GPIO_I2C_SCL	0
 #define PB44_GPIO_I2C_SDA	1
 
 #define PB44_GPIO_EXP_BASE	16
+#define PB44_GPIO_SW_RESET	(PB44_GPIO_EXP_BASE + 6)
+#define PB44_GPIO_SW_JUMP	(PB44_GPIO_EXP_BASE + 8)
 #define PB44_GPIO_LED_JUMP1	(PB44_GPIO_EXP_BASE + 9)
 #define PB44_GPIO_LED_JUMP2	(PB44_GPIO_EXP_BASE + 10)
+
+#define PB44_KEYS_POLL_INTERVAL		20	/* msecs */
+#define PB44_KEYS_DEBOUNCE_INTERVAL	(3 * PB44_KEYS_POLL_INTERVAL)
 
 static struct i2c_gpio_platform_data pb44_i2c_gpio_data = {
 	.sda_pin        = PB44_GPIO_I2C_SDA,
···
 	},
 };
 
+static struct gpio_keys_button pb44_gpio_keys[] __initdata = {
+	{
+		.desc		= "soft_reset",
+		.type		= EV_KEY,
+		.code		= KEY_RESTART,
+		.debounce_interval = PB44_KEYS_DEBOUNCE_INTERVAL,
+		.gpio		= PB44_GPIO_SW_RESET,
+		.active_low	= 1,
+	} , {
+		.desc		= "jumpstart",
+		.type		= EV_KEY,
+		.code		= KEY_WPS_BUTTON,
+		.debounce_interval = PB44_KEYS_DEBOUNCE_INTERVAL,
+		.gpio		= PB44_GPIO_SW_JUMP,
+		.active_low	= 1,
+	}
+};
+
 static void __init pb44_init(void)
 {
 	i2c_register_board_info(0, pb44_i2c_board_info,
···
 
 	ath79_register_leds_gpio(-1, ARRAY_SIZE(pb44_leds_gpio),
 				 pb44_leds_gpio);
+	ath79_register_gpio_keys_polled(-1, PB44_KEYS_POLL_INTERVAL,
+					ARRAY_SIZE(pb44_gpio_keys),
+					pb44_gpio_keys);
 }
 
 MIPS_MACHINE(ATH79_MACH_PB44, "PB44", "Atheros PB44 reference board",