linux/drivers/input/of_keymap.c
Olof Johansson 2cd36877ad Input: of_keymap - add device tree bindings for simple key matrices
This adds a simple device tree binding for simple key matrix data and
a helper to fill in the platform data.

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2012-03-13 21:37:04 -07:00

88 lines
1.9 KiB
C

/*
* Helpers for open firmware matrix keyboard bindings
*
* Copyright (C) 2012 Google, Inc
*
* Author:
* Olof Johansson <olof@lixom.net>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/input.h>
#include <linux/of.h>
#include <linux/input/matrix_keypad.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <linux/slab.h>
struct matrix_keymap_data *
matrix_keyboard_of_fill_keymap(struct device_node *np,
const char *propname)
{
struct matrix_keymap_data *kd;
u32 *keymap;
int proplen, i;
const __be32 *prop;
if (!np)
return NULL;
if (!propname)
propname = "linux,keymap";
prop = of_get_property(np, propname, &proplen);
if (!prop)
return NULL;
if (proplen % sizeof(u32)) {
pr_warn("Malformed keymap property %s in %s\n",
propname, np->full_name);
return NULL;
}
kd = kzalloc(sizeof(*kd), GFP_KERNEL);
if (!kd)
return NULL;
kd->keymap = keymap = kzalloc(proplen, GFP_KERNEL);
if (!kd->keymap) {
kfree(kd);
return NULL;
}
kd->keymap_size = proplen / sizeof(u32);
for (i = 0; i < kd->keymap_size; i++) {
u32 tmp = be32_to_cpup(prop + i);
int key_code, row, col;
row = (tmp >> 24) & 0xff;
col = (tmp >> 16) & 0xff;
key_code = tmp & 0xffff;
keymap[i] = KEY(row, col, key_code);
}
return kd;
}
EXPORT_SYMBOL_GPL(matrix_keyboard_of_fill_keymap);
void matrix_keyboard_of_free_keymap(const struct matrix_keymap_data *kd)
{
if (kd) {
kfree(kd->keymap);
kfree(kd);
}
}
EXPORT_SYMBOL_GPL(matrix_keyboard_of_free_keymap);