linux/drivers/input/matrix-keymap.c
Dmitry Torokhov 5383116b86 Input: marix-keymap - automatically allocate memory for keymap
In device tree enabled setups requiring preallocated memory for storing keymap
is quite often awkward, so let's provide an option of allocating it directly
in matrix_keypad_build_keymap().

Reviewed-by: Alban Bedel <alban.bedel@avionic-design.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2012-11-14 08:35:07 -08:00

184 lines
5.1 KiB
C

/*
* Helpers for 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/device.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/input.h>
#include <linux/of.h>
#include <linux/export.h>
#include <linux/input/matrix_keypad.h>
static bool matrix_keypad_map_key(struct input_dev *input_dev,
unsigned int rows, unsigned int cols,
unsigned int row_shift, unsigned int key)
{
unsigned short *keymap = input_dev->keycode;
unsigned int row = KEY_ROW(key);
unsigned int col = KEY_COL(key);
unsigned short code = KEY_VAL(key);
if (row >= rows || col >= cols) {
dev_err(input_dev->dev.parent,
"%s: invalid keymap entry 0x%x (row: %d, col: %d, rows: %d, cols: %d)\n",
__func__, key, row, col, rows, cols);
return false;
}
keymap[MATRIX_SCAN_CODE(row, col, row_shift)] = code;
__set_bit(code, input_dev->keybit);
return true;
}
#ifdef CONFIG_OF
static int matrix_keypad_parse_of_keymap(const char *propname,
unsigned int rows, unsigned int cols,
struct input_dev *input_dev)
{
struct device *dev = input_dev->dev.parent;
struct device_node *np = dev->of_node;
unsigned int row_shift = get_count_order(cols);
unsigned int max_keys = rows << row_shift;
unsigned int proplen, i, size;
const __be32 *prop;
if (!np)
return -ENOENT;
if (!propname)
propname = "linux,keymap";
prop = of_get_property(np, propname, &proplen);
if (!prop) {
dev_err(dev, "OF: %s property not defined in %s\n",
propname, np->full_name);
return -ENOENT;
}
if (proplen % sizeof(u32)) {
dev_err(dev, "OF: Malformed keycode property %s in %s\n",
propname, np->full_name);
return -EINVAL;
}
size = proplen / sizeof(u32);
if (size > max_keys) {
dev_err(dev, "OF: %s size overflow\n", propname);
return -EINVAL;
}
for (i = 0; i < size; i++) {
unsigned int key = be32_to_cpup(prop + i);
if (!matrix_keypad_map_key(input_dev, rows, cols,
row_shift, key))
return -EINVAL;
}
return 0;
}
#else
static int matrix_keypad_parse_of_keymap(const char *propname,
unsigned int rows, unsigned int cols,
struct input_dev *input_dev)
{
return -ENOSYS;
}
#endif
/**
* matrix_keypad_build_keymap - convert platform keymap into matrix keymap
* @keymap_data: keymap supplied by the platform code
* @keymap_name: name of device tree property containing keymap (if device
* tree support is enabled).
* @rows: number of rows in target keymap array
* @cols: number of cols in target keymap array
* @keymap: expanded version of keymap that is suitable for use by
* matrix keyboard driver
* @input_dev: input devices for which we are setting up the keymap
*
* This function converts platform keymap (encoded with KEY() macro) into
* an array of keycodes that is suitable for using in a standard matrix
* keyboard driver that uses row and col as indices.
*
* If @keymap_data is not supplied and device tree support is enabled
* it will attempt load the keymap from property specified by @keymap_name
* argument (or "linux,keymap" if @keymap_name is %NULL).
*
* If @keymap is %NULL the function will automatically allocate managed
* block of memory to store the keymap. This memory will be associated with
* the parent device and automatically freed when device unbinds from the
* driver.
*
* Callers are expected to set up input_dev->dev.parent before calling this
* function.
*/
int matrix_keypad_build_keymap(const struct matrix_keymap_data *keymap_data,
const char *keymap_name,
unsigned int rows, unsigned int cols,
unsigned short *keymap,
struct input_dev *input_dev)
{
unsigned int row_shift = get_count_order(cols);
size_t max_keys = rows << row_shift;
int i;
int error;
if (WARN_ON(!input_dev->dev.parent))
return -EINVAL;
if (!keymap) {
keymap = devm_kzalloc(input_dev->dev.parent,
max_keys * sizeof(*keymap),
GFP_KERNEL);
if (!keymap) {
dev_err(input_dev->dev.parent,
"Unable to allocate memory for keymap");
return -ENOMEM;
}
}
input_dev->keycode = keymap;
input_dev->keycodesize = sizeof(*keymap);
input_dev->keycodemax = max_keys;
__set_bit(EV_KEY, input_dev->evbit);
if (keymap_data) {
for (i = 0; i < keymap_data->keymap_size; i++) {
unsigned int key = keymap_data->keymap[i];
if (!matrix_keypad_map_key(input_dev, rows, cols,
row_shift, key))
return -EINVAL;
}
} else {
error = matrix_keypad_parse_of_keymap(keymap_name, rows, cols,
input_dev);
if (error)
return error;
}
__clear_bit(KEY_RESERVED, input_dev->keybit);
return 0;
}
EXPORT_SYMBOL(matrix_keypad_build_keymap);