diff options
Diffstat (limited to 'drivers/input/matrix-keymap.c')
| -rw-r--r-- | drivers/input/matrix-keymap.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/input/matrix-keymap.c b/drivers/input/matrix-keymap.c new file mode 100644 index 000000000..4fa53423f --- /dev/null +++ b/drivers/input/matrix-keymap.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Helpers for matrix keyboard bindings + * + * Copyright (C) 2012 Google, Inc + * + * Author: + * Olof Johansson <olof@lixom.net> + */ + +#include <linux/device.h> +#include <linux/export.h> +#include <linux/gfp.h> +#include <linux/input.h> +#include <linux/input/matrix_keypad.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/slab.h> +#include <linux/types.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; +} + +/** + * matrix_keypad_parse_properties() - Read properties of matrix keypad + * + * @dev: Device containing properties + * @rows: Returns number of matrix rows + * @cols: Returns number of matrix columns + * @return 0 if OK, <0 on error + */ +int matrix_keypad_parse_properties(struct device *dev, + unsigned int *rows, unsigned int *cols) +{ + *rows = *cols = 0; + + device_property_read_u32(dev, "keypad,num-rows", rows); + device_property_read_u32(dev, "keypad,num-columns", cols); + + if (!*rows || !*cols) { + dev_err(dev, "number of keypad rows/columns not specified\n"); + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(matrix_keypad_parse_properties); + +static int matrix_keypad_parse_keymap(const char *propname, + unsigned int rows, unsigned int cols, + struct input_dev *input_dev) +{ + struct device *dev = input_dev->dev.parent; + unsigned int row_shift = get_count_order(cols); + unsigned int max_keys = rows << row_shift; + u32 *keys; + int i; + int size; + int retval; + + if (!propname) + propname = "linux,keymap"; + + size = device_property_count_u32(dev, propname); + if (size <= 0) { + dev_err(dev, "missing or malformed property %s: %d\n", + propname, size); + return size < 0 ? size : -EINVAL; + } + + if (size > max_keys) { + dev_err(dev, "%s size overflow (%d vs max %u)\n", + propname, size, max_keys); + return -EINVAL; + } + + keys = kmalloc_array(size, sizeof(u32), GFP_KERNEL); + if (!keys) + return -ENOMEM; + + retval = device_property_read_u32_array(dev, propname, keys, size); + if (retval) { + dev_err(dev, "failed to read %s property: %d\n", + propname, retval); + goto out; + } + + for (i = 0; i < size; i++) { + if (!matrix_keypad_map_key(input_dev, rows, cols, + row_shift, keys[i])) { + retval = -EINVAL; + goto out; + } + } + + retval = 0; + +out: + kfree(keys); + return retval; +} + +/** + * 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_kcalloc(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_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); + +MODULE_LICENSE("GPL"); |