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-rw-r--r--drivers/input/matrix-keymap.c202
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");