diff options
Diffstat (limited to 'drivers/media/IR/ir-keytable.c')
| -rw-r--r-- | drivers/media/IR/ir-keytable.c | 485 |
1 files changed, 485 insertions, 0 deletions
diff --git a/drivers/media/IR/ir-keytable.c b/drivers/media/IR/ir-keytable.c new file mode 100644 index 000000000000..b521ed9d6e2e --- /dev/null +++ b/drivers/media/IR/ir-keytable.c @@ -0,0 +1,485 @@ +/* ir-register.c - handle IR scancode->keycode tables + * + * Copyright (C) 2009 by Mauro Carvalho Chehab <mchehab@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation version 2 of the License. + * + * 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/input.h> +#include <media/ir-common.h> + +#define IR_TAB_MIN_SIZE 32 +#define IR_TAB_MAX_SIZE 1024 + +/** + * ir_seek_table() - returns the element order on the table + * @rc_tab: the ir_scancode_table with the keymap to be used + * @scancode: the scancode that we're seeking + * + * This routine is used by the input routines when a key is pressed at the + * IR. The scancode is received and needs to be converted into a keycode. + * If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the + * corresponding keycode from the table. + */ +static int ir_seek_table(struct ir_scancode_table *rc_tab, u32 scancode) +{ + int rc; + unsigned long flags; + struct ir_scancode *keymap = rc_tab->scan; + + spin_lock_irqsave(&rc_tab->lock, flags); + + /* FIXME: replace it by a binary search */ + + for (rc = 0; rc < rc_tab->size; rc++) + if (keymap[rc].scancode == scancode) + goto exit; + + /* Not found */ + rc = -EINVAL; + +exit: + spin_unlock_irqrestore(&rc_tab->lock, flags); + return rc; +} + +/** + * ir_roundup_tablesize() - gets an optimum value for the table size + * @n_elems: minimum number of entries to store keycodes + * + * This routine is used to choose the keycode table size. + * + * In order to have some empty space for new keycodes, + * and knowing in advance that kmalloc allocates only power of two + * segments, it optimizes the allocated space to have some spare space + * for those new keycodes by using the maximum number of entries that + * will be effectively be allocated by kmalloc. + * In order to reduce the quantity of table resizes, it has a minimum + * table size of IR_TAB_MIN_SIZE. + */ +int ir_roundup_tablesize(int n_elems) +{ + size_t size; + + if (n_elems < IR_TAB_MIN_SIZE) + n_elems = IR_TAB_MIN_SIZE; + + /* + * As kmalloc only allocates sizes of power of two, get as + * much entries as possible for the allocated memory segment + */ + size = roundup_pow_of_two(n_elems * sizeof(struct ir_scancode)); + n_elems = size / sizeof(struct ir_scancode); + + return n_elems; +} +EXPORT_SYMBOL_GPL(ir_roundup_tablesize); + +/** + * ir_copy_table() - copies a keytable, discarding the unused entries + * @destin: destin table + * @origin: origin table + * + * Copies all entries where the keycode is not KEY_UNKNOWN/KEY_RESERVED + */ + +int ir_copy_table(struct ir_scancode_table *destin, + const struct ir_scancode_table *origin) +{ + int i, j = 0; + + for (i = 0; i < origin->size; i++) { + if (origin->scan[i].keycode == KEY_UNKNOWN || + origin->scan[i].keycode == KEY_RESERVED) + continue; + + memcpy(&destin->scan[j], &origin->scan[i], sizeof(struct ir_scancode)); + j++; + } + destin->size = j; + + IR_dprintk(1, "Copied %d scancodes to the new keycode table\n", destin->size); + + return 0; +} +EXPORT_SYMBOL_GPL(ir_copy_table); + +/** + * ir_getkeycode() - get a keycode at the evdev scancode ->keycode table + * @dev: the struct input_dev device descriptor + * @scancode: the desired scancode + * @keycode: the keycode to be retorned. + * + * This routine is used to handle evdev EVIOCGKEY ioctl. + * If the key is not found, returns -EINVAL, otherwise, returns 0. + */ +static int ir_getkeycode(struct input_dev *dev, + int scancode, int *keycode) +{ + int elem; + struct ir_input_dev *ir_dev = input_get_drvdata(dev); + struct ir_scancode_table *rc_tab = &ir_dev->rc_tab; + + elem = ir_seek_table(rc_tab, scancode); + if (elem >= 0) { + *keycode = rc_tab->scan[elem].keycode; + return 0; + } + + /* + * Scancode not found and table can't be expanded + */ + if (elem < 0 && rc_tab->size == IR_TAB_MAX_SIZE) + return -EINVAL; + + /* + * If is there extra space, returns KEY_RESERVED, + * otherwise, input core won't let ir_setkeycode to work + */ + *keycode = KEY_RESERVED; + return 0; +} + +/** + * ir_is_resize_needed() - Check if the table needs rezise + * @table: keycode table that may need to resize + * @n_elems: minimum number of entries to store keycodes + * + * Considering that kmalloc uses power of two storage areas, this + * routine detects if the real alloced size will change. If not, it + * just returns without doing nothing. Otherwise, it will extend or + * reduce the table size to meet the new needs. + * + * It returns 0 if no resize is needed, 1 otherwise. + */ +static int ir_is_resize_needed(struct ir_scancode_table *table, int n_elems) +{ + int cur_size = ir_roundup_tablesize(table->size); + int new_size = ir_roundup_tablesize(n_elems); + + if (cur_size == new_size) + return 0; + + /* Resize is needed */ + return 1; +} + +/** + * ir_delete_key() - remove a keycode from the table + * @rc_tab: keycode table + * @elem: element to be removed + * + */ +static void ir_delete_key(struct ir_scancode_table *rc_tab, int elem) +{ + unsigned long flags = 0; + int newsize = rc_tab->size - 1; + int resize = ir_is_resize_needed(rc_tab, newsize); + struct ir_scancode *oldkeymap = rc_tab->scan; + struct ir_scancode *newkeymap; + + if (resize) { + newkeymap = kzalloc(ir_roundup_tablesize(newsize) * + sizeof(*newkeymap), GFP_ATOMIC); + + /* There's no memory for resize. Keep the old table */ + if (!newkeymap) + resize = 0; + } + + if (!resize) { + newkeymap = oldkeymap; + + /* We'll modify the live table. Lock it */ + spin_lock_irqsave(&rc_tab->lock, flags); + } + + /* + * Copy the elements before the one that will be deleted + * if (!resize), both oldkeymap and newkeymap points + * to the same place, so, there's no need to copy + */ + if (resize && elem > 0) + memcpy(newkeymap, oldkeymap, + elem * sizeof(*newkeymap)); + + /* + * Copy the other elements overwriting the element to be removed + * This operation applies to both resize and non-resize case + */ + if (elem < newsize) + memcpy(&newkeymap[elem], &oldkeymap[elem + 1], + (newsize - elem) * sizeof(*newkeymap)); + + if (resize) { + /* + * As the copy happened to a temporary table, only here + * it needs to lock while replacing the table pointers + * to use the new table + */ + spin_lock_irqsave(&rc_tab->lock, flags); + rc_tab->size = newsize; + rc_tab->scan = newkeymap; + spin_unlock_irqrestore(&rc_tab->lock, flags); + + /* Frees the old keytable */ + kfree(oldkeymap); + } else { + rc_tab->size = newsize; + spin_unlock_irqrestore(&rc_tab->lock, flags); + } +} + +/** + * ir_insert_key() - insert a keycode at the table + * @rc_tab: keycode table + * @scancode: the desired scancode + * @keycode: the keycode to be retorned. + * + */ +static int ir_insert_key(struct ir_scancode_table *rc_tab, + int scancode, int keycode) +{ + unsigned long flags; + int elem = rc_tab->size; + int newsize = rc_tab->size + 1; + int resize = ir_is_resize_needed(rc_tab, newsize); + struct ir_scancode *oldkeymap = rc_tab->scan; + struct ir_scancode *newkeymap; + + if (resize) { + newkeymap = kzalloc(ir_roundup_tablesize(newsize) * + sizeof(*newkeymap), GFP_ATOMIC); + if (!newkeymap) + return -ENOMEM; + + memcpy(newkeymap, oldkeymap, + rc_tab->size * sizeof(*newkeymap)); + } else + newkeymap = oldkeymap; + + /* Stores the new code at the table */ + IR_dprintk(1, "#%d: New scan 0x%04x with key 0x%04x\n", + rc_tab->size, scancode, keycode); + + spin_lock_irqsave(&rc_tab->lock, flags); + rc_tab->size = newsize; + if (resize) { + rc_tab->scan = newkeymap; + kfree(oldkeymap); + } + newkeymap[elem].scancode = scancode; + newkeymap[elem].keycode = keycode; + spin_unlock_irqrestore(&rc_tab->lock, flags); + + return 0; +} + +/** + * ir_setkeycode() - set a keycode at the evdev scancode ->keycode table + * @dev: the struct input_dev device descriptor + * @scancode: the desired scancode + * @keycode: the keycode to be retorned. + * + * This routine is used to handle evdev EVIOCSKEY ioctl. + * There's one caveat here: how can we increase the size of the table? + * If the key is not found, returns -EINVAL, otherwise, returns 0. + */ +static int ir_setkeycode(struct input_dev *dev, + int scancode, int keycode) +{ + int rc = 0; + struct ir_input_dev *ir_dev = input_get_drvdata(dev); + struct ir_scancode_table *rc_tab = &ir_dev->rc_tab; + struct ir_scancode *keymap = rc_tab->scan; + unsigned long flags; + + /* + * Handle keycode table deletions + * + * If userspace is adding a KEY_UNKNOWN or KEY_RESERVED, + * deal as a trial to remove an existing scancode attribution + * if table become too big, reduce it to save space + */ + if (keycode == KEY_UNKNOWN || keycode == KEY_RESERVED) { + rc = ir_seek_table(rc_tab, scancode); + if (rc < 0) + return 0; + + IR_dprintk(1, "#%d: Deleting scan 0x%04x\n", rc, scancode); + clear_bit(keymap[rc].keycode, dev->keybit); + ir_delete_key(rc_tab, rc); + + return 0; + } + + /* + * Handle keycode replacements + * + * If the scancode exists, just replace by the new value + */ + rc = ir_seek_table(rc_tab, scancode); + if (rc >= 0) { + IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n", + rc, scancode, keycode); + + clear_bit(keymap[rc].keycode, dev->keybit); + + spin_lock_irqsave(&rc_tab->lock, flags); + keymap[rc].keycode = keycode; + spin_unlock_irqrestore(&rc_tab->lock, flags); + + set_bit(keycode, dev->keybit); + + return 0; + } + + /* + * Handle new scancode inserts + * + * reallocate table if needed and insert a new keycode + */ + + /* Avoid growing the table indefinitely */ + if (rc_tab->size + 1 > IR_TAB_MAX_SIZE) + return -EINVAL; + + rc = ir_insert_key(rc_tab, scancode, keycode); + if (rc < 0) + return rc; + set_bit(keycode, dev->keybit); + + return 0; +} + +/** + * ir_g_keycode_from_table() - gets the keycode that corresponds to a scancode + * @input_dev: the struct input_dev descriptor of the device + * @scancode: the scancode that we're seeking + * + * This routine is used by the input routines when a key is pressed at the + * IR. The scancode is received and needs to be converted into a keycode. + * If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the + * corresponding keycode from the table. + */ +u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode) +{ + struct ir_input_dev *ir_dev = input_get_drvdata(dev); + struct ir_scancode_table *rc_tab = &ir_dev->rc_tab; + struct ir_scancode *keymap = rc_tab->scan; + int elem; + + elem = ir_seek_table(rc_tab, scancode); + if (elem >= 0) { + IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n", + dev->name, scancode, keymap[elem].keycode); + + return rc_tab->scan[elem].keycode; + } + + printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n", + dev->name, scancode); + + /* Reports userspace that an unknown keycode were got */ + return KEY_RESERVED; +} +EXPORT_SYMBOL_GPL(ir_g_keycode_from_table); + +/** + * ir_input_register() - sets the IR keycode table and add the handlers + * for keymap table get/set + * @input_dev: the struct input_dev descriptor of the device + * @rc_tab: the struct ir_scancode_table table of scancode/keymap + * + * This routine is used to initialize the input infrastructure to work with + * an IR. + * It should be called before registering the IR device. + */ +int ir_input_register(struct input_dev *input_dev, + struct ir_scancode_table *rc_tab) +{ + struct ir_input_dev *ir_dev; + struct ir_scancode *keymap = rc_tab->scan; + int i, rc; + + if (rc_tab->scan == NULL || !rc_tab->size) + return -EINVAL; + + ir_dev = kzalloc(sizeof(*ir_dev), GFP_KERNEL); + if (!ir_dev) + return -ENOMEM; + + spin_lock_init(&rc_tab->lock); + + ir_dev->rc_tab.size = ir_roundup_tablesize(rc_tab->size); + ir_dev->rc_tab.scan = kzalloc(ir_dev->rc_tab.size * + sizeof(struct ir_scancode), GFP_KERNEL); + if (!ir_dev->rc_tab.scan) + return -ENOMEM; + + IR_dprintk(1, "Allocated space for %d keycode entries (%zd bytes)\n", + ir_dev->rc_tab.size, + ir_dev->rc_tab.size * sizeof(ir_dev->rc_tab.scan)); + + ir_copy_table(&ir_dev->rc_tab, rc_tab); + + /* set the bits for the keys */ + IR_dprintk(1, "key map size: %d\n", rc_tab->size); + for (i = 0; i < rc_tab->size; i++) { + IR_dprintk(1, "#%d: setting bit for keycode 0x%04x\n", + i, keymap[i].keycode); + set_bit(keymap[i].keycode, input_dev->keybit); + } + clear_bit(0, input_dev->keybit); + + set_bit(EV_KEY, input_dev->evbit); + + input_dev->getkeycode = ir_getkeycode; + input_dev->setkeycode = ir_setkeycode; + input_set_drvdata(input_dev, ir_dev); + + rc = input_register_device(input_dev); + if (rc < 0) { + kfree(rc_tab->scan); + kfree(ir_dev); + input_set_drvdata(input_dev, NULL); + } + + return rc; +} +EXPORT_SYMBOL_GPL(ir_input_register); + +void ir_input_unregister(struct input_dev *dev) +{ + struct ir_input_dev *ir_dev = input_get_drvdata(dev); + struct ir_scancode_table *rc_tab; + + if (!ir_dev) + return; + + IR_dprintk(1, "Freed keycode table\n"); + + rc_tab = &ir_dev->rc_tab; + rc_tab->size = 0; + kfree(rc_tab->scan); + rc_tab->scan = NULL; + + kfree(ir_dev); + input_unregister_device(dev); +} +EXPORT_SYMBOL_GPL(ir_input_unregister); + +int ir_core_debug; /* ir_debug level (0,1,2) */ +EXPORT_SYMBOL_GPL(ir_core_debug); +module_param_named(debug, ir_core_debug, int, 0644); + +MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); +MODULE_LICENSE("GPL"); |