Input: gpio-keys - add support for disabling gpios through sysfs
Now gpio-keys input driver exports 4 new attributes to userland through sysfs: /sys/devices/platform/gpio-keys/keys [ro] /sys/devices/platform/gpio-keys/switches [ro] /sys/devices/platform/gpio-keys/disabled_keys [rw] /sys/devices/platform/gpio-keys/disables_switches [rw] With these attributes, userland program can read which keys and switches can be disabled and then disable/enable them as needed. Keys and switches are exported as stringified bitmap of codes (keycodes or switch codes). For example keys 15, 89, 100, 101, 102 are exported as: '15,89,100-102'. Description of the attributes: keys - bitmap of keys which can be disabled switches - bitmap of switches which can be disabled disabled_keys - bitmap of currently disabled keys (bit 1 means disabled, 0 enabled) disabled_switches - bitmap of currently disabled switches (bit 1 means disabled, 0 enabled) Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
parent
3d7bbd4575
commit
9e3af04f87
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@ -30,13 +30,289 @@ struct gpio_button_data {
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struct input_dev *input;
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struct input_dev *input;
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struct timer_list timer;
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struct timer_list timer;
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struct work_struct work;
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struct work_struct work;
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bool disabled;
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};
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};
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struct gpio_keys_drvdata {
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struct gpio_keys_drvdata {
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struct input_dev *input;
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struct input_dev *input;
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struct mutex disable_lock;
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unsigned int n_buttons;
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struct gpio_button_data data[0];
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struct gpio_button_data data[0];
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};
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};
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/*
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* SYSFS interface for enabling/disabling keys and switches:
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*
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* There are 4 attributes under /sys/devices/platform/gpio-keys/
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* keys [ro] - bitmap of keys (EV_KEY) which can be
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* disabled
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* switches [ro] - bitmap of switches (EV_SW) which can be
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* disabled
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* disabled_keys [rw] - bitmap of keys currently disabled
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* disabled_switches [rw] - bitmap of switches currently disabled
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*
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* Userland can change these values and hence disable event generation
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* for each key (or switch). Disabling a key means its interrupt line
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* is disabled.
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*
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* For example, if we have following switches set up as gpio-keys:
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* SW_DOCK = 5
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* SW_CAMERA_LENS_COVER = 9
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* SW_KEYPAD_SLIDE = 10
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* SW_FRONT_PROXIMITY = 11
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* This is read from switches:
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* 11-9,5
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* Next we want to disable proximity (11) and dock (5), we write:
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* 11,5
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* to file disabled_switches. Now proximity and dock IRQs are disabled.
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* This can be verified by reading the file disabled_switches:
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* 11,5
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* If we now want to enable proximity (11) switch we write:
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* 5
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* to disabled_switches.
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*
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* We can disable only those keys which don't allow sharing the irq.
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*/
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/**
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* get_n_events_by_type() - returns maximum number of events per @type
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* @type: type of button (%EV_KEY, %EV_SW)
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*
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* Return value of this function can be used to allocate bitmap
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* large enough to hold all bits for given type.
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*/
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static inline int get_n_events_by_type(int type)
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{
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BUG_ON(type != EV_SW && type != EV_KEY);
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return (type == EV_KEY) ? KEY_CNT : SW_CNT;
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}
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/**
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* gpio_keys_disable_button() - disables given GPIO button
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* @bdata: button data for button to be disabled
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*
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* Disables button pointed by @bdata. This is done by masking
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* IRQ line. After this function is called, button won't generate
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* input events anymore. Note that one can only disable buttons
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* that don't share IRQs.
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*
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* Make sure that @bdata->disable_lock is locked when entering
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* this function to avoid races when concurrent threads are
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* disabling buttons at the same time.
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*/
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static void gpio_keys_disable_button(struct gpio_button_data *bdata)
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{
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if (!bdata->disabled) {
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/*
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* Disable IRQ and possible debouncing timer.
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*/
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disable_irq(gpio_to_irq(bdata->button->gpio));
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if (bdata->button->debounce_interval)
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del_timer_sync(&bdata->timer);
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bdata->disabled = true;
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}
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}
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/**
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* gpio_keys_enable_button() - enables given GPIO button
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* @bdata: button data for button to be disabled
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*
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* Enables given button pointed by @bdata.
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*
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* Make sure that @bdata->disable_lock is locked when entering
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* this function to avoid races with concurrent threads trying
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* to enable the same button at the same time.
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*/
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static void gpio_keys_enable_button(struct gpio_button_data *bdata)
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{
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if (bdata->disabled) {
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enable_irq(gpio_to_irq(bdata->button->gpio));
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bdata->disabled = false;
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}
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}
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/**
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* gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
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* @ddata: pointer to drvdata
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* @buf: buffer where stringified bitmap is written
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* @type: button type (%EV_KEY, %EV_SW)
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* @only_disabled: does caller want only those buttons that are
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* currently disabled or all buttons that can be
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* disabled
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*
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* This function writes buttons that can be disabled to @buf. If
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* @only_disabled is true, then @buf contains only those buttons
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* that are currently disabled. Returns 0 on success or negative
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* errno on failure.
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*/
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static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
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char *buf, unsigned int type,
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bool only_disabled)
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{
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int n_events = get_n_events_by_type(type);
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unsigned long *bits;
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ssize_t ret;
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int i;
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bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
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if (!bits)
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return -ENOMEM;
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for (i = 0; i < ddata->n_buttons; i++) {
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struct gpio_button_data *bdata = &ddata->data[i];
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if (bdata->button->type != type)
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continue;
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if (only_disabled && !bdata->disabled)
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continue;
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__set_bit(bdata->button->code, bits);
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}
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ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
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buf[ret++] = '\n';
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buf[ret] = '\0';
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kfree(bits);
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return ret;
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}
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/**
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* gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
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* @ddata: pointer to drvdata
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* @buf: buffer from userspace that contains stringified bitmap
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* @type: button type (%EV_KEY, %EV_SW)
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*
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* This function parses stringified bitmap from @buf and disables/enables
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* GPIO buttons accordinly. Returns 0 on success and negative error
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* on failure.
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*/
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static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
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const char *buf, unsigned int type)
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{
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int n_events = get_n_events_by_type(type);
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unsigned long *bits;
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ssize_t error;
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int i;
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bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
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if (!bits)
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return -ENOMEM;
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error = bitmap_parselist(buf, bits, n_events);
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if (error)
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goto out;
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/* First validate */
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for (i = 0; i < ddata->n_buttons; i++) {
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struct gpio_button_data *bdata = &ddata->data[i];
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if (bdata->button->type != type)
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continue;
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if (test_bit(bdata->button->code, bits) &&
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!bdata->button->can_disable) {
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error = -EINVAL;
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goto out;
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}
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}
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mutex_lock(&ddata->disable_lock);
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for (i = 0; i < ddata->n_buttons; i++) {
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struct gpio_button_data *bdata = &ddata->data[i];
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if (bdata->button->type != type)
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continue;
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if (test_bit(bdata->button->code, bits))
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gpio_keys_disable_button(bdata);
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else
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gpio_keys_enable_button(bdata);
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}
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mutex_unlock(&ddata->disable_lock);
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out:
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kfree(bits);
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return error;
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}
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#define ATTR_SHOW_FN(name, type, only_disabled) \
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static ssize_t gpio_keys_show_##name(struct device *dev, \
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struct device_attribute *attr, \
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char *buf) \
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{ \
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struct platform_device *pdev = to_platform_device(dev); \
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struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
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\
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return gpio_keys_attr_show_helper(ddata, buf, \
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type, only_disabled); \
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}
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ATTR_SHOW_FN(keys, EV_KEY, false);
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ATTR_SHOW_FN(switches, EV_SW, false);
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ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
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ATTR_SHOW_FN(disabled_switches, EV_SW, true);
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/*
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* ATTRIBUTES:
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*
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* /sys/devices/platform/gpio-keys/keys [ro]
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* /sys/devices/platform/gpio-keys/switches [ro]
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*/
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static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
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static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
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#define ATTR_STORE_FN(name, type) \
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static ssize_t gpio_keys_store_##name(struct device *dev, \
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struct device_attribute *attr, \
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const char *buf, \
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size_t count) \
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{ \
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struct platform_device *pdev = to_platform_device(dev); \
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struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
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ssize_t error; \
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\
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error = gpio_keys_attr_store_helper(ddata, buf, type); \
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if (error) \
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return error; \
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\
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return count; \
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}
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ATTR_STORE_FN(disabled_keys, EV_KEY);
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ATTR_STORE_FN(disabled_switches, EV_SW);
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/*
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* ATTRIBUTES:
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*
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* /sys/devices/platform/gpio-keys/disabled_keys [rw]
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* /sys/devices/platform/gpio-keys/disables_switches [rw]
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*/
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static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
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gpio_keys_show_disabled_keys,
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gpio_keys_store_disabled_keys);
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static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
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gpio_keys_show_disabled_switches,
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gpio_keys_store_disabled_switches);
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static struct attribute *gpio_keys_attrs[] = {
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&dev_attr_keys.attr,
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&dev_attr_switches.attr,
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&dev_attr_disabled_keys.attr,
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&dev_attr_disabled_switches.attr,
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NULL,
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};
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static struct attribute_group gpio_keys_attr_group = {
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.attrs = gpio_keys_attrs,
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};
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static void gpio_keys_report_event(struct gpio_button_data *bdata)
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static void gpio_keys_report_event(struct gpio_button_data *bdata)
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{
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{
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struct gpio_keys_button *button = bdata->button;
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struct gpio_keys_button *button = bdata->button;
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@ -79,11 +355,13 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
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return IRQ_HANDLED;
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return IRQ_HANDLED;
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}
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}
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static int __devinit gpio_keys_setup_key(struct device *dev,
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static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
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struct gpio_button_data *bdata,
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struct gpio_button_data *bdata,
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struct gpio_keys_button *button)
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struct gpio_keys_button *button)
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{
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{
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char *desc = button->desc ? button->desc : "gpio_keys";
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char *desc = button->desc ? button->desc : "gpio_keys";
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struct device *dev = &pdev->dev;
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unsigned long irqflags;
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int irq, error;
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int irq, error;
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setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
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setup_timer(&bdata->timer, gpio_keys_timer, (unsigned long)bdata);
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@ -112,10 +390,15 @@ static int __devinit gpio_keys_setup_key(struct device *dev,
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goto fail3;
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goto fail3;
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}
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}
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error = request_irq(irq, gpio_keys_isr,
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irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
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IRQF_SHARED |
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/*
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IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
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* If platform has specified that the button can be disabled,
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desc, bdata);
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* we don't want it to share the interrupt line.
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*/
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if (!button->can_disable)
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irqflags |= IRQF_SHARED;
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error = request_irq(irq, gpio_keys_isr, irqflags, desc, bdata);
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if (error) {
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if (error) {
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dev_err(dev, "Unable to claim irq %d; error %d\n",
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dev_err(dev, "Unable to claim irq %d; error %d\n",
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irq, error);
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irq, error);
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@ -149,6 +432,10 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
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goto fail1;
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goto fail1;
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}
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}
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ddata->input = input;
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ddata->n_buttons = pdata->nbuttons;
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mutex_init(&ddata->disable_lock);
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platform_set_drvdata(pdev, ddata);
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platform_set_drvdata(pdev, ddata);
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input->name = pdev->name;
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input->name = pdev->name;
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@ -164,8 +451,6 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
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if (pdata->rep)
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if (pdata->rep)
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__set_bit(EV_REP, input->evbit);
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__set_bit(EV_REP, input->evbit);
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ddata->input = input;
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for (i = 0; i < pdata->nbuttons; i++) {
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for (i = 0; i < pdata->nbuttons; i++) {
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struct gpio_keys_button *button = &pdata->buttons[i];
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struct gpio_keys_button *button = &pdata->buttons[i];
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struct gpio_button_data *bdata = &ddata->data[i];
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struct gpio_button_data *bdata = &ddata->data[i];
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@ -174,7 +459,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
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bdata->input = input;
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bdata->input = input;
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bdata->button = button;
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bdata->button = button;
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error = gpio_keys_setup_key(dev, bdata, button);
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error = gpio_keys_setup_key(pdev, bdata, button);
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if (error)
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if (error)
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goto fail2;
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goto fail2;
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||||||
|
@ -184,11 +469,18 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
|
||||||
input_set_capability(input, type, button->code);
|
input_set_capability(input, type, button->code);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
|
||||||
|
if (error) {
|
||||||
|
dev_err(dev, "Unable to export keys/switches, error: %d\n",
|
||||||
|
error);
|
||||||
|
goto fail2;
|
||||||
|
}
|
||||||
|
|
||||||
error = input_register_device(input);
|
error = input_register_device(input);
|
||||||
if (error) {
|
if (error) {
|
||||||
dev_err(dev, "Unable to register input device, "
|
dev_err(dev, "Unable to register input device, error: %d\n",
|
||||||
"error: %d\n", error);
|
error);
|
||||||
goto fail2;
|
goto fail3;
|
||||||
}
|
}
|
||||||
|
|
||||||
/* get current state of buttons */
|
/* get current state of buttons */
|
||||||
|
@ -200,6 +492,8 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
|
||||||
|
|
||||||
return 0;
|
return 0;
|
||||||
|
|
||||||
|
fail3:
|
||||||
|
sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
|
||||||
fail2:
|
fail2:
|
||||||
while (--i >= 0) {
|
while (--i >= 0) {
|
||||||
free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
|
free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
|
||||||
|
@ -224,6 +518,8 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
|
||||||
struct input_dev *input = ddata->input;
|
struct input_dev *input = ddata->input;
|
||||||
int i;
|
int i;
|
||||||
|
|
||||||
|
sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
|
||||||
|
|
||||||
device_init_wakeup(&pdev->dev, 0);
|
device_init_wakeup(&pdev->dev, 0);
|
||||||
|
|
||||||
for (i = 0; i < pdata->nbuttons; i++) {
|
for (i = 0; i < pdata->nbuttons; i++) {
|
||||||
|
|
|
@ -10,6 +10,7 @@ struct gpio_keys_button {
|
||||||
int type; /* input event type (EV_KEY, EV_SW) */
|
int type; /* input event type (EV_KEY, EV_SW) */
|
||||||
int wakeup; /* configure the button as a wake-up source */
|
int wakeup; /* configure the button as a wake-up source */
|
||||||
int debounce_interval; /* debounce ticks interval in msecs */
|
int debounce_interval; /* debounce ticks interval in msecs */
|
||||||
|
bool can_disable;
|
||||||
};
|
};
|
||||||
|
|
||||||
struct gpio_keys_platform_data {
|
struct gpio_keys_platform_data {
|
||||||
|
|
Loading…
Reference in New Issue