redonkable
/
remarkable-linux
1
0
Fork 0
Code Releases Activity

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>
wifi-calibration
Mika Westerberg 2010-02-04 00:48:00 -08:00 committed by Dmitry Torokhov
parent 3d7bbd4575
commit 9e3af04f87
2 changed files with 308 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

318
drivers/input/keyboard/gpio_keys.c
View File

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

1
include/linux/gpio_keys.h
View File

@ -10,6 +10,7 @@ struct gpio_keys_button {
int type; /* input event type (EV_KEY, EV_SW) */
int wakeup; /* configure the button as a wake-up source */
int debounce_interval; /* debounce ticks interval in msecs */
bool can_disable;
};
struct gpio_keys_platform_data {