drivers/input/keyboard/ipaq-micro-keys.c

Source file repositories/reference/linux-study-clean/drivers/input/keyboard/ipaq-micro-keys.c

File Facts

System
Linux kernel
Corpus path
drivers/input/keyboard/ipaq-micro-keys.c
Extension
.c
Size
3959 bytes
Lines
166
Domain
Driver Families
Bucket
drivers/input
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct ipaq_micro_keys {
	struct ipaq_micro *micro;
	struct input_dev *input;
	u16 *codes;
};

static const u16 micro_keycodes[] = {
	KEY_RECORD,		/* 1:  Record button			*/
	KEY_CALENDAR,		/* 2:  Calendar				*/
	KEY_ADDRESSBOOK,	/* 3:  Contacts (looks like Outlook)	*/
	KEY_MAIL,		/* 4:  Envelope (Q on older iPAQs)	*/
	KEY_HOMEPAGE,		/* 5:  Start (looks like swoopy arrow)	*/
	KEY_UP,			/* 6:  Up				*/
	KEY_RIGHT,		/* 7:  Right				*/
	KEY_LEFT,		/* 8:  Left				*/
	KEY_DOWN,		/* 9:  Down				*/
};

static void micro_key_receive(void *data, int len, unsigned char *msg)
{
	struct ipaq_micro_keys *keys = data;
	int key, down;

	down = 0x80 & msg[0];
	key  = 0x7f & msg[0];

	if (key < ARRAY_SIZE(micro_keycodes)) {
		input_report_key(keys->input, keys->codes[key], down);
		input_sync(keys->input);
	}
}

static void micro_key_start(struct ipaq_micro_keys *keys)
{
	guard(spinlock)(&keys->micro->lock);

	keys->micro->key = micro_key_receive;
	keys->micro->key_data = keys;
}

static void micro_key_stop(struct ipaq_micro_keys *keys)
{
	guard(spinlock)(&keys->micro->lock);

	keys->micro->key = NULL;
	keys->micro->key_data = NULL;
}

static int micro_key_open(struct input_dev *input)
{
	struct ipaq_micro_keys *keys = input_get_drvdata(input);

	micro_key_start(keys);

	return 0;
}

static void micro_key_close(struct input_dev *input)
{
	struct ipaq_micro_keys *keys = input_get_drvdata(input);

	micro_key_stop(keys);
}

static int micro_key_probe(struct platform_device *pdev)
{
	struct ipaq_micro_keys *keys;
	int error;
	int i;

	keys = devm_kzalloc(&pdev->dev, sizeof(*keys), GFP_KERNEL);
	if (!keys)
		return -ENOMEM;

	keys->micro = dev_get_drvdata(pdev->dev.parent);

	keys->input = devm_input_allocate_device(&pdev->dev);
	if (!keys->input)
		return -ENOMEM;

	keys->input->keycodesize = sizeof(micro_keycodes[0]);
	keys->input->keycodemax = ARRAY_SIZE(micro_keycodes);
	keys->codes = devm_kmemdup_array(&pdev->dev, micro_keycodes, keys->input->keycodemax,
					 keys->input->keycodesize, GFP_KERNEL);
	if (!keys->codes)
		return -ENOMEM;

	keys->input->keycode = keys->codes;

	__set_bit(EV_KEY, keys->input->evbit);

Annotation

Implementation Notes