drivers/input/keyboard/imx_sc_key.c

Source file repositories/reference/linux-study-clean/drivers/input/keyboard/imx_sc_key.c

File Facts

System
Linux kernel
Corpus path
drivers/input/keyboard/imx_sc_key.c
Extension
.c
Size
4711 bytes
Lines
191
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 imx_key_drv_data {
	u32 keycode;
	bool keystate;  /* true: pressed, false: released */
	struct delayed_work check_work;
	struct input_dev *input;
	struct imx_sc_ipc *key_ipc_handle;
	struct notifier_block key_notifier;
};

struct imx_sc_msg_key {
	struct imx_sc_rpc_msg hdr;
	u32 state;
};

static int imx_sc_key_notify(struct notifier_block *nb,
			     unsigned long event, void *group)
{
	struct imx_key_drv_data *priv =
				 container_of(nb,
					      struct imx_key_drv_data,
					      key_notifier);

	if ((event & SC_IRQ_BUTTON) && (*(u8 *)group == SC_IRQ_GROUP_WAKE)) {
		schedule_delayed_work(&priv->check_work,
				      msecs_to_jiffies(DEBOUNCE_TIME));
		pm_wakeup_event(priv->input->dev.parent, 0);
	}

	return 0;
}

static void imx_sc_check_for_events(struct work_struct *work)
{
	struct imx_key_drv_data *priv =
				 container_of(work,
					      struct imx_key_drv_data,
					      check_work.work);
	struct input_dev *input = priv->input;
	struct imx_sc_msg_key msg;
	struct imx_sc_rpc_msg *hdr = &msg.hdr;
	bool state;
	int error;

	hdr->ver = IMX_SC_RPC_VERSION;
	hdr->svc = IMX_SC_RPC_SVC_MISC;
	hdr->func = IMX_SC_MISC_FUNC_GET_BUTTON_STATUS;
	hdr->size = 1;

	error = imx_scu_call_rpc(priv->key_ipc_handle, &msg, true);
	if (error) {
		dev_err(&input->dev, "read imx sc key failed, error %d\n", error);
		return;
	}

	/*
	 * The response data from SCU firmware is 4 bytes,
	 * but ONLY the first byte is the key state, other
	 * 3 bytes could be some dirty data, so we should
	 * ONLY take the first byte as key state.
	 */
	state = (bool)(msg.state & 0xff);

	if (state ^ priv->keystate) {
		priv->keystate = state;
		input_event(input, EV_KEY, priv->keycode, state);
		input_sync(input);
		if (!priv->keystate)
			pm_relax(priv->input->dev.parent);
	}

	if (state)
		schedule_delayed_work(&priv->check_work,
				      msecs_to_jiffies(REPEAT_INTERVAL));
}

static void imx_sc_key_action(void *data)
{
	struct imx_key_drv_data *priv = data;

	imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON, false);
	imx_scu_irq_unregister_notifier(&priv->key_notifier);
	cancel_delayed_work_sync(&priv->check_work);
}

static int imx_sc_key_probe(struct platform_device *pdev)
{
	struct imx_key_drv_data *priv;
	struct input_dev *input;
	int error;

Annotation

Implementation Notes