On Fri, Mar 23, 2018 at 12:14:22PM -0700, Trilok Soni wrote:

Hi Tirupathi,

quoted

+static irqreturn_t pm8941_resinkey_irq(int irq, void *_data)
+{
+	struct pm8941_pwrkey *pwrkey = _data;
+	unsigned int sts;
+	int error;
+	u32 key_code = pwrkey->resin_key_code;
+
+	error = regmap_read(pwrkey->regmap,
+			    pwrkey->baseaddr + PON_RT_STS, &sts);
+	if (error)
+		return IRQ_HANDLED;
+
+	input_report_key(pwrkey->input, key_code, !!(sts & PON_RESIN_N_SET));
+	input_sync(pwrkey->input);
+
+	return IRQ_HANDLED;
+}
+
  static int __maybe_unused pm8941_pwrkey_suspend(struct device *dev)
  {
  	struct pm8941_pwrkey *pwrkey = dev_get_drvdata(dev);

@@ -153,9 +175,56 @@ static int __maybe_unused pm8941_pwrkey_resume(struct device *dev)
  static SIMPLE_DEV_PM_OPS(pm8941_pwr_key_pm_ops,
  			 pm8941_pwrkey_suspend, pm8941_pwrkey_resume);
+static int pm8941_resin_key_init(struct pm8941_pwrkey *pwrkey,
+			struct device_node *np)
+{
+	int error, irq;
+	bool pull_up;
+
+	/*
+	 * Get the standard-key parameters. This might not be
+	 * specified if there is no key mapping on the reset line.
+	 */
+	error = of_property_read_u32(np, "linux,code", &pwrkey->resin_key_code);
+	if (error) {
+		dev_err(pwrkey->dev, "failed to read key-code for resin key\n");
+		return error;
+	}
+
+	pull_up = of_property_read_bool(np, "bias-pull-up");
+
+	irq = irq_of_parse_and_map(np, 0);
+	if (irq < 0) {
+		dev_err(pwrkey->dev, "failed to get resin irq\n");
+		return -EINVAL;
+	}
+
+	/* Register key configuration */
+	input_set_capability(pwrkey->input, EV_KEY, pwrkey->resin_key_code);
+
+	error = regmap_update_bits(pwrkey->regmap,
+				   pwrkey->baseaddr + PON_PULL_CTL,
+				   PON_RESIN_PULL_UP,
+				   pull_up ? PON_RESIN_PULL_UP : 0);
+	if (error) {
+		dev_err(pwrkey->dev, "failed to set resin pull: %d\n", error);
+		return error;
+	}
+
+	error = devm_request_threaded_irq(pwrkey->dev, irq, NULL,
+					  pm8941_resinkey_irq, IRQF_ONESHOT,
+					  "pm8941_resinkey", pwrkey);
+	if (error)
+		dev_err(pwrkey->dev, "failed requesting resin key IRQ: %d\n",
+			error);
+
+	return error;
+}
+
  static int pm8941_pwrkey_probe(struct platform_device *pdev)
  {
  	struct pm8941_pwrkey *pwrkey;
+	struct device_node *np = NULL;
  	bool pull_up;
  	u32 req_delay;
  	int error;

@@ -241,6 +310,18 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
  		return error;
  	}
+	np = of_find_node_by_name(pdev->dev.of_node, "resin");
+	if (np) {
+		/* resin key capabilities are defined in device node */
+		error = pm8941_resin_key_init(pwrkey, np);

What happens if interrupts comes as soon as you have done the key_init(..)
here? I see that you are registering the input device after it, right? Looks
like you should do this at the end of probe?

It should be fine, input devices properly allocated (with
input_allocate_device() or devm- version) are able to accept events even
if input device has not been registered yet. It is and advertised
feature:

drivers/input/input.c:

"
 * input_event() - report new input event
...
 * NOTE: input_event() may be safely used right after input device was
 * allocated with input_allocate_device(), even before it is registered
 * with input_register_device(), but the event will not reach any of the
 * input handlers. Such early invocation of input_event() may be used
 * to 'seed' initial state of a switch or initial position of absolute
 * axis, etc.
"

Thanks.

-- 
Dmitry