Hi Takashi,

On Tue, Aug 22, 2017 at 07:57:09AM +0200, Takashi Iwai wrote:

This provides a new input driver for supporting the power button on
Dollar Cove TI PMIC, found on Cherrytrail-based devices.
The patch is based on the original work by Intel, found at:
  https://github.com/01org/ProductionKernelQuilts

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=193891
Signed-off-by: Takashi Iwai <redacted>
---
 drivers/input/keyboard/Kconfig        |  7 +++
 drivers/input/keyboard/Makefile       |  1 +
 drivers/input/keyboard/dc_ti_pwrbtn.c | 85 +++++++++++++++++++++++++++++++++++

Not sure if it ends up in drivers/input/keyboard, or drivers/input/misc/
(where most power buttons live) or in platform drivers, still a few
comments below.

If keeping in input we customarily call out the module name (see a few
lines above).

BIT()?

+
+#define DRIVER_NAME "dc_ti_pwrbtn"
+
+static irqreturn_t dc_ti_pwrbtn_interrupt(int irq, void *dev_id)
+{
+	struct input_dev *pwrbtn_input = dev_id;
+	struct device *dev = pwrbtn_input->dev.parent;
+	struct regmap *regmap = dev_get_drvdata(dev);
+	int state;
+
+	if (!regmap_read(regmap, DC_TI_SIRQ_REG, &state)) {
+		dev_dbg(dev, "SIRQ_REG=0x%x\n", state);
+		state &= SIRQ_PWRBTN_REL;
+		input_event(pwrbtn_input, EV_KEY, KEY_POWER, !state);

Why not

		input_report_key(pwrbtn_input, KEY_POWER,
				 !(state & SIRQ_PWRBTN_REL));

+		input_sync(pwrbtn_input);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int dc_ti_pwrbtn_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct intel_soc_pmic *pmic = dev_get_drvdata(dev->parent);
+	struct input_dev *pwrbtn_input;
+	int irq;
+	int ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -EINVAL;

Why do you clobber return value? Simply return "irq".

+	pwrbtn_input = devm_input_allocate_device(dev);
+	if (!pwrbtn_input)
+		return -ENOMEM;
+	pwrbtn_input->name = pdev->name;
+	pwrbtn_input->phys = "dc-ti-power/input0";
+	pwrbtn_input->id.bustype = BUS_HOST;
+	pwrbtn_input->dev.parent = dev;

Not needed since devm_input_allocate_device() does it for us.

+	input_set_capability(pwrbtn_input, EV_KEY, KEY_POWER);
+	ret = input_register_device(pwrbtn_input);
+	if (ret)
+		return ret;

If staying in input, can we please call this variable err or error?

+
+	dev_set_drvdata(dev, pmic->regmap);
+
+	ret = devm_request_threaded_irq(dev, irq, NULL, dc_ti_pwrbtn_interrupt,
+					0, KBUILD_MODNAME, pwrbtn_input);
+	if (ret)
+		return ret;
+
+	ret = enable_irq_wake(irq);
+	if (ret)
+		dev_warn(dev, "Can't enable IRQ as wake source: %d\n", ret);

We do not normally enable wake IRQs in probe, but instead do:

	device_init_wakeup(&pdev->dev, true);

in probe() and then check it in suspend/resume:

	if (device_may_wakeup(dev)) {
		err = enable_irq_wake(XXX->irq);
		if (!err)
			XXX->irq_wake_enabled = true;
	}

...

	if (XXX->irq_wake_enabled)
		disable_irq_wake(XXX->irq);

This allows userspace to inhibit wakeup, if needed.

+
+	return 0;
+}
+
+static struct platform_driver dc_ti_pwrbtn_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+	},
+	.probe	= dc_ti_pwrbtn_probe,
+};
+
+module_platform_driver(dc_ti_pwrbtn_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);
-- 
2.14.0

Thanks!

-- 
Dmitry