RE: [PATCH 2/4] input: bbnsm_pwrkey: Add bbnsm power key support

Subject: Re: [PATCH 2/4] input: bbnsm_pwrkey: Add bbnsm power key
support

Hi Jacky,

On Mon, Nov 21, 2022 at 02:51:42PM +0800, Jacky Bai wrote:

quoted

The ON/OFF logic inside the BBNSM allows for connecting directly into
a PMIC or other voltage regulator device. The module has an button
input signal and a wakeup request input signal. It also has two
interrupts (set_pwr_off_irq and set_pwr_on_irq) and an active-low PMIC
enable (pmic_en_b) output.

Add the power key support for the ON/OFF button function found in
BBNSM module.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/input/keyboard/Kconfig        |  11 ++
 drivers/input/keyboard/Makefile       |   1 +
 drivers/input/keyboard/bbnsm_pwrkey.c | 196
++++++++++++++++++++++++++
 3 files changed, 208 insertions(+)
 create mode 100644 drivers/input/keyboard/bbnsm_pwrkey.c

diff --git a/drivers/input/keyboard/Kconfig

b/drivers/input/keyboard/Kconfig index 00292118b79b..8efcd95492b3
100644

--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig

@@ -456,6 +456,17 @@ config KEYBOARD_SNVS_PWRKEY
 	  To compile this driver as a module, choose M here; the
 	  module will be called snvs_pwrkey.

+config KEYBOARD_BBNSM_PWRKEY
+	tristate "NXP BBNSM Power Key Driver"
+	depends on ARCH_MXC || COMPILE_TEST
+	depends on OF
+	help
+	  This is the bbnsm powerkey driver for the NXP i.MX application
+	  processors.
+
+	  To compile this driver as a module, choose M here; the
+	  module will be called bbnsm_pwrkey.
+
 config KEYBOARD_IMX
 	tristate "IMX keypad support"
 	depends on ARCH_MXC || COMPILE_TEST

diff --git a/drivers/input/keyboard/Makefile

b/drivers/input/keyboard/Makefile index 5f67196bb2c1..0bc101e004ae
100644

--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile

@@ -62,6 +62,7 @@ obj-$(CONFIG_KEYBOARD_QT2160)		+=

qt2160.o

quoted

 obj-$(CONFIG_KEYBOARD_SAMSUNG)		+= samsung-keypad.o
 obj-$(CONFIG_KEYBOARD_SH_KEYSC)		+= sh_keysc.o
 obj-$(CONFIG_KEYBOARD_SNVS_PWRKEY)	+= snvs_pwrkey.o
+obj-$(CONFIG_KEYBOARD_BBNSM_PWRKEY)	+= bbnsm_pwrkey.o
 obj-$(CONFIG_KEYBOARD_SPEAR)		+= spear-keyboard.o
 obj-$(CONFIG_KEYBOARD_STMPE)		+= stmpe-keypad.o
 obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o

diff --git a/drivers/input/keyboard/bbnsm_pwrkey.c

b/drivers/input/keyboard/bbnsm_pwrkey.c
new file mode 100644
index 000000000000..288ee6844000

--- /dev/null
+++ b/drivers/input/keyboard/bbnsm_pwrkey.c

...

quoted

+
+static void bbnsm_pwrkey_check_for_events(struct timer_list *t) {
+	struct bbnsm_pwrkey *bbnsm = from_timer(bbnsm, t, check_timer);
+	struct input_dev *input = bbnsm->input;
+	u32 state;
+
+	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &state);

Can this fail?

Should no chance to fail. Any more tips?

quoted

+
+	state = state & BBNSM_BTN_PRESSED ? 1 : 0;
+
+	/* only report new event if status changed */
+	if (state ^ bbnsm->keystate) {
+		bbnsm->keystate = state;
+		input_event(input, EV_KEY, bbnsm->keycode, state);
+		input_sync(input);
+		pm_relax(bbnsm->input->dev.parent);
+	}
+
+	/* repeat check if pressed long */
+	if (state) {
+		mod_timer(&bbnsm->check_timer,
+			  jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
+	}

So interrupt is only generated once when key is pressed, but not on release?

Yes, at lease from my test, this interrupt can only be triggered when pressed.

quoted

+}
+
+static irqreturn_t bbnsm_pwrkey_interrupt(int irq, void *dev_id) {
+	struct platform_device *pdev = dev_id;
+	struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
+	struct input_dev *input = bbnsm->input;
+	u32 event;
+
+	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);
+	if (event & BBNSM_BTN_OFF)
+		mod_timer(&bbnsm->check_timer, jiffies +

msecs_to_jiffies(DEBOUNCE_TIME));

quoted

+	else
+		return IRQ_NONE;
+
+	pm_wakeup_event(input->dev.parent, 0);
+
+	/* clear PWR OFF */
+	regmap_write(bbnsm->regmap, BBNSM_EVENTS, BBNSM_BTN_OFF);
+
+	return IRQ_HANDLED;
+}
+
+static void bbnsm_pwrkey_act(void *pdata) {
+	struct bbnsm_pwrkey *bbnsm = pdata;
+
+	del_timer_sync(&bbnsm->check_timer);
+}
+
+static int bbnsm_pwrkey_probe(struct platform_device *pdev) {
+	struct bbnsm_pwrkey *bbnsm;
+	struct input_dev *input;
+	struct device_node *np = pdev->dev.of_node;
+	int error;
+
+	bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);
+	if (!bbnsm)
+		return -ENOMEM;
+
+	bbnsm->regmap =

syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");

quoted

+	if (IS_ERR(bbnsm->regmap)) {
+		dev_err(&pdev->dev, "bbnsm pwerkey get regmap failed\n");
+		return PTR_ERR(bbnsm->regmap);
+	}
+
+	if (of_property_read_u32(np, "linux,code", &bbnsm->keycode)) {

Please use device_property_read_u32() here.

Ok, will fix in V2.

quoted

+		bbnsm->keycode = KEY_POWER;
+		dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
+	}
+
+	bbnsm->irq = platform_get_irq(pdev, 0);
+	if (bbnsm->irq < 0)
+		return -EINVAL;
+
+	/* config the BBNSM power related register */
+	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, BBNSM_DP_EN,
+BBNSM_DP_EN);
+
+	/* clear the unexpected interrupt before driver ready */
+	regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS,

BBNSM_PWRKEY_EVENTS,

quoted

+BBNSM_PWRKEY_EVENTS);
+
+	timer_setup(&bbnsm->check_timer, bbnsm_pwrkey_check_for_events,

0);

quoted

+
+	input = devm_input_allocate_device(&pdev->dev);
+	if (!input) {
+		dev_err(&pdev->dev, "failed to allocate the input device\n");
+		error = -ENOMEM;
+		goto error_probe;

Please return directly here and below, since there is not explicit cleanup.

Thx, will fix in V2.

BR

quoted

+	}
+
+	input->name = pdev->name;
+	input->phys = "bbnsm-pwrkey/input0";
+	input->id.bustype = BUS_HOST;
+
+	input_set_capability(input, EV_KEY, bbnsm->keycode);
+
+	/* input customer action to cancel release timer */
+	error = devm_add_action(&pdev->dev, bbnsm_pwrkey_act, bbnsm);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register remove action\n");
+		goto error_probe;
+	}
+
+	bbnsm->input = input;
+	platform_set_drvdata(pdev, bbnsm);
+
+	error = devm_request_irq(&pdev->dev, bbnsm->irq,

bbnsm_pwrkey_interrupt,

quoted

+			       IRQF_SHARED, pdev->name, pdev);
+	if (error) {
+		dev_err(&pdev->dev, "interrupt not available.\n");
+		goto error_probe;
+	}
+
+	error = input_register_device(input);
+	if (error < 0) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		goto error_probe;
+	}
+
+	device_init_wakeup(&pdev->dev, true);
+	error = dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);
+	if (error)
+		dev_err(&pdev->dev, "irq wake enable failed.\n");
+
+	return 0;
+
+error_probe:
+	return error;
+}
+
+static const struct of_device_id bbnsm_pwrkey_ids[] = {
+	{ .compatible = "nxp,bbnsm-pwrkey" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bbnsm_pwrkey_ids);
+
+static struct platform_driver bbnsm_pwrkey_driver = {
+	.driver = {
+		.name = "bbnsm_pwrkey",
+		.of_match_table = bbnsm_pwrkey_ids,
+	},
+	.probe = bbnsm_pwrkey_probe,
+};
+module_platform_driver(bbnsm_pwrkey_driver);
+
+MODULE_AUTHOR("Jacky Bai [off-list ref]");
+MODULE_DESCRIPTION("NXP bbnsm power key Driver");
+MODULE_LICENSE("GPL");
--
2.37.1

Thanks.

--
Dmitry