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

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Jacky,

On Mon, Nov 21, 2022 at 02:51:42PM +0800, Jacky Bai wrote:
> 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-$(CONFIG_KEYBOARD_QT2160)		+= qt2160.o
>  obj-$(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
> @@ -0,0 +1,196 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +//
> +// Copyright 2022 NXP.
> +
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/input.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/jiffies.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_wakeirq.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +
> +#define BBNSM_CTRL		0x8
> +#define BBNSM_INT_EN		0x10
> +#define BBNSM_EVENTS		0x14
> +#define BBNSM_PAD_CTRL		0x24
> +
> +#define BBNSM_BTN_PRESSED	BIT(7)
> +#define BBNSM_PWR_ON		BIT(6)
> +#define BBNSM_BTN_OFF		BIT(5)
> +#define BBNSM_EMG_OFF		BIT(4)
> +#define BBNSM_PWRKEY_EVENTS	(BBNSM_PWR_ON | BBNSM_BTN_OFF | BBNSM_EMG_OFF)
> +#define BBNSM_DP_EN		BIT(24)
> +
> +#define DEBOUNCE_TIME		30
> +#define REPEAT_INTERVAL		60
> +
> +struct bbnsm_pwrkey {
> +	struct regmap *regmap;
> +	int irq;
> +	int keycode;
> +	int keystate;  /* 1:pressed */
> +	struct timer_list check_timer;
> +	struct input_dev *input;
> +};
> +
> +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?

> +
> +	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?

> +}
> +
> +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));
> +	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");
> +	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.

> +		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, BBNSM_PWRKEY_EVENTS);
> +
> +	timer_setup(&bbnsm->check_timer, bbnsm_pwrkey_check_for_events, 0);
> +
> +	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.

> +	}
> +
> +	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,
> +			       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 <ping.bai@nxp.com>");
> +MODULE_DESCRIPTION("NXP bbnsm power key Driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.37.1
> 

Thanks.

-- 
Dmitry