Re: [PATCH] staging: nvec: kbd: replace global state with dynamic allocation

[Marc Dietrich <marvin24@gmx.de>]

Hallo Igor,

On Fri, 10 Jul 2026, Igor Putko wrote:
> Remove the global static 'keys_dev' struct to allow multiple device
> instances. Allocate 'nvec_keys' dynamically per-device using
> devm_kzalloc() during probe, and fetch the context using
> input_get_drvdata() and container_of().

what could be the reason for allowing multiple keyboards? The hardware is 
not designed to provide this and it also makes little sense at a first 
glance.

Best wishes,

Marc


> Signed-off-by: Igor Putko <igorpetindev@gmail.com>
> ---
> drivers/staging/nvec/nvec_kbd.c | 40 ++++++++++++++++++++-------------
> 1 file changed, 24 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/staging/nvec/nvec_kbd.c b/drivers/staging/nvec/nvec_kbd.c
> index d2b91318f..4b61aebca 100644
> --- a/drivers/staging/nvec/nvec_kbd.c
> +++ b/drivers/staging/nvec/nvec_kbd.c
> @@ -35,19 +35,17 @@ struct nvec_keys {
> 	bool caps_lock;
> };
>
> -static struct nvec_keys keys_dev;
> -
> -static void nvec_kbd_toggle_led(void)
> +static void nvec_kbd_toggle_led(struct nvec_keys *keys)
> {
> 	char buf[] = { NVEC_KBD, SET_LEDS, 0 };
>
> -	keys_dev.caps_lock = !keys_dev.caps_lock;
> +	keys->caps_lock = !keys->caps_lock;
>
> -	if (keys_dev.caps_lock)
> +	if (keys->caps_lock)
> 		/* should be BIT(0) only, firmware bug? */
> 		buf[2] = BIT(0) | BIT(1) | BIT(2);
>
> -	nvec_write_async(keys_dev.nvec, buf, sizeof(buf));
> +	nvec_write_async(keys->nvec, buf, sizeof(buf));
> }
>
> static int nvec_keys_notifier(struct notifier_block *nb,
> @@ -55,6 +53,7 @@ static int nvec_keys_notifier(struct notifier_block *nb,
> {
> 	int code, state;
> 	unsigned char *msg = data;
> +	struct nvec_keys *keys = container_of(nb, struct nvec_keys, notifier);
>
> 	if (event_type == NVEC_KB_EVT) {
> 		int _size = (msg[0] & (3 << 5)) >> 5;
> @@ -70,11 +69,11 @@ static int nvec_keys_notifier(struct notifier_block *nb,
> 		state = msg[1] & 0x80;
>
> 		if (code_tabs[_size][code] == KEY_CAPSLOCK && state)
> -			nvec_kbd_toggle_led();
> +			nvec_kbd_toggle_led(keys);
>
> -		input_report_key(keys_dev.input, code_tabs[_size][code],
> +		input_report_key(keys->input, code_tabs[_size][code],
> 				 !state);
> -		input_sync(keys_dev.input);
> +		input_sync(keys->input);
>
> 		return NOTIFY_STOP;
> 	}
> @@ -85,7 +84,7 @@ static int nvec_keys_notifier(struct notifier_block *nb,
> static int nvec_kbd_event(struct input_dev *dev, unsigned int type,
> 			  unsigned int code, int value)
> {
> -	struct nvec_chip *nvec = keys_dev.nvec;
> +	struct nvec_keys *keys = input_get_drvdata(dev);
> 	char buf[] = { NVEC_KBD, SET_LEDS, 0 };
>
> 	if (type == EV_REP)
> @@ -98,7 +97,7 @@ static int nvec_kbd_event(struct input_dev *dev, unsigned int type,
> 		return -1;
>
> 	buf[2] = !!value;
> -	nvec_write_async(nvec, buf, sizeof(buf));
> +	nvec_write_async(keys->nvec, buf, sizeof(buf));
>
> 	return 0;
> }
> @@ -107,6 +106,7 @@ static int nvec_kbd_probe(struct platform_device *pdev)
> {
> 	struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);
> 	int i, j, err;
> +	struct nvec_keys *keys;
> 	struct input_dev *idev;
> 	char	clear_leds[] = { NVEC_KBD, SET_LEDS, 0 },
> 		enable_kbd[] = { NVEC_KBD, ENABLE_KBD },
> @@ -115,6 +115,9 @@ static int nvec_kbd_probe(struct platform_device *pdev)
> 						true };
>
> 	j = 0;
> +	keys = devm_kzalloc(&pdev->dev, sizeof(struct nvec_keys), GFP_KERNEL);
> +	if (!keys)
> +		return -ENOMEM;
>
> 	for (i = 0; i < ARRAY_SIZE(code_tab_102us); ++i)
> 		keycodes[j++] = code_tab_102us[i];
> @@ -138,14 +141,18 @@ static int nvec_kbd_probe(struct platform_device *pdev)
> 		set_bit(keycodes[i], idev->keybit);
>
> 	clear_bit(0, idev->keybit);
> +
> +	input_set_drvdata(idev, keys);
> +	platform_set_drvdata(pdev, keys);
> +
> 	err = input_register_device(idev);
> 	if (err)
> 		return err;
>
> -	keys_dev.input = idev;
> -	keys_dev.notifier.notifier_call = nvec_keys_notifier;
> -	keys_dev.nvec = nvec;
> -	nvec_register_notifier(nvec, &keys_dev.notifier, 0);
> +	keys->input = idev;
> +	keys->notifier.notifier_call = nvec_keys_notifier;
> +	keys->nvec = nvec;
> +	nvec_register_notifier(nvec, &keys->notifier, 0);
>
> 	/* Enable keyboard */
> 	nvec_write_sync(nvec, enable_kbd, 2, NULL);
> @@ -165,12 +172,13 @@ static int nvec_kbd_probe(struct platform_device *pdev)
> static void nvec_kbd_remove(struct platform_device *pdev)
> {
> 	struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);
> +	struct nvec_keys *keys = platform_get_drvdata(pdev);
> 	char disable_kbd[] = { NVEC_KBD, DISABLE_KBD },
> 	     uncnfg_wake_key_reporting[] = { NVEC_KBD, CNFG_WAKE_KEY_REPORTING,
> 						false };
> 	nvec_write_async(nvec, uncnfg_wake_key_reporting, 3);
> 	nvec_write_async(nvec, disable_kbd, 2);
> -	nvec_unregister_notifier(nvec, &keys_dev.notifier);
> +	nvec_unregister_notifier(nvec, &keys->notifier);
> }
>
> static struct platform_driver nvec_kbd_driver = {
> -- 
> 2.47.3
>
>