--- /dev/null
+// 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/mfd/syscon.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/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);
+
+ 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));
+}
+
+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);
+ u32 event;
+
+ regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);
+ if (!(event & BBNSM_BTN_OFF))
+ return IRQ_NONE;
+
+ pm_wakeup_event(bbnsm->input->dev.parent, 0);
+
+ mod_timer(&bbnsm->check_timer,
+ jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
+
+ /* 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;
+
+ timer_shutdown_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_node_to_regmap(np->parent);
+ if (IS_ERR(bbnsm->regmap)) {
+ dev_err(&pdev->dev, "bbnsm pwerkey get regmap failed\n");
+ return PTR_ERR(bbnsm->regmap);
+ }
+
+ if (device_property_read_u32(&pdev->dev, "linux,code",
+ &bbnsm->keycode)) {
+ bbnsm->keycode = KEY_POWER;
+ dev_warn(&pdev->dev, "key code is not specified, using default KEY_POWER\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");
+ return -ENOMEM;
+ }
+
+ 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");
+ return error;
+ }
+
+ 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");
+ return error;
+ }
+
+ error = input_register_device(input);
+ if (error) {
+ dev_err(&pdev->dev, "failed to register input device\n");
+ return error;
+ }
+
+ device_init_wakeup(&pdev->dev, true);
+ error = dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);
+ if (error)
+ dev_warn(&pdev->dev, "irq wake enable failed.\n");
+
+ return 0;
+}
+
+static const struct of_device_id bbnsm_pwrkey_ids[] = {
+ { .compatible = "nxp,imx93-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");
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