drivers/input/misc/nxp-bbnsm-pwrkey.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 // Copyright 2022 NXP.
   4
   5 #include <linux/device.h>
   6 #include <linux/err.h>
   7 #include <linux/init.h>
   8 #include <linux/input.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/io.h>
  11 #include <linux/jiffies.h>
  12 #include <linux/kernel.h>
  13 #include <linux/mfd/syscon.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/pm_wakeirq.h>
  19 #include <linux/regmap.h>
  20
  21 #define BBNSM_CTRL              0x8
  22 #define BBNSM_INT_EN            0x10
  23 #define BBNSM_EVENTS            0x14
  24 #define BBNSM_PAD_CTRL          0x24
  25
  26 #define BBNSM_BTN_PRESSED       BIT(7)
  27 #define BBNSM_PWR_ON            BIT(6)
  28 #define BBNSM_BTN_OFF           BIT(5)
  29 #define BBNSM_EMG_OFF           BIT(4)
  30 #define BBNSM_PWRKEY_EVENTS     (BBNSM_PWR_ON | BBNSM_BTN_OFF | BBNSM_EMG_OFF)
  31 #define BBNSM_DP_EN             BIT(24)
  32
  33 #define DEBOUNCE_TIME           30
  34 #define REPEAT_INTERVAL         60
  35
  36 struct bbnsm_pwrkey {
  37         struct regmap *regmap;
  38         int irq;
  39         int keycode;
  40         int keystate;  /* 1:pressed */
  41         struct timer_list check_timer;
  42         struct input_dev *input;
  43 };
  44
  45 static void bbnsm_pwrkey_check_for_events(struct timer_list *t)
  46 {
  47         struct bbnsm_pwrkey *bbnsm = from_timer(bbnsm, t, check_timer);
  48         struct input_dev *input = bbnsm->input;
  49         u32 state;
  50
  51         regmap_read(bbnsm->regmap, BBNSM_EVENTS, &state);
  52
  53         state = state & BBNSM_BTN_PRESSED ? 1 : 0;
  54
  55         /* only report new event if status changed */
  56         if (state ^ bbnsm->keystate) {
  57                 bbnsm->keystate = state;
  58                 input_event(input, EV_KEY, bbnsm->keycode, state);
  59                 input_sync(input);
  60                 pm_relax(bbnsm->input->dev.parent);
  61         }
  62
  63         /* repeat check if pressed long */
  64         if (state)
  65                 mod_timer(&bbnsm->check_timer,
  66                           jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
  67 }
  68
  69 static irqreturn_t bbnsm_pwrkey_interrupt(int irq, void *dev_id)
  70 {
  71         struct platform_device *pdev = dev_id;
  72         struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
  73         u32 event;
  74
  75         regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);
  76         if (!(event & BBNSM_BTN_OFF))
  77                 return IRQ_NONE;
  78
  79         pm_wakeup_event(bbnsm->input->dev.parent, 0);
  80
  81         mod_timer(&bbnsm->check_timer,
  82                    jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
  83
  84         /* clear PWR OFF */
  85         regmap_write(bbnsm->regmap, BBNSM_EVENTS, BBNSM_BTN_OFF);
  86
  87         return IRQ_HANDLED;
  88 }
  89
  90 static void bbnsm_pwrkey_act(void *pdata)
  91 {
  92         struct bbnsm_pwrkey *bbnsm = pdata;
  93
  94         timer_shutdown_sync(&bbnsm->check_timer);
  95 }
  96
  97 static int bbnsm_pwrkey_probe(struct platform_device *pdev)
  98 {
  99         struct bbnsm_pwrkey *bbnsm;
 100         struct input_dev *input;
 101         struct device_node *np = pdev->dev.of_node;
 102         int error;
 103
 104         bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);
 105         if (!bbnsm)
 106                 return -ENOMEM;
 107
 108         bbnsm->regmap = syscon_node_to_regmap(np->parent);
 109         if (IS_ERR(bbnsm->regmap)) {
 110                 dev_err(&pdev->dev, "bbnsm pwerkey get regmap failed\n");
 111                 return PTR_ERR(bbnsm->regmap);
 112         }
 113
 114         if (device_property_read_u32(&pdev->dev, "linux,code",
 115                                      &bbnsm->keycode)) {
 116                 bbnsm->keycode = KEY_POWER;
 117                 dev_warn(&pdev->dev, "key code is not specified, using default KEY_POWER\n");
 118         }
 119
 120         bbnsm->irq = platform_get_irq(pdev, 0);
 121         if (bbnsm->irq < 0)
 122                 return -EINVAL;
 123
 124         /* config the BBNSM power related register */
 125         regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, BBNSM_DP_EN, BBNSM_DP_EN);
 126
 127         /* clear the unexpected interrupt before driver ready */
 128         regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, BBNSM_PWRKEY_EVENTS,
 129                           BBNSM_PWRKEY_EVENTS);
 130
 131         timer_setup(&bbnsm->check_timer, bbnsm_pwrkey_check_for_events, 0);
 132
 133         input = devm_input_allocate_device(&pdev->dev);
 134         if (!input) {
 135                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 136                 return -ENOMEM;
 137         }
 138
 139         input->name = pdev->name;
 140         input->phys = "bbnsm-pwrkey/input0";
 141         input->id.bustype = BUS_HOST;
 142
 143         input_set_capability(input, EV_KEY, bbnsm->keycode);
 144
 145         /* input customer action to cancel release timer */
 146         error = devm_add_action(&pdev->dev, bbnsm_pwrkey_act, bbnsm);
 147         if (error) {
 148                 dev_err(&pdev->dev, "failed to register remove action\n");
 149                 return error;
 150         }
 151
 152         bbnsm->input = input;
 153         platform_set_drvdata(pdev, bbnsm);
 154
 155         error = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_pwrkey_interrupt,
 156                                  IRQF_SHARED, pdev->name, pdev);
 157         if (error) {
 158                 dev_err(&pdev->dev, "interrupt not available.\n");
 159                 return error;
 160         }
 161
 162         error = input_register_device(input);
 163         if (error) {
 164                 dev_err(&pdev->dev, "failed to register input device\n");
 165                 return error;
 166         }
 167
 168         device_init_wakeup(&pdev->dev, true);
 169         error = dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);
 170         if (error)
 171                 dev_warn(&pdev->dev, "irq wake enable failed.\n");
 172
 173         return 0;
 174 }
 175
 176 static const struct of_device_id bbnsm_pwrkey_ids[] = {
 177         { .compatible = "nxp,imx93-bbnsm-pwrkey" },
 178         { /* sentinel */ }
 179 };
 180 MODULE_DEVICE_TABLE(of, bbnsm_pwrkey_ids);
 181
 182 static struct platform_driver bbnsm_pwrkey_driver = {
 183         .driver = {
 184                 .name = "bbnsm_pwrkey",
 185                 .of_match_table = bbnsm_pwrkey_ids,
 186         },
 187         .probe = bbnsm_pwrkey_probe,
 188 };
 189 module_platform_driver(bbnsm_pwrkey_driver);
 190
 191 MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
 192 MODULE_DESCRIPTION("NXP bbnsm power key Driver");
 193 MODULE_LICENSE("GPL");