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         bool suspended;
  42         struct timer_list check_timer;
  43         struct input_dev *input;
  44 };
  45
  46 static void bbnsm_pwrkey_check_for_events(struct timer_list *t)
  47 {
  48         struct bbnsm_pwrkey *bbnsm = from_timer(bbnsm, t, check_timer);
  49         struct input_dev *input = bbnsm->input;
  50         u32 state;
  51
  52         regmap_read(bbnsm->regmap, BBNSM_EVENTS, &state);
  53
  54         state = state & BBNSM_BTN_PRESSED ? 1 : 0;
  55
  56         /* only report new event if status changed */
  57         if (state ^ bbnsm->keystate) {
  58                 bbnsm->keystate = state;
  59                 input_event(input, EV_KEY, bbnsm->keycode, state);
  60                 input_sync(input);
  61                 pm_relax(bbnsm->input->dev.parent);
  62         }
  63
  64         /* repeat check if pressed long */
  65         if (state)
  66                 mod_timer(&bbnsm->check_timer,
  67                           jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
  68 }
  69
  70 static irqreturn_t bbnsm_pwrkey_interrupt(int irq, void *dev_id)
  71 {
  72         struct platform_device *pdev = dev_id;
  73         struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
  74         struct input_dev *input = bbnsm->input;
  75         u32 event;
  76
  77         regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);
  78         if (!(event & BBNSM_BTN_OFF))
  79                 return IRQ_NONE;
  80
  81         pm_wakeup_event(bbnsm->input->dev.parent, 0);
  82
  83         /*
  84          * Directly report key event after resume to make sure key press
  85          * event is never missed.
  86          */
  87         if (bbnsm->suspended) {
  88                 bbnsm->keystate = 1;
  89                 input_event(input, EV_KEY, bbnsm->keycode, 1);
  90                 input_sync(input);
  91                 /* Fire at most once per suspend/resume cycle */
  92                 bbnsm->suspended = false;
  93         }
  94
  95         mod_timer(&bbnsm->check_timer,
  96                    jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
  97
  98         /* clear PWR OFF */
  99         regmap_write(bbnsm->regmap, BBNSM_EVENTS, BBNSM_BTN_OFF);
 100
 101         return IRQ_HANDLED;
 102 }
 103
 104 static void bbnsm_pwrkey_act(void *pdata)
 105 {
 106         struct bbnsm_pwrkey *bbnsm = pdata;
 107
 108         timer_shutdown_sync(&bbnsm->check_timer);
 109 }
 110
 111 static int bbnsm_pwrkey_probe(struct platform_device *pdev)
 112 {
 113         struct bbnsm_pwrkey *bbnsm;
 114         struct input_dev *input;
 115         struct device_node *np = pdev->dev.of_node;
 116         int error;
 117
 118         bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);
 119         if (!bbnsm)
 120                 return -ENOMEM;
 121
 122         bbnsm->regmap = syscon_node_to_regmap(np->parent);
 123         if (IS_ERR(bbnsm->regmap)) {
 124                 dev_err(&pdev->dev, "bbnsm pwerkey get regmap failed\n");
 125                 return PTR_ERR(bbnsm->regmap);
 126         }
 127
 128         if (device_property_read_u32(&pdev->dev, "linux,code",
 129                                      &bbnsm->keycode)) {
 130                 bbnsm->keycode = KEY_POWER;
 131                 dev_warn(&pdev->dev, "key code is not specified, using default KEY_POWER\n");
 132         }
 133
 134         bbnsm->irq = platform_get_irq(pdev, 0);
 135         if (bbnsm->irq < 0)
 136                 return -EINVAL;
 137
 138         /* config the BBNSM power related register */
 139         regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, BBNSM_DP_EN, BBNSM_DP_EN);
 140
 141         /* clear the unexpected interrupt before driver ready */
 142         regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, BBNSM_PWRKEY_EVENTS,
 143                           BBNSM_PWRKEY_EVENTS);
 144
 145         timer_setup(&bbnsm->check_timer, bbnsm_pwrkey_check_for_events, 0);
 146
 147         input = devm_input_allocate_device(&pdev->dev);
 148         if (!input) {
 149                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 150                 return -ENOMEM;
 151         }
 152
 153         input->name = pdev->name;
 154         input->phys = "bbnsm-pwrkey/input0";
 155         input->id.bustype = BUS_HOST;
 156
 157         input_set_capability(input, EV_KEY, bbnsm->keycode);
 158
 159         /* input customer action to cancel release timer */
 160         error = devm_add_action(&pdev->dev, bbnsm_pwrkey_act, bbnsm);
 161         if (error) {
 162                 dev_err(&pdev->dev, "failed to register remove action\n");
 163                 return error;
 164         }
 165
 166         bbnsm->input = input;
 167         platform_set_drvdata(pdev, bbnsm);
 168
 169         error = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_pwrkey_interrupt,
 170                                  IRQF_SHARED, pdev->name, pdev);
 171         if (error) {
 172                 dev_err(&pdev->dev, "interrupt not available.\n");
 173                 return error;
 174         }
 175
 176         error = input_register_device(input);
 177         if (error) {
 178                 dev_err(&pdev->dev, "failed to register input device\n");
 179                 return error;
 180         }
 181
 182         device_init_wakeup(&pdev->dev, true);
 183         error = dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);
 184         if (error)
 185                 dev_warn(&pdev->dev, "irq wake enable failed.\n");
 186
 187         return 0;
 188 }
 189
 190 static int __maybe_unused bbnsm_pwrkey_suspend(struct device *dev)
 191 {
 192         struct platform_device *pdev = to_platform_device(dev);
 193         struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
 194
 195         bbnsm->suspended = true;
 196
 197         return 0;
 198 }
 199
 200 static int __maybe_unused bbnsm_pwrkey_resume(struct device *dev)
 201 {
 202         struct platform_device *pdev = to_platform_device(dev);
 203         struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
 204
 205         bbnsm->suspended = false;
 206
 207         return 0;
 208 }
 209
 210 static SIMPLE_DEV_PM_OPS(bbnsm_pwrkey_pm_ops, bbnsm_pwrkey_suspend,
 211                 bbnsm_pwrkey_resume);
 212
 213 static const struct of_device_id bbnsm_pwrkey_ids[] = {
 214         { .compatible = "nxp,imx93-bbnsm-pwrkey" },
 215         { /* sentinel */ }
 216 };
 217 MODULE_DEVICE_TABLE(of, bbnsm_pwrkey_ids);
 218
 219 static struct platform_driver bbnsm_pwrkey_driver = {
 220         .driver = {
 221                 .name = "bbnsm_pwrkey",
 222                 .pm = &bbnsm_pwrkey_pm_ops,
 223                 .of_match_table = bbnsm_pwrkey_ids,
 224         },
 225         .probe = bbnsm_pwrkey_probe,
 226 };
 227 module_platform_driver(bbnsm_pwrkey_driver);
 228
 229 MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
 230 MODULE_DESCRIPTION("NXP bbnsm power key Driver");
 231 MODULE_LICENSE("GPL");