drivers/input/keyboard/snvs_pwrkey.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 // Driver for the IMX SNVS ON/OFF Power Key
   4 // Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved.
   5
   6 #include <linux/device.h>
   7 #include <linux/err.h>
   8 #include <linux/init.h>
   9 #include <linux/input.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/io.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.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/mfd/syscon.h>
  19 #include <linux/regmap.h>
  20
  21 #define SNVS_LPSR_REG   0x4C    /* LP Status Register */
  22 #define SNVS_LPCR_REG   0x38    /* LP Control Register */
  23 #define SNVS_HPSR_REG   0x14
  24 #define SNVS_HPSR_BTN   BIT(6)
  25 #define SNVS_LPSR_SPO   BIT(18)
  26 #define SNVS_LPCR_DEP_EN BIT(5)
  27
  28 #define DEBOUNCE_TIME 30
  29 #define REPEAT_INTERVAL 60
  30
  31 struct pwrkey_drv_data {
  32         struct regmap *snvs;
  33         int irq;
  34         int keycode;
  35         int keystate;  /* 1:pressed */
  36         int wakeup;
  37         struct timer_list check_timer;
  38         struct input_dev *input;
  39 };
  40
  41 static void imx_imx_snvs_check_for_events(struct timer_list *t)
  42 {
  43         struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
  44         struct input_dev *input = pdata->input;
  45         u32 state;
  46
  47         regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
  48         state = state & SNVS_HPSR_BTN ? 1 : 0;
  49
  50         /* only report new event if status changed */
  51         if (state ^ pdata->keystate) {
  52                 pdata->keystate = state;
  53                 input_event(input, EV_KEY, pdata->keycode, state);
  54                 input_sync(input);
  55                 pm_relax(pdata->input->dev.parent);
  56         }
  57
  58         /* repeat check if pressed long */
  59         if (state) {
  60                 mod_timer(&pdata->check_timer,
  61                           jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
  62         }
  63 }
  64
  65 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
  66 {
  67         struct platform_device *pdev = dev_id;
  68         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
  69         u32 lp_status;
  70
  71         pm_wakeup_event(pdata->input->dev.parent, 0);
  72
  73         regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
  74         if (lp_status & SNVS_LPSR_SPO)
  75                 mod_timer(&pdata->check_timer, jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
  76
  77         /* clear SPO status */
  78         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
  79
  80         return IRQ_HANDLED;
  81 }
  82
  83 static void imx_snvs_pwrkey_act(void *pdata)
  84 {
  85         struct pwrkey_drv_data *pd = pdata;
  86
  87         del_timer_sync(&pd->check_timer);
  88 }
  89
  90 static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
  91 {
  92         struct pwrkey_drv_data *pdata = NULL;
  93         struct input_dev *input = NULL;
  94         struct device_node *np;
  95         int error;
  96
  97         /* Get SNVS register Page */
  98         np = pdev->dev.of_node;
  99         if (!np)
 100                 return -ENODEV;
 101
 102         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 103         if (!pdata)
 104                 return -ENOMEM;
 105
 106         pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
 107         if (IS_ERR(pdata->snvs)) {
 108                 dev_err(&pdev->dev, "Can't get snvs syscon\n");
 109                 return PTR_ERR(pdata->snvs);
 110         }
 111
 112         if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
 113                 pdata->keycode = KEY_POWER;
 114                 dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
 115         }
 116
 117         pdata->wakeup = of_property_read_bool(np, "wakeup-source");
 118
 119         pdata->irq = platform_get_irq(pdev, 0);
 120         if (pdata->irq < 0) {
 121                 dev_err(&pdev->dev, "no irq defined in platform data\n");
 122                 return -EINVAL;
 123         }
 124
 125         regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
 126
 127         /* clear the unexpected interrupt before driver ready */
 128         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
 129
 130         timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
 131
 132         input = devm_input_allocate_device(&pdev->dev);
 133         if (!input) {
 134                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 135                 return -ENOMEM;
 136         }
 137
 138         input->name = pdev->name;
 139         input->phys = "snvs-pwrkey/input0";
 140         input->id.bustype = BUS_HOST;
 141
 142         input_set_capability(input, EV_KEY, pdata->keycode);
 143
 144         /* input customer action to cancel release timer */
 145         error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
 146         if (error) {
 147                 dev_err(&pdev->dev, "failed to register remove action\n");
 148                 return error;
 149         }
 150
 151         pdata->input = input;
 152         platform_set_drvdata(pdev, pdata);
 153
 154         error = devm_request_irq(&pdev->dev, pdata->irq,
 155                                imx_snvs_pwrkey_interrupt,
 156                                0, pdev->name, pdev);
 157
 158         if (error) {
 159                 dev_err(&pdev->dev, "interrupt not available.\n");
 160                 return error;
 161         }
 162
 163         error = input_register_device(input);
 164         if (error < 0) {
 165                 dev_err(&pdev->dev, "failed to register input device\n");
 166                 return error;
 167         }
 168
 169         device_init_wakeup(&pdev->dev, pdata->wakeup);
 170
 171         return 0;
 172 }
 173
 174 static int __maybe_unused imx_snvs_pwrkey_suspend(struct device *dev)
 175 {
 176         struct platform_device *pdev = to_platform_device(dev);
 177         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
 178
 179         if (device_may_wakeup(&pdev->dev))
 180                 enable_irq_wake(pdata->irq);
 181
 182         return 0;
 183 }
 184
 185 static int __maybe_unused imx_snvs_pwrkey_resume(struct device *dev)
 186 {
 187         struct platform_device *pdev = to_platform_device(dev);
 188         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
 189
 190         if (device_may_wakeup(&pdev->dev))
 191                 disable_irq_wake(pdata->irq);
 192
 193         return 0;
 194 }
 195
 196 static const struct of_device_id imx_snvs_pwrkey_ids[] = {
 197         { .compatible = "fsl,sec-v4.0-pwrkey" },
 198         { /* sentinel */ }
 199 };
 200 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
 201
 202 static SIMPLE_DEV_PM_OPS(imx_snvs_pwrkey_pm_ops, imx_snvs_pwrkey_suspend,
 203                                 imx_snvs_pwrkey_resume);
 204
 205 static struct platform_driver imx_snvs_pwrkey_driver = {
 206         .driver = {
 207                 .name = "snvs_pwrkey",
 208                 .pm     = &imx_snvs_pwrkey_pm_ops,
 209                 .of_match_table = imx_snvs_pwrkey_ids,
 210         },
 211         .probe = imx_snvs_pwrkey_probe,
 212 };
 213 module_platform_driver(imx_snvs_pwrkey_driver);
 214
 215 MODULE_AUTHOR("Freescale Semiconductor");
 216 MODULE_DESCRIPTION("i.MX snvs power key Driver");
 217 MODULE_LICENSE("GPL");