linux/drivers/input/keyboard/snvs_pwrkey.c
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   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
  31struct 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
  41static 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
  65static 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
  83static 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
  90static 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        error = devm_request_irq(&pdev->dev, pdata->irq,
 152                               imx_snvs_pwrkey_interrupt,
 153                               0, pdev->name, pdev);
 154
 155        if (error) {
 156                dev_err(&pdev->dev, "interrupt not available.\n");
 157                return error;
 158        }
 159
 160        error = input_register_device(input);
 161        if (error < 0) {
 162                dev_err(&pdev->dev, "failed to register input device\n");
 163                return error;
 164        }
 165
 166        pdata->input = input;
 167        platform_set_drvdata(pdev, pdata);
 168
 169        device_init_wakeup(&pdev->dev, pdata->wakeup);
 170
 171        return 0;
 172}
 173
 174static 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
 185static 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
 196static const struct of_device_id imx_snvs_pwrkey_ids[] = {
 197        { .compatible = "fsl,sec-v4.0-pwrkey" },
 198        { /* sentinel */ }
 199};
 200MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
 201
 202static SIMPLE_DEV_PM_OPS(imx_snvs_pwrkey_pm_ops, imx_snvs_pwrkey_suspend,
 203                                imx_snvs_pwrkey_resume);
 204
 205static 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};
 213module_platform_driver(imx_snvs_pwrkey_driver);
 214
 215MODULE_AUTHOR("Freescale Semiconductor");
 216MODULE_DESCRIPTION("i.MX snvs power key Driver");
 217MODULE_LICENSE("GPL");
 218