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/pm_wakeirq.h>
  19 #include <linux/mfd/syscon.h>
  20 #include <linux/regmap.h>
  21
  22 #define SNVS_HPVIDR1_REG        0xF8
  23 #define SNVS_LPSR_REG           0x4C    /* LP Status Register */
  24 #define SNVS_LPCR_REG           0x38    /* LP Control Register */
  25 #define SNVS_HPSR_REG           0x14
  26 #define SNVS_HPSR_BTN           BIT(6)
  27 #define SNVS_LPSR_SPO           BIT(18)
  28 #define SNVS_LPCR_DEP_EN        BIT(5)
  29
  30 #define DEBOUNCE_TIME           30
  31 #define REPEAT_INTERVAL         60
  32
  33 struct pwrkey_drv_data {
  34         struct regmap *snvs;
  35         int irq;
  36         int keycode;
  37         int keystate;  /* 1:pressed */
  38         int wakeup;
  39         struct timer_list check_timer;
  40         struct input_dev *input;
  41         u8 minor_rev;
  42 };
  43
  44 static void imx_imx_snvs_check_for_events(struct timer_list *t)
  45 {
  46         struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
  47         struct input_dev *input = pdata->input;
  48         u32 state;
  49
  50         regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
  51         state = state & SNVS_HPSR_BTN ? 1 : 0;
  52
  53         /* only report new event if status changed */
  54         if (state ^ pdata->keystate) {
  55                 pdata->keystate = state;
  56                 input_event(input, EV_KEY, pdata->keycode, state);
  57                 input_sync(input);
  58                 pm_relax(pdata->input->dev.parent);
  59         }
  60
  61         /* repeat check if pressed long */
  62         if (state) {
  63                 mod_timer(&pdata->check_timer,
  64                           jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
  65         }
  66 }
  67
  68 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
  69 {
  70         struct platform_device *pdev = dev_id;
  71         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
  72         struct input_dev *input = pdata->input;
  73         u32 lp_status;
  74
  75         pm_wakeup_event(input->dev.parent, 0);
  76
  77         regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
  78         if (lp_status & SNVS_LPSR_SPO) {
  79                 if (pdata->minor_rev == 0) {
  80                         /*
  81                          * The first generation i.MX6 SoCs only sends an
  82                          * interrupt on button release. To mimic power-key
  83                          * usage, we'll prepend a press event.
  84                          */
  85                         input_report_key(input, pdata->keycode, 1);
  86                         input_sync(input);
  87                         input_report_key(input, pdata->keycode, 0);
  88                         input_sync(input);
  89                         pm_relax(input->dev.parent);
  90                 } else {
  91                         mod_timer(&pdata->check_timer,
  92                                   jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
  93                 }
  94         }
  95
  96         /* clear SPO status */
  97         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
  98
  99         return IRQ_HANDLED;
 100 }
 101
 102 static void imx_snvs_pwrkey_act(void *pdata)
 103 {
 104         struct pwrkey_drv_data *pd = pdata;
 105
 106         del_timer_sync(&pd->check_timer);
 107 }
 108
 109 static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
 110 {
 111         struct pwrkey_drv_data *pdata;
 112         struct input_dev *input;
 113         struct device_node *np;
 114         int error;
 115         u32 vid;
 116
 117         /* Get SNVS register Page */
 118         np = pdev->dev.of_node;
 119         if (!np)
 120                 return -ENODEV;
 121
 122         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 123         if (!pdata)
 124                 return -ENOMEM;
 125
 126         pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
 127         if (IS_ERR(pdata->snvs)) {
 128                 dev_err(&pdev->dev, "Can't get snvs syscon\n");
 129                 return PTR_ERR(pdata->snvs);
 130         }
 131
 132         if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
 133                 pdata->keycode = KEY_POWER;
 134                 dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
 135         }
 136
 137         pdata->wakeup = of_property_read_bool(np, "wakeup-source");
 138
 139         pdata->irq = platform_get_irq(pdev, 0);
 140         if (pdata->irq < 0)
 141                 return -EINVAL;
 142
 143         regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
 144         pdata->minor_rev = vid & 0xff;
 145
 146         regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
 147
 148         /* clear the unexpected interrupt before driver ready */
 149         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
 150
 151         timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
 152
 153         input = devm_input_allocate_device(&pdev->dev);
 154         if (!input) {
 155                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 156                 return -ENOMEM;
 157         }
 158
 159         input->name = pdev->name;
 160         input->phys = "snvs-pwrkey/input0";
 161         input->id.bustype = BUS_HOST;
 162
 163         input_set_capability(input, EV_KEY, pdata->keycode);
 164
 165         /* input customer action to cancel release timer */
 166         error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
 167         if (error) {
 168                 dev_err(&pdev->dev, "failed to register remove action\n");
 169                 return error;
 170         }
 171
 172         pdata->input = input;
 173         platform_set_drvdata(pdev, pdata);
 174
 175         error = devm_request_irq(&pdev->dev, pdata->irq,
 176                                imx_snvs_pwrkey_interrupt,
 177                                0, pdev->name, pdev);
 178
 179         if (error) {
 180                 dev_err(&pdev->dev, "interrupt not available.\n");
 181                 return error;
 182         }
 183
 184         error = input_register_device(input);
 185         if (error < 0) {
 186                 dev_err(&pdev->dev, "failed to register input device\n");
 187                 return error;
 188         }
 189
 190         device_init_wakeup(&pdev->dev, pdata->wakeup);
 191         error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
 192         if (error)
 193                 dev_err(&pdev->dev, "irq wake enable failed.\n");
 194
 195         return 0;
 196 }
 197
 198 static const struct of_device_id imx_snvs_pwrkey_ids[] = {
 199         { .compatible = "fsl,sec-v4.0-pwrkey" },
 200         { /* sentinel */ }
 201 };
 202 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
 203
 204 static struct platform_driver imx_snvs_pwrkey_driver = {
 205         .driver = {
 206                 .name = "snvs_pwrkey",
 207                 .of_match_table = imx_snvs_pwrkey_ids,
 208         },
 209         .probe = imx_snvs_pwrkey_probe,
 210 };
 211 module_platform_driver(imx_snvs_pwrkey_driver);
 212
 213 MODULE_AUTHOR("Freescale Semiconductor");
 214 MODULE_DESCRIPTION("i.MX snvs power key Driver");
 215 MODULE_LICENSE("GPL");