drivers/input/keyboard/snvs_pwrkey.c

   1 /*
   2  * Driver for the IMX SNVS ON/OFF Power Key
   3  * Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved.
   4  *
   5  * The code contained herein is licensed under the GNU General Public
   6  * License. You may obtain a copy of the GNU General Public License
   7  * Version 2 or later at the following locations:
   8  *
   9  * http://www.opensource.org/licenses/gpl-license.html
  10  * http://www.gnu.org/copyleft/gpl.html
  11  */
  12
  13 #include <linux/device.h>
  14 #include <linux/err.h>
  15 #include <linux/init.h>
  16 #include <linux/input.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/jiffies.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/of_address.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/mfd/syscon.h>
  26 #include <linux/regmap.h>
  27
  28 #define SNVS_LPSR_REG   0x4C    /* LP Status Register */
  29 #define SNVS_LPCR_REG   0x38    /* LP Control Register */
  30 #define SNVS_HPSR_REG   0x14
  31 #define SNVS_HPSR_BTN   BIT(6)
  32 #define SNVS_LPSR_SPO   BIT(18)
  33 #define SNVS_LPCR_DEP_EN BIT(5)
  34
  35 #define DEBOUNCE_TIME 30
  36 #define REPEAT_INTERVAL 60
  37
  38 struct pwrkey_drv_data {
  39         struct regmap *snvs;
  40         int irq;
  41         int keycode;
  42         int keystate;  /* 1:pressed */
  43         int wakeup;
  44         struct timer_list check_timer;
  45         struct input_dev *input;
  46 };
  47
  48 static void imx_imx_snvs_check_for_events(unsigned long data)
  49 {
  50         struct pwrkey_drv_data *pdata = (struct pwrkey_drv_data *) data;
  51         struct input_dev *input = pdata->input;
  52         u32 state;
  53
  54         regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
  55         state = state & SNVS_HPSR_BTN ? 1 : 0;
  56
  57         /* only report new event if status changed */
  58         if (state ^ pdata->keystate) {
  59                 pdata->keystate = state;
  60                 input_event(input, EV_KEY, pdata->keycode, state);
  61                 input_sync(input);
  62                 pm_relax(pdata->input->dev.parent);
  63         }
  64
  65         /* repeat check if pressed long */
  66         if (state) {
  67                 mod_timer(&pdata->check_timer,
  68                           jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
  69         }
  70 }
  71
  72 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
  73 {
  74         struct platform_device *pdev = dev_id;
  75         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
  76         u32 lp_status;
  77
  78         pm_wakeup_event(pdata->input->dev.parent, 0);
  79
  80         regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
  81         if (lp_status & SNVS_LPSR_SPO)
  82                 mod_timer(&pdata->check_timer, jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
  83
  84         /* clear SPO status */
  85         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
  86
  87         return IRQ_HANDLED;
  88 }
  89
  90 static void imx_snvs_pwrkey_act(void *pdata)
  91 {
  92         struct pwrkey_drv_data *pd = pdata;
  93
  94         del_timer_sync(&pd->check_timer);
  95 }
  96
  97 static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
  98 {
  99         struct pwrkey_drv_data *pdata = NULL;
 100         struct input_dev *input = NULL;
 101         struct device_node *np;
 102         int error;
 103
 104         /* Get SNVS register Page */
 105         np = pdev->dev.of_node;
 106         if (!np)
 107                 return -ENODEV;
 108
 109         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 110         if (!pdata)
 111                 return -ENOMEM;
 112
 113         pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
 114         if (!pdata->snvs) {
 115                 dev_err(&pdev->dev, "Can't get snvs syscon\n");
 116                 return -ENODEV;
 117         }
 118
 119         if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
 120                 pdata->keycode = KEY_POWER;
 121                 dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
 122         }
 123
 124         pdata->wakeup = of_property_read_bool(np, "wakeup-source");
 125
 126         pdata->irq = platform_get_irq(pdev, 0);
 127         if (pdata->irq < 0) {
 128                 dev_err(&pdev->dev, "no irq defined in platform data\n");
 129                 return -EINVAL;
 130         }
 131
 132         regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
 133
 134         /* clear the unexpected interrupt before driver ready */
 135         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
 136
 137         setup_timer(&pdata->check_timer,
 138                     imx_imx_snvs_check_for_events, (unsigned long) pdata);
 139
 140         input = devm_input_allocate_device(&pdev->dev);
 141         if (!input) {
 142                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 143                 return -ENOMEM;
 144         }
 145
 146         input->name = pdev->name;
 147         input->phys = "snvs-pwrkey/input0";
 148         input->id.bustype = BUS_HOST;
 149
 150         input_set_capability(input, EV_KEY, pdata->keycode);
 151
 152         /* input customer action to cancel release timer */
 153         error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
 154         if (error) {
 155                 dev_err(&pdev->dev, "failed to register remove action\n");
 156                 return error;
 157         }
 158
 159         error = devm_request_irq(&pdev->dev, pdata->irq,
 160                                imx_snvs_pwrkey_interrupt,
 161                                0, pdev->name, pdev);
 162
 163         if (error) {
 164                 dev_err(&pdev->dev, "interrupt not available.\n");
 165                 return error;
 166         }
 167
 168         error = input_register_device(input);
 169         if (error < 0) {
 170                 dev_err(&pdev->dev, "failed to register input device\n");
 171                 input_free_device(input);
 172                 return error;
 173         }
 174
 175         pdata->input = input;
 176         platform_set_drvdata(pdev, pdata);
 177
 178         device_init_wakeup(&pdev->dev, pdata->wakeup);
 179
 180         return 0;
 181 }
 182
 183 static int imx_snvs_pwrkey_suspend(struct device *dev)
 184 {
 185         struct platform_device *pdev = to_platform_device(dev);
 186         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
 187
 188         if (device_may_wakeup(&pdev->dev))
 189                 enable_irq_wake(pdata->irq);
 190
 191         return 0;
 192 }
 193
 194 static int imx_snvs_pwrkey_resume(struct device *dev)
 195 {
 196         struct platform_device *pdev = to_platform_device(dev);
 197         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
 198
 199         if (device_may_wakeup(&pdev->dev))
 200                 disable_irq_wake(pdata->irq);
 201
 202         return 0;
 203 }
 204
 205 static const struct of_device_id imx_snvs_pwrkey_ids[] = {
 206         { .compatible = "fsl,sec-v4.0-pwrkey" },
 207         { /* sentinel */ }
 208 };
 209 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
 210
 211 static SIMPLE_DEV_PM_OPS(imx_snvs_pwrkey_pm_ops, imx_snvs_pwrkey_suspend,
 212                                 imx_snvs_pwrkey_resume);
 213
 214 static struct platform_driver imx_snvs_pwrkey_driver = {
 215         .driver = {
 216                 .name = "snvs_pwrkey",
 217                 .pm     = &imx_snvs_pwrkey_pm_ops,
 218                 .of_match_table = imx_snvs_pwrkey_ids,
 219         },
 220         .probe = imx_snvs_pwrkey_probe,
 221 };
 222 module_platform_driver(imx_snvs_pwrkey_driver);
 223
 224 MODULE_AUTHOR("Freescale Semiconductor");
 225 MODULE_DESCRIPTION("i.MX snvs power key Driver");
 226 MODULE_LICENSE("GPL");