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/clk.h>
   7 #include <linux/device.h>
   8 #include <linux/err.h>
   9 #include <linux/init.h>
  10 #include <linux/input.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/io.h>
  13 #include <linux/jiffies.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/pm_wakeirq.h>
  20 #include <linux/mfd/syscon.h>
  21 #include <linux/regmap.h>
  22
  23 #define SNVS_HPVIDR1_REG        0xBF8
  24 #define SNVS_LPSR_REG           0x4C    /* LP Status Register */
  25 #define SNVS_LPCR_REG           0x38    /* LP Control Register */
  26 #define SNVS_HPSR_REG           0x14
  27 #define SNVS_HPSR_BTN           BIT(6)
  28 #define SNVS_LPSR_SPO           BIT(18)
  29 #define SNVS_LPCR_DEP_EN        BIT(5)
  30
  31 #define DEBOUNCE_TIME           30
  32 #define REPEAT_INTERVAL         60
  33
  34 struct pwrkey_drv_data {
  35         struct regmap *snvs;
  36         int irq;
  37         int keycode;
  38         int keystate;  /* 1:pressed */
  39         int wakeup;
  40         struct timer_list check_timer;
  41         struct input_dev *input;
  42         u8 minor_rev;
  43 };
  44
  45 static void imx_imx_snvs_check_for_events(struct timer_list *t)
  46 {
  47         struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
  48         struct input_dev *input = pdata->input;
  49         u32 state;
  50
  51         regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
  52         state = state & SNVS_HPSR_BTN ? 1 : 0;
  53
  54         /* only report new event if status changed */
  55         if (state ^ pdata->keystate) {
  56                 pdata->keystate = state;
  57                 input_event(input, EV_KEY, pdata->keycode, state);
  58                 input_sync(input);
  59                 pm_relax(pdata->input->dev.parent);
  60         }
  61
  62         /* repeat check if pressed long */
  63         if (state) {
  64                 mod_timer(&pdata->check_timer,
  65                           jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
  66         }
  67 }
  68
  69 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
  70 {
  71         struct platform_device *pdev = dev_id;
  72         struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
  73         struct input_dev *input = pdata->input;
  74         u32 lp_status;
  75
  76         pm_wakeup_event(input->dev.parent, 0);
  77
  78         regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
  79         if (lp_status & SNVS_LPSR_SPO) {
  80                 if (pdata->minor_rev == 0) {
  81                         /*
  82                          * The first generation i.MX6 SoCs only sends an
  83                          * interrupt on button release. To mimic power-key
  84                          * usage, we'll prepend a press event.
  85                          */
  86                         input_report_key(input, pdata->keycode, 1);
  87                         input_sync(input);
  88                         input_report_key(input, pdata->keycode, 0);
  89                         input_sync(input);
  90                         pm_relax(input->dev.parent);
  91                 } else {
  92                         mod_timer(&pdata->check_timer,
  93                                   jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
  94                 }
  95         }
  96
  97         /* clear SPO status */
  98         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
  99
 100         return IRQ_HANDLED;
 101 }
 102
 103 static void imx_snvs_pwrkey_act(void *pdata)
 104 {
 105         struct pwrkey_drv_data *pd = pdata;
 106
 107         del_timer_sync(&pd->check_timer);
 108 }
 109
 110 static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
 111 {
 112         struct pwrkey_drv_data *pdata;
 113         struct input_dev *input;
 114         struct device_node *np;
 115         struct clk *clk;
 116         int error;
 117         u32 vid;
 118
 119         /* Get SNVS register Page */
 120         np = pdev->dev.of_node;
 121         if (!np)
 122                 return -ENODEV;
 123
 124         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 125         if (!pdata)
 126                 return -ENOMEM;
 127
 128         pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
 129         if (IS_ERR(pdata->snvs)) {
 130                 dev_err(&pdev->dev, "Can't get snvs syscon\n");
 131                 return PTR_ERR(pdata->snvs);
 132         }
 133
 134         if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
 135                 pdata->keycode = KEY_POWER;
 136                 dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
 137         }
 138
 139         clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);
 140         if (IS_ERR(clk)) {
 141                 dev_err(&pdev->dev, "Failed to get snvs clock (%pe)\n", clk);
 142                 return PTR_ERR(clk);
 143         }
 144
 145         pdata->wakeup = of_property_read_bool(np, "wakeup-source");
 146
 147         pdata->irq = platform_get_irq(pdev, 0);
 148         if (pdata->irq < 0)
 149                 return -EINVAL;
 150
 151         regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
 152         pdata->minor_rev = vid & 0xff;
 153
 154         regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
 155
 156         /* clear the unexpected interrupt before driver ready */
 157         regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
 158
 159         timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
 160
 161         input = devm_input_allocate_device(&pdev->dev);
 162         if (!input) {
 163                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 164                 return -ENOMEM;
 165         }
 166
 167         input->name = pdev->name;
 168         input->phys = "snvs-pwrkey/input0";
 169         input->id.bustype = BUS_HOST;
 170
 171         input_set_capability(input, EV_KEY, pdata->keycode);
 172
 173         /* input customer action to cancel release timer */
 174         error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
 175         if (error) {
 176                 dev_err(&pdev->dev, "failed to register remove action\n");
 177                 return error;
 178         }
 179
 180         pdata->input = input;
 181         platform_set_drvdata(pdev, pdata);
 182
 183         error = devm_request_irq(&pdev->dev, pdata->irq,
 184                                imx_snvs_pwrkey_interrupt,
 185                                0, pdev->name, pdev);
 186         if (error) {
 187                 dev_err(&pdev->dev, "interrupt not available.\n");
 188                 return error;
 189         }
 190
 191         error = input_register_device(input);
 192         if (error < 0) {
 193                 dev_err(&pdev->dev, "failed to register input device\n");
 194                 return error;
 195         }
 196
 197         device_init_wakeup(&pdev->dev, pdata->wakeup);
 198         error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
 199         if (error)
 200                 dev_err(&pdev->dev, "irq wake enable failed.\n");
 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 struct platform_driver imx_snvs_pwrkey_driver = {
 212         .driver = {
 213                 .name = "snvs_pwrkey",
 214                 .of_match_table = imx_snvs_pwrkey_ids,
 215         },
 216         .probe = imx_snvs_pwrkey_probe,
 217 };
 218 module_platform_driver(imx_snvs_pwrkey_driver);
 219
 220 MODULE_AUTHOR("Freescale Semiconductor");
 221 MODULE_DESCRIPTION("i.MX snvs power key Driver");
 222 MODULE_LICENSE("GPL");