drivers/input/keyboard/imx_sc_key.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2019 NXP.
   4  */
   5
   6 #include <linux/err.h>
   7 #include <linux/device.h>
   8 #include <linux/firmware/imx/sci.h>
   9 #include <linux/init.h>
  10 #include <linux/input.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/property.h>
  18
  19 #define DEBOUNCE_TIME                           30
  20 #define REPEAT_INTERVAL                         60
  21
  22 #define SC_IRQ_BUTTON                           1
  23 #define SC_IRQ_GROUP_WAKE                       3
  24
  25 #define IMX_SC_MISC_FUNC_GET_BUTTON_STATUS      18
  26
  27 struct imx_key_drv_data {
  28         u32 keycode;
  29         bool keystate;  /* true: pressed, false: released */
  30         struct delayed_work check_work;
  31         struct input_dev *input;
  32         struct imx_sc_ipc *key_ipc_handle;
  33         struct notifier_block key_notifier;
  34 };
  35
  36 struct imx_sc_msg_key {
  37         struct imx_sc_rpc_msg hdr;
  38         u32 state;
  39 };
  40
  41 static int imx_sc_key_notify(struct notifier_block *nb,
  42                              unsigned long event, void *group)
  43 {
  44         struct imx_key_drv_data *priv =
  45                                  container_of(nb,
  46                                               struct imx_key_drv_data,
  47                                               key_notifier);
  48
  49         if ((event & SC_IRQ_BUTTON) && (*(u8 *)group == SC_IRQ_GROUP_WAKE)) {
  50                 schedule_delayed_work(&priv->check_work,
  51                                       msecs_to_jiffies(DEBOUNCE_TIME));
  52                 pm_wakeup_event(priv->input->dev.parent, 0);
  53         }
  54
  55         return 0;
  56 }
  57
  58 static void imx_sc_check_for_events(struct work_struct *work)
  59 {
  60         struct imx_key_drv_data *priv =
  61                                  container_of(work,
  62                                               struct imx_key_drv_data,
  63                                               check_work.work);
  64         struct input_dev *input = priv->input;
  65         struct imx_sc_msg_key msg;
  66         struct imx_sc_rpc_msg *hdr = &msg.hdr;
  67         bool state;
  68         int error;
  69
  70         hdr->ver = IMX_SC_RPC_VERSION;
  71         hdr->svc = IMX_SC_RPC_SVC_MISC;
  72         hdr->func = IMX_SC_MISC_FUNC_GET_BUTTON_STATUS;
  73         hdr->size = 1;
  74
  75         error = imx_scu_call_rpc(priv->key_ipc_handle, &msg, true);
  76         if (error) {
  77                 dev_err(&input->dev, "read imx sc key failed, error %d\n", error);
  78                 return;
  79         }
  80
  81         /*
  82          * The response data from SCU firmware is 4 bytes,
  83          * but ONLY the first byte is the key state, other
  84          * 3 bytes could be some dirty data, so we should
  85          * ONLY take the first byte as key state.
  86          */
  87         state = (bool)(msg.state & 0xff);
  88
  89         if (state ^ priv->keystate) {
  90                 priv->keystate = state;
  91                 input_event(input, EV_KEY, priv->keycode, state);
  92                 input_sync(input);
  93                 if (!priv->keystate)
  94                         pm_relax(priv->input->dev.parent);
  95         }
  96
  97         if (state)
  98                 schedule_delayed_work(&priv->check_work,
  99                                       msecs_to_jiffies(REPEAT_INTERVAL));
 100 }
 101
 102 static int imx_sc_key_probe(struct platform_device *pdev)
 103 {
 104         struct imx_key_drv_data *priv;
 105         struct input_dev *input;
 106         int error;
 107
 108         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 109         if (!priv)
 110                 return -ENOMEM;
 111
 112         error = imx_scu_get_handle(&priv->key_ipc_handle);
 113         if (error)
 114                 return error;
 115
 116         if (device_property_read_u32(&pdev->dev, "linux,keycodes",
 117                                      &priv->keycode)) {
 118                 dev_err(&pdev->dev, "missing linux,keycodes property\n");
 119                 return -EINVAL;
 120         }
 121
 122         INIT_DELAYED_WORK(&priv->check_work, imx_sc_check_for_events);
 123
 124         input = devm_input_allocate_device(&pdev->dev);
 125         if (!input) {
 126                 dev_err(&pdev->dev, "failed to allocate the input device\n");
 127                 return -ENOMEM;
 128         }
 129
 130         input->name = pdev->name;
 131         input->phys = "imx-sc-key/input0";
 132         input->id.bustype = BUS_HOST;
 133
 134         input_set_capability(input, EV_KEY, priv->keycode);
 135
 136         error = input_register_device(input);
 137         if (error) {
 138                 dev_err(&pdev->dev, "failed to register input device\n");
 139                 return error;
 140         }
 141
 142         priv->input = input;
 143         platform_set_drvdata(pdev, priv);
 144
 145         error = imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON,
 146                                          true);
 147         if (error) {
 148                 dev_err(&pdev->dev, "failed to enable scu group irq\n");
 149                 return error;
 150         }
 151
 152         priv->key_notifier.notifier_call = imx_sc_key_notify;
 153         error = imx_scu_irq_register_notifier(&priv->key_notifier);
 154         if (error) {
 155                 imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON,
 156                                          false);
 157                 dev_err(&pdev->dev, "failed to register scu notifier\n");
 158                 return error;
 159         }
 160
 161         return 0;
 162 }
 163
 164 static int imx_sc_key_remove(struct platform_device *pdev)
 165 {
 166         struct imx_key_drv_data *priv = platform_get_drvdata(pdev);
 167
 168         imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON, false);
 169         imx_scu_irq_unregister_notifier(&priv->key_notifier);
 170         cancel_delayed_work_sync(&priv->check_work);
 171
 172         return 0;
 173 }
 174
 175 static const struct of_device_id imx_sc_key_ids[] = {
 176         { .compatible = "fsl,imx-sc-key" },
 177         { /* sentinel */ }
 178 };
 179 MODULE_DEVICE_TABLE(of, imx_sc_key_ids);
 180
 181 static struct platform_driver imx_sc_key_driver = {
 182         .driver = {
 183                 .name = "imx-sc-key",
 184                 .of_match_table = imx_sc_key_ids,
 185         },
 186         .probe = imx_sc_key_probe,
 187         .remove = imx_sc_key_remove,
 188 };
 189 module_platform_driver(imx_sc_key_driver);
 190
 191 MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
 192 MODULE_DESCRIPTION("i.MX System Controller Key Driver");
 193 MODULE_LICENSE("GPL v2");