linux/drivers/input/keyboard/imx_sc_key.c
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   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
  27struct 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
  36struct imx_sc_msg_key {
  37        struct imx_sc_rpc_msg hdr;
  38        u32 state;
  39};
  40
  41static 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
  58static 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
 102static void imx_sc_key_action(void *data)
 103{
 104        struct imx_key_drv_data *priv = data;
 105
 106        imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON, false);
 107        imx_scu_irq_unregister_notifier(&priv->key_notifier);
 108        cancel_delayed_work_sync(&priv->check_work);
 109}
 110
 111static int imx_sc_key_probe(struct platform_device *pdev)
 112{
 113        struct imx_key_drv_data *priv;
 114        struct input_dev *input;
 115        int error;
 116
 117        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 118        if (!priv)
 119                return -ENOMEM;
 120
 121        error = imx_scu_get_handle(&priv->key_ipc_handle);
 122        if (error)
 123                return error;
 124
 125        if (device_property_read_u32(&pdev->dev, "linux,keycodes",
 126                                     &priv->keycode)) {
 127                dev_err(&pdev->dev, "missing linux,keycodes property\n");
 128                return -EINVAL;
 129        }
 130
 131        INIT_DELAYED_WORK(&priv->check_work, imx_sc_check_for_events);
 132
 133        input = devm_input_allocate_device(&pdev->dev);
 134        if (!input) {
 135                dev_err(&pdev->dev, "failed to allocate the input device\n");
 136                return -ENOMEM;
 137        }
 138
 139        input->name = pdev->name;
 140        input->phys = "imx-sc-key/input0";
 141        input->id.bustype = BUS_HOST;
 142
 143        input_set_capability(input, EV_KEY, priv->keycode);
 144
 145        error = input_register_device(input);
 146        if (error) {
 147                dev_err(&pdev->dev, "failed to register input device\n");
 148                return error;
 149        }
 150
 151        priv->input = input;
 152        platform_set_drvdata(pdev, priv);
 153
 154        error = imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON,
 155                                         true);
 156        if (error) {
 157                dev_err(&pdev->dev, "failed to enable scu group irq\n");
 158                return error;
 159        }
 160
 161        error = devm_add_action_or_reset(&pdev->dev, imx_sc_key_action, &priv);
 162        if (error)
 163                return error;
 164
 165        priv->key_notifier.notifier_call = imx_sc_key_notify;
 166        error = imx_scu_irq_register_notifier(&priv->key_notifier);
 167        if (error)
 168                dev_err(&pdev->dev, "failed to register scu notifier\n");
 169
 170        return error;
 171}
 172
 173static const struct of_device_id imx_sc_key_ids[] = {
 174        { .compatible = "fsl,imx-sc-key" },
 175        { /* sentinel */ }
 176};
 177MODULE_DEVICE_TABLE(of, imx_sc_key_ids);
 178
 179static struct platform_driver imx_sc_key_driver = {
 180        .driver = {
 181                .name = "imx-sc-key",
 182                .of_match_table = imx_sc_key_ids,
 183        },
 184        .probe = imx_sc_key_probe,
 185};
 186module_platform_driver(imx_sc_key_driver);
 187
 188MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
 189MODULE_DESCRIPTION("i.MX System Controller Key Driver");
 190MODULE_LICENSE("GPL v2");
 191