arch/x86/platform/intel-mid/device_libs/platform_mrfld_power_btn.c

   1 /*
   2  * Intel Merrifield power button support
   3  *
   4  * (C) Copyright 2017 Intel Corporation
   5  *
   6  * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; version 2
  11  * of the License.
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/ioport.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/sfi.h>
  18
  19 #include <asm/intel-mid.h>
  20 #include <asm/intel_scu_ipc.h>
  21
  22 static struct resource mrfld_power_btn_resources[] = {
  23         {
  24                 .flags          = IORESOURCE_IRQ,
  25         },
  26 };
  27
  28 static struct platform_device mrfld_power_btn_dev = {
  29         .name           = "msic_power_btn",
  30         .id             = PLATFORM_DEVID_NONE,
  31         .num_resources  = ARRAY_SIZE(mrfld_power_btn_resources),
  32         .resource       = mrfld_power_btn_resources,
  33 };
  34
  35 static int mrfld_power_btn_scu_status_change(struct notifier_block *nb,
  36                                              unsigned long code, void *data)
  37 {
  38         if (code == SCU_DOWN) {
  39                 platform_device_unregister(&mrfld_power_btn_dev);
  40                 return 0;
  41         }
  42
  43         return platform_device_register(&mrfld_power_btn_dev);
  44 }
  45
  46 static struct notifier_block mrfld_power_btn_scu_notifier = {
  47         .notifier_call  = mrfld_power_btn_scu_status_change,
  48 };
  49
  50 static int __init register_mrfld_power_btn(void)
  51 {
  52         if (intel_mid_identify_cpu() != INTEL_MID_CPU_CHIP_TANGIER)
  53                 return -ENODEV;
  54
  55         /*
  56          * We need to be sure that the SCU IPC is ready before
  57          * PMIC power button device can be registered:
  58          */
  59         intel_scu_notifier_add(&mrfld_power_btn_scu_notifier);
  60
  61         return 0;
  62 }
  63 arch_initcall(register_mrfld_power_btn);
  64
  65 static void __init *mrfld_power_btn_platform_data(void *info)
  66 {
  67         struct resource *res = mrfld_power_btn_resources;
  68         struct sfi_device_table_entry *pentry = info;
  69
  70         res->start = res->end = pentry->irq;
  71         return NULL;
  72 }
  73
  74 static const struct devs_id mrfld_power_btn_dev_id __initconst = {
  75         .name                   = "bcove_power_btn",
  76         .type                   = SFI_DEV_TYPE_IPC,
  77         .delay                  = 1,
  78         .msic                   = 1,
  79         .get_platform_data      = &mrfld_power_btn_platform_data,
  80 };
  81
  82 sfi_device(mrfld_power_btn_dev_id);