drivers/platform/x86/intel_scu_wdt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel Merrifield watchdog platform device library file
   4  *
   5  * (C) Copyright 2014 Intel Corporation
   6  * Author: David Cohen <david.a.cohen@linux.intel.com>
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/platform_device.h>
  12
  13 #include <asm/cpu_device_id.h>
  14 #include <asm/intel-family.h>
  15 #include <asm/io_apic.h>
  16 #include <asm/hw_irq.h>
  17
  18 #include <linux/platform_data/x86/intel-mid_wdt.h>
  19
  20 #define TANGIER_EXT_TIMER0_MSI 12
  21
  22 static struct platform_device wdt_dev = {
  23         .name = "intel_mid_wdt",
  24         .id = -1,
  25 };
  26
  27 static int tangier_probe(struct platform_device *pdev)
  28 {
  29         struct irq_alloc_info info;
  30         struct intel_mid_wdt_pdata *pdata = pdev->dev.platform_data;
  31         int gsi = TANGIER_EXT_TIMER0_MSI;
  32         int irq;
  33
  34         if (!pdata)
  35                 return -EINVAL;
  36
  37         /* IOAPIC builds identity mapping between GSI and IRQ on MID */
  38         ioapic_set_alloc_attr(&info, cpu_to_node(0), 1, 0);
  39         irq = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info);
  40         if (irq < 0) {
  41                 dev_warn(&pdev->dev, "cannot find interrupt %d in ioapic\n", gsi);
  42                 return irq;
  43         }
  44
  45         pdata->irq = irq;
  46         return 0;
  47 }
  48
  49 static struct intel_mid_wdt_pdata tangier_pdata = {
  50         .probe = tangier_probe,
  51 };
  52
  53 static const struct x86_cpu_id intel_mid_cpu_ids[] = {
  54         X86_MATCH_VFM(INTEL_ATOM_SILVERMONT_MID, &tangier_pdata),
  55         {}
  56 };
  57
  58 static int __init register_mid_wdt(void)
  59 {
  60         const struct x86_cpu_id *id;
  61
  62         id = x86_match_cpu(intel_mid_cpu_ids);
  63         if (!id)
  64                 return -ENODEV;
  65
  66         wdt_dev.dev.platform_data = (struct intel_mid_wdt_pdata *)id->driver_data;
  67         return platform_device_register(&wdt_dev);
  68 }
  69 arch_initcall(register_mid_wdt);
  70
  71 static void __exit unregister_mid_wdt(void)
  72 {
  73         platform_device_unregister(&wdt_dev);
  74 }
  75 __exitcall(unregister_mid_wdt);