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

   1 /*
   2  * platform_wdt.c: Watchdog platform library file
   3  *
   4  * (C) Copyright 2014 Intel Corporation
   5  * Author: David Cohen <david.a.cohen@linux.intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; version 2
  10  * of the License.
  11  */
  12
  13 #include <linux/init.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/platform_data/intel-mid_wdt.h>
  17 #include <asm/intel-mid.h>
  18 #include <asm/io_apic.h>
  19
  20 #define TANGIER_EXT_TIMER0_MSI 15
  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         int gsi;
  30         struct irq_alloc_info info;
  31         struct intel_mid_wdt_pdata *pdata = pdev->dev.platform_data;
  32
  33         if (!pdata)
  34                 return -EINVAL;
  35
  36         /* IOAPIC builds identity mapping between GSI and IRQ on MID */
  37         gsi = pdata->irq;
  38         ioapic_set_alloc_attr(&info, cpu_to_node(0), 1, 0);
  39         if (mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info) <= 0) {
  40                 dev_warn(&pdev->dev, "cannot find interrupt %d in ioapic\n",
  41                          gsi);
  42                 return -EINVAL;
  43         }
  44
  45         return 0;
  46 }
  47
  48 static struct intel_mid_wdt_pdata tangier_pdata = {
  49         .irq = TANGIER_EXT_TIMER0_MSI,
  50         .probe = tangier_probe,
  51 };
  52
  53 static int __init register_mid_wdt(void)
  54 {
  55         if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER) {
  56                 wdt_dev.dev.platform_data = &tangier_pdata;
  57                 return platform_device_register(&wdt_dev);
  58         }
  59
  60         return -ENODEV;
  61 }
  62
  63 rootfs_initcall(register_mid_wdt);