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 intel_mid_wdt_pdata *pdata = pdev->dev.platform_data;
  31
  32         if (!pdata)
  33                 return -EINVAL;
  34
  35         /* IOAPIC builds identity mapping between GSI and IRQ on MID */
  36         gsi = pdata->irq;
  37         if (mp_set_gsi_attr(gsi, 1, 0, cpu_to_node(0)) ||
  38             mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC) <= 0) {
  39                 dev_warn(&pdev->dev, "cannot find interrupt %d in ioapic\n",
  40                          gsi);
  41                 return -EINVAL;
  42         }
  43
  44         return 0;
  45 }
  46
  47 static struct intel_mid_wdt_pdata tangier_pdata = {
  48         .irq = TANGIER_EXT_TIMER0_MSI,
  49         .probe = tangier_probe,
  50 };
  51
  52 static int __init register_mid_wdt(void)
  53 {
  54         if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER) {
  55                 wdt_dev.dev.platform_data = &tangier_pdata;
  56                 return platform_device_register(&wdt_dev);
  57         }
  58
  59         return -ENODEV;
  60 }
  61
  62 rootfs_initcall(register_mid_wdt);