platform/x86/intel_scu_wdt.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Intel Merrifield watchdog platform device library file
0004  *
0005  * (C) Copyright 2014 Intel Corporation
0006  * Author: David Cohen <david.a.cohen@linux.intel.com>
0007  */
0008
0009 #include <linux/init.h>
0010 #include <linux/interrupt.h>
0011 #include <linux/platform_device.h>
0012 #include <linux/platform_data/intel-mid_wdt.h>
0013
0014 #include <asm/cpu_device_id.h>
0015 #include <asm/intel-family.h>
0016 #include <asm/intel-mid.h>
0017 #include <asm/io_apic.h>
0018 #include <asm/hw_irq.h>
0019
0020 #define TANGIER_EXT_TIMER0_MSI 12
0021
0022 static struct platform_device wdt_dev = {
0023     .name = "intel_mid_wdt",
0024     .id = -1,
0025 };
0026
0027 static int tangier_probe(struct platform_device *pdev)
0028 {
0029     struct irq_alloc_info info;
0030     struct intel_mid_wdt_pdata *pdata = pdev->dev.platform_data;
0031     int gsi = TANGIER_EXT_TIMER0_MSI;
0032     int irq;
0033
0034     if (!pdata)
0035         return -EINVAL;
0036
0037     /* IOAPIC builds identity mapping between GSI and IRQ on MID */
0038     ioapic_set_alloc_attr(&info, cpu_to_node(0), 1, 0);
0039     irq = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info);
0040     if (irq < 0) {
0041         dev_warn(&pdev->dev, "cannot find interrupt %d in ioapic\n", gsi);
0042         return irq;
0043     }
0044
0045     pdata->irq = irq;
0046     return 0;
0047 }
0048
0049 static struct intel_mid_wdt_pdata tangier_pdata = {
0050     .probe = tangier_probe,
0051 };
0052
0053 static const struct x86_cpu_id intel_mid_cpu_ids[] = {
0054     X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID, &tangier_pdata),
0055     {}
0056 };
0057
0058 static int __init register_mid_wdt(void)
0059 {
0060     const struct x86_cpu_id *id;
0061
0062     id = x86_match_cpu(intel_mid_cpu_ids);
0063     if (!id)
0064         return -ENODEV;
0065
0066     wdt_dev.dev.platform_data = (struct intel_mid_wdt_pdata *)id->driver_data;
0067     return platform_device_register(&wdt_dev);
0068 }
0069 arch_initcall(register_mid_wdt);
0070
0071 static void __exit unregister_mid_wdt(void)
0072 {
0073     platform_device_unregister(&wdt_dev);
0074 }
0075 __exitcall(unregister_mid_wdt);