1 // SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause 2 /* 3 * Copyright (C) 2020 VMware, Inc., Palo Alto, CA., USA 4 * 5 * PTP clock driver for VMware precision clock virtual device. 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/acpi.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/ptp_clock_kernel.h> 14 #include <asm/hypervisor.h> 15 #include <asm/vmware.h> 16 17 #define VMWARE_CMD_PCLK(nr) ((nr << 16) | 97) 18 #define VMWARE_CMD_PCLK_GETTIME VMWARE_CMD_PCLK(0) 19 20 static struct acpi_device *ptp_vmw_acpi_device; 21 static struct ptp_clock *ptp_vmw_clock; 22 23 24 static int ptp_vmw_pclk_read(u64 *ns) 25 { 26 u32 ret, nsec_hi, nsec_lo; 27 28 ret = vmware_hypercall3(VMWARE_CMD_PCLK_GETTIME, 0, 29 &nsec_hi, &nsec_lo); 30 if (ret == 0) 31 *ns = ((u64)nsec_hi << 32) | nsec_lo; 32 return ret; 33 } 34 35 /* 36 * PTP clock ops. 37 */ 38 39 static int ptp_vmw_adjtime(struct ptp_clock_info *info, s64 delta) 40 { 41 return -EOPNOTSUPP; 42 } 43 44 static int ptp_vmw_adjfine(struct ptp_clock_info *info, long delta) 45 { 46 return -EOPNOTSUPP; 47 } 48 49 static int ptp_vmw_gettime(struct ptp_clock_info *info, struct timespec64 *ts) 50 { 51 u64 ns; 52 53 if (ptp_vmw_pclk_read(&ns) != 0) 54 return -EIO; 55 *ts = ns_to_timespec64(ns); 56 return 0; 57 } 58 59 static int ptp_vmw_settime(struct ptp_clock_info *info, 60 const struct timespec64 *ts) 61 { 62 return -EOPNOTSUPP; 63 } 64 65 static int ptp_vmw_enable(struct ptp_clock_info *info, 66 struct ptp_clock_request *request, int on) 67 { 68 return -EOPNOTSUPP; 69 } 70 71 static struct ptp_clock_info ptp_vmw_clock_info = { 72 .owner = THIS_MODULE, 73 .name = "ptp_vmw", 74 .max_adj = 0, 75 .adjtime = ptp_vmw_adjtime, 76 .adjfine = ptp_vmw_adjfine, 77 .gettime64 = ptp_vmw_gettime, 78 .settime64 = ptp_vmw_settime, 79 .enable = ptp_vmw_enable, 80 }; 81 82 /* 83 * ACPI driver ops for VMware "precision clock" virtual device. 84 */ 85 86 static int ptp_vmw_acpi_add(struct acpi_device *device) 87 { 88 ptp_vmw_clock = ptp_clock_register(&ptp_vmw_clock_info, NULL); 89 if (IS_ERR(ptp_vmw_clock)) { 90 pr_err("failed to register ptp clock\n"); 91 return PTR_ERR(ptp_vmw_clock); 92 } 93 94 ptp_vmw_acpi_device = device; 95 return 0; 96 } 97 98 static void ptp_vmw_acpi_remove(struct acpi_device *device) 99 { 100 ptp_clock_unregister(ptp_vmw_clock); 101 } 102 103 static const struct acpi_device_id ptp_vmw_acpi_device_ids[] = { 104 { "VMW0005", 0 }, 105 { "", 0 }, 106 }; 107 108 MODULE_DEVICE_TABLE(acpi, ptp_vmw_acpi_device_ids); 109 110 static struct acpi_driver ptp_vmw_acpi_driver = { 111 .name = "ptp_vmw", 112 .ids = ptp_vmw_acpi_device_ids, 113 .ops = { 114 .add = ptp_vmw_acpi_add, 115 .remove = ptp_vmw_acpi_remove 116 }, 117 }; 118 119 static int __init ptp_vmw_init(void) 120 { 121 if (x86_hyper_type != X86_HYPER_VMWARE) 122 return -1; 123 return acpi_bus_register_driver(&ptp_vmw_acpi_driver); 124 } 125 126 static void __exit ptp_vmw_exit(void) 127 { 128 acpi_bus_unregister_driver(&ptp_vmw_acpi_driver); 129 } 130 131 module_init(ptp_vmw_init); 132 module_exit(ptp_vmw_exit); 133 134 MODULE_DESCRIPTION("VMware virtual PTP clock driver"); 135 MODULE_AUTHOR("VMware, Inc."); 136 MODULE_LICENSE("Dual BSD/GPL"); 137