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/platform_device.h> 14 #include <linux/ptp_clock_kernel.h> 15 #include <asm/hypervisor.h> 16 #include <asm/vmware.h> 17 18 #define VMWARE_CMD_PCLK(nr) ((nr << 16) | 97) 19 #define VMWARE_CMD_PCLK_GETTIME VMWARE_CMD_PCLK(0) 20 21 static struct acpi_device *ptp_vmw_acpi_device; 22 static struct ptp_clock *ptp_vmw_clock; 23 24 25 static int ptp_vmw_pclk_read(u64 *ns) 26 { 27 u32 ret, nsec_hi, nsec_lo; 28 29 ret = vmware_hypercall3(VMWARE_CMD_PCLK_GETTIME, 0, 30 &nsec_hi, &nsec_lo); 31 if (ret == 0) 32 *ns = ((u64)nsec_hi << 32) | nsec_lo; 33 return ret; 34 } 35 36 /* 37 * PTP clock ops. 38 */ 39 40 static int ptp_vmw_adjtime(struct ptp_clock_info *info, s64 delta) 41 { 42 return -EOPNOTSUPP; 43 } 44 45 static int ptp_vmw_adjfine(struct ptp_clock_info *info, long delta) 46 { 47 return -EOPNOTSUPP; 48 } 49 50 static int ptp_vmw_gettime(struct ptp_clock_info *info, struct timespec64 *ts) 51 { 52 u64 ns; 53 54 if (ptp_vmw_pclk_read(&ns) != 0) 55 return -EIO; 56 *ts = ns_to_timespec64(ns); 57 return 0; 58 } 59 60 static int ptp_vmw_settime(struct ptp_clock_info *info, 61 const struct timespec64 *ts) 62 { 63 return -EOPNOTSUPP; 64 } 65 66 static int ptp_vmw_enable(struct ptp_clock_info *info, 67 struct ptp_clock_request *request, int on) 68 { 69 return -EOPNOTSUPP; 70 } 71 72 static struct ptp_clock_info ptp_vmw_clock_info = { 73 .owner = THIS_MODULE, 74 .name = "ptp_vmw", 75 .max_adj = 0, 76 .adjtime = ptp_vmw_adjtime, 77 .adjfine = ptp_vmw_adjfine, 78 .gettime64 = ptp_vmw_gettime, 79 .settime64 = ptp_vmw_settime, 80 .enable = ptp_vmw_enable, 81 }; 82 83 /* 84 * ACPI driver ops for VMware "precision clock" virtual device. 85 */ 86 87 static int ptp_vmw_acpi_probe(struct platform_device *pdev) 88 { 89 ptp_vmw_clock = ptp_clock_register(&ptp_vmw_clock_info, NULL); 90 if (IS_ERR(ptp_vmw_clock)) { 91 pr_err("failed to register ptp clock\n"); 92 return PTR_ERR(ptp_vmw_clock); 93 } 94 95 ptp_vmw_acpi_device = ACPI_COMPANION(&pdev->dev); 96 return 0; 97 } 98 99 static void ptp_vmw_acpi_remove(struct platform_device *pdev) 100 { 101 ptp_clock_unregister(ptp_vmw_clock); 102 } 103 104 static const struct acpi_device_id ptp_vmw_acpi_device_ids[] = { 105 { "VMW0005", 0 }, 106 { "", 0 }, 107 }; 108 109 MODULE_DEVICE_TABLE(acpi, ptp_vmw_acpi_device_ids); 110 111 static struct platform_driver ptp_vmw_acpi_driver = { 112 .probe = ptp_vmw_acpi_probe, 113 .remove = ptp_vmw_acpi_remove, 114 .driver = { 115 .name = "ptp_vmw_acpi", 116 .acpi_match_table = ptp_vmw_acpi_device_ids, 117 }, 118 }; 119 120 static int __init ptp_vmw_init(void) 121 { 122 if (x86_hyper_type != X86_HYPER_VMWARE) 123 return -1; 124 return platform_driver_register(&ptp_vmw_acpi_driver); 125 } 126 127 static void __exit ptp_vmw_exit(void) 128 { 129 platform_driver_unregister(&ptp_vmw_acpi_driver); 130 } 131 132 module_init(ptp_vmw_init); 133 module_exit(ptp_vmw_exit); 134 135 MODULE_DESCRIPTION("VMware virtual PTP clock driver"); 136 MODULE_AUTHOR("VMware, Inc."); 137 MODULE_LICENSE("Dual BSD/GPL"); 138