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1// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause2/*3 * Copyright (C) 2020 VMware, Inc., Palo Alto, CA., USA4 *5 * PTP clock driver for VMware precision clock virtual device.6 */7 8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt9 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 20static struct acpi_device *ptp_vmw_acpi_device;21static struct ptp_clock *ptp_vmw_clock;22 23 24static 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 39static int ptp_vmw_adjtime(struct ptp_clock_info *info, s64 delta)40{41 return -EOPNOTSUPP;42}43 44static int ptp_vmw_adjfine(struct ptp_clock_info *info, long delta)45{46 return -EOPNOTSUPP;47}48 49static 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 59static int ptp_vmw_settime(struct ptp_clock_info *info,60 const struct timespec64 *ts)61{62 return -EOPNOTSUPP;63}64 65static int ptp_vmw_enable(struct ptp_clock_info *info,66 struct ptp_clock_request *request, int on)67{68 return -EOPNOTSUPP;69}70 71static 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 86static 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 98static void ptp_vmw_acpi_remove(struct acpi_device *device)99{100 ptp_clock_unregister(ptp_vmw_clock);101}102 103static const struct acpi_device_id ptp_vmw_acpi_device_ids[] = {104 { "VMW0005", 0 },105 { "", 0 },106};107 108MODULE_DEVICE_TABLE(acpi, ptp_vmw_acpi_device_ids);109 110static 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_remove116 },117};118 119static 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 126static void __exit ptp_vmw_exit(void)127{128 acpi_bus_unregister_driver(&ptp_vmw_acpi_driver);129}130 131module_init(ptp_vmw_init);132module_exit(ptp_vmw_exit);133 134MODULE_DESCRIPTION("VMware virtual PTP clock driver");135MODULE_AUTHOR("VMware, Inc.");136MODULE_LICENSE("Dual BSD/GPL");137