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- // SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
- /*
- * Copyright (C) 2020 VMware, Inc., Palo Alto, CA., USA
- *
- * PTP clock driver for VMware precision clock virtual device.
- */
- #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
- #include <linux/acpi.h>
- #include <linux/kernel.h>
- #include <linux/module.h>
- #include <linux/ptp_clock_kernel.h>
- #include <asm/hypervisor.h>
- #include <asm/vmware.h>
- #define VMWARE_MAGIC 0x564D5868
- #define VMWARE_CMD_PCLK(nr) ((nr << 16) | 97)
- #define VMWARE_CMD_PCLK_GETTIME VMWARE_CMD_PCLK(0)
- static struct acpi_device *ptp_vmw_acpi_device;
- static struct ptp_clock *ptp_vmw_clock;
- static int ptp_vmw_pclk_read(u64 *ns)
- {
- u32 ret, nsec_hi, nsec_lo, unused1, unused2, unused3;
- asm volatile (VMWARE_HYPERCALL :
- "=a"(ret), "=b"(nsec_hi), "=c"(nsec_lo), "=d"(unused1),
- "=S"(unused2), "=D"(unused3) :
- "a"(VMWARE_MAGIC), "b"(0),
- "c"(VMWARE_CMD_PCLK_GETTIME), "d"(0) :
- "memory");
- if (ret == 0)
- *ns = ((u64)nsec_hi << 32) | nsec_lo;
- return ret;
- }
- /*
- * PTP clock ops.
- */
- static int ptp_vmw_adjtime(struct ptp_clock_info *info, s64 delta)
- {
- return -EOPNOTSUPP;
- }
- static int ptp_vmw_adjfreq(struct ptp_clock_info *info, s32 delta)
- {
- return -EOPNOTSUPP;
- }
- static int ptp_vmw_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
- {
- u64 ns;
- if (ptp_vmw_pclk_read(&ns) != 0)
- return -EIO;
- *ts = ns_to_timespec64(ns);
- return 0;
- }
- static int ptp_vmw_settime(struct ptp_clock_info *info,
- const struct timespec64 *ts)
- {
- return -EOPNOTSUPP;
- }
- static int ptp_vmw_enable(struct ptp_clock_info *info,
- struct ptp_clock_request *request, int on)
- {
- return -EOPNOTSUPP;
- }
- static struct ptp_clock_info ptp_vmw_clock_info = {
- .owner = THIS_MODULE,
- .name = "ptp_vmw",
- .max_adj = 0,
- .adjtime = ptp_vmw_adjtime,
- .adjfreq = ptp_vmw_adjfreq,
- .gettime64 = ptp_vmw_gettime,
- .settime64 = ptp_vmw_settime,
- .enable = ptp_vmw_enable,
- };
- /*
- * ACPI driver ops for VMware "precision clock" virtual device.
- */
- static int ptp_vmw_acpi_add(struct acpi_device *device)
- {
- ptp_vmw_clock = ptp_clock_register(&ptp_vmw_clock_info, NULL);
- if (IS_ERR(ptp_vmw_clock)) {
- pr_err("failed to register ptp clock\n");
- return PTR_ERR(ptp_vmw_clock);
- }
- ptp_vmw_acpi_device = device;
- return 0;
- }
- static int ptp_vmw_acpi_remove(struct acpi_device *device)
- {
- ptp_clock_unregister(ptp_vmw_clock);
- return 0;
- }
- static const struct acpi_device_id ptp_vmw_acpi_device_ids[] = {
- { "VMW0005", 0 },
- { "", 0 },
- };
- MODULE_DEVICE_TABLE(acpi, ptp_vmw_acpi_device_ids);
- static struct acpi_driver ptp_vmw_acpi_driver = {
- .name = "ptp_vmw",
- .ids = ptp_vmw_acpi_device_ids,
- .ops = {
- .add = ptp_vmw_acpi_add,
- .remove = ptp_vmw_acpi_remove
- },
- .owner = THIS_MODULE
- };
- static int __init ptp_vmw_init(void)
- {
- if (x86_hyper_type != X86_HYPER_VMWARE)
- return -1;
- return acpi_bus_register_driver(&ptp_vmw_acpi_driver);
- }
- static void __exit ptp_vmw_exit(void)
- {
- acpi_bus_unregister_driver(&ptp_vmw_acpi_driver);
- }
- module_init(ptp_vmw_init);
- module_exit(ptp_vmw_exit);
- MODULE_DESCRIPTION("VMware virtual PTP clock driver");
- MODULE_AUTHOR("VMware, Inc.");
- MODULE_LICENSE("Dual BSD/GPL");
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