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In all cases in which a struct acpi_driver is used for binding a driver to an ACPI device object, a corresponding platform device is created by the ACPI core and that device is regarded as a proper representation of underlying hardware. Accordingly, a struct platform_driver should be used by driver code to bind to that device. There are multiple reasons why drivers should not bind directly to ACPI device objects [1]. Overall, it is better to bind drivers to platform devices than to their ACPI companions, so convert the PTP VMware ACPI driver to a platform one. While this is not expected to alter functionality, it changes sysfs layout and so it will be visible to user space. Link: https://lore.kernel.org/all/2396510.ElGaqSPkdT@rafael.j.wysocki/ [1] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/12883468.O9o76ZdvQC@rafael.j.wysocki Signed-off-by: Jakub Kicinski <kuba@kernel.org>
138 lines
2.9 KiB
C
138 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
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/*
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* Copyright (C) 2020 VMware, Inc., Palo Alto, CA., USA
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*
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* PTP clock driver for VMware precision clock virtual device.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/acpi.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/ptp_clock_kernel.h>
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#include <asm/hypervisor.h>
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#include <asm/vmware.h>
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#define VMWARE_CMD_PCLK(nr) ((nr << 16) | 97)
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#define VMWARE_CMD_PCLK_GETTIME VMWARE_CMD_PCLK(0)
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static struct acpi_device *ptp_vmw_acpi_device;
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static struct ptp_clock *ptp_vmw_clock;
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static int ptp_vmw_pclk_read(u64 *ns)
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{
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u32 ret, nsec_hi, nsec_lo;
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ret = vmware_hypercall3(VMWARE_CMD_PCLK_GETTIME, 0,
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&nsec_hi, &nsec_lo);
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if (ret == 0)
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*ns = ((u64)nsec_hi << 32) | nsec_lo;
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return ret;
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}
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/*
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* PTP clock ops.
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*/
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static int ptp_vmw_adjtime(struct ptp_clock_info *info, s64 delta)
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{
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return -EOPNOTSUPP;
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}
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static int ptp_vmw_adjfine(struct ptp_clock_info *info, long delta)
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{
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return -EOPNOTSUPP;
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}
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static int ptp_vmw_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
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{
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u64 ns;
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if (ptp_vmw_pclk_read(&ns) != 0)
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return -EIO;
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*ts = ns_to_timespec64(ns);
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return 0;
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}
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static int ptp_vmw_settime(struct ptp_clock_info *info,
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const struct timespec64 *ts)
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{
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return -EOPNOTSUPP;
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}
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static int ptp_vmw_enable(struct ptp_clock_info *info,
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struct ptp_clock_request *request, int on)
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{
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return -EOPNOTSUPP;
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}
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static struct ptp_clock_info ptp_vmw_clock_info = {
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.owner = THIS_MODULE,
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.name = "ptp_vmw",
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.max_adj = 0,
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.adjtime = ptp_vmw_adjtime,
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.adjfine = ptp_vmw_adjfine,
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.gettime64 = ptp_vmw_gettime,
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.settime64 = ptp_vmw_settime,
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.enable = ptp_vmw_enable,
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};
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/*
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* ACPI driver ops for VMware "precision clock" virtual device.
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*/
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static int ptp_vmw_acpi_probe(struct platform_device *pdev)
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{
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ptp_vmw_clock = ptp_clock_register(&ptp_vmw_clock_info, NULL);
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if (IS_ERR(ptp_vmw_clock)) {
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pr_err("failed to register ptp clock\n");
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return PTR_ERR(ptp_vmw_clock);
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}
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ptp_vmw_acpi_device = ACPI_COMPANION(&pdev->dev);
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return 0;
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}
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static void ptp_vmw_acpi_remove(struct platform_device *pdev)
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{
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ptp_clock_unregister(ptp_vmw_clock);
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}
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static const struct acpi_device_id ptp_vmw_acpi_device_ids[] = {
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{ "VMW0005", 0 },
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{ "", 0 },
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};
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MODULE_DEVICE_TABLE(acpi, ptp_vmw_acpi_device_ids);
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static struct platform_driver ptp_vmw_acpi_driver = {
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.probe = ptp_vmw_acpi_probe,
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.remove = ptp_vmw_acpi_remove,
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.driver = {
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.name = "ptp_vmw_acpi",
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.acpi_match_table = ptp_vmw_acpi_device_ids,
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},
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};
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static int __init ptp_vmw_init(void)
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{
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if (x86_hyper_type != X86_HYPER_VMWARE)
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return -1;
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return platform_driver_register(&ptp_vmw_acpi_driver);
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}
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static void __exit ptp_vmw_exit(void)
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{
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platform_driver_unregister(&ptp_vmw_acpi_driver);
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}
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module_init(ptp_vmw_init);
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module_exit(ptp_vmw_exit);
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MODULE_DESCRIPTION("VMware virtual PTP clock driver");
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MODULE_AUTHOR("VMware, Inc.");
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MODULE_LICENSE("Dual BSD/GPL");
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