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// SPDX-License-Identifier: GPL-2.0
/* cavium_ptp.c - PTP 1588 clock on Cavium hardware
* Copyright (c) 2003-2015, 2017 Cavium, Inc.
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/timecounter.h>
#include <linux/pci.h>
#include "cavium_ptp.h"
#define DRV_NAME "cavium_ptp"
#define PCI_DEVICE_ID_CAVIUM_PTP 0xA00C
#define PCI_SUBSYS_DEVID_88XX_PTP 0xA10C
#define PCI_SUBSYS_DEVID_81XX_PTP 0XA20C
#define PCI_SUBSYS_DEVID_83XX_PTP 0xA30C
#define PCI_DEVICE_ID_CAVIUM_RST 0xA00E
#define PCI_PTP_BAR_NO 0
#define PCI_RST_BAR_NO 0
#define PTP_CLOCK_CFG 0xF00ULL
#define PTP_CLOCK_CFG_PTP_EN BIT(0)
#define PTP_CLOCK_LO 0xF08ULL
#define PTP_CLOCK_HI 0xF10ULL
#define PTP_CLOCK_COMP 0xF18ULL
#define RST_BOOT 0x1600ULL
#define CLOCK_BASE_RATE 50000000ULL
static u64 ptp_cavium_clock_get(void)
{
struct pci_dev *pdev;
void __iomem *base;
u64 ret = CLOCK_BASE_RATE * 16;
pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
PCI_DEVICE_ID_CAVIUM_RST, NULL);
if (!pdev)
goto error;
base = pci_ioremap_bar(pdev, PCI_RST_BAR_NO);
if (!base)
goto error_put_pdev;
ret = CLOCK_BASE_RATE * ((readq(base + RST_BOOT) >> 33) & 0x3f);
iounmap(base);
error_put_pdev:
pci_dev_put(pdev);
error:
return ret;
}
struct cavium_ptp *cavium_ptp_get(void)
{
struct cavium_ptp *ptp;
struct pci_dev *pdev;
pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
PCI_DEVICE_ID_CAVIUM_PTP, NULL);
if (!pdev)
return ERR_PTR(-ENODEV);
ptp = pci_get_drvdata(pdev);
if (!ptp)
ptp = ERR_PTR(-EPROBE_DEFER);
if (IS_ERR(ptp))
pci_dev_put(pdev);
return ptp;
}
EXPORT_SYMBOL(cavium_ptp_get);
void cavium_ptp_put(struct cavium_ptp *ptp)
{
if (!ptp)
return;
pci_dev_put(ptp->pdev);
}
EXPORT_SYMBOL(cavium_ptp_put);
/**
* cavium_ptp_adjfine() - Adjust ptp frequency
* @ptp_info: PTP clock info
* @scaled_ppm: how much to adjust by, in parts per million, but with a
* 16 bit binary fractional field
*/
static int cavium_ptp_adjfine(struct ptp_clock_info *ptp_info, long scaled_ppm)
{
struct cavium_ptp *clock =
container_of(ptp_info, struct cavium_ptp, ptp_info);
unsigned long flags;
u64 comp;
u64 adj;
bool neg_adj = false;
if (scaled_ppm < 0) {
neg_adj = true;
scaled_ppm = -scaled_ppm;
}
/* The hardware adds the clock compensation value to the PTP clock
* on every coprocessor clock cycle. Typical convention is that it
* represent number of nanosecond betwen each cycle. In this
* convention compensation value is in 64 bit fixed-point
* representation where upper 32 bits are number of nanoseconds
* and lower is fractions of nanosecond.
* The scaled_ppm represent the ratio in "parts per bilion" by which the
* compensation value should be corrected.
* To calculate new compenstation value we use 64bit fixed point
* arithmetic on following formula
* comp = tbase + tbase * scaled_ppm / (1M * 2^16)
* where tbase is the basic compensation value calculated initialy
* in cavium_ptp_init() -> tbase = 1/Hz. Then we use endian
* independent structure definition to write data to PTP register.
*/
comp = ((u64)1000000000ull << 32) / clock->clock_rate;
adj = comp * scaled_ppm;
adj >>= 16;
adj = div_u64(adj, 1000000ull);
comp = neg_adj ? comp - adj : comp + adj;
spin_lock_irqsave(&clock->spin_lock, flags);
writeq(comp, clock->reg_base + PTP_CLOCK_COMP);
spin_unlock_irqrestore(&clock->spin_lock, flags);
return 0;
}
/**
* cavium_ptp_adjtime() - Adjust ptp time
* @ptp_info: PTP clock info
* @delta: how much to adjust by, in nanosecs
*/
static int cavium_ptp_adjtime(struct ptp_clock_info *ptp_info, s64 delta)
{
struct cavium_ptp *clock =
container_of(ptp_info, struct cavium_ptp, ptp_info);
unsigned long flags;
spin_lock_irqsave(&clock->spin_lock, flags);
timecounter_adjtime(&clock->time_counter, delta);
spin_unlock_irqrestore(&clock->spin_lock, flags);
/* Sync, for network driver to get latest value */
smp_mb();
return 0;
}
/**
* cavium_ptp_gettime() - Get hardware clock time with adjustment
* @ptp_info: PTP clock info
* @ts: timespec
*/
static int cavium_ptp_gettime(struct ptp_clock_info *ptp_info,
struct timespec64 *ts)
{
struct cavium_ptp *clock =
container_of(ptp_info, struct cavium_ptp, ptp_info);
unsigned long flags;
u64 nsec;
spin_lock_irqsave(&clock->spin_lock, flags);
nsec = timecounter_read(&clock->time_counter);
spin_unlock_irqrestore(&clock->spin_lock, flags);
*ts = ns_to_timespec64(nsec);
return 0;
}
/**
* cavium_ptp_settime() - Set hardware clock time. Reset adjustment
* @ptp_info: PTP clock info
* @ts: timespec
*/
static int cavium_ptp_settime(struct ptp_clock_info *ptp_info,
const struct timespec64 *ts)
{
struct cavium_ptp *clock =
container_of(ptp_info, struct cavium_ptp, ptp_info);
unsigned long flags;
u64 nsec;
nsec = timespec64_to_ns(ts);
spin_lock_irqsave(&clock->spin_lock, flags);
timecounter_init(&clock->time_counter, &clock->cycle_counter, nsec);
spin_unlock_irqrestore(&clock->spin_lock, flags);
return 0;
}
/**
* cavium_ptp_enable() - Request to enable or disable an ancillary feature.
* @ptp_info: PTP clock info
* @rq: request
* @on: is it on
*/
static int cavium_ptp_enable(struct ptp_clock_info *ptp_info,
struct ptp_clock_request *rq, int on)
{
return -EOPNOTSUPP;
}
static u64 cavium_ptp_cc_read(const struct cyclecounter *cc)
{
struct cavium_ptp *clock =
container_of(cc, struct cavium_ptp, cycle_counter);
return readq(clock->reg_base + PTP_CLOCK_HI);
}
static int cavium_ptp_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
struct device *dev = &pdev->dev;
struct cavium_ptp *clock;
struct cyclecounter *cc;
u64 clock_cfg;
u64 clock_comp;
int err;
clock = devm_kzalloc(dev, sizeof(*clock), GFP_KERNEL);
if (!clock) {
err = -ENOMEM;
goto error;
}
clock->pdev = pdev;
err = pcim_enable_device(pdev);
if (err)
goto error_free;
err = pcim_iomap_regions(pdev, 1 << PCI_PTP_BAR_NO, pci_name(pdev));
if (err)
goto error_free;
clock->reg_base = pcim_iomap_table(pdev)[PCI_PTP_BAR_NO];
spin_lock_init(&clock->spin_lock);
cc = &clock->cycle_counter;
cc->read = cavium_ptp_cc_read;
cc->mask = CYCLECOUNTER_MASK(64);
cc->mult = 1;
cc->shift = 0;
timecounter_init(&clock->time_counter, &clock->cycle_counter,
ktime_to_ns(ktime_get_real()));
clock->clock_rate = ptp_cavium_clock_get();
clock->ptp_info = (struct ptp_clock_info) {
.owner = THIS_MODULE,
.name = "ThunderX PTP",
.max_adj = 1000000000ull,
.n_ext_ts = 0,
.n_pins = 0,
.pps = 0,
.adjfine = cavium_ptp_adjfine,
.adjtime = cavium_ptp_adjtime,
.gettime64 = cavium_ptp_gettime,
.settime64 = cavium_ptp_settime,
.enable = cavium_ptp_enable,
};
clock_cfg = readq(clock->reg_base + PTP_CLOCK_CFG);
clock_cfg |= PTP_CLOCK_CFG_PTP_EN;
writeq(clock_cfg, clock->reg_base + PTP_CLOCK_CFG);
clock_comp = ((u64)1000000000ull << 32) / clock->clock_rate;
writeq(clock_comp, clock->reg_base + PTP_CLOCK_COMP);
clock->ptp_clock = ptp_clock_register(&clock->ptp_info, dev);
if (IS_ERR(clock->ptp_clock)) {
err = PTR_ERR(clock->ptp_clock);
goto error_stop;
}
pci_set_drvdata(pdev, clock);
return 0;
error_stop:
clock_cfg = readq(clock->reg_base + PTP_CLOCK_CFG);
clock_cfg &= ~PTP_CLOCK_CFG_PTP_EN;
writeq(clock_cfg, clock->reg_base + PTP_CLOCK_CFG);
pcim_iounmap_regions(pdev, 1 << PCI_PTP_BAR_NO);
error_free:
devm_kfree(dev, clock);
error:
/* For `cavium_ptp_get()` we need to differentiate between the case
* when the core has not tried to probe this device and the case when
* the probe failed. In the later case we pretend that the
* initialization was successful and keep the error in
* `dev->driver_data`.
*/
pci_set_drvdata(pdev, ERR_PTR(err));
return 0;
}
static void cavium_ptp_remove(struct pci_dev *pdev)
{
struct cavium_ptp *clock = pci_get_drvdata(pdev);
u64 clock_cfg;
if (IS_ERR_OR_NULL(clock))
return;
ptp_clock_unregister(clock->ptp_clock);
clock_cfg = readq(clock->reg_base + PTP_CLOCK_CFG);
clock_cfg &= ~PTP_CLOCK_CFG_PTP_EN;
writeq(clock_cfg, clock->reg_base + PTP_CLOCK_CFG);
}
static const struct pci_device_id cavium_ptp_id_table[] = {
{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_CAVIUM_PTP,
PCI_VENDOR_ID_CAVIUM, PCI_SUBSYS_DEVID_88XX_PTP) },
{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_CAVIUM_PTP,
PCI_VENDOR_ID_CAVIUM, PCI_SUBSYS_DEVID_81XX_PTP) },
{ PCI_DEVICE_SUB(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_CAVIUM_PTP,
PCI_VENDOR_ID_CAVIUM, PCI_SUBSYS_DEVID_83XX_PTP) },
{ 0, }
};
static struct pci_driver cavium_ptp_driver = {
.name = DRV_NAME,
.id_table = cavium_ptp_id_table,
.probe = cavium_ptp_probe,
.remove = cavium_ptp_remove,
};
module_pci_driver(cavium_ptp_driver);
MODULE_DESCRIPTION(DRV_NAME);
MODULE_AUTHOR("Cavium Networks <support@cavium.com>");
MODULE_LICENSE("GPL v2");
MODULE_DEVICE_TABLE(pci, cavium_ptp_id_table);