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ptp: Add clock driver for the OpenCompute TimeCard.
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The OpenCompute time card is an atomic clock along with
a GPS receiver that provides a Grandmaster clock source
for a PTP enabled network.

More information is available at http://www.timingcard.com/

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20201204035128.2219252-2-jonathan.lemon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Jonathan Lemon authored and Jakub Kicinski committed Dec 5, 2020
1 parent bcd684a commit a7e1aba
Showing 3 changed files with 413 additions and 0 deletions.
14 changes: 14 additions & 0 deletions drivers/ptp/Kconfig
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@@ -151,4 +151,18 @@ config PTP_1588_CLOCK_VMW
To compile this driver as a module, choose M here: the module
will be called ptp_vmw.

config PTP_1588_CLOCK_OCP
tristate "OpenCompute TimeCard as PTP clock"
depends on PTP_1588_CLOCK
depends on HAS_IOMEM && PCI
default n
help
This driver adds support for an OpenCompute time card.

The OpenCompute time card is an atomic clock along with
a GPS receiver that provides a Grandmaster clock source
for a PTP enabled network.

More information is available at http://www.timingcard.com/

endmenu
1 change: 1 addition & 0 deletions drivers/ptp/Makefile
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@@ -15,3 +15,4 @@ ptp-qoriq-$(CONFIG_DEBUG_FS) += ptp_qoriq_debugfs.o
obj-$(CONFIG_PTP_1588_CLOCK_IDTCM) += ptp_clockmatrix.o
obj-$(CONFIG_PTP_1588_CLOCK_IDT82P33) += ptp_idt82p33.o
obj-$(CONFIG_PTP_1588_CLOCK_VMW) += ptp_vmw.o
obj-$(CONFIG_PTP_1588_CLOCK_OCP) += ptp_ocp.o
398 changes: 398 additions & 0 deletions drivers/ptp/ptp_ocp.c
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@@ -0,0 +1,398 @@
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2020 Facebook */

#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/ptp_clock_kernel.h>

static const struct pci_device_id ptp_ocp_pcidev_id[] = {
{ PCI_DEVICE(0x1d9b, 0x0400) },
{ 0 }
};
MODULE_DEVICE_TABLE(pci, ptp_ocp_pcidev_id);

#define OCP_REGISTER_OFFSET 0x01000000

struct ocp_reg {
u32 ctrl;
u32 status;
u32 select;
u32 version;
u32 time_ns;
u32 time_sec;
u32 __pad0[2];
u32 adjust_ns;
u32 adjust_sec;
u32 __pad1[2];
u32 offset_ns;
u32 offset_window_ns;
};

#define OCP_CTRL_ENABLE BIT(0)
#define OCP_CTRL_ADJUST_TIME BIT(1)
#define OCP_CTRL_ADJUST_OFFSET BIT(2)
#define OCP_CTRL_READ_TIME_REQ BIT(30)
#define OCP_CTRL_READ_TIME_DONE BIT(31)

#define OCP_STATUS_IN_SYNC BIT(0)

#define OCP_SELECT_CLK_NONE 0
#define OCP_SELECT_CLK_REG 6

struct tod_reg {
u32 ctrl;
u32 status;
u32 uart_polarity;
u32 version;
u32 correction_sec;
u32 __pad0[3];
u32 uart_baud;
u32 __pad1[3];
u32 utc_status;
u32 leap;
};

#define TOD_REGISTER_OFFSET 0x01050000

#define TOD_CTRL_PROTOCOL BIT(28)
#define TOD_CTRL_DISABLE_FMT_A BIT(17)
#define TOD_CTRL_DISABLE_FMT_B BIT(16)
#define TOD_CTRL_ENABLE BIT(0)
#define TOD_CTRL_GNSS_MASK ((1U << 4) - 1)
#define TOD_CTRL_GNSS_SHIFT 24

#define TOD_STATUS_UTC_MASK 0xff
#define TOD_STATUS_UTC_VALID BIT(8)
#define TOD_STATUS_LEAP_VALID BIT(16)

struct ptp_ocp {
struct pci_dev *pdev;
spinlock_t lock;
void __iomem *base;
struct ocp_reg __iomem *reg;
struct tod_reg __iomem *tod;
struct ptp_clock *ptp;
struct ptp_clock_info ptp_info;
};

static int
__ptp_ocp_gettime_locked(struct ptp_ocp *bp, struct timespec64 *ts,
struct ptp_system_timestamp *sts)
{
u32 ctrl, time_sec, time_ns;
int i;

ctrl = ioread32(&bp->reg->ctrl);
ctrl |= OCP_CTRL_READ_TIME_REQ;

ptp_read_system_prets(sts);
iowrite32(ctrl, &bp->reg->ctrl);

for (i = 0; i < 100; i++) {
ctrl = ioread32(&bp->reg->ctrl);
if (ctrl & OCP_CTRL_READ_TIME_DONE)
break;
}
ptp_read_system_postts(sts);

time_ns = ioread32(&bp->reg->time_ns);
time_sec = ioread32(&bp->reg->time_sec);

ts->tv_sec = time_sec;
ts->tv_nsec = time_ns;

return ctrl & OCP_CTRL_READ_TIME_DONE ? 0 : -ETIMEDOUT;
}

static int
ptp_ocp_gettimex(struct ptp_clock_info *ptp_info, struct timespec64 *ts,
struct ptp_system_timestamp *sts)
{
struct ptp_ocp *bp = container_of(ptp_info, struct ptp_ocp, ptp_info);
unsigned long flags;
int err;

spin_lock_irqsave(&bp->lock, flags);
err = __ptp_ocp_gettime_locked(bp, ts, sts);
spin_unlock_irqrestore(&bp->lock, flags);

return err;
}

static void
__ptp_ocp_settime_locked(struct ptp_ocp *bp, const struct timespec64 *ts)
{
u32 ctrl, time_sec, time_ns;
u32 select;

time_ns = ts->tv_nsec;
time_sec = ts->tv_sec;

select = ioread32(&bp->reg->select);
iowrite32(OCP_SELECT_CLK_REG, &bp->reg->select);

iowrite32(time_ns, &bp->reg->adjust_ns);
iowrite32(time_sec, &bp->reg->adjust_sec);

ctrl = ioread32(&bp->reg->ctrl);
ctrl |= OCP_CTRL_ADJUST_TIME;
iowrite32(ctrl, &bp->reg->ctrl);

/* restore clock selection */
iowrite32(select >> 16, &bp->reg->select);
}

static int
ptp_ocp_settime(struct ptp_clock_info *ptp_info, const struct timespec64 *ts)
{
struct ptp_ocp *bp = container_of(ptp_info, struct ptp_ocp, ptp_info);
unsigned long flags;

if (ioread32(&bp->reg->status) & OCP_STATUS_IN_SYNC)
return 0;

spin_lock_irqsave(&bp->lock, flags);
__ptp_ocp_settime_locked(bp, ts);
spin_unlock_irqrestore(&bp->lock, flags);

return 0;
}

static int
ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns)
{
struct ptp_ocp *bp = container_of(ptp_info, struct ptp_ocp, ptp_info);
struct timespec64 ts;
unsigned long flags;
int err;

if (ioread32(&bp->reg->status) & OCP_STATUS_IN_SYNC)
return 0;

spin_lock_irqsave(&bp->lock, flags);
err = __ptp_ocp_gettime_locked(bp, &ts, NULL);
if (likely(!err)) {
timespec64_add_ns(&ts, delta_ns);
__ptp_ocp_settime_locked(bp, &ts);
}
spin_unlock_irqrestore(&bp->lock, flags);

return err;
}

static int
ptp_ocp_null_adjfine(struct ptp_clock_info *ptp_info, long scaled_ppm)
{
if (scaled_ppm == 0)
return 0;

return -EOPNOTSUPP;
}

static const struct ptp_clock_info ptp_ocp_clock_info = {
.owner = THIS_MODULE,
.name = KBUILD_MODNAME,
.max_adj = 100000000,
.gettimex64 = ptp_ocp_gettimex,
.settime64 = ptp_ocp_settime,
.adjtime = ptp_ocp_adjtime,
.adjfine = ptp_ocp_null_adjfine,
};

static int
ptp_ocp_check_clock(struct ptp_ocp *bp)
{
struct timespec64 ts;
bool sync;
u32 ctrl;

/* make sure clock is enabled */
ctrl = ioread32(&bp->reg->ctrl);
ctrl |= OCP_CTRL_ENABLE;
iowrite32(ctrl, &bp->reg->ctrl);

if ((ioread32(&bp->reg->ctrl) & OCP_CTRL_ENABLE) == 0) {
dev_err(&bp->pdev->dev, "clock not enabled\n");
return -ENODEV;
}

sync = ioread32(&bp->reg->status) & OCP_STATUS_IN_SYNC;
if (!sync) {
ktime_get_real_ts64(&ts);
ptp_ocp_settime(&bp->ptp_info, &ts);
}
if (!ptp_ocp_gettimex(&bp->ptp_info, &ts, NULL))
dev_info(&bp->pdev->dev, "Time: %lld.%ld, %s\n",
ts.tv_sec, ts.tv_nsec,
sync ? "in-sync" : "UNSYNCED");

return 0;
}

static void
ptp_ocp_tod_info(struct ptp_ocp *bp)
{
static const char * const proto_name[] = {
"NMEA", "NMEA_ZDA", "NMEA_RMC", "NMEA_none",
"UBX", "UBX_UTC", "UBX_LS", "UBX_none"
};
static const char * const gnss_name[] = {
"ALL", "COMBINED", "GPS", "GLONASS", "GALILEO", "BEIDOU",
};
u32 version, ctrl, reg;
int idx;

version = ioread32(&bp->tod->version);
dev_info(&bp->pdev->dev, "TOD Version %d.%d.%d\n",
version >> 24, (version >> 16) & 0xff, version & 0xffff);

ctrl = ioread32(&bp->tod->ctrl);
ctrl |= TOD_CTRL_PROTOCOL | TOD_CTRL_ENABLE;
ctrl &= ~(TOD_CTRL_DISABLE_FMT_A | TOD_CTRL_DISABLE_FMT_B);
iowrite32(ctrl, &bp->tod->ctrl);

ctrl = ioread32(&bp->tod->ctrl);
idx = ctrl & TOD_CTRL_PROTOCOL ? 4 : 0;
idx += (ctrl >> 16) & 3;
dev_info(&bp->pdev->dev, "control: %x\n", ctrl);
dev_info(&bp->pdev->dev, "TOD Protocol %s %s\n", proto_name[idx],
ctrl & TOD_CTRL_ENABLE ? "enabled" : "");

idx = (ctrl >> TOD_CTRL_GNSS_SHIFT) & TOD_CTRL_GNSS_MASK;
if (idx < ARRAY_SIZE(gnss_name))
dev_info(&bp->pdev->dev, "GNSS %s\n", gnss_name[idx]);

reg = ioread32(&bp->tod->status);
dev_info(&bp->pdev->dev, "status: %x\n", reg);

reg = ioread32(&bp->tod->correction_sec);
dev_info(&bp->pdev->dev, "correction: %d\n", reg);

reg = ioread32(&bp->tod->utc_status);
dev_info(&bp->pdev->dev, "utc_status: %x\n", reg);
dev_info(&bp->pdev->dev, "utc_offset: %d valid:%d leap_valid:%d\n",
reg & TOD_STATUS_UTC_MASK, reg & TOD_STATUS_UTC_VALID ? 1 : 0,
reg & TOD_STATUS_LEAP_VALID ? 1 : 0);
}

static void
ptp_ocp_info(struct ptp_ocp *bp)
{
static const char * const clock_name[] = {
"NO", "TOD", "IRIG", "PPS", "PTP", "RTC", "REGS", "EXT"
};
u32 version, select;

version = ioread32(&bp->reg->version);
select = ioread32(&bp->reg->select);
dev_info(&bp->pdev->dev, "Version %d.%d.%d, clock %s, device ptp%d\n",
version >> 24, (version >> 16) & 0xff, version & 0xffff,
clock_name[select & 7],
ptp_clock_index(bp->ptp));

ptp_ocp_tod_info(bp);
}

static int
ptp_ocp_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct ptp_ocp *bp;
int err;

bp = kzalloc(sizeof(*bp), GFP_KERNEL);
if (!bp)
return -ENOMEM;
bp->pdev = pdev;
pci_set_drvdata(pdev, bp);

err = pci_enable_device(pdev);
if (err) {
dev_err(&pdev->dev, "pci_enable_device\n");
goto out_free;
}

err = pci_request_regions(pdev, KBUILD_MODNAME);
if (err) {
dev_err(&pdev->dev, "pci_request_region\n");
goto out_disable;
}

bp->base = pci_ioremap_bar(pdev, 0);
if (!bp->base) {
dev_err(&pdev->dev, "io_remap bar0\n");
err = -ENOMEM;
goto out;
}
bp->reg = bp->base + OCP_REGISTER_OFFSET;
bp->tod = bp->base + TOD_REGISTER_OFFSET;
bp->ptp_info = ptp_ocp_clock_info;
spin_lock_init(&bp->lock);

err = ptp_ocp_check_clock(bp);
if (err)
goto out;

bp->ptp = ptp_clock_register(&bp->ptp_info, &pdev->dev);
if (IS_ERR(bp->ptp)) {
dev_err(&pdev->dev, "ptp_clock_register\n");
err = PTR_ERR(bp->ptp);
goto out;
}

ptp_ocp_info(bp);

return 0;

out:
pci_release_regions(pdev);
out_disable:
pci_disable_device(pdev);
out_free:
kfree(bp);

return err;
}

static void
ptp_ocp_remove(struct pci_dev *pdev)
{
struct ptp_ocp *bp = pci_get_drvdata(pdev);

ptp_clock_unregister(bp->ptp);
pci_iounmap(pdev, bp->base);
pci_release_regions(pdev);
pci_disable_device(pdev);
pci_set_drvdata(pdev, NULL);
kfree(bp);
}

static struct pci_driver ptp_ocp_driver = {
.name = KBUILD_MODNAME,
.id_table = ptp_ocp_pcidev_id,
.probe = ptp_ocp_probe,
.remove = ptp_ocp_remove,
};

static int __init
ptp_ocp_init(void)
{
int err;

err = pci_register_driver(&ptp_ocp_driver);
return err;
}

static void __exit
ptp_ocp_fini(void)
{
pci_unregister_driver(&ptp_ocp_driver);
}

module_init(ptp_ocp_init);
module_exit(ptp_ocp_fini);

MODULE_DESCRIPTION("OpenCompute TimeCard driver");
MODULE_LICENSE("GPL v2");

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