drivers/net/ethernet/cavium/common/cavium_ptp.c - hafnium/third_party/linux - Git at Google

 // 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 Driver"

 #define PCI_DEVICE_ID_CAVIUM_PTP	0xA00C
 #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: 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:   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: 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: 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: 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 (!clock->ptp_clock) {
 		err = -ENODEV;
 		goto error_stop;
 	}
 	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(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_CAVIUM_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);
	// 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 Driver"

	#define PCI_DEVICE_ID_CAVIUM_PTP 0xA00C
	#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: 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: 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: 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: 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: 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 (!clock->ptp_clock) {
	err = -ENODEV;
	goto error_stop;
	}
	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(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_CAVIUM_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);