linux-zen-server/drivers/net/ethernet/xscale/ptp_ixp46x.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PTP 1588 clock using the IXP46X
*
* Copyright (C) 2010 OMICRON electronics GmbH
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/ptp_clock_kernel.h>
#include <linux/platform_device.h>
#include <linux/soc/ixp4xx/cpu.h>
#include "ixp46x_ts.h"
#define DRIVER "ptp_ixp46x"
#define N_EXT_TS 2
struct ixp_clock {
struct ixp46x_ts_regs *regs;
struct ptp_clock *ptp_clock;
struct ptp_clock_info caps;
int exts0_enabled;
int exts1_enabled;
int slave_irq;
int master_irq;
};
static DEFINE_SPINLOCK(register_lock);
/*
* Register access functions
*/
static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
{
u64 ns;
u32 lo, hi;
lo = __raw_readl(&regs->systime_lo);
hi = __raw_readl(&regs->systime_hi);
ns = ((u64) hi) << 32;
ns |= lo;
ns <<= TICKS_NS_SHIFT;
return ns;
}
static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
{
u32 hi, lo;
ns >>= TICKS_NS_SHIFT;
hi = ns >> 32;
lo = ns & 0xffffffff;
__raw_writel(lo, &regs->systime_lo);
__raw_writel(hi, &regs->systime_hi);
}
/*
* Interrupt service routine
*/
static irqreturn_t isr(int irq, void *priv)
{
struct ixp_clock *ixp_clock = priv;
struct ixp46x_ts_regs *regs = ixp_clock->regs;
struct ptp_clock_event event;
u32 ack = 0, lo, hi, val;
val = __raw_readl(&regs->event);
if (val & TSER_SNS) {
ack |= TSER_SNS;
if (ixp_clock->exts0_enabled) {
hi = __raw_readl(&regs->asms_hi);
lo = __raw_readl(&regs->asms_lo);
event.type = PTP_CLOCK_EXTTS;
event.index = 0;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
event.timestamp <<= TICKS_NS_SHIFT;
ptp_clock_event(ixp_clock->ptp_clock, &event);
}
}
if (val & TSER_SNM) {
ack |= TSER_SNM;
if (ixp_clock->exts1_enabled) {
hi = __raw_readl(&regs->amms_hi);
lo = __raw_readl(&regs->amms_lo);
event.type = PTP_CLOCK_EXTTS;
event.index = 1;
event.timestamp = ((u64) hi) << 32;
event.timestamp |= lo;
event.timestamp <<= TICKS_NS_SHIFT;
ptp_clock_event(ixp_clock->ptp_clock, &event);
}
}
if (val & TTIPEND)
ack |= TTIPEND; /* this bit seems to be always set */
if (ack) {
__raw_writel(ack, &regs->event);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
/*
* PTP clock operations
*/
static int ptp_ixp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
u32 addend;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
addend = adjust_by_scaled_ppm(DEFAULT_ADDEND, scaled_ppm);
__raw_writel(addend, &regs->addend);
return 0;
}
static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
s64 now;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
spin_lock_irqsave(&register_lock, flags);
now = ixp_systime_read(regs);
now += delta;
ixp_systime_write(regs, now);
spin_unlock_irqrestore(&register_lock, flags);
return 0;
}
static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
{
u64 ns;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
spin_lock_irqsave(&register_lock, flags);
ns = ixp_systime_read(regs);
spin_unlock_irqrestore(&register_lock, flags);
*ts = ns_to_timespec64(ns);
return 0;
}
static int ptp_ixp_settime(struct ptp_clock_info *ptp,
const struct timespec64 *ts)
{
u64 ns;
unsigned long flags;
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
struct ixp46x_ts_regs *regs = ixp_clock->regs;
ns = timespec64_to_ns(ts);
spin_lock_irqsave(&register_lock, flags);
ixp_systime_write(regs, ns);
spin_unlock_irqrestore(&register_lock, flags);
return 0;
}
static int ptp_ixp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
switch (rq->type) {
case PTP_CLK_REQ_EXTTS:
switch (rq->extts.index) {
case 0:
ixp_clock->exts0_enabled = on ? 1 : 0;
break;
case 1:
ixp_clock->exts1_enabled = on ? 1 : 0;
break;
default:
return -EINVAL;
}
return 0;
default:
break;
}
return -EOPNOTSUPP;
}
static const struct ptp_clock_info ptp_ixp_caps = {
.owner = THIS_MODULE,
.name = "IXP46X timer",
.max_adj = 66666655,
.n_ext_ts = N_EXT_TS,
.n_pins = 0,
.pps = 0,
.adjfine = ptp_ixp_adjfine,
.adjtime = ptp_ixp_adjtime,
.gettime64 = ptp_ixp_gettime,
.settime64 = ptp_ixp_settime,
.enable = ptp_ixp_enable,
};
/* module operations */
static struct ixp_clock ixp_clock;
int ixp46x_ptp_find(struct ixp46x_ts_regs *__iomem *regs, int *phc_index)
{
*regs = ixp_clock.regs;
*phc_index = ptp_clock_index(ixp_clock.ptp_clock);
if (!ixp_clock.ptp_clock)
return -EPROBE_DEFER;
return 0;
}
EXPORT_SYMBOL_GPL(ixp46x_ptp_find);
/* Called from the registered devm action */
static void ptp_ixp_unregister_action(void *d)
{
struct ptp_clock *ptp_clock = d;
ptp_clock_unregister(ptp_clock);
ixp_clock.ptp_clock = NULL;
}
static int ptp_ixp_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int ret;
ixp_clock.regs = devm_platform_ioremap_resource(pdev, 0);
ixp_clock.master_irq = platform_get_irq(pdev, 0);
ixp_clock.slave_irq = platform_get_irq(pdev, 1);
if (IS_ERR(ixp_clock.regs) ||
ixp_clock.master_irq < 0 || ixp_clock.slave_irq < 0)
return -ENXIO;
ixp_clock.caps = ptp_ixp_caps;
ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
if (IS_ERR(ixp_clock.ptp_clock))
return PTR_ERR(ixp_clock.ptp_clock);
ret = devm_add_action_or_reset(dev, ptp_ixp_unregister_action,
ixp_clock.ptp_clock);
if (ret) {
dev_err(dev, "failed to install clock removal handler\n");
return ret;
}
__raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
__raw_writel(1, &ixp_clock.regs->trgt_lo);
__raw_writel(0, &ixp_clock.regs->trgt_hi);
__raw_writel(TTIPEND, &ixp_clock.regs->event);
ret = devm_request_irq(dev, ixp_clock.master_irq, isr,
0, DRIVER, &ixp_clock);
if (ret)
return dev_err_probe(dev, ret,
"request_irq failed for irq %d\n",
ixp_clock.master_irq);
ret = devm_request_irq(dev, ixp_clock.slave_irq, isr,
0, DRIVER, &ixp_clock);
if (ret)
return dev_err_probe(dev, ret,
"request_irq failed for irq %d\n",
ixp_clock.slave_irq);
return 0;
}
static const struct of_device_id ptp_ixp_match[] = {
{
.compatible = "intel,ixp46x-ptp-timer",
},
{ },
};
static struct platform_driver ptp_ixp_driver = {
.driver = {
.name = "ptp-ixp46x",
.of_match_table = ptp_ixp_match,
.suppress_bind_attrs = true,
},
.probe = ptp_ixp_probe,
};
module_platform_driver(ptp_ixp_driver);
MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
MODULE_LICENSE("GPL");