1 files changed, 332 insertions, 0 deletions

diff --git a/drivers/net/ethernet/xscale/ptp_ixp46x.c b/drivers/net/ethernet/xscale/ptp_ixp46x.c
new file mode 100644
index 000000000..9abbdb71e
--- /dev/null
+++ b/drivers/net/ethernet/xscale/ptp_ixp46x.c
@@ -0,0 +1,332 @@
+// 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_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+	u64 adj;
+	u32 diff, addend;
+	int neg_adj = 0;
+	struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+	struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+	if (ppb < 0) {
+		neg_adj = 1;
+		ppb = -ppb;
+	}
+	addend = DEFAULT_ADDEND;
+	adj = addend;
+	adj *= ppb;
+	diff = div_u64(adj, 1000000000ULL);
+
+	addend = neg_adj ? addend - diff : addend + diff;
+
+	__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,
+	.adjfreq	= ptp_ixp_adjfreq,
+	.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");