Merge branch 'ptp-add-pulse-signal-loopback-support-for-debugging'

Wei Fang says:

====================
ptp: add pulse signal loopback support for debugging

Some PTP devices support looping back the periodic pulse signal for
debugging. For example, the PTP device of QorIQ platform and the NETC v4
Timer has the ability to loop back the pulse signal and record the extts
events for the loopback signal. So we can make sure that the pulse
intervals and their phase alignment are correct from the perspective of
the emitting PHC's time base. In addition, we can use this loopback
feature as a built-in extts event generator when we have no external
equipment which does that. Therefore, add the generic debugfs interfaces
to the ptp_clock driver. The first two patch are separated from the
previous patch set [1]. The third patch is new added.

[1]: https://lore.kernel.org/imx/20250827063332.1217664-1-wei.fang@nxp.com/ #patch 3 and 9
====================

Link: https://patch.msgid.link/20250905030711.1509648-1-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

9 files changed, 128 insertions, 118 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index b81595e9ea95..e3907f0c1243 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9817,7 +9817,6 @@ F:	drivers/net/ethernet/freescale/dpaa2/dpaa2-ptp*
 F:	drivers/net/ethernet/freescale/dpaa2/dprtc*
 F:	drivers/net/ethernet/freescale/enetc/enetc_ptp.c
 F:	drivers/ptp/ptp_qoriq.c
-F:	drivers/ptp/ptp_qoriq_debugfs.c
 F:	include/linux/fsl/ptp_qoriq.h
 
 FREESCALE QUAD SPI DRIVER
diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index 9256bf2e8ad4..5f8ea34d11d6 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -67,7 +67,7 @@ config PTP_1588_CLOCK_QORIQ
 	  packets using the SO_TIMESTAMPING API.
 
 	  To compile this driver as a module, choose M here: the module
-	  will be called ptp-qoriq.
+	  will be called ptp_qoriq.
 
 comment "Enable PHYLIB and NETWORK_PHY_TIMESTAMPING to see the additional clocks."
 	depends on PHYLIB=n || NETWORK_PHY_TIMESTAMPING=n
diff --git a/drivers/ptp/Makefile b/drivers/ptp/Makefile
index 8985d723d29c..bdc47e284f14 100644
--- a/drivers/ptp/Makefile
+++ b/drivers/ptp/Makefile
@@ -12,9 +12,7 @@ obj-$(CONFIG_PTP_1588_CLOCK_INES)	+= ptp_ines.o
 obj-$(CONFIG_PTP_1588_CLOCK_PCH)	+= ptp_pch.o
 obj-$(CONFIG_PTP_1588_CLOCK_KVM)	+= ptp_kvm.o
 obj-$(CONFIG_PTP_1588_CLOCK_VMCLOCK)	+= ptp_vmclock.o
-obj-$(CONFIG_PTP_1588_CLOCK_QORIQ)	+= ptp-qoriq.o
-ptp-qoriq-y				+= ptp_qoriq.o
-ptp-qoriq-$(CONFIG_DEBUG_FS)		+= ptp_qoriq_debugfs.o
+obj-$(CONFIG_PTP_1588_CLOCK_QORIQ)	+= ptp_qoriq.o
 obj-$(CONFIG_PTP_1588_CLOCK_IDTCM)	+= ptp_clockmatrix.o
 obj-$(CONFIG_PTP_1588_CLOCK_FC3W)	+= ptp_fc3.o
 obj-$(CONFIG_PTP_1588_CLOCK_IDT82P33)	+= ptp_idt82p33.o
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 5739a57958c7..1d920f8e20a8 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -248,6 +248,69 @@ static void ptp_aux_kworker(struct kthread_work *work)
 		kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
 }
 
+static ssize_t ptp_n_perout_loopback_read(struct file *filep,
+					  char __user *buffer,
+					  size_t count, loff_t *pos)
+{
+	struct ptp_clock *ptp = filep->private_data;
+	char buf[12] = {};
+
+	snprintf(buf, sizeof(buf), "%d\n", ptp->info->n_per_lp);
+
+	return simple_read_from_buffer(buffer, count, pos, buf, strlen(buf));
+}
+
+static const struct file_operations ptp_n_perout_loopback_fops = {
+	.owner	= THIS_MODULE,
+	.open	= simple_open,
+	.read	= ptp_n_perout_loopback_read,
+};
+
+static ssize_t ptp_perout_loopback_write(struct file *filep,
+					 const char __user *buffer,
+					 size_t count, loff_t *ppos)
+{
+	struct ptp_clock *ptp = filep->private_data;
+	struct ptp_clock_info *ops = ptp->info;
+	unsigned int index, enable;
+	int len, cnt, err;
+	char buf[32] = {};
+
+	if (*ppos || !count)
+		return -EINVAL;
+
+	if (count >= sizeof(buf))
+		return -ENOSPC;
+
+	len = simple_write_to_buffer(buf, sizeof(buf) - 1,
+				     ppos, buffer, count);
+	if (len < 0)
+		return len;
+
+	buf[len] = '\0';
+	cnt = sscanf(buf, "%u %u", &index, &enable);
+	if (cnt != 2)
+		return -EINVAL;
+
+	if (index >= ops->n_per_lp)
+		return -EINVAL;
+
+	if (enable != 0 && enable != 1)
+		return -EINVAL;
+
+	err = ops->perout_loopback(ops, index, enable);
+	if (err)
+		return err;
+
+	return count;
+}
+
+static const struct file_operations ptp_perout_loopback_ops = {
+	.owner   = THIS_MODULE,
+	.open    = simple_open,
+	.write	 = ptp_perout_loopback_write,
+};
+
 /* public interface */
 
 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
@@ -389,6 +452,12 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	/* Debugfs initialization */
 	snprintf(debugfsname, sizeof(debugfsname), "ptp%d", ptp->index);
 	ptp->debugfs_root = debugfs_create_dir(debugfsname, NULL);
+	if (info->n_per_lp > 0 && info->perout_loopback) {
+		debugfs_create_file("n_perout_loopback", 0400, ptp->debugfs_root,
+				    ptp, &ptp_n_perout_loopback_fops);
+		debugfs_create_file("perout_loopback", 0200, ptp->debugfs_root,
+				    ptp, &ptp_perout_loopback_ops);
+	}
 
 	return ptp;
 
diff --git a/drivers/ptp/ptp_netc.c b/drivers/ptp/ptp_netc.c
index 8c5fea1f43fa..75594f47807d 100644
--- a/drivers/ptp/ptp_netc.c
+++ b/drivers/ptp/ptp_netc.c
@@ -21,6 +21,7 @@
 #define  TMR_ETEP(i)			BIT(8 + (i))
 #define  TMR_COMP_MODE			BIT(15)
 #define  TMR_CTRL_TCLK_PERIOD		GENMASK(25, 16)
+#define  TMR_CTRL_PPL(i)		BIT(27 - (i))
 #define  TMR_CTRL_FS			BIT(28)
 
 #define NETC_TMR_TEVENT			0x0084
@@ -609,6 +610,28 @@ static int netc_timer_enable(struct ptp_clock_info *ptp,
 	}
 }
 
+static int netc_timer_perout_loopback(struct ptp_clock_info *ptp,
+				      unsigned int index, int on)
+{
+	struct netc_timer *priv = ptp_to_netc_timer(ptp);
+	unsigned long flags;
+	u32 tmr_ctrl;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	tmr_ctrl = netc_timer_rd(priv, NETC_TMR_CTRL);
+	if (on)
+		tmr_ctrl |= TMR_CTRL_PPL(index);
+	else
+		tmr_ctrl &= ~TMR_CTRL_PPL(index);
+
+	netc_timer_wr(priv, NETC_TMR_CTRL, tmr_ctrl);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
 static void netc_timer_adjust_period(struct netc_timer *priv, u64 period)
 {
 	u32 fractional_period = lower_32_bits(period);
@@ -717,6 +740,7 @@ static const struct ptp_clock_info netc_timer_ptp_caps = {
 	.pps		= 1,
 	.n_per_out	= 3,
 	.n_ext_ts	= 2,
+	.n_per_lp	= 2,
 	.supported_extts_flags = PTP_RISING_EDGE | PTP_FALLING_EDGE |
 				 PTP_STRICT_FLAGS,
 	.adjfine	= netc_timer_adjfine,
@@ -724,6 +748,7 @@ static const struct ptp_clock_info netc_timer_ptp_caps = {
 	.gettimex64	= netc_timer_gettimex64,
 	.settime64	= netc_timer_settime64,
 	.enable		= netc_timer_enable,
+	.perout_loopback = netc_timer_perout_loopback,
 };
 
 static void netc_timer_init(struct netc_timer *priv)
diff --git a/drivers/ptp/ptp_qoriq.c b/drivers/ptp/ptp_qoriq.c
index 4d488c1f1941..8da995e36aeb 100644
--- a/drivers/ptp/ptp_qoriq.c
+++ b/drivers/ptp/ptp_qoriq.c
@@ -465,6 +465,25 @@ static int ptp_qoriq_auto_config(struct ptp_qoriq *ptp_qoriq,
 	return 0;
 }
 
+static int ptp_qoriq_perout_loopback(struct ptp_clock_info *ptp,
+				     unsigned int index, int on)
+{
+	struct ptp_qoriq *ptp_qoriq = container_of(ptp, struct ptp_qoriq, caps);
+	struct ptp_qoriq_registers *regs = &ptp_qoriq->regs;
+	u32 loopback_bit = index ? PP2L : PP1L;
+	u32 tmr_ctrl;
+
+	tmr_ctrl = ptp_qoriq->read(&regs->ctrl_regs->tmr_ctrl);
+	if (on)
+		tmr_ctrl |= loopback_bit;
+	else
+		tmr_ctrl &= ~loopback_bit;
+
+	ptp_qoriq->write(&regs->ctrl_regs->tmr_ctrl, tmr_ctrl);
+
+	return 0;
+}
+
 int ptp_qoriq_init(struct ptp_qoriq *ptp_qoriq, void __iomem *base,
 		   const struct ptp_clock_info *caps)
 {
@@ -479,6 +498,8 @@ int ptp_qoriq_init(struct ptp_qoriq *ptp_qoriq, void __iomem *base,
 
 	ptp_qoriq->base = base;
 	ptp_qoriq->caps = *caps;
+	ptp_qoriq->caps.n_per_lp = 2;
+	ptp_qoriq->caps.perout_loopback = ptp_qoriq_perout_loopback;
 
 	if (of_property_read_u32(node, "fsl,cksel", &ptp_qoriq->cksel))
 		ptp_qoriq->cksel = DEFAULT_CKSEL;
@@ -568,7 +589,7 @@ int ptp_qoriq_init(struct ptp_qoriq *ptp_qoriq, void __iomem *base,
 		return PTR_ERR(ptp_qoriq->clock);
 
 	ptp_qoriq->phc_index = ptp_clock_index(ptp_qoriq->clock);
-	ptp_qoriq_create_debugfs(ptp_qoriq);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(ptp_qoriq_init);
@@ -580,7 +601,6 @@ void ptp_qoriq_free(struct ptp_qoriq *ptp_qoriq)
 	ptp_qoriq->write(&regs->ctrl_regs->tmr_temask, 0);
 	ptp_qoriq->write(&regs->ctrl_regs->tmr_ctrl,   0);
 
-	ptp_qoriq_remove_debugfs(ptp_qoriq);
 	ptp_clock_unregister(ptp_qoriq->clock);
 	iounmap(ptp_qoriq->base);
 	free_irq(ptp_qoriq->irq, ptp_qoriq);
diff --git a/drivers/ptp/ptp_qoriq_debugfs.c b/drivers/ptp/ptp_qoriq_debugfs.c
deleted file mode 100644
index e8dddcedf288..000000000000
--- a/drivers/ptp/ptp_qoriq_debugfs.c
+++ /dev/null
@@ -1,101 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/* Copyright 2019 NXP
- */
-#include <linux/device.h>
-#include <linux/debugfs.h>
-#include <linux/fsl/ptp_qoriq.h>
-
-static int ptp_qoriq_fiper1_lpbk_get(void *data, u64 *val)
-{
-	struct ptp_qoriq *ptp_qoriq = data;
-	struct ptp_qoriq_registers *regs = &ptp_qoriq->regs;
-	u32 ctrl;
-
-	ctrl = ptp_qoriq->read(&regs->ctrl_regs->tmr_ctrl);
-	*val = ctrl & PP1L ? 1 : 0;
-
-	return 0;
-}
-
-static int ptp_qoriq_fiper1_lpbk_set(void *data, u64 val)
-{
-	struct ptp_qoriq *ptp_qoriq = data;
-	struct ptp_qoriq_registers *regs = &ptp_qoriq->regs;
-	u32 ctrl;
-
-	ctrl = ptp_qoriq->read(&regs->ctrl_regs->tmr_ctrl);
-	if (val == 0)
-		ctrl &= ~PP1L;
-	else
-		ctrl |= PP1L;
-
-	ptp_qoriq->write(&regs->ctrl_regs->tmr_ctrl, ctrl);
-	return 0;
-}
-
-DEFINE_DEBUGFS_ATTRIBUTE(ptp_qoriq_fiper1_fops, ptp_qoriq_fiper1_lpbk_get,
-			 ptp_qoriq_fiper1_lpbk_set, "%llu\n");
-
-static int ptp_qoriq_fiper2_lpbk_get(void *data, u64 *val)
-{
-	struct ptp_qoriq *ptp_qoriq = data;
-	struct ptp_qoriq_registers *regs = &ptp_qoriq->regs;
-	u32 ctrl;
-
-	ctrl = ptp_qoriq->read(&regs->ctrl_regs->tmr_ctrl);
-	*val = ctrl & PP2L ? 1 : 0;
-
-	return 0;
-}
-
-static int ptp_qoriq_fiper2_lpbk_set(void *data, u64 val)
-{
-	struct ptp_qoriq *ptp_qoriq = data;
-	struct ptp_qoriq_registers *regs = &ptp_qoriq->regs;
-	u32 ctrl;
-
-	ctrl = ptp_qoriq->read(&regs->ctrl_regs->tmr_ctrl);
-	if (val == 0)
-		ctrl &= ~PP2L;
-	else
-		ctrl |= PP2L;
-
-	ptp_qoriq->write(&regs->ctrl_regs->tmr_ctrl, ctrl);
-	return 0;
-}
-
-DEFINE_DEBUGFS_ATTRIBUTE(ptp_qoriq_fiper2_fops, ptp_qoriq_fiper2_lpbk_get,
-			 ptp_qoriq_fiper2_lpbk_set, "%llu\n");
-
-void ptp_qoriq_create_debugfs(struct ptp_qoriq *ptp_qoriq)
-{
-	struct dentry *root;
-
-	root = debugfs_create_dir(dev_name(ptp_qoriq->dev), NULL);
-	if (IS_ERR(root))
-		return;
-	if (!root)
-		goto err_root;
-
-	ptp_qoriq->debugfs_root = root;
-
-	if (!debugfs_create_file_unsafe("fiper1-loopback", 0600, root,
-					ptp_qoriq, &ptp_qoriq_fiper1_fops))
-		goto err_node;
-	if (!debugfs_create_file_unsafe("fiper2-loopback", 0600, root,
-					ptp_qoriq, &ptp_qoriq_fiper2_fops))
-		goto err_node;
-	return;
-
-err_node:
-	debugfs_remove_recursive(root);
-	ptp_qoriq->debugfs_root = NULL;
-err_root:
-	dev_err(ptp_qoriq->dev, "failed to initialize debugfs\n");
-}
-
-void ptp_qoriq_remove_debugfs(struct ptp_qoriq *ptp_qoriq)
-{
-	debugfs_remove_recursive(ptp_qoriq->debugfs_root);
-	ptp_qoriq->debugfs_root = NULL;
-}
diff --git a/include/linux/fsl/ptp_qoriq.h b/include/linux/fsl/ptp_qoriq.h
index b301bf7199d3..3601e25779ba 100644
--- a/include/linux/fsl/ptp_qoriq.h
+++ b/include/linux/fsl/ptp_qoriq.h
@@ -145,7 +145,6 @@ struct ptp_qoriq {
 	struct ptp_clock *clock;
 	struct ptp_clock_info caps;
 	struct resource *rsrc;
-	struct dentry *debugfs_root;
 	struct device *dev;
 	bool extts_fifo_support;
 	bool fiper3_support;
@@ -195,14 +194,5 @@ int ptp_qoriq_settime(struct ptp_clock_info *ptp,
 int ptp_qoriq_enable(struct ptp_clock_info *ptp,
 		     struct ptp_clock_request *rq, int on);
 int extts_clean_up(struct ptp_qoriq *ptp_qoriq, int index, bool update_event);
-#ifdef CONFIG_DEBUG_FS
-void ptp_qoriq_create_debugfs(struct ptp_qoriq *ptp_qoriq);
-void ptp_qoriq_remove_debugfs(struct ptp_qoriq *ptp_qoriq);
-#else
-static inline void ptp_qoriq_create_debugfs(struct ptp_qoriq *ptp_qoriq)
-{ }
-static inline void ptp_qoriq_remove_debugfs(struct ptp_qoriq *ptp_qoriq)
-{ }
-#endif
 
 #endif
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index 7dd7951b23d5..884364596dd3 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -67,6 +67,8 @@ struct ptp_system_timestamp {
  * @n_ext_ts:  The number of external time stamp channels.
  * @n_per_out: The number of programmable periodic signals.
  * @n_pins:    The number of programmable pins.
+ * @n_per_lp:  The number of channels that support loopback the periodic
+ *             output signal.
  * @pps:       Indicates whether the clock supports a PPS callback.
  *
  * @supported_perout_flags:  The set of flags the driver supports for the
@@ -175,6 +177,11 @@ struct ptp_system_timestamp {
  *                scheduling time (>=0) or negative value in case further
  *                scheduling is not required.
  *
+ * @perout_loopback: Request driver to enable or disable the periodic output
+ *                   signal loopback.
+ *                   parameter index: index of the periodic output signal channel.
+ *                   parameter on: caller passes one to enable or zero to disable.
+ *
  * Drivers should embed their ptp_clock_info within a private
  * structure, obtaining a reference to it using container_of().
  *
@@ -189,6 +196,7 @@ struct ptp_clock_info {
 	int n_ext_ts;
 	int n_per_out;
 	int n_pins;
+	int n_per_lp;
 	int pps;
 	unsigned int supported_perout_flags;
 	unsigned int supported_extts_flags;
@@ -213,6 +221,8 @@ struct ptp_clock_info {
 	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
 		      enum ptp_pin_function func, unsigned int chan);
 	long (*do_aux_work)(struct ptp_clock_info *ptp);
+	int (*perout_loopback)(struct ptp_clock_info *ptp, unsigned int index,
+			       int on);
 };
 
 struct ptp_clock;