Merge tag 'counter-updates-for-6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter into char-misc-next

William writes:

Counter updates for 6.15

counter:
- Introduce the COUNTER_EVENT_DIRECTION_CHANGE event
- Introduce the COUNTER_COMP_COMPARE helper macro
microchip-tcb-cpature:
- Add IRQ handling
- Add support for capture extensions
- Add support for compare extension
ti-eqep:
- Add support for reading and detecting changes in direction
tools/counter:
- Add counter_watch_events executable to .gitignore
- Support COUNTER_EVENT_DIRECTION_CHANGE in counter_watch_events tool

* tag 'counter-updates-for-6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
counter: microchip-tcb-capture: Add support for RC Compare
counter: Introduce the compare component
counter: microchip-tcb-capture: Add capture extensions for registers RA/RB
counter: microchip-tcb-capture: Add IRQ handling
counter: ti-eqep: add direction support
tools/counter: add direction change event to watcher
counter: add direction change event
tools/counter: gitignore counter_watch_events

Documentation/ABI/testing/sysfs-bus-counter

···
 Description:
 		Count data of Count Y represented as a string.
 
+What:		/sys/bus/counter/devices/counterX/countY/compare
+KernelVersion:	6.15
+Contact:	[e-mail]
+Description:
+		If the counter device supports compare registers -- registers
+		used to compare counter channels against a particular count --
+		the compare count for channel Y is provided by this attribute.
+
 What:		/sys/bus/counter/devices/counterX/countY/capture
 KernelVersion:	6.1
 Contact:	[e-mail]
···
 
 What:		/sys/bus/counter/devices/counterX/cascade_counts_enable_component_id
 What:		/sys/bus/counter/devices/counterX/external_input_phase_clock_select_component_id
+What:		/sys/bus/counter/devices/counterX/countY/compare_component_id
 What:		/sys/bus/counter/devices/counterX/countY/capture_component_id
 What:		/sys/bus/counter/devices/counterX/countY/ceiling_component_id
 What:		/sys/bus/counter/devices/counterX/countY/floor_component_id

MAINTAINERS

···
 L:	[e-mail]
 S:	Maintained
 F:	drivers/counter/microchip-tcb-capture.c
+F:	include/uapi/linux/counter/microchip-tcb-capture.h
 
 MICROCHIP USB251XB DRIVER
 M:	Richard Leitner <[e-mail]>

drivers/counter/microchip-tcb-capture.c

···
  */
 #include <linux/clk.h>
 #include <linux/counter.h>
+#include <linux/interrupt.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <uapi/linux/counter/microchip-tcb-capture.h>
 #include <soc/at91/atmel_tcb.h>
 
 #define ATMEL_TC_CMR_MASK	(ATMEL_TC_LDRA_RISING | ATMEL_TC_LDRB_FALLING | \
 				 ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_LDBDIS | \
 				 ATMEL_TC_LDBSTOP)
+
+#define ATMEL_TC_DEF_IRQS	(ATMEL_TC_ETRGS | ATMEL_TC_COVFS | \
+				 ATMEL_TC_LDRAS | ATMEL_TC_LDRBS | ATMEL_TC_CPCS)
 
 #define ATMEL_TC_QDEN			BIT(8)
 #define ATMEL_TC_POSEN			BIT(9)
···
 	return 0;
 }
 
+static int mchp_tc_count_cap_read(struct counter_device *counter,
+				  struct counter_count *count, size_t idx, u64 *val)
+{
+	struct mchp_tc_data *const priv = counter_priv(counter);
+	u32 cnt;
+	int ret;
+
+	switch (idx) {
+	case COUNTER_MCHP_EXCAP_RA:
+		ret = regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], RA), &cnt);
+		break;
+	case COUNTER_MCHP_EXCAP_RB:
+		ret = regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], RB), &cnt);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (ret < 0)
+		return ret;
+
+	*val = cnt;
+
+	return 0;
+}
+
+static int mchp_tc_count_cap_write(struct counter_device *counter,
+				   struct counter_count *count, size_t idx, u64 val)
+{
+	struct mchp_tc_data *const priv = counter_priv(counter);
+	int ret;
+
+	if (val > U32_MAX)
+		return -ERANGE;
+
+	switch (idx) {
+	case COUNTER_MCHP_EXCAP_RA:
+		ret = regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], RA), val);
+		break;
+	case COUNTER_MCHP_EXCAP_RB:
+		ret = regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], RB), val);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int mchp_tc_count_compare_read(struct counter_device *counter, struct counter_count *count,
+				      u64 *val)
+{
+	struct mchp_tc_data *const priv = counter_priv(counter);
+	u32 cnt;
+	int ret;
+
+	ret = regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], RC), &cnt);
+	if (ret < 0)
+		return ret;
+
+	*val = cnt;
+
+	return 0;
+}
+
+static int mchp_tc_count_compare_write(struct counter_device *counter, struct counter_count *count,
+				       u64 val)
+{
+	struct mchp_tc_data *const priv = counter_priv(counter);
+
+	if (val > U32_MAX)
+		return -ERANGE;
+
+	return regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], RC), val);
+}
+
+static DEFINE_COUNTER_ARRAY_CAPTURE(mchp_tc_cnt_cap_array, 2);
+
+static struct counter_comp mchp_tc_count_ext[] = {
+	COUNTER_COMP_ARRAY_CAPTURE(mchp_tc_count_cap_read, mchp_tc_count_cap_write,
+				   mchp_tc_cnt_cap_array),
+	COUNTER_COMP_COMPARE(mchp_tc_count_compare_read, mchp_tc_count_compare_write),
+};
+
 static struct counter_count mchp_tc_counts[] = {
 	{
 		.id = 0,
···
 		.num_functions = ARRAY_SIZE(mchp_tc_count_functions),
 		.synapses = mchp_tc_count_synapses,
 		.num_synapses = ARRAY_SIZE(mchp_tc_count_synapses),
+		.ext = mchp_tc_count_ext,
+		.num_ext = ARRAY_SIZE(mchp_tc_count_ext),
 	},
 };
 
···
 	{ .compatible = "atmel,sama5d3-tcb", .data = &tcb_sama5d3_config, },
 	{ /* sentinel */ }
 };
+
+static irqreturn_t mchp_tc_isr(int irq, void *dev_id)
+{
+	struct counter_device *const counter = dev_id;
+	struct mchp_tc_data *const priv = counter_priv(counter);
+	u32 sr, mask;
+
+	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr);
+	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], IMR), &mask);
+
+	sr &= mask;
+	if (!(sr & ATMEL_TC_ALL_IRQ))
+		return IRQ_NONE;
+
+	if (sr & ATMEL_TC_ETRGS)
+		counter_push_event(counter, COUNTER_EVENT_CHANGE_OF_STATE,
+				   COUNTER_MCHP_EVCHN_CV);
+	if (sr & ATMEL_TC_LDRAS)
+		counter_push_event(counter, COUNTER_EVENT_CAPTURE,
+				   COUNTER_MCHP_EVCHN_RA);
+	if (sr & ATMEL_TC_LDRBS)
+		counter_push_event(counter, COUNTER_EVENT_CAPTURE,
+				   COUNTER_MCHP_EVCHN_RB);
+	if (sr & ATMEL_TC_CPCS)
+		counter_push_event(counter, COUNTER_EVENT_THRESHOLD,
+				   COUNTER_MCHP_EVCHN_RC);
+	if (sr & ATMEL_TC_COVFS)
+		counter_push_event(counter, COUNTER_EVENT_OVERFLOW,
+				   COUNTER_MCHP_EVCHN_CV);
+
+	return IRQ_HANDLED;
+}
+
+static void mchp_tc_irq_remove(void *ptr)
+{
+	struct mchp_tc_data *priv = ptr;
+
+	regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], IDR), ATMEL_TC_DEF_IRQS);
+}
+
+static int mchp_tc_irq_enable(struct counter_device *const counter, int irq)
+{
+	struct mchp_tc_data *const priv = counter_priv(counter);
+	int ret = devm_request_irq(counter->parent, irq, mchp_tc_isr, 0,
+				   dev_name(counter->parent), counter);
+
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], IER), ATMEL_TC_DEF_IRQS);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_add_action_or_reset(counter->parent, mchp_tc_irq_remove, priv);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
 
 static void mchp_tc_clk_remove(void *ptr)
 {
···
 	counter->counts = mchp_tc_counts;
 	counter->num_signals = ARRAY_SIZE(mchp_tc_count_signals);
 	counter->signals = mchp_tc_count_signals;
+
+	i = of_irq_get(np->parent, 0);
+	if (i == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	if (i > 0) {
+		ret = mchp_tc_irq_enable(counter, i);
+		if (ret < 0)
+			return dev_err_probe(&pdev->dev, ret, "Failed to set up IRQ");
+	}
 
 	ret = devm_counter_add(&pdev->dev, counter);
 	if (ret < 0)

drivers/counter/ti-eqep.c

···
 #define QCLR_PCE		BIT(1)
 #define QCLR_INT		BIT(0)
 
+#define QEPSTS_UPEVNT		BIT(7)
+#define QEPSTS_FDF		BIT(6)
+#define QEPSTS_QDF		BIT(5)
+#define QEPSTS_QDLF		BIT(4)
+#define QEPSTS_COEF		BIT(3)
+#define QEPSTS_CDEF		BIT(2)
+#define QEPSTS_FIMF		BIT(1)
+#define QEPSTS_PCEF		BIT(0)
+
 /* EQEP Inputs */
 enum {
 	TI_EQEP_SIGNAL_QEPA,	/* QEPA/XCLK */
···
 		case COUNTER_EVENT_UNDERFLOW:
 			qeint |= QEINT_PCU;
 			break;
+		case COUNTER_EVENT_DIRECTION_CHANGE:
+			qeint |= QEINT_QDC;
+			break;
 		}
 	}
 
···
 	switch (watch->event) {
 	case COUNTER_EVENT_OVERFLOW:
 	case COUNTER_EVENT_UNDERFLOW:
+	case COUNTER_EVENT_DIRECTION_CHANGE:
 		if (watch->channel != 0)
 			return -EINVAL;
 
···
 	return 0;
 }
 
+static int ti_eqep_direction_read(struct counter_device *counter,
+				  struct counter_count *count,
+				  enum counter_count_direction *direction)
+{
+	struct ti_eqep_cnt *priv = counter_priv(counter);
+	u32 qepsts;
+
+	regmap_read(priv->regmap16, QEPSTS, &qepsts);
+
+	*direction = (qepsts & QEPSTS_QDF) ? COUNTER_COUNT_DIRECTION_FORWARD
+					   : COUNTER_COUNT_DIRECTION_BACKWARD;
+
+	return 0;
+}
+
 static struct counter_comp ti_eqep_position_ext[] = {
 	COUNTER_COMP_CEILING(ti_eqep_position_ceiling_read,
 			     ti_eqep_position_ceiling_write),
 	COUNTER_COMP_ENABLE(ti_eqep_position_enable_read,
 			    ti_eqep_position_enable_write),
+	COUNTER_COMP_DIRECTION(ti_eqep_direction_read),
 };
 
 static struct counter_signal ti_eqep_signals[] = {
···
 
 	if (qflg & QFLG_PCU)
 		counter_push_event(counter, COUNTER_EVENT_UNDERFLOW, 0);
+
+	if (qflg & QFLG_QDC)
+		counter_push_event(counter, COUNTER_EVENT_DIRECTION_CHANGE, 0);
 
 	regmap_write(priv->regmap16, QCLR, qflg);
 

include/linux/counter.h

···
 #define COUNTER_COMP_CEILING(_read, _write) \
 	COUNTER_COMP_COUNT_U64("ceiling", _read, _write)
 
+#define COUNTER_COMP_COMPARE(_read, _write) \
+	COUNTER_COMP_COUNT_U64("compare", _read, _write)
+
 #define COUNTER_COMP_COUNT_MODE(_read, _write, _available) \
 { \
 	.type = COUNTER_COMP_COUNT_MODE, \

include/uapi/linux/counter.h

···
 	COUNTER_EVENT_CHANGE_OF_STATE,
 	/* Count value captured */
 	COUNTER_EVENT_CAPTURE,
+	/* Direction change detected */
+	COUNTER_EVENT_DIRECTION_CHANGE,
 };
 
 /**

include/uapi/linux/counter/microchip-tcb-capture.h

···
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Channel numbers used by the microchip-tcb-capture driver
+ * Copyright (C) 2025 Bence Csókás
+ */
+#ifndef _UAPI_COUNTER_MCHP_TCB_H_
+#define _UAPI_COUNTER_MCHP_TCB_H_
+
+/*
+ * The driver defines the following components:
+ *
+ * Count 0
+ * \__  Synapse 0 -- Signal 0 (Channel A, i.e. TIOA)
+ * \__  Synapse 1 -- Signal 1 (Channel B, i.e. TIOB)
+ * \__  Extension capture0    (RA register)
+ * \__  Extension capture1    (RB register)
+ *
+ * It also supports the following events:
+ *
+ * Channel 0:
+ * - CV register changed
+ * - CV overflowed
+ * - RA captured
+ * Channel 1:
+ * - RB captured
+ * Channel 2:
+ * - RC compare triggered
+ */
+
+/* Capture extensions */
+#define COUNTER_MCHP_EXCAP_RA 0
+#define COUNTER_MCHP_EXCAP_RB 1
+
+/* Event channels */
+#define COUNTER_MCHP_EVCHN_CV 0
+#define COUNTER_MCHP_EVCHN_RA 0
+#define COUNTER_MCHP_EVCHN_RB 1
+#define COUNTER_MCHP_EVCHN_RC 2
+
+#endif /* _UAPI_COUNTER_MCHP_TCB_H_ */

tools/counter/.gitignore

···
 /counter_example
+/counter_watch_events
 /include/linux/counter.h

tools/counter/counter_watch_events.c

···
 	"COUNTER_EVENT_INDEX",
 	"COUNTER_EVENT_CHANGE_OF_STATE",
 	"COUNTER_EVENT_CAPTURE",
+	"COUNTER_EVENT_DIRECTION_CHANGE",
 };
 
 static const char * const counter_component_type_name[] = {
···
 		"  evt_index                  (COUNTER_EVENT_INDEX)\n"
 		"  evt_change_of_state        (COUNTER_EVENT_CHANGE_OF_STATE)\n"
 		"  evt_capture                (COUNTER_EVENT_CAPTURE)\n"
+		"  evt_direction_change       (COUNTER_EVENT_DIRECTION_CHANGE)\n"
 		"\n"
 		"  chan=<n>                   channel <n> for this watch [default: 0]\n"
 		"  id=<n>                     component id <n> for this watch [default: 0]\n"
···
 	WATCH_EVENT_INDEX,
 	WATCH_EVENT_CHANGE_OF_STATE,
 	WATCH_EVENT_CAPTURE,
+	WATCH_EVENT_DIRECTION_CHANGE,
 	WATCH_CHANNEL,
 	WATCH_ID,
 	WATCH_PARENT,
···
 	[WATCH_EVENT_INDEX] = "evt_index",
 	[WATCH_EVENT_CHANGE_OF_STATE] = "evt_change_of_state",
 	[WATCH_EVENT_CAPTURE] = "evt_capture",
+	[WATCH_EVENT_DIRECTION_CHANGE] = "evt_direction_change",
 	/* channel, id, parent */
 	[WATCH_CHANNEL] = "chan",
 	[WATCH_ID] = "id",
···
 				case WATCH_EVENT_INDEX:
 				case WATCH_EVENT_CHANGE_OF_STATE:
 				case WATCH_EVENT_CAPTURE:
+				case WATCH_EVENT_DIRECTION_CHANGE:
 					/* match counter_event_type: subtract enum value */
 					ret -= WATCH_EVENT_OVERFLOW;
 					watches[i].event = ret;