Commit e5d58139 authored by Bence Csókás's avatar Bence Csókás Committed by William Breathitt Gray
Browse files

counter: microchip-tcb-capture: Add IRQ handling 



Add interrupt servicing to allow userspace to wait for the following:
* Change-of-state caused by external trigger
* Capture of timer value into RA/RB
* Compare to RC register
* Overflow

Signed-off-by: default avatarBence Csókás <csokas.bence@prolan.hu>
Link: https://lore.kernel.org/r/20250306134441.582819-2-csokas.bence@prolan.hu


Signed-off-by: default avatarWilliam Breathitt Gray <wbg@kernel.org>
parent c2a75666

MAINTAINERS

+1 −0
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@@ -15642,6 +15642,7 @@ L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) 
L:	linux-iio@vger.kernel.org

S:	Maintained

F:	drivers/counter/microchip-tcb-capture.c

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









MICROCHIP USB251XB DRIVER









M:	Richard Leitner <richard.leitner@skidata.com>
































drivers/counter/microchip-tcb-capture.c



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@@ -6,18 +6,24 @@







 */









#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)


















@@ -294,6 +300,65 @@ static const struct of_device_id atmel_tc_of_match[] = {







	{ /* 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)









{









	clk_disable_unprepare((struct clk *)ptr);








@@ -378,6 +443,15 @@ static int mchp_tc_probe(struct platform_device *pdev)







	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)









		return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n");
































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









 *









 * It also supports the following events:









 *









 * Channel 0:









 * - CV register changed









 * - CV overflowed









 * - RA captured









 * Channel 1:









 * - RB captured









 * Channel 2:









 * - RC compare triggered









 */



















/* 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_ */