Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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: Bence Csókás <csokas.bence@prolan.hu>
Link: https://lore.kernel.org/r/20250306134441.582819-2-csokas.bence@prolan.hu
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
authored by
Bence Csókás
and committed by
William Breathitt Gray
e5d58139
c2a75666
+109
+1
MAINTAINERS
+1
MAINTAINERS
+74
drivers/counter/microchip-tcb-capture.c
+74
drivers/counter/microchip-tcb-capture.c
···
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*/
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#include <linux/clk.h>
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#include <linux/counter.h>
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#include <linux/interrupt.h>
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/of_irq.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <uapi/linux/counter/microchip-tcb-capture.h>
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#include <soc/at91/atmel_tcb.h>
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#define ATMEL_TC_CMR_MASK (ATMEL_TC_LDRA_RISING | ATMEL_TC_LDRB_FALLING | \
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ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_LDBDIS | \
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ATMEL_TC_LDBSTOP)
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#define ATMEL_TC_DEF_IRQS (ATMEL_TC_ETRGS | ATMEL_TC_COVFS | \
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ATMEL_TC_LDRAS | ATMEL_TC_LDRBS | ATMEL_TC_CPCS)
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#define ATMEL_TC_QDEN BIT(8)
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#define ATMEL_TC_POSEN BIT(9)
···
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{ /* sentinel */ }
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};
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static irqreturn_t mchp_tc_isr(int irq, void *dev_id)
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{
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struct counter_device *const counter = dev_id;
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struct mchp_tc_data *const priv = counter_priv(counter);
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u32 sr, mask;
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regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr);
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regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], IMR), &mask);
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sr &= mask;
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if (!(sr & ATMEL_TC_ALL_IRQ))
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return IRQ_NONE;
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if (sr & ATMEL_TC_ETRGS)
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counter_push_event(counter, COUNTER_EVENT_CHANGE_OF_STATE,
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COUNTER_MCHP_EVCHN_CV);
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if (sr & ATMEL_TC_LDRAS)
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counter_push_event(counter, COUNTER_EVENT_CAPTURE,
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COUNTER_MCHP_EVCHN_RA);
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if (sr & ATMEL_TC_LDRBS)
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counter_push_event(counter, COUNTER_EVENT_CAPTURE,
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COUNTER_MCHP_EVCHN_RB);
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if (sr & ATMEL_TC_CPCS)
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counter_push_event(counter, COUNTER_EVENT_THRESHOLD,
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COUNTER_MCHP_EVCHN_RC);
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if (sr & ATMEL_TC_COVFS)
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counter_push_event(counter, COUNTER_EVENT_OVERFLOW,
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COUNTER_MCHP_EVCHN_CV);
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return IRQ_HANDLED;
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}
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static void mchp_tc_irq_remove(void *ptr)
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{
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struct mchp_tc_data *priv = ptr;
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regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], IDR), ATMEL_TC_DEF_IRQS);
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}
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static int mchp_tc_irq_enable(struct counter_device *const counter, int irq)
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{
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struct mchp_tc_data *const priv = counter_priv(counter);
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int ret = devm_request_irq(counter->parent, irq, mchp_tc_isr, 0,
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dev_name(counter->parent), counter);
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if (ret < 0)
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return ret;
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ret = regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], IER), ATMEL_TC_DEF_IRQS);
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if (ret < 0)
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return ret;
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ret = devm_add_action_or_reset(counter->parent, mchp_tc_irq_remove, priv);
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if (ret < 0)
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return ret;
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return 0;
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}
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static void mchp_tc_clk_remove(void *ptr)
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{
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clk_disable_unprepare((struct clk *)ptr);
···
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counter->counts = mchp_tc_counts;
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counter->num_signals = ARRAY_SIZE(mchp_tc_count_signals);
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counter->signals = mchp_tc_count_signals;
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i = of_irq_get(np->parent, 0);
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if (i == -EPROBE_DEFER)
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return -EPROBE_DEFER;
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if (i > 0) {
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ret = mchp_tc_irq_enable(counter, i);
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if (ret < 0)
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return dev_err_probe(&pdev->dev, ret, "Failed to set up IRQ");
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}
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ret = devm_counter_add(&pdev->dev, counter);
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if (ret < 0)
+34
include/uapi/linux/counter/microchip-tcb-capture.h
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include/uapi/linux/counter/microchip-tcb-capture.h
···
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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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/*
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* Channel numbers used by the microchip-tcb-capture driver
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* Copyright (C) 2025 Bence Csókás
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*/
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#ifndef _UAPI_COUNTER_MCHP_TCB_H_
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#define _UAPI_COUNTER_MCHP_TCB_H_
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/*
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* The driver defines the following components:
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*
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* Count 0
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* \__ Synapse 0 -- Signal 0 (Channel A, i.e. TIOA)
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* \__ Synapse 1 -- Signal 1 (Channel B, i.e. TIOB)
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*
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* It also supports the following events:
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*
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* Channel 0:
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* - CV register changed
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* - CV overflowed
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* - RA captured
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* Channel 1:
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* - RB captured
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* Channel 2:
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* - RC compare triggered
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*/
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/* Event channels */
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#define COUNTER_MCHP_EVCHN_CV 0
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#define COUNTER_MCHP_EVCHN_RA 0
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#define COUNTER_MCHP_EVCHN_RB 1
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#define COUNTER_MCHP_EVCHN_RC 2
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#endif /* _UAPI_COUNTER_MCHP_TCB_H_ */