// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved. * Copyright (C) 2018-2024 Linaro Ltd. */ /* DOC: IPA Interrupts * * The IPA has an interrupt line distinct from the interrupt used by the GSI * code.  Whereas GSI interrupts are generally related to channel events (like * transfer completions), IPA interrupts are related to other events related * to the IPA.  Some of the IPA interrupts come from a microcontroller * embedded in the IPA.  Each IPA interrupt type can be both masked and * acknowledged independent of the others. * * Two of the IPA interrupts are initiated by the microcontroller.  A third * can be generated to signal the need for a wakeup/resume when an IPA * endpoint has been suspended.  There are other IPA events, but at this * time only these three are supported. */ #include <linux/interrupt.h>#include <linux/platform_device.h>#include <linux/pm_runtime.h>#include <linux/pm_wakeirq.h>#include <linux/types.h> #include "ipa.h"#include "ipa_endpoint.h"#include "ipa_interrupt.h"#include "ipa_power.h"#include "ipa_reg.h"#include "ipa_uc.h" /** * struct ipa_interrupt - IPA interrupt information * @ipa:		IPA pointer * @irq:		Linux IRQ number used for IPA interrupts * @enabled:		Mask indicating which interrupts are enabled * @suspend_enabled:	Bitmap of endpoints with the SUSPEND interrupt enabled */struct ipa_interrupt {	struct ipa *ipa;	u32 irq;	u32 enabled;	unsigned long *suspend_enabled;}; /* Clear the suspend interrupt for all endpoints that signaled it */static void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt){	struct ipa *ipa = interrupt->ipa;	u32 unit_count;	u32 unit; 	unit_count = DIV_ROUND_UP(ipa->endpoint_count, 32);	for (unit = 0; unit < unit_count; unit++) {		const struct reg *reg;		u32 val; 		reg = ipa_reg(ipa, IRQ_SUSPEND_INFO);		val = ioread32(ipa->reg_virt + reg_n_offset(reg, unit)); 		/* SUSPEND interrupt status isn't cleared on IPA version 3.0 */		if (!val || ipa->version == IPA_VERSION_3_0)			continue; 		reg = ipa_reg(ipa, IRQ_SUSPEND_CLR);		iowrite32(val, ipa->reg_virt + reg_n_offset(reg, unit));	}} /* Process a particular interrupt type that has been received */static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id){	struct ipa *ipa = interrupt->ipa;	const struct reg *reg;	u32 mask = BIT(irq_id);	u32 offset; 	reg = ipa_reg(ipa, IPA_IRQ_CLR);	offset = reg_offset(reg); 	switch (irq_id) {	case IPA_IRQ_UC_0:	case IPA_IRQ_UC_1:		/* For microcontroller interrupts, clear the interrupt right		 * away, "to avoid clearing unhandled interrupts."		 */		iowrite32(mask, ipa->reg_virt + offset);		ipa_uc_interrupt_handler(ipa, irq_id);		break; 	case IPA_IRQ_TX_SUSPEND:		/* Clearing the SUSPEND_TX interrupt also clears the		 * register that tells us which suspended endpoint(s)		 * caused the interrupt, so defer clearing until after		 * the handler has been called.		 */		ipa_interrupt_suspend_clear_all(interrupt);		fallthrough; 	default:	/* Silently ignore (and clear) any other condition */		iowrite32(mask, ipa->reg_virt + offset);		break;	}} /* IPA IRQ handler is threaded */static irqreturn_t ipa_isr_thread(int irq, void *dev_id){	struct ipa_interrupt *interrupt = dev_id;	struct ipa *ipa = interrupt->ipa;	u32 enabled = interrupt->enabled;	struct device *dev = ipa->dev;	const struct reg *reg;	u32 pending;	u32 offset;	u32 mask;	int ret; 	ret = pm_runtime_get_sync(dev);	if (WARN_ON(ret < 0))		goto out_power_put; 	/* The status register indicates which conditions are present,	 * including conditions whose interrupt is not enabled.  Handle	 * only the enabled ones.	 */	reg = ipa_reg(ipa, IPA_IRQ_STTS);	offset = reg_offset(reg);	pending = ioread32(ipa->reg_virt + offset);	while ((mask = pending & enabled)) {		do {			u32 irq_id = __ffs(mask); 			mask ^= BIT(irq_id); 			ipa_interrupt_process(interrupt, irq_id);		} while (mask);		pending = ioread32(ipa->reg_virt + offset);	} 	/* If any disabled interrupts are pending, clear them */	if (pending) {		dev_dbg(dev, "clearing disabled IPA interrupts 0x%08x\n",			pending);		reg = ipa_reg(ipa, IPA_IRQ_CLR);		iowrite32(pending, ipa->reg_virt + reg_offset(reg));	}out_power_put:	(void)pm_runtime_put_autosuspend(dev); 	return IRQ_HANDLED;} static void ipa_interrupt_enabled_update(struct ipa *ipa){	const struct reg *reg = ipa_reg(ipa, IPA_IRQ_EN); 	iowrite32(ipa->interrupt->enabled, ipa->reg_virt + reg_offset(reg));} /* Enable an IPA interrupt type */void ipa_interrupt_enable(struct ipa *ipa, enum ipa_irq_id ipa_irq){	/* Update the IPA interrupt mask to enable it */	ipa->interrupt->enabled |= BIT(ipa_irq);	ipa_interrupt_enabled_update(ipa);} /* Disable an IPA interrupt type */void ipa_interrupt_disable(struct ipa *ipa, enum ipa_irq_id ipa_irq){	/* Update the IPA interrupt mask to disable it */	ipa->interrupt->enabled &= ~BIT(ipa_irq);	ipa_interrupt_enabled_update(ipa);} void ipa_interrupt_irq_disable(struct ipa *ipa){	disable_irq(ipa->interrupt->irq);} void ipa_interrupt_irq_enable(struct ipa *ipa){	enable_irq(ipa->interrupt->irq);} /* Common function used to enable/disable TX_SUSPEND for an endpoint */static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,					  u32 endpoint_id, bool enable){	struct ipa *ipa = interrupt->ipa;	u32 mask = BIT(endpoint_id % 32);	u32 unit = endpoint_id / 32;	const struct reg *reg;	unsigned long weight;	u32 offset;	u32 val; 	WARN_ON(!test_bit(endpoint_id, ipa->available)); 	/* IPA version 3.0 does not support TX_SUSPEND interrupt control */	if (ipa->version == IPA_VERSION_3_0)		return; 	weight = bitmap_weight(interrupt->suspend_enabled, ipa->endpoint_count);	if (weight == 1 && !enable)		ipa_interrupt_disable(ipa, IPA_IRQ_TX_SUSPEND); 	reg = ipa_reg(ipa, IRQ_SUSPEND_EN);	offset = reg_n_offset(reg, unit);	val = ioread32(ipa->reg_virt + offset); 	if (enable)		val |= mask;	else		val &= ~mask;	__change_bit(endpoint_id, interrupt->suspend_enabled); 	iowrite32(val, ipa->reg_virt + offset); 	if (!weight && enable)		ipa_interrupt_enable(ipa, IPA_IRQ_TX_SUSPEND);} /* Enable TX_SUSPEND for an endpoint */voidipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id){	ipa_interrupt_suspend_control(interrupt, endpoint_id, true);} /* Disable TX_SUSPEND for an endpoint */voidipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id){	ipa_interrupt_suspend_control(interrupt, endpoint_id, false);} /* Simulate arrival of an IPA TX_SUSPEND interrupt */void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt){	ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND);} /* Configure the IPA interrupt framework */int ipa_interrupt_config(struct ipa *ipa){	struct ipa_interrupt *interrupt = ipa->interrupt;	unsigned int irq = interrupt->irq;	struct device *dev = ipa->dev;	const struct reg *reg;	int ret; 	interrupt->ipa = ipa; 	/* Initially all IPA interrupt types are disabled */	interrupt->enabled = 0;	interrupt->suspend_enabled = bitmap_zalloc(ipa->endpoint_count,						   GFP_KERNEL);	if (!interrupt->suspend_enabled) {		ret = -ENOMEM;		goto err_kfree;	} 	/* Disable IPA interrupt types */	reg = ipa_reg(ipa, IPA_IRQ_EN);	iowrite32(0, ipa->reg_virt + reg_offset(reg)); 	ret = request_threaded_irq(irq, NULL, ipa_isr_thread, IRQF_ONESHOT,				   "ipa", interrupt);	if (ret) {		dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);		goto err_free_bitmap;	} 	ret = device_init_wakeup(dev, true);	if (ret) {		dev_err(dev, "error %d enabling wakeup\n", ret);		goto err_free_irq;	} 	ret = dev_pm_set_wake_irq(dev, irq);	if (ret) {		dev_err(dev, "error %d registering \"ipa\" IRQ as wakeirq\n",			ret);		goto err_disable_wakeup;	} 	ipa->interrupt = interrupt; 	return 0; err_disable_wakeup:	(void)device_init_wakeup(dev, false);err_free_irq:	free_irq(interrupt->irq, interrupt);err_free_bitmap:	bitmap_free(interrupt->suspend_enabled);err_kfree:	kfree(interrupt); 	return ret;} /* Inverse of ipa_interrupt_config() */void ipa_interrupt_deconfig(struct ipa *ipa){	struct ipa_interrupt *interrupt = ipa->interrupt;	struct device *dev = ipa->dev; 	ipa->interrupt = NULL; 	dev_pm_clear_wake_irq(dev);	(void)device_init_wakeup(dev, false);	free_irq(interrupt->irq, interrupt);	bitmap_free(interrupt->suspend_enabled);} /* Initialize the IPA interrupt structure */struct ipa_interrupt *ipa_interrupt_init(struct platform_device *pdev){	struct ipa_interrupt *interrupt;	int irq; 	irq = platform_get_irq_byname(pdev, "ipa");	if (irq <= 0)		return ERR_PTR(irq ? : -EINVAL); 	interrupt = kzalloc_obj(*interrupt);	if (!interrupt)		return ERR_PTR(-ENOMEM);	interrupt->irq = irq; 	return interrupt;} /* Inverse of ipa_interrupt_init() */void ipa_interrupt_exit(struct ipa_interrupt *interrupt){	kfree(interrupt);}