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267 lines
7.4 KiB
267 lines
7.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved. |
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* Copyright (C) 2018-2020 Linaro Ltd. |
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*/ |
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/* DOC: IPA Interrupts |
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* |
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* The IPA has an interrupt line distinct from the interrupt used by the GSI |
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* code. Whereas GSI interrupts are generally related to channel events (like |
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* transfer completions), IPA interrupts are related to other events related |
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* to the IPA. Some of the IPA interrupts come from a microcontroller |
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* embedded in the IPA. Each IPA interrupt type can be both masked and |
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* acknowledged independent of the others. |
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* |
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* Two of the IPA interrupts are initiated by the microcontroller. A third |
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* can be generated to signal the need for a wakeup/resume when an IPA |
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* endpoint has been suspended. There are other IPA events, but at this |
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* time only these three are supported. |
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*/ |
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#include <linux/types.h> |
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#include <linux/interrupt.h> |
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#include "ipa.h" |
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#include "ipa_clock.h" |
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#include "ipa_reg.h" |
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#include "ipa_endpoint.h" |
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#include "ipa_interrupt.h" |
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/** |
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* struct ipa_interrupt - IPA interrupt information |
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* @ipa: IPA pointer |
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* @irq: Linux IRQ number used for IPA interrupts |
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* @enabled: Mask indicating which interrupts are enabled |
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* @handler: Array of handlers indexed by IPA interrupt ID |
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*/ |
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struct ipa_interrupt { |
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struct ipa *ipa; |
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u32 irq; |
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u32 enabled; |
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ipa_irq_handler_t handler[IPA_IRQ_COUNT]; |
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}; |
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/* Returns true if the interrupt type is associated with the microcontroller */ |
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static bool ipa_interrupt_uc(struct ipa_interrupt *interrupt, u32 irq_id) |
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{ |
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return irq_id == IPA_IRQ_UC_0 || irq_id == IPA_IRQ_UC_1; |
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} |
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/* Process a particular interrupt type that has been received */ |
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static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id) |
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{ |
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bool uc_irq = ipa_interrupt_uc(interrupt, irq_id); |
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struct ipa *ipa = interrupt->ipa; |
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u32 mask = BIT(irq_id); |
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/* For microcontroller interrupts, clear the interrupt right away, |
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* "to avoid clearing unhandled interrupts." |
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*/ |
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if (uc_irq) |
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iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET); |
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if (irq_id < IPA_IRQ_COUNT && interrupt->handler[irq_id]) |
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interrupt->handler[irq_id](interrupt->ipa, irq_id); |
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/* Clearing the SUSPEND_TX interrupt also clears the register |
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* that tells us which suspended endpoint(s) caused the interrupt, |
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* so defer clearing until after the handler has been called. |
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*/ |
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if (!uc_irq) |
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iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET); |
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} |
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/* Process all IPA interrupt types that have been signaled */ |
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static void ipa_interrupt_process_all(struct ipa_interrupt *interrupt) |
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{ |
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struct ipa *ipa = interrupt->ipa; |
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u32 enabled = interrupt->enabled; |
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u32 mask; |
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/* The status register indicates which conditions are present, |
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* including conditions whose interrupt is not enabled. Handle |
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* only the enabled ones. |
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*/ |
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mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET); |
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while ((mask &= enabled)) { |
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do { |
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u32 irq_id = __ffs(mask); |
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mask ^= BIT(irq_id); |
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ipa_interrupt_process(interrupt, irq_id); |
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} while (mask); |
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mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET); |
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} |
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} |
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/* Threaded part of the IPA IRQ handler */ |
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static irqreturn_t ipa_isr_thread(int irq, void *dev_id) |
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{ |
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struct ipa_interrupt *interrupt = dev_id; |
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ipa_clock_get(interrupt->ipa); |
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ipa_interrupt_process_all(interrupt); |
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ipa_clock_put(interrupt->ipa); |
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return IRQ_HANDLED; |
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} |
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/* Hard part (i.e., "real" IRQ handler) of the IRQ handler */ |
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static irqreturn_t ipa_isr(int irq, void *dev_id) |
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{ |
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struct ipa_interrupt *interrupt = dev_id; |
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struct ipa *ipa = interrupt->ipa; |
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u32 mask; |
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mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET); |
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if (mask & interrupt->enabled) |
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return IRQ_WAKE_THREAD; |
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/* Nothing in the mask was supposed to cause an interrupt */ |
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iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET); |
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dev_err(&ipa->pdev->dev, "%s: unexpected interrupt, mask 0x%08x\n", |
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__func__, mask); |
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return IRQ_HANDLED; |
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} |
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/* Common function used to enable/disable TX_SUSPEND for an endpoint */ |
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static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt, |
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u32 endpoint_id, bool enable) |
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{ |
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struct ipa *ipa = interrupt->ipa; |
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u32 mask = BIT(endpoint_id); |
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u32 val; |
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/* assert(mask & ipa->available); */ |
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val = ioread32(ipa->reg_virt + IPA_REG_IRQ_SUSPEND_EN_OFFSET); |
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if (enable) |
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val |= mask; |
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else |
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val &= ~mask; |
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iowrite32(val, ipa->reg_virt + IPA_REG_IRQ_SUSPEND_EN_OFFSET); |
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} |
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/* Enable TX_SUSPEND for an endpoint */ |
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void |
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ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id) |
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{ |
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ipa_interrupt_suspend_control(interrupt, endpoint_id, true); |
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} |
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/* Disable TX_SUSPEND for an endpoint */ |
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void |
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ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id) |
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{ |
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ipa_interrupt_suspend_control(interrupt, endpoint_id, false); |
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} |
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/* Clear the suspend interrupt for all endpoints that signaled it */ |
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void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt) |
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{ |
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struct ipa *ipa = interrupt->ipa; |
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u32 val; |
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val = ioread32(ipa->reg_virt + IPA_REG_IRQ_SUSPEND_INFO_OFFSET); |
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iowrite32(val, ipa->reg_virt + IPA_REG_IRQ_SUSPEND_CLR_OFFSET); |
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} |
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/* Simulate arrival of an IPA TX_SUSPEND interrupt */ |
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void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt) |
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{ |
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ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND); |
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} |
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/* Add a handler for an IPA interrupt */ |
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void ipa_interrupt_add(struct ipa_interrupt *interrupt, |
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enum ipa_irq_id ipa_irq, ipa_irq_handler_t handler) |
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{ |
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struct ipa *ipa = interrupt->ipa; |
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/* assert(ipa_irq < IPA_IRQ_COUNT); */ |
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interrupt->handler[ipa_irq] = handler; |
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/* Update the IPA interrupt mask to enable it */ |
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interrupt->enabled |= BIT(ipa_irq); |
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iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET); |
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} |
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/* Remove the handler for an IPA interrupt type */ |
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void |
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ipa_interrupt_remove(struct ipa_interrupt *interrupt, enum ipa_irq_id ipa_irq) |
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{ |
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struct ipa *ipa = interrupt->ipa; |
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/* assert(ipa_irq < IPA_IRQ_COUNT); */ |
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/* Update the IPA interrupt mask to disable it */ |
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interrupt->enabled &= ~BIT(ipa_irq); |
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iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET); |
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interrupt->handler[ipa_irq] = NULL; |
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} |
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/* Set up the IPA interrupt framework */ |
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struct ipa_interrupt *ipa_interrupt_setup(struct ipa *ipa) |
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{ |
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struct device *dev = &ipa->pdev->dev; |
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struct ipa_interrupt *interrupt; |
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unsigned int irq; |
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int ret; |
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ret = platform_get_irq_byname(ipa->pdev, "ipa"); |
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if (ret <= 0) { |
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dev_err(dev, "DT error %d getting \"ipa\" IRQ property\n", |
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ret); |
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return ERR_PTR(ret ? : -EINVAL); |
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} |
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irq = ret; |
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interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL); |
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if (!interrupt) |
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return ERR_PTR(-ENOMEM); |
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interrupt->ipa = ipa; |
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interrupt->irq = irq; |
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/* Start with all IPA interrupts disabled */ |
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iowrite32(0, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET); |
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ret = request_threaded_irq(irq, ipa_isr, ipa_isr_thread, IRQF_ONESHOT, |
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"ipa", interrupt); |
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if (ret) { |
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dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret); |
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goto err_kfree; |
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} |
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ret = enable_irq_wake(irq); |
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if (ret) { |
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dev_err(dev, "error %d enabling wakeup for \"ipa\" IRQ\n", ret); |
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goto err_free_irq; |
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} |
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return interrupt; |
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err_free_irq: |
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free_irq(interrupt->irq, interrupt); |
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err_kfree: |
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kfree(interrupt); |
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return ERR_PTR(ret); |
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} |
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/* Tear down the IPA interrupt framework */ |
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void ipa_interrupt_teardown(struct ipa_interrupt *interrupt) |
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{ |
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struct device *dev = &interrupt->ipa->pdev->dev; |
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int ret; |
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ret = disable_irq_wake(interrupt->irq); |
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if (ret) |
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dev_err(dev, "error %d disabling \"ipa\" IRQ wakeup\n", ret); |
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free_irq(interrupt->irq, interrupt); |
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kfree(interrupt); |
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}
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