1ba764c4dSAlex Elder // SPDX-License-Identifier: GPL-2.0 2ba764c4dSAlex Elder 3ba764c4dSAlex Elder /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved. 4ba764c4dSAlex Elder * Copyright (C) 2018-2020 Linaro Ltd. 5ba764c4dSAlex Elder */ 6ba764c4dSAlex Elder 7ba764c4dSAlex Elder /* DOC: IPA Interrupts 8ba764c4dSAlex Elder * 9ba764c4dSAlex Elder * The IPA has an interrupt line distinct from the interrupt used by the GSI 10ba764c4dSAlex Elder * code. Whereas GSI interrupts are generally related to channel events (like 11ba764c4dSAlex Elder * transfer completions), IPA interrupts are related to other events related 12ba764c4dSAlex Elder * to the IPA. Some of the IPA interrupts come from a microcontroller 13ba764c4dSAlex Elder * embedded in the IPA. Each IPA interrupt type can be both masked and 14ba764c4dSAlex Elder * acknowledged independent of the others. 15ba764c4dSAlex Elder * 16ba764c4dSAlex Elder * Two of the IPA interrupts are initiated by the microcontroller. A third 17ba764c4dSAlex Elder * can be generated to signal the need for a wakeup/resume when an IPA 18ba764c4dSAlex Elder * endpoint has been suspended. There are other IPA events, but at this 19ba764c4dSAlex Elder * time only these three are supported. 20ba764c4dSAlex Elder */ 21ba764c4dSAlex Elder 22ba764c4dSAlex Elder #include <linux/types.h> 23ba764c4dSAlex Elder #include <linux/interrupt.h> 24ba764c4dSAlex Elder 25ba764c4dSAlex Elder #include "ipa.h" 26ba764c4dSAlex Elder #include "ipa_clock.h" 27ba764c4dSAlex Elder #include "ipa_reg.h" 28ba764c4dSAlex Elder #include "ipa_endpoint.h" 29ba764c4dSAlex Elder #include "ipa_interrupt.h" 30ba764c4dSAlex Elder 31ba764c4dSAlex Elder /** 32ba764c4dSAlex Elder * struct ipa_interrupt - IPA interrupt information 33ba764c4dSAlex Elder * @ipa: IPA pointer 34ba764c4dSAlex Elder * @irq: Linux IRQ number used for IPA interrupts 35ba764c4dSAlex Elder * @enabled: Mask indicating which interrupts are enabled 36ba764c4dSAlex Elder * @handler: Array of handlers indexed by IPA interrupt ID 37ba764c4dSAlex Elder */ 38ba764c4dSAlex Elder struct ipa_interrupt { 39ba764c4dSAlex Elder struct ipa *ipa; 40ba764c4dSAlex Elder u32 irq; 41ba764c4dSAlex Elder u32 enabled; 42ba764c4dSAlex Elder ipa_irq_handler_t handler[IPA_IRQ_COUNT]; 43ba764c4dSAlex Elder }; 44ba764c4dSAlex Elder 45ba764c4dSAlex Elder /* Returns true if the interrupt type is associated with the microcontroller */ 46ba764c4dSAlex Elder static bool ipa_interrupt_uc(struct ipa_interrupt *interrupt, u32 irq_id) 47ba764c4dSAlex Elder { 48ba764c4dSAlex Elder return irq_id == IPA_IRQ_UC_0 || irq_id == IPA_IRQ_UC_1; 49ba764c4dSAlex Elder } 50ba764c4dSAlex Elder 51ba764c4dSAlex Elder /* Process a particular interrupt type that has been received */ 52ba764c4dSAlex Elder static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id) 53ba764c4dSAlex Elder { 54ba764c4dSAlex Elder bool uc_irq = ipa_interrupt_uc(interrupt, irq_id); 55ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 56ba764c4dSAlex Elder u32 mask = BIT(irq_id); 57ba764c4dSAlex Elder 58ba764c4dSAlex Elder /* For microcontroller interrupts, clear the interrupt right away, 59ba764c4dSAlex Elder * "to avoid clearing unhandled interrupts." 60ba764c4dSAlex Elder */ 61ba764c4dSAlex Elder if (uc_irq) 62ba764c4dSAlex Elder iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET); 63ba764c4dSAlex Elder 64ba764c4dSAlex Elder if (irq_id < IPA_IRQ_COUNT && interrupt->handler[irq_id]) 65ba764c4dSAlex Elder interrupt->handler[irq_id](interrupt->ipa, irq_id); 66ba764c4dSAlex Elder 67ba764c4dSAlex Elder /* Clearing the SUSPEND_TX interrupt also clears the register 68ba764c4dSAlex Elder * that tells us which suspended endpoint(s) caused the interrupt, 69ba764c4dSAlex Elder * so defer clearing until after the handler has been called. 70ba764c4dSAlex Elder */ 71ba764c4dSAlex Elder if (!uc_irq) 72ba764c4dSAlex Elder iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET); 73ba764c4dSAlex Elder } 74ba764c4dSAlex Elder 75ba764c4dSAlex Elder /* Process all IPA interrupt types that have been signaled */ 76ba764c4dSAlex Elder static void ipa_interrupt_process_all(struct ipa_interrupt *interrupt) 77ba764c4dSAlex Elder { 78ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 79ba764c4dSAlex Elder u32 enabled = interrupt->enabled; 80ba764c4dSAlex Elder u32 mask; 81ba764c4dSAlex Elder 82ba764c4dSAlex Elder /* The status register indicates which conditions are present, 83ba764c4dSAlex Elder * including conditions whose interrupt is not enabled. Handle 84ba764c4dSAlex Elder * only the enabled ones. 85ba764c4dSAlex Elder */ 86ba764c4dSAlex Elder mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET); 87ba764c4dSAlex Elder while ((mask &= enabled)) { 88ba764c4dSAlex Elder do { 89ba764c4dSAlex Elder u32 irq_id = __ffs(mask); 90ba764c4dSAlex Elder 91ba764c4dSAlex Elder mask ^= BIT(irq_id); 92ba764c4dSAlex Elder 93ba764c4dSAlex Elder ipa_interrupt_process(interrupt, irq_id); 94ba764c4dSAlex Elder } while (mask); 95ba764c4dSAlex Elder mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET); 96ba764c4dSAlex Elder } 97ba764c4dSAlex Elder } 98ba764c4dSAlex Elder 99ba764c4dSAlex Elder /* Threaded part of the IPA IRQ handler */ 100ba764c4dSAlex Elder static irqreturn_t ipa_isr_thread(int irq, void *dev_id) 101ba764c4dSAlex Elder { 102ba764c4dSAlex Elder struct ipa_interrupt *interrupt = dev_id; 103ba764c4dSAlex Elder 104ba764c4dSAlex Elder ipa_clock_get(interrupt->ipa); 105ba764c4dSAlex Elder 106ba764c4dSAlex Elder ipa_interrupt_process_all(interrupt); 107ba764c4dSAlex Elder 108ba764c4dSAlex Elder ipa_clock_put(interrupt->ipa); 109ba764c4dSAlex Elder 110ba764c4dSAlex Elder return IRQ_HANDLED; 111ba764c4dSAlex Elder } 112ba764c4dSAlex Elder 113ba764c4dSAlex Elder /* Hard part (i.e., "real" IRQ handler) of the IRQ handler */ 114ba764c4dSAlex Elder static irqreturn_t ipa_isr(int irq, void *dev_id) 115ba764c4dSAlex Elder { 116ba764c4dSAlex Elder struct ipa_interrupt *interrupt = dev_id; 117ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 118ba764c4dSAlex Elder u32 mask; 119ba764c4dSAlex Elder 120ba764c4dSAlex Elder mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET); 121ba764c4dSAlex Elder if (mask & interrupt->enabled) 122ba764c4dSAlex Elder return IRQ_WAKE_THREAD; 123ba764c4dSAlex Elder 124ba764c4dSAlex Elder /* Nothing in the mask was supposed to cause an interrupt */ 125ba764c4dSAlex Elder iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET); 126ba764c4dSAlex Elder 127ba764c4dSAlex Elder dev_err(&ipa->pdev->dev, "%s: unexpected interrupt, mask 0x%08x\n", 128ba764c4dSAlex Elder __func__, mask); 129ba764c4dSAlex Elder 130ba764c4dSAlex Elder return IRQ_HANDLED; 131ba764c4dSAlex Elder } 132ba764c4dSAlex Elder 133ba764c4dSAlex Elder /* Common function used to enable/disable TX_SUSPEND for an endpoint */ 134ba764c4dSAlex Elder static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt, 135ba764c4dSAlex Elder u32 endpoint_id, bool enable) 136ba764c4dSAlex Elder { 137ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 138ba764c4dSAlex Elder u32 mask = BIT(endpoint_id); 139ba764c4dSAlex Elder u32 val; 140ba764c4dSAlex Elder 141ba764c4dSAlex Elder /* assert(mask & ipa->available); */ 142ba764c4dSAlex Elder val = ioread32(ipa->reg_virt + IPA_REG_SUSPEND_IRQ_EN_OFFSET); 143ba764c4dSAlex Elder if (enable) 144ba764c4dSAlex Elder val |= mask; 145ba764c4dSAlex Elder else 146ba764c4dSAlex Elder val &= ~mask; 147ba764c4dSAlex Elder iowrite32(val, ipa->reg_virt + IPA_REG_SUSPEND_IRQ_EN_OFFSET); 148ba764c4dSAlex Elder } 149ba764c4dSAlex Elder 150ba764c4dSAlex Elder /* Enable TX_SUSPEND for an endpoint */ 151ba764c4dSAlex Elder void 152ba764c4dSAlex Elder ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id) 153ba764c4dSAlex Elder { 154ba764c4dSAlex Elder ipa_interrupt_suspend_control(interrupt, endpoint_id, true); 155ba764c4dSAlex Elder } 156ba764c4dSAlex Elder 157ba764c4dSAlex Elder /* Disable TX_SUSPEND for an endpoint */ 158ba764c4dSAlex Elder void 159ba764c4dSAlex Elder ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id) 160ba764c4dSAlex Elder { 161ba764c4dSAlex Elder ipa_interrupt_suspend_control(interrupt, endpoint_id, false); 162ba764c4dSAlex Elder } 163ba764c4dSAlex Elder 164ba764c4dSAlex Elder /* Clear the suspend interrupt for all endpoints that signaled it */ 165ba764c4dSAlex Elder void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt) 166ba764c4dSAlex Elder { 167ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 168ba764c4dSAlex Elder u32 val; 169ba764c4dSAlex Elder 170ba764c4dSAlex Elder val = ioread32(ipa->reg_virt + IPA_REG_IRQ_SUSPEND_INFO_OFFSET); 171ba764c4dSAlex Elder iowrite32(val, ipa->reg_virt + IPA_REG_SUSPEND_IRQ_CLR_OFFSET); 172ba764c4dSAlex Elder } 173ba764c4dSAlex Elder 174ba764c4dSAlex Elder /* Simulate arrival of an IPA TX_SUSPEND interrupt */ 175ba764c4dSAlex Elder void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt) 176ba764c4dSAlex Elder { 177ba764c4dSAlex Elder ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND); 178ba764c4dSAlex Elder } 179ba764c4dSAlex Elder 180ba764c4dSAlex Elder /* Add a handler for an IPA interrupt */ 181ba764c4dSAlex Elder void ipa_interrupt_add(struct ipa_interrupt *interrupt, 182ba764c4dSAlex Elder enum ipa_irq_id ipa_irq, ipa_irq_handler_t handler) 183ba764c4dSAlex Elder { 184ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 185ba764c4dSAlex Elder 186ba764c4dSAlex Elder /* assert(ipa_irq < IPA_IRQ_COUNT); */ 187ba764c4dSAlex Elder interrupt->handler[ipa_irq] = handler; 188ba764c4dSAlex Elder 189ba764c4dSAlex Elder /* Update the IPA interrupt mask to enable it */ 190ba764c4dSAlex Elder interrupt->enabled |= BIT(ipa_irq); 191ba764c4dSAlex Elder iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET); 192ba764c4dSAlex Elder } 193ba764c4dSAlex Elder 194ba764c4dSAlex Elder /* Remove the handler for an IPA interrupt type */ 195ba764c4dSAlex Elder void 196ba764c4dSAlex Elder ipa_interrupt_remove(struct ipa_interrupt *interrupt, enum ipa_irq_id ipa_irq) 197ba764c4dSAlex Elder { 198ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 199ba764c4dSAlex Elder 200ba764c4dSAlex Elder /* assert(ipa_irq < IPA_IRQ_COUNT); */ 201ba764c4dSAlex Elder /* Update the IPA interrupt mask to disable it */ 202ba764c4dSAlex Elder interrupt->enabled &= ~BIT(ipa_irq); 203ba764c4dSAlex Elder iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET); 204ba764c4dSAlex Elder 205ba764c4dSAlex Elder interrupt->handler[ipa_irq] = NULL; 206ba764c4dSAlex Elder } 207ba764c4dSAlex Elder 208ba764c4dSAlex Elder /* Set up the IPA interrupt framework */ 209ba764c4dSAlex Elder struct ipa_interrupt *ipa_interrupt_setup(struct ipa *ipa) 210ba764c4dSAlex Elder { 211ba764c4dSAlex Elder struct device *dev = &ipa->pdev->dev; 212ba764c4dSAlex Elder struct ipa_interrupt *interrupt; 213ba764c4dSAlex Elder unsigned int irq; 214ba764c4dSAlex Elder int ret; 215ba764c4dSAlex Elder 216ba764c4dSAlex Elder ret = platform_get_irq_byname(ipa->pdev, "ipa"); 217ba764c4dSAlex Elder if (ret <= 0) { 218ba764c4dSAlex Elder dev_err(dev, "DT error %d getting \"ipa\" IRQ property\n", 219ba764c4dSAlex Elder ret); 220ba764c4dSAlex Elder return ERR_PTR(ret ? : -EINVAL); 221ba764c4dSAlex Elder } 222ba764c4dSAlex Elder irq = ret; 223ba764c4dSAlex Elder 224ba764c4dSAlex Elder interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL); 225ba764c4dSAlex Elder if (!interrupt) 226ba764c4dSAlex Elder return ERR_PTR(-ENOMEM); 227ba764c4dSAlex Elder interrupt->ipa = ipa; 228ba764c4dSAlex Elder interrupt->irq = irq; 229ba764c4dSAlex Elder 230ba764c4dSAlex Elder /* Start with all IPA interrupts disabled */ 231ba764c4dSAlex Elder iowrite32(0, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET); 232ba764c4dSAlex Elder 233ba764c4dSAlex Elder ret = request_threaded_irq(irq, ipa_isr, ipa_isr_thread, IRQF_ONESHOT, 234ba764c4dSAlex Elder "ipa", interrupt); 235ba764c4dSAlex Elder if (ret) { 236ba764c4dSAlex Elder dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret); 237ba764c4dSAlex Elder goto err_kfree; 238ba764c4dSAlex Elder } 239ba764c4dSAlex Elder 240ba764c4dSAlex Elder return interrupt; 241ba764c4dSAlex Elder 242ba764c4dSAlex Elder err_kfree: 243ba764c4dSAlex Elder kfree(interrupt); 244ba764c4dSAlex Elder 245ba764c4dSAlex Elder return ERR_PTR(ret); 246ba764c4dSAlex Elder } 247ba764c4dSAlex Elder 248ba764c4dSAlex Elder /* Tear down the IPA interrupt framework */ 249ba764c4dSAlex Elder void ipa_interrupt_teardown(struct ipa_interrupt *interrupt) 250ba764c4dSAlex Elder { 251ba764c4dSAlex Elder free_irq(interrupt->irq, interrupt); 252ba764c4dSAlex Elder kfree(interrupt); 253ba764c4dSAlex Elder } 254