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); 57*e666aa97SAlex Elder u32 offset; 58ba764c4dSAlex Elder 59ba764c4dSAlex Elder /* For microcontroller interrupts, clear the interrupt right away, 60ba764c4dSAlex Elder * "to avoid clearing unhandled interrupts." 61ba764c4dSAlex Elder */ 62*e666aa97SAlex Elder offset = ipa_reg_irq_clr_offset(ipa->version); 63ba764c4dSAlex Elder if (uc_irq) 64*e666aa97SAlex Elder iowrite32(mask, ipa->reg_virt + offset); 65ba764c4dSAlex Elder 66ba764c4dSAlex Elder if (irq_id < IPA_IRQ_COUNT && interrupt->handler[irq_id]) 67ba764c4dSAlex Elder interrupt->handler[irq_id](interrupt->ipa, irq_id); 68ba764c4dSAlex Elder 69ba764c4dSAlex Elder /* Clearing the SUSPEND_TX interrupt also clears the register 70ba764c4dSAlex Elder * that tells us which suspended endpoint(s) caused the interrupt, 71ba764c4dSAlex Elder * so defer clearing until after the handler has been called. 72ba764c4dSAlex Elder */ 73ba764c4dSAlex Elder if (!uc_irq) 74*e666aa97SAlex Elder iowrite32(mask, ipa->reg_virt + offset); 75ba764c4dSAlex Elder } 76ba764c4dSAlex Elder 77ba764c4dSAlex Elder /* Process all IPA interrupt types that have been signaled */ 78ba764c4dSAlex Elder static void ipa_interrupt_process_all(struct ipa_interrupt *interrupt) 79ba764c4dSAlex Elder { 80ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 81ba764c4dSAlex Elder u32 enabled = interrupt->enabled; 82*e666aa97SAlex Elder u32 offset; 83ba764c4dSAlex Elder u32 mask; 84ba764c4dSAlex Elder 85ba764c4dSAlex Elder /* The status register indicates which conditions are present, 86ba764c4dSAlex Elder * including conditions whose interrupt is not enabled. Handle 87ba764c4dSAlex Elder * only the enabled ones. 88ba764c4dSAlex Elder */ 89*e666aa97SAlex Elder offset = ipa_reg_irq_stts_offset(ipa->version); 90*e666aa97SAlex Elder mask = ioread32(ipa->reg_virt + offset); 91ba764c4dSAlex Elder while ((mask &= enabled)) { 92ba764c4dSAlex Elder do { 93ba764c4dSAlex Elder u32 irq_id = __ffs(mask); 94ba764c4dSAlex Elder 95ba764c4dSAlex Elder mask ^= BIT(irq_id); 96ba764c4dSAlex Elder 97ba764c4dSAlex Elder ipa_interrupt_process(interrupt, irq_id); 98ba764c4dSAlex Elder } while (mask); 99*e666aa97SAlex Elder mask = ioread32(ipa->reg_virt + offset); 100ba764c4dSAlex Elder } 101ba764c4dSAlex Elder } 102ba764c4dSAlex Elder 103ba764c4dSAlex Elder /* Threaded part of the IPA IRQ handler */ 104ba764c4dSAlex Elder static irqreturn_t ipa_isr_thread(int irq, void *dev_id) 105ba764c4dSAlex Elder { 106ba764c4dSAlex Elder struct ipa_interrupt *interrupt = dev_id; 107ba764c4dSAlex Elder 108ba764c4dSAlex Elder ipa_clock_get(interrupt->ipa); 109ba764c4dSAlex Elder 110ba764c4dSAlex Elder ipa_interrupt_process_all(interrupt); 111ba764c4dSAlex Elder 112ba764c4dSAlex Elder ipa_clock_put(interrupt->ipa); 113ba764c4dSAlex Elder 114ba764c4dSAlex Elder return IRQ_HANDLED; 115ba764c4dSAlex Elder } 116ba764c4dSAlex Elder 117ba764c4dSAlex Elder /* Hard part (i.e., "real" IRQ handler) of the IRQ handler */ 118ba764c4dSAlex Elder static irqreturn_t ipa_isr(int irq, void *dev_id) 119ba764c4dSAlex Elder { 120ba764c4dSAlex Elder struct ipa_interrupt *interrupt = dev_id; 121ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 122*e666aa97SAlex Elder u32 offset; 123ba764c4dSAlex Elder u32 mask; 124ba764c4dSAlex Elder 125*e666aa97SAlex Elder offset = ipa_reg_irq_stts_offset(ipa->version); 126*e666aa97SAlex Elder mask = ioread32(ipa->reg_virt + offset); 127ba764c4dSAlex Elder if (mask & interrupt->enabled) 128ba764c4dSAlex Elder return IRQ_WAKE_THREAD; 129ba764c4dSAlex Elder 130ba764c4dSAlex Elder /* Nothing in the mask was supposed to cause an interrupt */ 131*e666aa97SAlex Elder offset = ipa_reg_irq_clr_offset(ipa->version); 132*e666aa97SAlex Elder iowrite32(mask, ipa->reg_virt + offset); 133ba764c4dSAlex Elder 134ba764c4dSAlex Elder dev_err(&ipa->pdev->dev, "%s: unexpected interrupt, mask 0x%08x\n", 135ba764c4dSAlex Elder __func__, mask); 136ba764c4dSAlex Elder 137ba764c4dSAlex Elder return IRQ_HANDLED; 138ba764c4dSAlex Elder } 139ba764c4dSAlex Elder 140ba764c4dSAlex Elder /* Common function used to enable/disable TX_SUSPEND for an endpoint */ 141ba764c4dSAlex Elder static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt, 142ba764c4dSAlex Elder u32 endpoint_id, bool enable) 143ba764c4dSAlex Elder { 144ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 145ba764c4dSAlex Elder u32 mask = BIT(endpoint_id); 146*e666aa97SAlex Elder u32 offset; 147ba764c4dSAlex Elder u32 val; 148ba764c4dSAlex Elder 149ba764c4dSAlex Elder /* assert(mask & ipa->available); */ 150*e666aa97SAlex Elder 151*e666aa97SAlex Elder /* IPA version 3.0 does not support TX_SUSPEND interrupt control */ 152*e666aa97SAlex Elder if (ipa->version == IPA_VERSION_3_0) 153*e666aa97SAlex Elder return; 154*e666aa97SAlex Elder 155*e666aa97SAlex Elder offset = ipa_reg_irq_suspend_en_offset(ipa->version); 156*e666aa97SAlex Elder val = ioread32(ipa->reg_virt + offset); 157ba764c4dSAlex Elder if (enable) 158ba764c4dSAlex Elder val |= mask; 159ba764c4dSAlex Elder else 160ba764c4dSAlex Elder val &= ~mask; 161*e666aa97SAlex Elder iowrite32(val, ipa->reg_virt + offset); 162ba764c4dSAlex Elder } 163ba764c4dSAlex Elder 164ba764c4dSAlex Elder /* Enable TX_SUSPEND for an endpoint */ 165ba764c4dSAlex Elder void 166ba764c4dSAlex Elder ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id) 167ba764c4dSAlex Elder { 168ba764c4dSAlex Elder ipa_interrupt_suspend_control(interrupt, endpoint_id, true); 169ba764c4dSAlex Elder } 170ba764c4dSAlex Elder 171ba764c4dSAlex Elder /* Disable TX_SUSPEND for an endpoint */ 172ba764c4dSAlex Elder void 173ba764c4dSAlex Elder ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id) 174ba764c4dSAlex Elder { 175ba764c4dSAlex Elder ipa_interrupt_suspend_control(interrupt, endpoint_id, false); 176ba764c4dSAlex Elder } 177ba764c4dSAlex Elder 178ba764c4dSAlex Elder /* Clear the suspend interrupt for all endpoints that signaled it */ 179ba764c4dSAlex Elder void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt) 180ba764c4dSAlex Elder { 181ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 182*e666aa97SAlex Elder u32 offset; 183ba764c4dSAlex Elder u32 val; 184ba764c4dSAlex Elder 185*e666aa97SAlex Elder offset = ipa_reg_irq_suspend_info_offset(ipa->version); 186*e666aa97SAlex Elder val = ioread32(ipa->reg_virt + offset); 187*e666aa97SAlex Elder 188*e666aa97SAlex Elder /* SUSPEND interrupt status isn't cleared on IPA version 3.0 */ 189*e666aa97SAlex Elder if (ipa->version == IPA_VERSION_3_0) 190*e666aa97SAlex Elder return; 191*e666aa97SAlex Elder 192*e666aa97SAlex Elder offset = ipa_reg_irq_suspend_clr_offset(ipa->version); 193*e666aa97SAlex Elder iowrite32(val, ipa->reg_virt + offset); 194ba764c4dSAlex Elder } 195ba764c4dSAlex Elder 196ba764c4dSAlex Elder /* Simulate arrival of an IPA TX_SUSPEND interrupt */ 197ba764c4dSAlex Elder void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt) 198ba764c4dSAlex Elder { 199ba764c4dSAlex Elder ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND); 200ba764c4dSAlex Elder } 201ba764c4dSAlex Elder 202ba764c4dSAlex Elder /* Add a handler for an IPA interrupt */ 203ba764c4dSAlex Elder void ipa_interrupt_add(struct ipa_interrupt *interrupt, 204ba764c4dSAlex Elder enum ipa_irq_id ipa_irq, ipa_irq_handler_t handler) 205ba764c4dSAlex Elder { 206ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 207*e666aa97SAlex Elder u32 offset; 208ba764c4dSAlex Elder 209ba764c4dSAlex Elder /* assert(ipa_irq < IPA_IRQ_COUNT); */ 210ba764c4dSAlex Elder interrupt->handler[ipa_irq] = handler; 211ba764c4dSAlex Elder 212ba764c4dSAlex Elder /* Update the IPA interrupt mask to enable it */ 213ba764c4dSAlex Elder interrupt->enabled |= BIT(ipa_irq); 214*e666aa97SAlex Elder offset = ipa_reg_irq_en_offset(ipa->version); 215*e666aa97SAlex Elder iowrite32(interrupt->enabled, ipa->reg_virt + offset); 216ba764c4dSAlex Elder } 217ba764c4dSAlex Elder 218ba764c4dSAlex Elder /* Remove the handler for an IPA interrupt type */ 219ba764c4dSAlex Elder void 220ba764c4dSAlex Elder ipa_interrupt_remove(struct ipa_interrupt *interrupt, enum ipa_irq_id ipa_irq) 221ba764c4dSAlex Elder { 222ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa; 223*e666aa97SAlex Elder u32 offset; 224ba764c4dSAlex Elder 225ba764c4dSAlex Elder /* assert(ipa_irq < IPA_IRQ_COUNT); */ 226ba764c4dSAlex Elder /* Update the IPA interrupt mask to disable it */ 227ba764c4dSAlex Elder interrupt->enabled &= ~BIT(ipa_irq); 228*e666aa97SAlex Elder offset = ipa_reg_irq_en_offset(ipa->version); 229*e666aa97SAlex Elder iowrite32(interrupt->enabled, ipa->reg_virt + offset); 230ba764c4dSAlex Elder 231ba764c4dSAlex Elder interrupt->handler[ipa_irq] = NULL; 232ba764c4dSAlex Elder } 233ba764c4dSAlex Elder 234ba764c4dSAlex Elder /* Set up the IPA interrupt framework */ 235ba764c4dSAlex Elder struct ipa_interrupt *ipa_interrupt_setup(struct ipa *ipa) 236ba764c4dSAlex Elder { 237ba764c4dSAlex Elder struct device *dev = &ipa->pdev->dev; 238ba764c4dSAlex Elder struct ipa_interrupt *interrupt; 239ba764c4dSAlex Elder unsigned int irq; 240*e666aa97SAlex Elder u32 offset; 241ba764c4dSAlex Elder int ret; 242ba764c4dSAlex Elder 243ba764c4dSAlex Elder ret = platform_get_irq_byname(ipa->pdev, "ipa"); 244ba764c4dSAlex Elder if (ret <= 0) { 245ba764c4dSAlex Elder dev_err(dev, "DT error %d getting \"ipa\" IRQ property\n", 246ba764c4dSAlex Elder ret); 247ba764c4dSAlex Elder return ERR_PTR(ret ? : -EINVAL); 248ba764c4dSAlex Elder } 249ba764c4dSAlex Elder irq = ret; 250ba764c4dSAlex Elder 251ba764c4dSAlex Elder interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL); 252ba764c4dSAlex Elder if (!interrupt) 253ba764c4dSAlex Elder return ERR_PTR(-ENOMEM); 254ba764c4dSAlex Elder interrupt->ipa = ipa; 255ba764c4dSAlex Elder interrupt->irq = irq; 256ba764c4dSAlex Elder 257ba764c4dSAlex Elder /* Start with all IPA interrupts disabled */ 258*e666aa97SAlex Elder offset = ipa_reg_irq_en_offset(ipa->version); 259*e666aa97SAlex Elder iowrite32(0, ipa->reg_virt + offset); 260ba764c4dSAlex Elder 261ba764c4dSAlex Elder ret = request_threaded_irq(irq, ipa_isr, ipa_isr_thread, IRQF_ONESHOT, 262ba764c4dSAlex Elder "ipa", interrupt); 263ba764c4dSAlex Elder if (ret) { 264ba764c4dSAlex Elder dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret); 265ba764c4dSAlex Elder goto err_kfree; 266ba764c4dSAlex Elder } 267ba764c4dSAlex Elder 268d1b5126aSAlex Elder ret = enable_irq_wake(irq); 269d1b5126aSAlex Elder if (ret) { 270d1b5126aSAlex Elder dev_err(dev, "error %d enabling wakeup for \"ipa\" IRQ\n", ret); 271d1b5126aSAlex Elder goto err_free_irq; 272d1b5126aSAlex Elder } 273d1b5126aSAlex Elder 274ba764c4dSAlex Elder return interrupt; 275ba764c4dSAlex Elder 276d1b5126aSAlex Elder err_free_irq: 277d1b5126aSAlex Elder free_irq(interrupt->irq, interrupt); 278ba764c4dSAlex Elder err_kfree: 279ba764c4dSAlex Elder kfree(interrupt); 280ba764c4dSAlex Elder 281ba764c4dSAlex Elder return ERR_PTR(ret); 282ba764c4dSAlex Elder } 283ba764c4dSAlex Elder 284ba764c4dSAlex Elder /* Tear down the IPA interrupt framework */ 285ba764c4dSAlex Elder void ipa_interrupt_teardown(struct ipa_interrupt *interrupt) 286ba764c4dSAlex Elder { 287d1b5126aSAlex Elder struct device *dev = &interrupt->ipa->pdev->dev; 288d1b5126aSAlex Elder int ret; 289d1b5126aSAlex Elder 290d1b5126aSAlex Elder ret = disable_irq_wake(interrupt->irq); 291d1b5126aSAlex Elder if (ret) 292d1b5126aSAlex Elder dev_err(dev, "error %d disabling \"ipa\" IRQ wakeup\n", ret); 293ba764c4dSAlex Elder free_irq(interrupt->irq, interrupt); 294ba764c4dSAlex Elder kfree(interrupt); 295ba764c4dSAlex Elder } 296