1 // SPDX-License-Identifier: GPL-2.0 2 3 /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved. 4 * Copyright (C) 2018-2022 Linaro Ltd. 5 */ 6 7 /* DOC: IPA Interrupts 8 * 9 * The IPA has an interrupt line distinct from the interrupt used by the GSI 10 * code. Whereas GSI interrupts are generally related to channel events (like 11 * transfer completions), IPA interrupts are related to other events related 12 * to the IPA. Some of the IPA interrupts come from a microcontroller 13 * embedded in the IPA. Each IPA interrupt type can be both masked and 14 * acknowledged independent of the others. 15 * 16 * Two of the IPA interrupts are initiated by the microcontroller. A third 17 * can be generated to signal the need for a wakeup/resume when an IPA 18 * endpoint has been suspended. There are other IPA events, but at this 19 * time only these three are supported. 20 */ 21 22 #include <linux/types.h> 23 #include <linux/interrupt.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/pm_wakeirq.h> 26 27 #include "ipa.h" 28 #include "ipa_reg.h" 29 #include "ipa_endpoint.h" 30 #include "ipa_power.h" 31 #include "ipa_uc.h" 32 #include "ipa_interrupt.h" 33 34 /** 35 * struct ipa_interrupt - IPA interrupt information 36 * @ipa: IPA pointer 37 * @irq: Linux IRQ number used for IPA interrupts 38 * @enabled: Mask indicating which interrupts are enabled 39 */ 40 struct ipa_interrupt { 41 struct ipa *ipa; 42 u32 irq; 43 u32 enabled; 44 }; 45 46 /* Clear the suspend interrupt for all endpoints that signaled it */ 47 static void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt) 48 { 49 struct ipa *ipa = interrupt->ipa; 50 u32 unit_count; 51 u32 unit; 52 53 unit_count = DIV_ROUND_UP(ipa->endpoint_count, 32); 54 for (unit = 0; unit < unit_count; unit++) { 55 const struct reg *reg; 56 u32 val; 57 58 reg = ipa_reg(ipa, IRQ_SUSPEND_INFO); 59 val = ioread32(ipa->reg_virt + reg_n_offset(reg, unit)); 60 61 /* SUSPEND interrupt status isn't cleared on IPA version 3.0 */ 62 if (!val || ipa->version == IPA_VERSION_3_0) 63 continue; 64 65 reg = ipa_reg(ipa, IRQ_SUSPEND_CLR); 66 iowrite32(val, ipa->reg_virt + reg_n_offset(reg, unit)); 67 } 68 } 69 70 /* Process a particular interrupt type that has been received */ 71 static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id) 72 { 73 struct ipa *ipa = interrupt->ipa; 74 const struct reg *reg; 75 u32 mask = BIT(irq_id); 76 u32 offset; 77 78 reg = ipa_reg(ipa, IPA_IRQ_CLR); 79 offset = reg_offset(reg); 80 81 switch (irq_id) { 82 case IPA_IRQ_UC_0: 83 case IPA_IRQ_UC_1: 84 /* For microcontroller interrupts, clear the interrupt right 85 * away, "to avoid clearing unhandled interrupts." 86 */ 87 iowrite32(mask, ipa->reg_virt + offset); 88 ipa_uc_interrupt_handler(ipa, irq_id); 89 break; 90 91 case IPA_IRQ_TX_SUSPEND: 92 /* Clearing the SUSPEND_TX interrupt also clears the 93 * register that tells us which suspended endpoint(s) 94 * caused the interrupt, so defer clearing until after 95 * the handler has been called. 96 */ 97 ipa_interrupt_suspend_clear_all(interrupt); 98 fallthrough; 99 100 default: /* Silently ignore (and clear) any other condition */ 101 iowrite32(mask, ipa->reg_virt + offset); 102 break; 103 } 104 } 105 106 /* IPA IRQ handler is threaded */ 107 static irqreturn_t ipa_isr_thread(int irq, void *dev_id) 108 { 109 struct ipa_interrupt *interrupt = dev_id; 110 struct ipa *ipa = interrupt->ipa; 111 u32 enabled = interrupt->enabled; 112 const struct reg *reg; 113 struct device *dev; 114 u32 pending; 115 u32 offset; 116 u32 mask; 117 int ret; 118 119 dev = &ipa->pdev->dev; 120 ret = pm_runtime_get_sync(dev); 121 if (WARN_ON(ret < 0)) 122 goto out_power_put; 123 124 /* The status register indicates which conditions are present, 125 * including conditions whose interrupt is not enabled. Handle 126 * only the enabled ones. 127 */ 128 reg = ipa_reg(ipa, IPA_IRQ_STTS); 129 offset = reg_offset(reg); 130 pending = ioread32(ipa->reg_virt + offset); 131 while ((mask = pending & enabled)) { 132 do { 133 u32 irq_id = __ffs(mask); 134 135 mask ^= BIT(irq_id); 136 137 ipa_interrupt_process(interrupt, irq_id); 138 } while (mask); 139 pending = ioread32(ipa->reg_virt + offset); 140 } 141 142 /* If any disabled interrupts are pending, clear them */ 143 if (pending) { 144 dev_dbg(dev, "clearing disabled IPA interrupts 0x%08x\n", 145 pending); 146 reg = ipa_reg(ipa, IPA_IRQ_CLR); 147 iowrite32(pending, ipa->reg_virt + reg_offset(reg)); 148 } 149 out_power_put: 150 pm_runtime_mark_last_busy(dev); 151 (void)pm_runtime_put_autosuspend(dev); 152 153 return IRQ_HANDLED; 154 } 155 156 static void ipa_interrupt_enabled_update(struct ipa *ipa) 157 { 158 const struct reg *reg = ipa_reg(ipa, IPA_IRQ_EN); 159 160 iowrite32(ipa->interrupt->enabled, ipa->reg_virt + reg_offset(reg)); 161 } 162 163 /* Enable an IPA interrupt type */ 164 void ipa_interrupt_enable(struct ipa *ipa, enum ipa_irq_id ipa_irq) 165 { 166 /* Update the IPA interrupt mask to enable it */ 167 ipa->interrupt->enabled |= BIT(ipa_irq); 168 ipa_interrupt_enabled_update(ipa); 169 } 170 171 /* Disable an IPA interrupt type */ 172 void ipa_interrupt_disable(struct ipa *ipa, enum ipa_irq_id ipa_irq) 173 { 174 /* Update the IPA interrupt mask to disable it */ 175 ipa->interrupt->enabled &= ~BIT(ipa_irq); 176 ipa_interrupt_enabled_update(ipa); 177 } 178 179 void ipa_interrupt_irq_disable(struct ipa *ipa) 180 { 181 disable_irq(ipa->interrupt->irq); 182 } 183 184 void ipa_interrupt_irq_enable(struct ipa *ipa) 185 { 186 enable_irq(ipa->interrupt->irq); 187 } 188 189 /* Common function used to enable/disable TX_SUSPEND for an endpoint */ 190 static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt, 191 u32 endpoint_id, bool enable) 192 { 193 struct ipa *ipa = interrupt->ipa; 194 u32 mask = BIT(endpoint_id % 32); 195 u32 unit = endpoint_id / 32; 196 const struct reg *reg; 197 u32 offset; 198 u32 val; 199 200 WARN_ON(!test_bit(endpoint_id, ipa->available)); 201 202 /* IPA version 3.0 does not support TX_SUSPEND interrupt control */ 203 if (ipa->version == IPA_VERSION_3_0) 204 return; 205 206 reg = ipa_reg(ipa, IRQ_SUSPEND_EN); 207 offset = reg_n_offset(reg, unit); 208 val = ioread32(ipa->reg_virt + offset); 209 210 if (enable) 211 val |= mask; 212 else 213 val &= ~mask; 214 215 iowrite32(val, ipa->reg_virt + offset); 216 } 217 218 /* Enable TX_SUSPEND for an endpoint */ 219 void 220 ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id) 221 { 222 ipa_interrupt_suspend_control(interrupt, endpoint_id, true); 223 } 224 225 /* Disable TX_SUSPEND for an endpoint */ 226 void 227 ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id) 228 { 229 ipa_interrupt_suspend_control(interrupt, endpoint_id, false); 230 } 231 232 /* Simulate arrival of an IPA TX_SUSPEND interrupt */ 233 void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt) 234 { 235 ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND); 236 } 237 238 /* Configure the IPA interrupt framework */ 239 struct ipa_interrupt *ipa_interrupt_config(struct ipa *ipa) 240 { 241 struct device *dev = &ipa->pdev->dev; 242 struct ipa_interrupt *interrupt; 243 const struct reg *reg; 244 unsigned int irq; 245 int ret; 246 247 ret = platform_get_irq_byname(ipa->pdev, "ipa"); 248 if (ret <= 0) { 249 dev_err(dev, "DT error %d getting \"ipa\" IRQ property\n", 250 ret); 251 return ERR_PTR(ret ? : -EINVAL); 252 } 253 irq = ret; 254 255 interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL); 256 if (!interrupt) 257 return ERR_PTR(-ENOMEM); 258 interrupt->ipa = ipa; 259 interrupt->irq = irq; 260 261 /* Start with all IPA interrupts disabled */ 262 reg = ipa_reg(ipa, IPA_IRQ_EN); 263 iowrite32(0, ipa->reg_virt + reg_offset(reg)); 264 265 ret = request_threaded_irq(irq, NULL, ipa_isr_thread, IRQF_ONESHOT, 266 "ipa", interrupt); 267 if (ret) { 268 dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret); 269 goto err_kfree; 270 } 271 272 ret = dev_pm_set_wake_irq(dev, irq); 273 if (ret) { 274 dev_err(dev, "error %d registering \"ipa\" IRQ as wakeirq\n", ret); 275 goto err_free_irq; 276 } 277 278 return interrupt; 279 280 err_free_irq: 281 free_irq(interrupt->irq, interrupt); 282 err_kfree: 283 kfree(interrupt); 284 285 return ERR_PTR(ret); 286 } 287 288 /* Inverse of ipa_interrupt_config() */ 289 void ipa_interrupt_deconfig(struct ipa_interrupt *interrupt) 290 { 291 struct device *dev = &interrupt->ipa->pdev->dev; 292 293 dev_pm_clear_wake_irq(dev); 294 free_irq(interrupt->irq, interrupt); 295 kfree(interrupt); 296 } 297