1 // SPDX-License-Identifier: GPL-2.0 2 3 /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved. 4 * Copyright (C) 2018-2024 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/interrupt.h> 23 #include <linux/platform_device.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/pm_wakeirq.h> 26 #include <linux/types.h> 27 28 #include "ipa.h" 29 #include "ipa_endpoint.h" 30 #include "ipa_interrupt.h" 31 #include "ipa_power.h" 32 #include "ipa_reg.h" 33 #include "ipa_uc.h" 34 35 /** 36 * struct ipa_interrupt - IPA interrupt information 37 * @ipa: IPA pointer 38 * @irq: Linux IRQ number used for IPA interrupts 39 * @enabled: Mask indicating which interrupts are enabled 40 * @suspend_enabled: Bitmap of endpoints with the SUSPEND interrupt enabled 41 */ 42 struct ipa_interrupt { 43 struct ipa *ipa; 44 u32 irq; 45 u32 enabled; 46 unsigned long *suspend_enabled; 47 }; 48 49 /* Clear the suspend interrupt for all endpoints that signaled it */ 50 static void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt) 51 { 52 struct ipa *ipa = interrupt->ipa; 53 u32 unit_count; 54 u32 unit; 55 56 unit_count = DIV_ROUND_UP(ipa->endpoint_count, 32); 57 for (unit = 0; unit < unit_count; unit++) { 58 const struct reg *reg; 59 u32 val; 60 61 reg = ipa_reg(ipa, IRQ_SUSPEND_INFO); 62 val = ioread32(ipa->reg_virt + reg_n_offset(reg, unit)); 63 64 /* SUSPEND interrupt status isn't cleared on IPA version 3.0 */ 65 if (!val || ipa->version == IPA_VERSION_3_0) 66 continue; 67 68 reg = ipa_reg(ipa, IRQ_SUSPEND_CLR); 69 iowrite32(val, ipa->reg_virt + reg_n_offset(reg, unit)); 70 } 71 } 72 73 /* Process a particular interrupt type that has been received */ 74 static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id) 75 { 76 struct ipa *ipa = interrupt->ipa; 77 const struct reg *reg; 78 u32 mask = BIT(irq_id); 79 u32 offset; 80 81 reg = ipa_reg(ipa, IPA_IRQ_CLR); 82 offset = reg_offset(reg); 83 84 switch (irq_id) { 85 case IPA_IRQ_UC_0: 86 case IPA_IRQ_UC_1: 87 /* For microcontroller interrupts, clear the interrupt right 88 * away, "to avoid clearing unhandled interrupts." 89 */ 90 iowrite32(mask, ipa->reg_virt + offset); 91 ipa_uc_interrupt_handler(ipa, irq_id); 92 break; 93 94 case IPA_IRQ_TX_SUSPEND: 95 /* Clearing the SUSPEND_TX interrupt also clears the 96 * register that tells us which suspended endpoint(s) 97 * caused the interrupt, so defer clearing until after 98 * the handler has been called. 99 */ 100 ipa_interrupt_suspend_clear_all(interrupt); 101 fallthrough; 102 103 default: /* Silently ignore (and clear) any other condition */ 104 iowrite32(mask, ipa->reg_virt + offset); 105 break; 106 } 107 } 108 109 /* IPA IRQ handler is threaded */ 110 static irqreturn_t ipa_isr_thread(int irq, void *dev_id) 111 { 112 struct ipa_interrupt *interrupt = dev_id; 113 struct ipa *ipa = interrupt->ipa; 114 u32 enabled = interrupt->enabled; 115 struct device *dev = ipa->dev; 116 const struct reg *reg; 117 u32 pending; 118 u32 offset; 119 u32 mask; 120 int ret; 121 122 ret = pm_runtime_get_sync(dev); 123 if (WARN_ON(ret < 0)) 124 goto out_power_put; 125 126 /* The status register indicates which conditions are present, 127 * including conditions whose interrupt is not enabled. Handle 128 * only the enabled ones. 129 */ 130 reg = ipa_reg(ipa, IPA_IRQ_STTS); 131 offset = reg_offset(reg); 132 pending = ioread32(ipa->reg_virt + offset); 133 while ((mask = pending & enabled)) { 134 do { 135 u32 irq_id = __ffs(mask); 136 137 mask ^= BIT(irq_id); 138 139 ipa_interrupt_process(interrupt, irq_id); 140 } while (mask); 141 pending = ioread32(ipa->reg_virt + offset); 142 } 143 144 /* If any disabled interrupts are pending, clear them */ 145 if (pending) { 146 dev_dbg(dev, "clearing disabled IPA interrupts 0x%08x\n", 147 pending); 148 reg = ipa_reg(ipa, IPA_IRQ_CLR); 149 iowrite32(pending, ipa->reg_virt + reg_offset(reg)); 150 } 151 out_power_put: 152 (void)pm_runtime_put_autosuspend(dev); 153 154 return IRQ_HANDLED; 155 } 156 157 static void ipa_interrupt_enabled_update(struct ipa *ipa) 158 { 159 const struct reg *reg = ipa_reg(ipa, IPA_IRQ_EN); 160 161 iowrite32(ipa->interrupt->enabled, ipa->reg_virt + reg_offset(reg)); 162 } 163 164 /* Enable an IPA interrupt type */ 165 void ipa_interrupt_enable(struct ipa *ipa, enum ipa_irq_id ipa_irq) 166 { 167 /* Update the IPA interrupt mask to enable it */ 168 ipa->interrupt->enabled |= BIT(ipa_irq); 169 ipa_interrupt_enabled_update(ipa); 170 } 171 172 /* Disable an IPA interrupt type */ 173 void ipa_interrupt_disable(struct ipa *ipa, enum ipa_irq_id ipa_irq) 174 { 175 /* Update the IPA interrupt mask to disable it */ 176 ipa->interrupt->enabled &= ~BIT(ipa_irq); 177 ipa_interrupt_enabled_update(ipa); 178 } 179 180 void ipa_interrupt_irq_disable(struct ipa *ipa) 181 { 182 disable_irq(ipa->interrupt->irq); 183 } 184 185 void ipa_interrupt_irq_enable(struct ipa *ipa) 186 { 187 enable_irq(ipa->interrupt->irq); 188 } 189 190 /* Common function used to enable/disable TX_SUSPEND for an endpoint */ 191 static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt, 192 u32 endpoint_id, bool enable) 193 { 194 struct ipa *ipa = interrupt->ipa; 195 u32 mask = BIT(endpoint_id % 32); 196 u32 unit = endpoint_id / 32; 197 const struct reg *reg; 198 unsigned long weight; 199 u32 offset; 200 u32 val; 201 202 WARN_ON(!test_bit(endpoint_id, ipa->available)); 203 204 /* IPA version 3.0 does not support TX_SUSPEND interrupt control */ 205 if (ipa->version == IPA_VERSION_3_0) 206 return; 207 208 weight = bitmap_weight(interrupt->suspend_enabled, ipa->endpoint_count); 209 if (weight == 1 && !enable) 210 ipa_interrupt_disable(ipa, IPA_IRQ_TX_SUSPEND); 211 212 reg = ipa_reg(ipa, IRQ_SUSPEND_EN); 213 offset = reg_n_offset(reg, unit); 214 val = ioread32(ipa->reg_virt + offset); 215 216 if (enable) 217 val |= mask; 218 else 219 val &= ~mask; 220 __change_bit(endpoint_id, interrupt->suspend_enabled); 221 222 iowrite32(val, ipa->reg_virt + offset); 223 224 if (!weight && enable) 225 ipa_interrupt_enable(ipa, IPA_IRQ_TX_SUSPEND); 226 } 227 228 /* Enable TX_SUSPEND for an endpoint */ 229 void 230 ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id) 231 { 232 ipa_interrupt_suspend_control(interrupt, endpoint_id, true); 233 } 234 235 /* Disable TX_SUSPEND for an endpoint */ 236 void 237 ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id) 238 { 239 ipa_interrupt_suspend_control(interrupt, endpoint_id, false); 240 } 241 242 /* Simulate arrival of an IPA TX_SUSPEND interrupt */ 243 void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt) 244 { 245 ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND); 246 } 247 248 /* Configure the IPA interrupt framework */ 249 int ipa_interrupt_config(struct ipa *ipa) 250 { 251 struct ipa_interrupt *interrupt = ipa->interrupt; 252 unsigned int irq = interrupt->irq; 253 struct device *dev = ipa->dev; 254 const struct reg *reg; 255 int ret; 256 257 interrupt->ipa = ipa; 258 259 /* Initially all IPA interrupt types are disabled */ 260 interrupt->enabled = 0; 261 interrupt->suspend_enabled = bitmap_zalloc(ipa->endpoint_count, 262 GFP_KERNEL); 263 if (!interrupt->suspend_enabled) { 264 ret = -ENOMEM; 265 goto err_kfree; 266 } 267 268 /* Disable IPA interrupt types */ 269 reg = ipa_reg(ipa, IPA_IRQ_EN); 270 iowrite32(0, ipa->reg_virt + reg_offset(reg)); 271 272 ret = request_threaded_irq(irq, NULL, ipa_isr_thread, IRQF_ONESHOT, 273 "ipa", interrupt); 274 if (ret) { 275 dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret); 276 goto err_free_bitmap; 277 } 278 279 ret = device_init_wakeup(dev, true); 280 if (ret) { 281 dev_err(dev, "error %d enabling wakeup\n", ret); 282 goto err_free_irq; 283 } 284 285 ret = dev_pm_set_wake_irq(dev, irq); 286 if (ret) { 287 dev_err(dev, "error %d registering \"ipa\" IRQ as wakeirq\n", 288 ret); 289 goto err_disable_wakeup; 290 } 291 292 ipa->interrupt = interrupt; 293 294 return 0; 295 296 err_disable_wakeup: 297 (void)device_init_wakeup(dev, false); 298 err_free_irq: 299 free_irq(interrupt->irq, interrupt); 300 err_free_bitmap: 301 bitmap_free(interrupt->suspend_enabled); 302 err_kfree: 303 kfree(interrupt); 304 305 return ret; 306 } 307 308 /* Inverse of ipa_interrupt_config() */ 309 void ipa_interrupt_deconfig(struct ipa *ipa) 310 { 311 struct ipa_interrupt *interrupt = ipa->interrupt; 312 struct device *dev = ipa->dev; 313 314 ipa->interrupt = NULL; 315 316 dev_pm_clear_wake_irq(dev); 317 (void)device_init_wakeup(dev, false); 318 free_irq(interrupt->irq, interrupt); 319 bitmap_free(interrupt->suspend_enabled); 320 } 321 322 /* Initialize the IPA interrupt structure */ 323 struct ipa_interrupt *ipa_interrupt_init(struct platform_device *pdev) 324 { 325 struct ipa_interrupt *interrupt; 326 int irq; 327 328 irq = platform_get_irq_byname(pdev, "ipa"); 329 if (irq <= 0) 330 return ERR_PTR(irq ? : -EINVAL); 331 332 interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL); 333 if (!interrupt) 334 return ERR_PTR(-ENOMEM); 335 interrupt->irq = irq; 336 337 return interrupt; 338 } 339 340 /* Inverse of ipa_interrupt_init() */ 341 void ipa_interrupt_exit(struct ipa_interrupt *interrupt) 342 { 343 kfree(interrupt); 344 } 345