1 /* 2 * STM32L4x5 GPIO (General Purpose Input/Ouput) 3 * 4 * Copyright (c) 2024 Arnaud Minier <arnaud.minier@telecom-paris.fr> 5 * Copyright (c) 2024 Inès Varhol <ines.varhol@telecom-paris.fr> 6 * 7 * SPDX-License-Identifier: GPL-2.0-or-later 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 13 /* 14 * The reference used is the STMicroElectronics RM0351 Reference manual 15 * for STM32L4x5 and STM32L4x6 advanced Arm ® -based 32-bit MCUs. 16 * https://www.st.com/en/microcontrollers-microprocessors/stm32l4x5/documentation.html 17 */ 18 19 #include "qemu/osdep.h" 20 #include "qemu/log.h" 21 #include "hw/gpio/stm32l4x5_gpio.h" 22 #include "hw/irq.h" 23 #include "hw/qdev-clock.h" 24 #include "hw/qdev-properties.h" 25 #include "qapi/visitor.h" 26 #include "qapi/error.h" 27 #include "migration/vmstate.h" 28 #include "trace.h" 29 30 #define GPIO_MODER 0x00 31 #define GPIO_OTYPER 0x04 32 #define GPIO_OSPEEDR 0x08 33 #define GPIO_PUPDR 0x0C 34 #define GPIO_IDR 0x10 35 #define GPIO_ODR 0x14 36 #define GPIO_BSRR 0x18 37 #define GPIO_LCKR 0x1C 38 #define GPIO_AFRL 0x20 39 #define GPIO_AFRH 0x24 40 #define GPIO_BRR 0x28 41 #define GPIO_ASCR 0x2C 42 43 /* 0b11111111_11111111_00000000_00000000 */ 44 #define RESERVED_BITS_MASK 0xFFFF0000 45 46 static void update_gpio_idr(Stm32l4x5GpioState *s); 47 48 static bool is_pull_up(Stm32l4x5GpioState *s, unsigned pin) 49 { 50 return extract32(s->pupdr, 2 * pin, 2) == 1; 51 } 52 53 static bool is_pull_down(Stm32l4x5GpioState *s, unsigned pin) 54 { 55 return extract32(s->pupdr, 2 * pin, 2) == 2; 56 } 57 58 static bool is_output(Stm32l4x5GpioState *s, unsigned pin) 59 { 60 return extract32(s->moder, 2 * pin, 2) == 1; 61 } 62 63 static bool is_open_drain(Stm32l4x5GpioState *s, unsigned pin) 64 { 65 return extract32(s->otyper, pin, 1) == 1; 66 } 67 68 static bool is_push_pull(Stm32l4x5GpioState *s, unsigned pin) 69 { 70 return extract32(s->otyper, pin, 1) == 0; 71 } 72 73 static void stm32l4x5_gpio_reset_hold(Object *obj) 74 { 75 Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj); 76 77 s->moder = s->moder_reset; 78 s->otyper = 0x00000000; 79 s->ospeedr = s->ospeedr_reset; 80 s->pupdr = s->pupdr_reset; 81 s->idr = 0x00000000; 82 s->odr = 0x00000000; 83 s->lckr = 0x00000000; 84 s->afrl = 0x00000000; 85 s->afrh = 0x00000000; 86 s->ascr = 0x00000000; 87 88 s->disconnected_pins = 0xFFFF; 89 s->pins_connected_high = 0x0000; 90 update_gpio_idr(s); 91 } 92 93 static void stm32l4x5_gpio_set(void *opaque, int line, int level) 94 { 95 Stm32l4x5GpioState *s = opaque; 96 /* 97 * The pin isn't set if line is configured in output mode 98 * except if level is 0 and the output is open-drain. 99 * This way there will be no short-circuit prone situations. 100 */ 101 if (is_output(s, line) && !(is_open_drain(s, line) && (level == 0))) { 102 qemu_log_mask(LOG_GUEST_ERROR, "Line %d can't be driven externally\n", 103 line); 104 return; 105 } 106 107 s->disconnected_pins &= ~(1 << line); 108 if (level) { 109 s->pins_connected_high |= (1 << line); 110 } else { 111 s->pins_connected_high &= ~(1 << line); 112 } 113 trace_stm32l4x5_gpio_pins(s->name, s->disconnected_pins, 114 s->pins_connected_high); 115 update_gpio_idr(s); 116 } 117 118 119 static void update_gpio_idr(Stm32l4x5GpioState *s) 120 { 121 uint32_t new_idr_mask = 0; 122 uint32_t new_idr = s->odr; 123 uint32_t old_idr = s->idr; 124 int new_pin_state, old_pin_state; 125 126 for (int i = 0; i < GPIO_NUM_PINS; i++) { 127 if (is_output(s, i)) { 128 if (is_push_pull(s, i)) { 129 new_idr_mask |= (1 << i); 130 } else if (!(s->odr & (1 << i))) { 131 /* open-drain ODR 0 */ 132 new_idr_mask |= (1 << i); 133 /* open-drain ODR 1 */ 134 } else if (!(s->disconnected_pins & (1 << i)) && 135 !(s->pins_connected_high & (1 << i))) { 136 /* open-drain ODR 1 with pin connected low */ 137 new_idr_mask |= (1 << i); 138 new_idr &= ~(1 << i); 139 /* open-drain ODR 1 with unactive pin */ 140 } else if (is_pull_up(s, i)) { 141 new_idr_mask |= (1 << i); 142 } else if (is_pull_down(s, i)) { 143 new_idr_mask |= (1 << i); 144 new_idr &= ~(1 << i); 145 } 146 /* 147 * The only case left is for open-drain ODR 1 148 * with unactive pin without pull-up or pull-down : 149 * the value is floating. 150 */ 151 /* input or analog mode with connected pin */ 152 } else if (!(s->disconnected_pins & (1 << i))) { 153 if (s->pins_connected_high & (1 << i)) { 154 /* pin high */ 155 new_idr_mask |= (1 << i); 156 new_idr |= (1 << i); 157 } else { 158 /* pin low */ 159 new_idr_mask |= (1 << i); 160 new_idr &= ~(1 << i); 161 } 162 /* input or analog mode with disconnected pin */ 163 } else { 164 if (is_pull_up(s, i)) { 165 /* pull-up */ 166 new_idr_mask |= (1 << i); 167 new_idr |= (1 << i); 168 } else if (is_pull_down(s, i)) { 169 /* pull-down */ 170 new_idr_mask |= (1 << i); 171 new_idr &= ~(1 << i); 172 } 173 /* 174 * The only case left is for a disconnected pin 175 * without pull-up or pull-down : 176 * the value is floating. 177 */ 178 } 179 } 180 181 s->idr = (old_idr & ~new_idr_mask) | (new_idr & new_idr_mask); 182 trace_stm32l4x5_gpio_update_idr(s->name, old_idr, s->idr); 183 184 for (int i = 0; i < GPIO_NUM_PINS; i++) { 185 if (new_idr_mask & (1 << i)) { 186 new_pin_state = (new_idr & (1 << i)) > 0; 187 old_pin_state = (old_idr & (1 << i)) > 0; 188 if (new_pin_state > old_pin_state) { 189 qemu_irq_raise(s->pin[i]); 190 } else if (new_pin_state < old_pin_state) { 191 qemu_irq_lower(s->pin[i]); 192 } 193 } 194 } 195 } 196 197 /* 198 * Return mask of pins that are both configured in output 199 * mode and externally driven (except pins in open-drain 200 * mode externally set to 0). 201 */ 202 static uint32_t get_gpio_pinmask_to_disconnect(Stm32l4x5GpioState *s) 203 { 204 uint32_t pins_to_disconnect = 0; 205 for (int i = 0; i < GPIO_NUM_PINS; i++) { 206 /* for each connected pin in output mode */ 207 if (!(s->disconnected_pins & (1 << i)) && is_output(s, i)) { 208 /* if either push-pull or high level */ 209 if (is_push_pull(s, i) || s->pins_connected_high & (1 << i)) { 210 pins_to_disconnect |= (1 << i); 211 qemu_log_mask(LOG_GUEST_ERROR, 212 "Line %d can't be driven externally\n", 213 i); 214 } 215 } 216 } 217 return pins_to_disconnect; 218 } 219 220 /* 221 * Set field `disconnected_pins` and call `update_gpio_idr()` 222 */ 223 static void disconnect_gpio_pins(Stm32l4x5GpioState *s, uint16_t lines) 224 { 225 s->disconnected_pins |= lines; 226 trace_stm32l4x5_gpio_pins(s->name, s->disconnected_pins, 227 s->pins_connected_high); 228 update_gpio_idr(s); 229 } 230 231 static void disconnected_pins_set(Object *obj, Visitor *v, 232 const char *name, void *opaque, Error **errp) 233 { 234 Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj); 235 uint16_t value; 236 if (!visit_type_uint16(v, name, &value, errp)) { 237 return; 238 } 239 disconnect_gpio_pins(s, value); 240 } 241 242 static void disconnected_pins_get(Object *obj, Visitor *v, 243 const char *name, void *opaque, Error **errp) 244 { 245 visit_type_uint16(v, name, (uint16_t *)opaque, errp); 246 } 247 248 static void clock_freq_get(Object *obj, Visitor *v, 249 const char *name, void *opaque, Error **errp) 250 { 251 Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj); 252 uint32_t clock_freq_hz = clock_get_hz(s->clk); 253 visit_type_uint32(v, name, &clock_freq_hz, errp); 254 } 255 256 static void stm32l4x5_gpio_write(void *opaque, hwaddr addr, 257 uint64_t val64, unsigned int size) 258 { 259 Stm32l4x5GpioState *s = opaque; 260 261 uint32_t value = val64; 262 trace_stm32l4x5_gpio_write(s->name, addr, val64); 263 264 switch (addr) { 265 case GPIO_MODER: 266 s->moder = value; 267 disconnect_gpio_pins(s, get_gpio_pinmask_to_disconnect(s)); 268 qemu_log_mask(LOG_UNIMP, 269 "%s: Analog and AF modes aren't supported\n\ 270 Analog and AF mode behave like input mode\n", 271 __func__); 272 return; 273 case GPIO_OTYPER: 274 s->otyper = value & ~RESERVED_BITS_MASK; 275 disconnect_gpio_pins(s, get_gpio_pinmask_to_disconnect(s)); 276 return; 277 case GPIO_OSPEEDR: 278 qemu_log_mask(LOG_UNIMP, 279 "%s: Changing I/O output speed isn't supported\n\ 280 I/O speed is already maximal\n", 281 __func__); 282 s->ospeedr = value; 283 return; 284 case GPIO_PUPDR: 285 s->pupdr = value; 286 update_gpio_idr(s); 287 return; 288 case GPIO_IDR: 289 qemu_log_mask(LOG_UNIMP, 290 "%s: GPIO->IDR is read-only\n", 291 __func__); 292 return; 293 case GPIO_ODR: 294 s->odr = value & ~RESERVED_BITS_MASK; 295 update_gpio_idr(s); 296 return; 297 case GPIO_BSRR: { 298 uint32_t bits_to_reset = (value & RESERVED_BITS_MASK) >> GPIO_NUM_PINS; 299 uint32_t bits_to_set = value & ~RESERVED_BITS_MASK; 300 /* If both BSx and BRx are set, BSx has priority.*/ 301 s->odr &= ~bits_to_reset; 302 s->odr |= bits_to_set; 303 update_gpio_idr(s); 304 return; 305 } 306 case GPIO_LCKR: 307 qemu_log_mask(LOG_UNIMP, 308 "%s: Locking port bits configuration isn't supported\n", 309 __func__); 310 s->lckr = value & ~RESERVED_BITS_MASK; 311 return; 312 case GPIO_AFRL: 313 qemu_log_mask(LOG_UNIMP, 314 "%s: Alternate functions aren't supported\n", 315 __func__); 316 s->afrl = value; 317 return; 318 case GPIO_AFRH: 319 qemu_log_mask(LOG_UNIMP, 320 "%s: Alternate functions aren't supported\n", 321 __func__); 322 s->afrh = value; 323 return; 324 case GPIO_BRR: { 325 uint32_t bits_to_reset = value & ~RESERVED_BITS_MASK; 326 s->odr &= ~bits_to_reset; 327 update_gpio_idr(s); 328 return; 329 } 330 case GPIO_ASCR: 331 qemu_log_mask(LOG_UNIMP, 332 "%s: ADC function isn't supported\n", 333 __func__); 334 s->ascr = value & ~RESERVED_BITS_MASK; 335 return; 336 default: 337 qemu_log_mask(LOG_GUEST_ERROR, 338 "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, addr); 339 } 340 } 341 342 static uint64_t stm32l4x5_gpio_read(void *opaque, hwaddr addr, 343 unsigned int size) 344 { 345 Stm32l4x5GpioState *s = opaque; 346 347 trace_stm32l4x5_gpio_read(s->name, addr); 348 349 switch (addr) { 350 case GPIO_MODER: 351 return s->moder; 352 case GPIO_OTYPER: 353 return s->otyper; 354 case GPIO_OSPEEDR: 355 return s->ospeedr; 356 case GPIO_PUPDR: 357 return s->pupdr; 358 case GPIO_IDR: 359 return s->idr; 360 case GPIO_ODR: 361 return s->odr; 362 case GPIO_BSRR: 363 return 0; 364 case GPIO_LCKR: 365 return s->lckr; 366 case GPIO_AFRL: 367 return s->afrl; 368 case GPIO_AFRH: 369 return s->afrh; 370 case GPIO_BRR: 371 return 0; 372 case GPIO_ASCR: 373 return s->ascr; 374 default: 375 qemu_log_mask(LOG_GUEST_ERROR, 376 "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, addr); 377 return 0; 378 } 379 } 380 381 static const MemoryRegionOps stm32l4x5_gpio_ops = { 382 .read = stm32l4x5_gpio_read, 383 .write = stm32l4x5_gpio_write, 384 .endianness = DEVICE_NATIVE_ENDIAN, 385 .impl = { 386 .min_access_size = 4, 387 .max_access_size = 4, 388 .unaligned = false, 389 }, 390 .valid = { 391 .min_access_size = 4, 392 .max_access_size = 4, 393 .unaligned = false, 394 }, 395 }; 396 397 static void stm32l4x5_gpio_init(Object *obj) 398 { 399 Stm32l4x5GpioState *s = STM32L4X5_GPIO(obj); 400 401 memory_region_init_io(&s->mmio, obj, &stm32l4x5_gpio_ops, s, 402 TYPE_STM32L4X5_GPIO, 0x400); 403 404 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio); 405 406 qdev_init_gpio_out(DEVICE(obj), s->pin, GPIO_NUM_PINS); 407 qdev_init_gpio_in(DEVICE(obj), stm32l4x5_gpio_set, GPIO_NUM_PINS); 408 409 s->clk = qdev_init_clock_in(DEVICE(s), "clk", NULL, s, 0); 410 411 object_property_add(obj, "disconnected-pins", "uint16", 412 disconnected_pins_get, disconnected_pins_set, 413 NULL, &s->disconnected_pins); 414 object_property_add(obj, "clock-freq-hz", "uint32", 415 clock_freq_get, NULL, NULL, NULL); 416 } 417 418 static void stm32l4x5_gpio_realize(DeviceState *dev, Error **errp) 419 { 420 Stm32l4x5GpioState *s = STM32L4X5_GPIO(dev); 421 if (!clock_has_source(s->clk)) { 422 error_setg(errp, "GPIO: clk input must be connected"); 423 return; 424 } 425 } 426 427 static const VMStateDescription vmstate_stm32l4x5_gpio = { 428 .name = TYPE_STM32L4X5_GPIO, 429 .version_id = 1, 430 .minimum_version_id = 1, 431 .fields = (VMStateField[]){ 432 VMSTATE_UINT32(moder, Stm32l4x5GpioState), 433 VMSTATE_UINT32(otyper, Stm32l4x5GpioState), 434 VMSTATE_UINT32(ospeedr, Stm32l4x5GpioState), 435 VMSTATE_UINT32(pupdr, Stm32l4x5GpioState), 436 VMSTATE_UINT32(idr, Stm32l4x5GpioState), 437 VMSTATE_UINT32(odr, Stm32l4x5GpioState), 438 VMSTATE_UINT32(lckr, Stm32l4x5GpioState), 439 VMSTATE_UINT32(afrl, Stm32l4x5GpioState), 440 VMSTATE_UINT32(afrh, Stm32l4x5GpioState), 441 VMSTATE_UINT32(ascr, Stm32l4x5GpioState), 442 VMSTATE_UINT16(disconnected_pins, Stm32l4x5GpioState), 443 VMSTATE_UINT16(pins_connected_high, Stm32l4x5GpioState), 444 VMSTATE_END_OF_LIST() 445 } 446 }; 447 448 static Property stm32l4x5_gpio_properties[] = { 449 DEFINE_PROP_STRING("name", Stm32l4x5GpioState, name), 450 DEFINE_PROP_UINT32("mode-reset", Stm32l4x5GpioState, moder_reset, 0), 451 DEFINE_PROP_UINT32("ospeed-reset", Stm32l4x5GpioState, ospeedr_reset, 0), 452 DEFINE_PROP_UINT32("pupd-reset", Stm32l4x5GpioState, pupdr_reset, 0), 453 DEFINE_PROP_END_OF_LIST(), 454 }; 455 456 static void stm32l4x5_gpio_class_init(ObjectClass *klass, void *data) 457 { 458 DeviceClass *dc = DEVICE_CLASS(klass); 459 ResettableClass *rc = RESETTABLE_CLASS(klass); 460 461 device_class_set_props(dc, stm32l4x5_gpio_properties); 462 dc->vmsd = &vmstate_stm32l4x5_gpio; 463 dc->realize = stm32l4x5_gpio_realize; 464 rc->phases.hold = stm32l4x5_gpio_reset_hold; 465 } 466 467 static const TypeInfo stm32l4x5_gpio_types[] = { 468 { 469 .name = TYPE_STM32L4X5_GPIO, 470 .parent = TYPE_SYS_BUS_DEVICE, 471 .instance_size = sizeof(Stm32l4x5GpioState), 472 .instance_init = stm32l4x5_gpio_init, 473 .class_init = stm32l4x5_gpio_class_init, 474 }, 475 }; 476 477 DEFINE_TYPES(stm32l4x5_gpio_types) 478