pca9552.c (11729B)
1 /* 2 * PCA9552 I2C LED blinker 3 * 4 * https://www.nxp.com/docs/en/application-note/AN264.pdf 5 * 6 * Copyright (c) 2017-2018, IBM Corporation. 7 * Copyright (c) 2020 Philippe Mathieu-Daudé 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or 10 * later. See the COPYING file in the top-level directory. 11 */ 12 13 #include "qemu/osdep.h" 14 #include "qemu/log.h" 15 #include "qemu/module.h" 16 #include "qemu/bitops.h" 17 #include "hw/qdev-properties.h" 18 #include "hw/misc/pca9552.h" 19 #include "hw/misc/pca9552_regs.h" 20 #include "hw/irq.h" 21 #include "migration/vmstate.h" 22 #include "qapi/error.h" 23 #include "qapi/visitor.h" 24 #include "trace.h" 25 #include "qom/object.h" 26 27 struct PCA955xClass { 28 /*< private >*/ 29 I2CSlaveClass parent_class; 30 /*< public >*/ 31 32 uint8_t pin_count; 33 uint8_t max_reg; 34 }; 35 typedef struct PCA955xClass PCA955xClass; 36 37 DECLARE_CLASS_CHECKERS(PCA955xClass, PCA955X, 38 TYPE_PCA955X) 39 40 #define PCA9552_LED_ON 0x0 41 #define PCA9552_LED_OFF 0x1 42 #define PCA9552_LED_PWM0 0x2 43 #define PCA9552_LED_PWM1 0x3 44 45 static const char *led_state[] = {"on", "off", "pwm0", "pwm1"}; 46 47 static uint8_t pca955x_pin_get_config(PCA955xState *s, int pin) 48 { 49 uint8_t reg = PCA9552_LS0 + (pin / 4); 50 uint8_t shift = (pin % 4) << 1; 51 52 return extract32(s->regs[reg], shift, 2); 53 } 54 55 /* Return INPUT status (bit #N belongs to GPIO #N) */ 56 static uint16_t pca955x_pins_get_status(PCA955xState *s) 57 { 58 return (s->regs[PCA9552_INPUT1] << 8) | s->regs[PCA9552_INPUT0]; 59 } 60 61 static void pca955x_display_pins_status(PCA955xState *s, 62 uint16_t previous_pins_status) 63 { 64 PCA955xClass *k = PCA955X_GET_CLASS(s); 65 uint16_t pins_status, pins_changed; 66 int i; 67 68 pins_status = pca955x_pins_get_status(s); 69 pins_changed = previous_pins_status ^ pins_status; 70 if (!pins_changed) { 71 return; 72 } 73 if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_STATUS)) { 74 char *buf = g_newa(char, k->pin_count + 1); 75 76 for (i = 0; i < k->pin_count; i++) { 77 if (extract32(pins_status, i, 1)) { 78 buf[i] = '*'; 79 } else { 80 buf[i] = '.'; 81 } 82 } 83 buf[i] = '\0'; 84 trace_pca955x_gpio_status(s->description, buf); 85 } 86 if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_CHANGE)) { 87 for (i = 0; i < k->pin_count; i++) { 88 if (extract32(pins_changed, i, 1)) { 89 unsigned new_state = extract32(pins_status, i, 1); 90 91 /* 92 * We display the state using the PCA logic ("active-high"). 93 * This is not the state of the LED, which signal might be 94 * wired "active-low" on the board. 95 */ 96 trace_pca955x_gpio_change(s->description, i, 97 !new_state, new_state); 98 } 99 } 100 } 101 } 102 103 static void pca955x_update_pin_input(PCA955xState *s) 104 { 105 PCA955xClass *k = PCA955X_GET_CLASS(s); 106 int i; 107 108 for (i = 0; i < k->pin_count; i++) { 109 uint8_t input_reg = PCA9552_INPUT0 + (i / 8); 110 uint8_t input_shift = (i % 8); 111 uint8_t config = pca955x_pin_get_config(s, i); 112 113 switch (config) { 114 case PCA9552_LED_ON: 115 qemu_set_irq(s->gpio[i], 1); 116 s->regs[input_reg] |= 1 << input_shift; 117 break; 118 case PCA9552_LED_OFF: 119 qemu_set_irq(s->gpio[i], 0); 120 s->regs[input_reg] &= ~(1 << input_shift); 121 break; 122 case PCA9552_LED_PWM0: 123 case PCA9552_LED_PWM1: 124 /* TODO */ 125 default: 126 break; 127 } 128 } 129 } 130 131 static uint8_t pca955x_read(PCA955xState *s, uint8_t reg) 132 { 133 switch (reg) { 134 case PCA9552_INPUT0: 135 case PCA9552_INPUT1: 136 case PCA9552_PSC0: 137 case PCA9552_PWM0: 138 case PCA9552_PSC1: 139 case PCA9552_PWM1: 140 case PCA9552_LS0: 141 case PCA9552_LS1: 142 case PCA9552_LS2: 143 case PCA9552_LS3: 144 return s->regs[reg]; 145 default: 146 qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected read to register %d\n", 147 __func__, reg); 148 return 0xFF; 149 } 150 } 151 152 static void pca955x_write(PCA955xState *s, uint8_t reg, uint8_t data) 153 { 154 uint16_t pins_status; 155 156 switch (reg) { 157 case PCA9552_PSC0: 158 case PCA9552_PWM0: 159 case PCA9552_PSC1: 160 case PCA9552_PWM1: 161 s->regs[reg] = data; 162 break; 163 164 case PCA9552_LS0: 165 case PCA9552_LS1: 166 case PCA9552_LS2: 167 case PCA9552_LS3: 168 pins_status = pca955x_pins_get_status(s); 169 s->regs[reg] = data; 170 pca955x_update_pin_input(s); 171 pca955x_display_pins_status(s, pins_status); 172 break; 173 174 case PCA9552_INPUT0: 175 case PCA9552_INPUT1: 176 default: 177 qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected write to register %d\n", 178 __func__, reg); 179 } 180 } 181 182 /* 183 * When Auto-Increment is on, the register address is incremented 184 * after each byte is sent to or received by the device. The index 185 * rollovers to 0 when the maximum register address is reached. 186 */ 187 static void pca955x_autoinc(PCA955xState *s) 188 { 189 PCA955xClass *k = PCA955X_GET_CLASS(s); 190 191 if (s->pointer != 0xFF && s->pointer & PCA9552_AUTOINC) { 192 uint8_t reg = s->pointer & 0xf; 193 194 reg = (reg + 1) % (k->max_reg + 1); 195 s->pointer = reg | PCA9552_AUTOINC; 196 } 197 } 198 199 static uint8_t pca955x_recv(I2CSlave *i2c) 200 { 201 PCA955xState *s = PCA955X(i2c); 202 uint8_t ret; 203 204 ret = pca955x_read(s, s->pointer & 0xf); 205 206 /* 207 * From the Specs: 208 * 209 * Important Note: When a Read sequence is initiated and the 210 * AI bit is set to Logic Level 1, the Read Sequence MUST 211 * start by a register different from 0. 212 * 213 * I don't know what should be done in this case, so throw an 214 * error. 215 */ 216 if (s->pointer == PCA9552_AUTOINC) { 217 qemu_log_mask(LOG_GUEST_ERROR, 218 "%s: Autoincrement read starting with register 0\n", 219 __func__); 220 } 221 222 pca955x_autoinc(s); 223 224 return ret; 225 } 226 227 static int pca955x_send(I2CSlave *i2c, uint8_t data) 228 { 229 PCA955xState *s = PCA955X(i2c); 230 231 /* First byte sent by is the register address */ 232 if (s->len == 0) { 233 s->pointer = data; 234 s->len++; 235 } else { 236 pca955x_write(s, s->pointer & 0xf, data); 237 238 pca955x_autoinc(s); 239 } 240 241 return 0; 242 } 243 244 static int pca955x_event(I2CSlave *i2c, enum i2c_event event) 245 { 246 PCA955xState *s = PCA955X(i2c); 247 248 s->len = 0; 249 return 0; 250 } 251 252 static void pca955x_get_led(Object *obj, Visitor *v, const char *name, 253 void *opaque, Error **errp) 254 { 255 PCA955xClass *k = PCA955X_GET_CLASS(obj); 256 PCA955xState *s = PCA955X(obj); 257 int led, rc, reg; 258 uint8_t state; 259 260 rc = sscanf(name, "led%2d", &led); 261 if (rc != 1) { 262 error_setg(errp, "%s: error reading %s", __func__, name); 263 return; 264 } 265 if (led < 0 || led > k->pin_count) { 266 error_setg(errp, "%s invalid led %s", __func__, name); 267 return; 268 } 269 /* 270 * Get the LSx register as the qom interface should expose the device 271 * state, not the modeled 'input line' behaviour which would come from 272 * reading the INPUTx reg 273 */ 274 reg = PCA9552_LS0 + led / 4; 275 state = (pca955x_read(s, reg) >> ((led % 4) * 2)) & 0x3; 276 visit_type_str(v, name, (char **)&led_state[state], errp); 277 } 278 279 /* 280 * Return an LED selector register value based on an existing one, with 281 * the appropriate 2-bit state value set for the given LED number (0-3). 282 */ 283 static inline uint8_t pca955x_ledsel(uint8_t oldval, int led_num, int state) 284 { 285 return (oldval & (~(0x3 << (led_num << 1)))) | 286 ((state & 0x3) << (led_num << 1)); 287 } 288 289 static void pca955x_set_led(Object *obj, Visitor *v, const char *name, 290 void *opaque, Error **errp) 291 { 292 PCA955xClass *k = PCA955X_GET_CLASS(obj); 293 PCA955xState *s = PCA955X(obj); 294 int led, rc, reg, val; 295 uint8_t state; 296 char *state_str; 297 298 if (!visit_type_str(v, name, &state_str, errp)) { 299 return; 300 } 301 rc = sscanf(name, "led%2d", &led); 302 if (rc != 1) { 303 error_setg(errp, "%s: error reading %s", __func__, name); 304 return; 305 } 306 if (led < 0 || led > k->pin_count) { 307 error_setg(errp, "%s invalid led %s", __func__, name); 308 return; 309 } 310 311 for (state = 0; state < ARRAY_SIZE(led_state); state++) { 312 if (!strcmp(state_str, led_state[state])) { 313 break; 314 } 315 } 316 if (state >= ARRAY_SIZE(led_state)) { 317 error_setg(errp, "%s invalid led state %s", __func__, state_str); 318 return; 319 } 320 321 reg = PCA9552_LS0 + led / 4; 322 val = pca955x_read(s, reg); 323 val = pca955x_ledsel(val, led % 4, state); 324 pca955x_write(s, reg, val); 325 } 326 327 static const VMStateDescription pca9552_vmstate = { 328 .name = "PCA9552", 329 .version_id = 0, 330 .minimum_version_id = 0, 331 .fields = (VMStateField[]) { 332 VMSTATE_UINT8(len, PCA955xState), 333 VMSTATE_UINT8(pointer, PCA955xState), 334 VMSTATE_UINT8_ARRAY(regs, PCA955xState, PCA955X_NR_REGS), 335 VMSTATE_I2C_SLAVE(i2c, PCA955xState), 336 VMSTATE_END_OF_LIST() 337 } 338 }; 339 340 static void pca9552_reset(DeviceState *dev) 341 { 342 PCA955xState *s = PCA955X(dev); 343 344 s->regs[PCA9552_PSC0] = 0xFF; 345 s->regs[PCA9552_PWM0] = 0x80; 346 s->regs[PCA9552_PSC1] = 0xFF; 347 s->regs[PCA9552_PWM1] = 0x80; 348 s->regs[PCA9552_LS0] = 0x55; /* all OFF */ 349 s->regs[PCA9552_LS1] = 0x55; 350 s->regs[PCA9552_LS2] = 0x55; 351 s->regs[PCA9552_LS3] = 0x55; 352 353 pca955x_update_pin_input(s); 354 355 s->pointer = 0xFF; 356 s->len = 0; 357 } 358 359 static void pca955x_initfn(Object *obj) 360 { 361 PCA955xClass *k = PCA955X_GET_CLASS(obj); 362 int led; 363 364 assert(k->pin_count <= PCA955X_PIN_COUNT_MAX); 365 for (led = 0; led < k->pin_count; led++) { 366 char *name; 367 368 name = g_strdup_printf("led%d", led); 369 object_property_add(obj, name, "bool", pca955x_get_led, pca955x_set_led, 370 NULL, NULL); 371 g_free(name); 372 } 373 } 374 375 static void pca955x_realize(DeviceState *dev, Error **errp) 376 { 377 PCA955xClass *k = PCA955X_GET_CLASS(dev); 378 PCA955xState *s = PCA955X(dev); 379 380 if (!s->description) { 381 s->description = g_strdup("pca-unspecified"); 382 } 383 384 qdev_init_gpio_out(dev, s->gpio, k->pin_count); 385 } 386 387 static Property pca955x_properties[] = { 388 DEFINE_PROP_STRING("description", PCA955xState, description), 389 DEFINE_PROP_END_OF_LIST(), 390 }; 391 392 static void pca955x_class_init(ObjectClass *klass, void *data) 393 { 394 DeviceClass *dc = DEVICE_CLASS(klass); 395 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); 396 397 k->event = pca955x_event; 398 k->recv = pca955x_recv; 399 k->send = pca955x_send; 400 dc->realize = pca955x_realize; 401 device_class_set_props(dc, pca955x_properties); 402 } 403 404 static const TypeInfo pca955x_info = { 405 .name = TYPE_PCA955X, 406 .parent = TYPE_I2C_SLAVE, 407 .instance_init = pca955x_initfn, 408 .instance_size = sizeof(PCA955xState), 409 .class_init = pca955x_class_init, 410 .class_size = sizeof(PCA955xClass), 411 .abstract = true, 412 }; 413 414 static void pca9552_class_init(ObjectClass *oc, void *data) 415 { 416 DeviceClass *dc = DEVICE_CLASS(oc); 417 PCA955xClass *pc = PCA955X_CLASS(oc); 418 419 dc->reset = pca9552_reset; 420 dc->vmsd = &pca9552_vmstate; 421 pc->max_reg = PCA9552_LS3; 422 pc->pin_count = 16; 423 } 424 425 static const TypeInfo pca9552_info = { 426 .name = TYPE_PCA9552, 427 .parent = TYPE_PCA955X, 428 .class_init = pca9552_class_init, 429 }; 430 431 static void pca955x_register_types(void) 432 { 433 type_register_static(&pca955x_info); 434 type_register_static(&pca9552_info); 435 } 436 437 type_init(pca955x_register_types)