2 * PCA9552 I2C LED blinker
4 * https://www.nxp.com/docs/en/application-note/AN264.pdf
6 * Copyright (c) 2017-2018, IBM Corporation.
7 * Copyright (c) 2020 Philippe Mathieu-Daudé
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.
13 #include "qemu/osdep.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"
21 #include "migration/vmstate.h"
22 #include "qapi/error.h"
23 #include "qapi/visitor.h"
25 #include "qom/object.h"
29 I2CSlaveClass parent_class;
35 typedef struct PCA955xClass PCA955xClass;
37 DECLARE_CLASS_CHECKERS(PCA955xClass, PCA955X,
40 #define PCA9552_LED_ON 0x0
41 #define PCA9552_LED_OFF 0x1
42 #define PCA9552_LED_PWM0 0x2
43 #define PCA9552_LED_PWM1 0x3
45 static const char *led_state[] = {"on", "off", "pwm0", "pwm1"};
47 static uint8_t pca955x_pin_get_config(PCA955xState *s, int pin)
49 uint8_t reg = PCA9552_LS0 + (pin / 4);
50 uint8_t shift = (pin % 4) << 1;
52 return extract32(s->regs[reg], shift, 2);
55 /* Return INPUT status (bit #N belongs to GPIO #N) */
56 static uint16_t pca955x_pins_get_status(PCA955xState *s)
58 return (s->regs[PCA9552_INPUT1] << 8) | s->regs[PCA9552_INPUT0];
61 static void pca955x_display_pins_status(PCA955xState *s,
62 uint16_t previous_pins_status)
64 PCA955xClass *k = PCA955X_GET_CLASS(s);
65 uint16_t pins_status, pins_changed;
68 pins_status = pca955x_pins_get_status(s);
69 pins_changed = previous_pins_status ^ pins_status;
73 if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_STATUS)) {
74 char *buf = g_newa(char, k->pin_count + 1);
76 for (i = 0; i < k->pin_count; i++) {
77 if (extract32(pins_status, i, 1)) {
84 trace_pca955x_gpio_status(s->description, buf);
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);
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.
96 trace_pca955x_gpio_change(s->description, i,
97 !new_state, new_state);
103 static void pca955x_update_pin_input(PCA955xState *s)
105 PCA955xClass *k = PCA955X_GET_CLASS(s);
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);
115 qemu_set_irq(s->gpio[i], 1);
116 s->regs[input_reg] |= 1 << input_shift;
118 case PCA9552_LED_OFF:
119 qemu_set_irq(s->gpio[i], 0);
120 s->regs[input_reg] &= ~(1 << input_shift);
122 case PCA9552_LED_PWM0:
123 case PCA9552_LED_PWM1:
131 static uint8_t pca955x_read(PCA955xState *s, uint8_t reg)
146 qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected read to register %d\n",
152 static void pca955x_write(PCA955xState *s, uint8_t reg, uint8_t data)
154 uint16_t pins_status;
168 pins_status = pca955x_pins_get_status(s);
170 pca955x_update_pin_input(s);
171 pca955x_display_pins_status(s, pins_status);
177 qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected write to register %d\n",
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.
187 static void pca955x_autoinc(PCA955xState *s)
189 PCA955xClass *k = PCA955X_GET_CLASS(s);
191 if (s->pointer != 0xFF && s->pointer & PCA9552_AUTOINC) {
192 uint8_t reg = s->pointer & 0xf;
194 reg = (reg + 1) % (k->max_reg + 1);
195 s->pointer = reg | PCA9552_AUTOINC;
199 static uint8_t pca955x_recv(I2CSlave *i2c)
201 PCA955xState *s = PCA955X(i2c);
204 ret = pca955x_read(s, s->pointer & 0xf);
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.
213 * I don't know what should be done in this case, so throw an
216 if (s->pointer == PCA9552_AUTOINC) {
217 qemu_log_mask(LOG_GUEST_ERROR,
218 "%s: Autoincrement read starting with register 0\n",
227 static int pca955x_send(I2CSlave *i2c, uint8_t data)
229 PCA955xState *s = PCA955X(i2c);
231 /* First byte sent by is the register address */
236 pca955x_write(s, s->pointer & 0xf, data);
244 static int pca955x_event(I2CSlave *i2c, enum i2c_event event)
246 PCA955xState *s = PCA955X(i2c);
252 static void pca955x_get_led(Object *obj, Visitor *v, const char *name,
253 void *opaque, Error **errp)
255 PCA955xClass *k = PCA955X_GET_CLASS(obj);
256 PCA955xState *s = PCA955X(obj);
260 rc = sscanf(name, "led%2d", &led);
262 error_setg(errp, "%s: error reading %s", __func__, name);
265 if (led < 0 || led > k->pin_count) {
266 error_setg(errp, "%s invalid led %s", __func__, name);
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
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);
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).
283 static inline uint8_t pca955x_ledsel(uint8_t oldval, int led_num, int state)
285 return (oldval & (~(0x3 << (led_num << 1)))) |
286 ((state & 0x3) << (led_num << 1));
289 static void pca955x_set_led(Object *obj, Visitor *v, const char *name,
290 void *opaque, Error **errp)
292 PCA955xClass *k = PCA955X_GET_CLASS(obj);
293 PCA955xState *s = PCA955X(obj);
294 int led, rc, reg, val;
298 if (!visit_type_str(v, name, &state_str, errp)) {
301 rc = sscanf(name, "led%2d", &led);
303 error_setg(errp, "%s: error reading %s", __func__, name);
306 if (led < 0 || led > k->pin_count) {
307 error_setg(errp, "%s invalid led %s", __func__, name);
311 for (state = 0; state < ARRAY_SIZE(led_state); state++) {
312 if (!strcmp(state_str, led_state[state])) {
316 if (state >= ARRAY_SIZE(led_state)) {
317 error_setg(errp, "%s invalid led state %s", __func__, state_str);
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);
327 static const VMStateDescription pca9552_vmstate = {
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()
340 static void pca9552_reset(DeviceState *dev)
342 PCA955xState *s = PCA955X(dev);
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;
353 pca955x_update_pin_input(s);
359 static void pca955x_initfn(Object *obj)
361 PCA955xClass *k = PCA955X_GET_CLASS(obj);
364 assert(k->pin_count <= PCA955X_PIN_COUNT_MAX);
365 for (led = 0; led < k->pin_count; led++) {
368 name = g_strdup_printf("led%d", led);
369 object_property_add(obj, name, "bool", pca955x_get_led, pca955x_set_led,
375 static void pca955x_realize(DeviceState *dev, Error **errp)
377 PCA955xClass *k = PCA955X_GET_CLASS(dev);
378 PCA955xState *s = PCA955X(dev);
380 if (!s->description) {
381 s->description = g_strdup("pca-unspecified");
384 qdev_init_gpio_out(dev, s->gpio, k->pin_count);
387 static Property pca955x_properties[] = {
388 DEFINE_PROP_STRING("description", PCA955xState, description),
389 DEFINE_PROP_END_OF_LIST(),
392 static void pca955x_class_init(ObjectClass *klass, void *data)
394 DeviceClass *dc = DEVICE_CLASS(klass);
395 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
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);
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),
414 static void pca9552_class_init(ObjectClass *oc, void *data)
416 DeviceClass *dc = DEVICE_CLASS(oc);
417 PCA955xClass *pc = PCA955X_CLASS(oc);
419 dc->reset = pca9552_reset;
420 dc->vmsd = &pca9552_vmstate;
421 pc->max_reg = PCA9552_LS3;
425 static const TypeInfo pca9552_info = {
426 .name = TYPE_PCA9552,
427 .parent = TYPE_PCA955X,
428 .class_init = pca9552_class_init,
431 static void pca955x_register_types(void)
433 type_register_static(&pca955x_info);
434 type_register_static(&pca9552_info);
437 type_init(pca955x_register_types)