/*
* PCA9552 I2C LED blinker
*
* https://www.nxp.com/docs/en/application-note/AN264.pdf
*
* Copyright (c) 2017-2018, IBM Corporation.
* Copyright (c) 2020 Philippe Mathieu-Daudé
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "qemu/bitops.h"
#include "hw/qdev-properties.h"
#include "hw/misc/pca9552.h"
#include "hw/misc/pca9552_regs.h"
#include "hw/irq.h"
#include "migration/vmstate.h"
#include "qapi/error.h"
#include "qapi/visitor.h"
#include "trace.h"
#include "qom/object.h"
struct PCA955xClass {
/*< private >*/
I2CSlaveClass parent_class;
/*< public >*/
uint8_t pin_count;
uint8_t max_reg;
};
typedef struct PCA955xClass PCA955xClass;
DECLARE_CLASS_CHECKERS(PCA955xClass, PCA955X,
TYPE_PCA955X)
#define PCA9552_LED_ON 0x0
#define PCA9552_LED_OFF 0x1
#define PCA9552_LED_PWM0 0x2
#define PCA9552_LED_PWM1 0x3
static const char *led_state[] = {"on", "off", "pwm0", "pwm1"};
static uint8_t pca955x_pin_get_config(PCA955xState *s, int pin)
{
uint8_t reg = PCA9552_LS0 + (pin / 4);
uint8_t shift = (pin % 4) << 1;
return extract32(s->regs[reg], shift, 2);
}
/* Return INPUT status (bit #N belongs to GPIO #N) */
static uint16_t pca955x_pins_get_status(PCA955xState *s)
{
return (s->regs[PCA9552_INPUT1] << 8) | s->regs[PCA9552_INPUT0];
}
static void pca955x_display_pins_status(PCA955xState *s,
uint16_t previous_pins_status)
{
PCA955xClass *k = PCA955X_GET_CLASS(s);
uint16_t pins_status, pins_changed;
int i;
pins_status = pca955x_pins_get_status(s);
pins_changed = previous_pins_status ^ pins_status;
if (!pins_changed) {
return;
}
if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_STATUS)) {
char *buf = g_newa(char, k->pin_count + 1);
for (i = 0; i < k->pin_count; i++) {
if (extract32(pins_status, i, 1)) {
buf[i] = '*';
} else {
buf[i] = '.';
}
}
buf[i] = '\0';
trace_pca955x_gpio_status(s->description, buf);
}
if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_CHANGE)) {
for (i = 0; i < k->pin_count; i++) {
if (extract32(pins_changed, i, 1)) {
unsigned new_state = extract32(pins_status, i, 1);
/*
* We display the state using the PCA logic ("active-high").
* This is not the state of the LED, which signal might be
* wired "active-low" on the board.
*/
trace_pca955x_gpio_change(s->description, i,
!new_state, new_state);
}
}
}
}
static void pca955x_update_pin_input(PCA955xState *s)
{
PCA955xClass *k = PCA955X_GET_CLASS(s);
int i;
for (i = 0; i < k->pin_count; i++) {
uint8_t input_reg = PCA9552_INPUT0 + (i / 8);
uint8_t input_shift = (i % 8);
uint8_t config = pca955x_pin_get_config(s, i);
switch (config) {
case PCA9552_LED_ON:
qemu_set_irq(s->gpio[i], 1);
s->regs[input_reg] |= 1 << input_shift;
break;
case PCA9552_LED_OFF:
qemu_set_irq(s->gpio[i], 0);
s->regs[input_reg] &= ~(1 << input_shift);
break;
case PCA9552_LED_PWM0:
case PCA9552_LED_PWM1:
/* TODO */
default:
break;
}
}
}
static uint8_t pca955x_read(PCA955xState *s, uint8_t reg)
{
switch (reg) {
case PCA9552_INPUT0:
case PCA9552_INPUT1:
case PCA9552_PSC0:
case PCA9552_PWM0:
case PCA9552_PSC1:
case PCA9552_PWM1:
case PCA9552_LS0:
case PCA9552_LS1:
case PCA9552_LS2:
case PCA9552_LS3:
return s->regs[reg];
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected read to register %d\n",
__func__, reg);
return 0xFF;
}
}
static void pca955x_write(PCA955xState *s, uint8_t reg, uint8_t data)
{
uint16_t pins_status;
switch (reg) {
case PCA9552_PSC0:
case PCA9552_PWM0:
case PCA9552_PSC1:
case PCA9552_PWM1:
s->regs[reg] = data;
break;
case PCA9552_LS0:
case PCA9552_LS1:
case PCA9552_LS2:
case PCA9552_LS3:
pins_status = pca955x_pins_get_status(s);
s->regs[reg] = data;
pca955x_update_pin_input(s);
pca955x_display_pins_status(s, pins_status);
break;
case PCA9552_INPUT0:
case PCA9552_INPUT1:
default:
qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected write to register %d\n",
__func__, reg);
}
}
/*
* When Auto-Increment is on, the register address is incremented
* after each byte is sent to or received by the device. The index
* rollovers to 0 when the maximum register address is reached.
*/
static void pca955x_autoinc(PCA955xState *s)
{
PCA955xClass *k = PCA955X_GET_CLASS(s);
if (s->pointer != 0xFF && s->pointer & PCA9552_AUTOINC) {
uint8_t reg = s->pointer & 0xf;
reg = (reg + 1) % (k->max_reg + 1);
s->pointer = reg | PCA9552_AUTOINC;
}
}
static uint8_t pca955x_recv(I2CSlave *i2c)
{
PCA955xState *s = PCA955X(i2c);
uint8_t ret;
ret = pca955x_read(s, s->pointer & 0xf);
/*
* From the Specs:
*
* Important Note: When a Read sequence is initiated and the
* AI bit is set to Logic Level 1, the Read Sequence MUST
* start by a register different from 0.
*
* I don't know what should be done in this case, so throw an
* error.
*/
if (s->pointer == PCA9552_AUTOINC) {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: Autoincrement read starting with register 0\n",
__func__);
}
pca955x_autoinc(s);
return ret;
}
static int pca955x_send(I2CSlave *i2c, uint8_t data)
{
PCA955xState *s = PCA955X(i2c);
/* First byte sent by is the register address */
if (s->len == 0) {
s->pointer = data;
s->len++;
} else {
pca955x_write(s, s->pointer & 0xf, data);
pca955x_autoinc(s);
}
return 0;
}
static int pca955x_event(I2CSlave *i2c, enum i2c_event event)
{
PCA955xState *s = PCA955X(i2c);
s->len = 0;
return 0;
}
static void pca955x_get_led(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
PCA955xClass *k = PCA955X_GET_CLASS(obj);
PCA955xState *s = PCA955X(obj);
int led, rc, reg;
uint8_t state;
rc = sscanf(name, "led%2d", &led);
if (rc != 1) {
error_setg(errp, "%s: error reading %s", __func__, name);
return;
}
if (led < 0 || led > k->pin_count) {
error_setg(errp, "%s invalid led %s", __func__, name);
return;
}
/*
* Get the LSx register as the qom interface should expose the device
* state, not the modeled 'input line' behaviour which would come from
* reading the INPUTx reg
*/
reg = PCA9552_LS0 + led / 4;
state = (pca955x_read(s, reg) >> (led % 8)) & 0x3;
visit_type_str(v, name, (char **)&led_state[state], errp);
}
/*
* Return an LED selector register value based on an existing one, with
* the appropriate 2-bit state value set for the given LED number (0-3).
*/
static inline uint8_t pca955x_ledsel(uint8_t oldval, int led_num, int state)
{
return (oldval & (~(0x3 << (led_num << 1)))) |
((state & 0x3) << (led_num << 1));
}
static void pca955x_set_led(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
PCA955xClass *k = PCA955X_GET_CLASS(obj);
PCA955xState *s = PCA955X(obj);
int led, rc, reg, val;
uint8_t state;
char *state_str;
if (!visit_type_str(v, name, &state_str, errp)) {
return;
}
rc = sscanf(name, "led%2d", &led);
if (rc != 1) {
error_setg(errp, "%s: error reading %s", __func__, name);
return;
}
if (led < 0 || led > k->pin_count) {
error_setg(errp, "%s invalid led %s", __func__, name);
return;
}
for (state = 0; state < ARRAY_SIZE(led_state); state++) {
if (!strcmp(state_str, led_state[state])) {
break;
}
}
if (state >= ARRAY_SIZE(led_state)) {
error_setg(errp, "%s invalid led state %s", __func__, state_str);
return;
}
reg = PCA9552_LS0 + led / 4;
val = pca955x_read(s, reg);
val = pca955x_ledsel(val, led % 4, state);
pca955x_write(s, reg, val);
}
static const VMStateDescription pca9552_vmstate = {
.name = "PCA9552",
.version_id = 0,
.minimum_version_id = 0,
.fields = (VMStateField[]) {
VMSTATE_UINT8(len, PCA955xState),
VMSTATE_UINT8(pointer, PCA955xState),
VMSTATE_UINT8_ARRAY(regs, PCA955xState, PCA955X_NR_REGS),
VMSTATE_I2C_SLAVE(i2c, PCA955xState),
VMSTATE_END_OF_LIST()
}
};
static void pca9552_reset(DeviceState *dev)
{
PCA955xState *s = PCA955X(dev);
s->regs[PCA9552_PSC0] = 0xFF;
s->regs[PCA9552_PWM0] = 0x80;
s->regs[PCA9552_PSC1] = 0xFF;
s->regs[PCA9552_PWM1] = 0x80;
s->regs[PCA9552_LS0] = 0x55; /* all OFF */
s->regs[PCA9552_LS1] = 0x55;
s->regs[PCA9552_LS2] = 0x55;
s->regs[PCA9552_LS3] = 0x55;
pca955x_update_pin_input(s);
s->pointer = 0xFF;
s->len = 0;
}
static void pca955x_initfn(Object *obj)
{
PCA955xClass *k = PCA955X_GET_CLASS(obj);
int led;
assert(k->pin_count <= PCA955X_PIN_COUNT_MAX);
for (led = 0; led < k->pin_count; led++) {
char *name;
name = g_strdup_printf("led%d", led);
object_property_add(obj, name, "bool", pca955x_get_led, pca955x_set_led,
NULL, NULL);
g_free(name);
}
}
static void pca955x_realize(DeviceState *dev, Error **errp)
{
PCA955xClass *k = PCA955X_GET_CLASS(dev);
PCA955xState *s = PCA955X(dev);
if (!s->description) {
s->description = g_strdup("pca-unspecified");
}
qdev_init_gpio_out(dev, s->gpio, k->pin_count);
}
static Property pca955x_properties[] = {
DEFINE_PROP_STRING("description", PCA955xState, description),
DEFINE_PROP_END_OF_LIST(),
};
static void pca955x_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
k->event = pca955x_event;
k->recv = pca955x_recv;
k->send = pca955x_send;
dc->realize = pca955x_realize;
device_class_set_props(dc, pca955x_properties);
}
static const TypeInfo pca955x_info = {
.name = TYPE_PCA955X,
.parent = TYPE_I2C_SLAVE,
.instance_init = pca955x_initfn,
.instance_size = sizeof(PCA955xState),
.class_init = pca955x_class_init,
.class_size = sizeof(PCA955xClass),
.abstract = true,
};
static void pca9552_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
PCA955xClass *pc = PCA955X_CLASS(oc);
dc->reset = pca9552_reset;
dc->vmsd = &pca9552_vmstate;
pc->max_reg = PCA9552_LS3;
pc->pin_count = 16;
}
static const TypeInfo pca9552_info = {
.name = TYPE_PCA9552,
.parent = TYPE_PCA955X,
.class_init = pca9552_class_init,
};
static void pca955x_register_types(void)
{
type_register_static(&pca955x_info);
type_register_static(&pca9552_info);
}
type_init(pca955x_register_types)
