Specs are available here:
https://www.nxp.com/docs/en/data-sheet/PCA9554_9554A.pdf
This is a simple model supporting the basic registers for GPIO
mode. The device also supports an interrupt output line but the
model does not yet support this.
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
---
No changes from v2
MAINTAINERS | 2 +
hw/misc/pca9554.c | 328 +++++++++++++++++++++++++++++++++
include/hw/misc/pca9554.h | 36 ++++
include/hw/misc/pca9554_regs.h | 19 ++
4 files changed, 385 insertions(+)
create mode 100644 hw/misc/pca9554.c
create mode 100644 include/hw/misc/pca9554.h
create mode 100644 include/hw/misc/pca9554_regs.h
diff --git a/MAINTAINERS b/MAINTAINERS
index e73a3ff544..209080e1a0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1504,8 +1504,10 @@ F: hw/ppc/pnv*
F: hw/intc/pnv*
F: hw/intc/xics_pnv.c
F: hw/pci-host/pnv*
+F: hw/misc/pca9554.c
F: include/hw/ppc/pnv*
F: include/hw/pci-host/pnv*
+F: include/hw/misc/pca9554*.h
F: pc-bios/skiboot.lid
F: tests/qtest/pnv*
diff --git a/hw/misc/pca9554.c b/hw/misc/pca9554.c
new file mode 100644
index 0000000000..778b32e443
--- /dev/null
+++ b/hw/misc/pca9554.c
@@ -0,0 +1,328 @@
+/*
+ * PCA9554 I/O port
+ *
+ * Copyright (c) 2023, IBM Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qemu/bitops.h"
+#include "hw/qdev-properties.h"
+#include "hw/misc/pca9554.h"
+#include "hw/misc/pca9554_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 PCA9554Class {
+ /*< private >*/
+ I2CSlaveClass parent_class;
+ /*< public >*/
+};
+typedef struct PCA9554Class PCA9554Class;
+
+DECLARE_CLASS_CHECKERS(PCA9554Class, PCA9554,
+ TYPE_PCA9554)
+
+#define PCA9554_PIN_LOW 0x0
+#define PCA9554_PIN_HIZ 0x1
+
+static const char *pin_state[] = {"low", "high"};
+
+static void pca9554_update_pin_input(PCA9554State *s)
+{
+ int i;
+ uint8_t config = s->regs[PCA9554_CONFIG];
+ uint8_t output = s->regs[PCA9554_OUTPUT];
+ uint8_t internal_state = config | output;
+
+ for (i = 0; i < PCA9554_PIN_COUNT; i++) {
+ uint8_t bit_mask = 1 << i;
+ uint8_t internal_pin_state = (internal_state >> i) & 0x1;
+ uint8_t old_value = s->regs[PCA9554_INPUT] & bit_mask;
+ uint8_t new_value;
+
+ switch (internal_pin_state) {
+ case PCA9554_PIN_LOW:
+ s->regs[PCA9554_INPUT] &= ~bit_mask;
+ break;
+ case PCA9554_PIN_HIZ:
+ /*
+ * pullup sets it to a logical 1 unless
+ * external device drives it low.
+ */
+ if (s->ext_state[i] == PCA9554_PIN_LOW) {
+ s->regs[PCA9554_INPUT] &= ~bit_mask;
+ } else {
+ s->regs[PCA9554_INPUT] |= bit_mask;
+ }
+ break;
+ default:
+ break;
+ }
+
+ /* update irq state only if pin state changed */
+ new_value = s->regs[PCA9554_INPUT] & bit_mask;
+ if (new_value != old_value) {
+ if (new_value) {
+ /* changed from 0 to 1 */
+ qemu_set_irq(s->gpio_out[i], 1);
+ } else {
+ /* changed from 1 to 0 */
+ qemu_set_irq(s->gpio_out[i], 0);
+ }
+ }
+ }
+}
+
+static uint8_t pca9554_read(PCA9554State *s, uint8_t reg)
+{
+ switch (reg) {
+ case PCA9554_INPUT:
+ return s->regs[PCA9554_INPUT] ^ s->regs[PCA9554_POLARITY];
+ case PCA9554_OUTPUT:
+ case PCA9554_POLARITY:
+ case PCA9554_CONFIG:
+ return s->regs[reg];
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected read to register %d\n",
+ __func__, reg);
+ return 0xFF;
+ }
+}
+
+static void pca9554_write(PCA9554State *s, uint8_t reg, uint8_t data)
+{
+ switch (reg) {
+ case PCA9554_OUTPUT:
+ case PCA9554_CONFIG:
+ s->regs[reg] = data;
+ pca9554_update_pin_input(s);
+ break;
+ case PCA9554_POLARITY:
+ s->regs[reg] = data;
+ break;
+ case PCA9554_INPUT:
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected write to register %d\n",
+ __func__, reg);
+ }
+}
+
+static uint8_t pca9554_recv(I2CSlave *i2c)
+{
+ PCA9554State *s = PCA9554(i2c);
+ uint8_t ret;
+
+ ret = pca9554_read(s, s->pointer & 0x3);
+
+ return ret;
+}
+
+static int pca9554_send(I2CSlave *i2c, uint8_t data)
+{
+ PCA9554State *s = PCA9554(i2c);
+
+ /* First byte sent by is the register address */
+ if (s->len == 0) {
+ s->pointer = data;
+ s->len++;
+ } else {
+ pca9554_write(s, s->pointer & 0x3, data);
+ }
+
+ return 0;
+}
+
+static int pca9554_event(I2CSlave *i2c, enum i2c_event event)
+{
+ PCA9554State *s = PCA9554(i2c);
+
+ s->len = 0;
+ return 0;
+}
+
+static void pca9554_get_pin(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ PCA9554State *s = PCA9554(obj);
+ int pin, rc;
+ uint8_t state;
+
+ rc = sscanf(name, "pin%2d", &pin);
+ if (rc != 1) {
+ error_setg(errp, "%s: error reading %s", __func__, name);
+ return;
+ }
+ if (pin < 0 || pin > PCA9554_PIN_COUNT) {
+ error_setg(errp, "%s invalid pin %s", __func__, name);
+ return;
+ }
+
+ state = pca9554_read(s, PCA9554_CONFIG);
+ state |= pca9554_read(s, PCA9554_OUTPUT);
+ state = (state >> pin) & 0x1;
+ visit_type_str(v, name, (char **)&pin_state[state], errp);
+}
+
+static void pca9554_set_pin(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ PCA9554State *s = PCA9554(obj);
+ int pin, rc, val;
+ uint8_t state, mask;
+ char *state_str;
+
+ if (!visit_type_str(v, name, &state_str, errp)) {
+ return;
+ }
+ rc = sscanf(name, "pin%2d", &pin);
+ if (rc != 1) {
+ error_setg(errp, "%s: error reading %s", __func__, name);
+ return;
+ }
+ if (pin < 0 || pin > PCA9554_PIN_COUNT) {
+ error_setg(errp, "%s invalid pin %s", __func__, name);
+ return;
+ }
+
+ for (state = 0; state < ARRAY_SIZE(pin_state); state++) {
+ if (!strcmp(state_str, pin_state[state])) {
+ break;
+ }
+ }
+ if (state >= ARRAY_SIZE(pin_state)) {
+ error_setg(errp, "%s invalid pin state %s", __func__, state_str);
+ return;
+ }
+
+ /* First, modify the output register bit */
+ val = pca9554_read(s, PCA9554_OUTPUT);
+ mask = 0x1 << pin;
+ if (state == PCA9554_PIN_LOW) {
+ val &= ~(mask);
+ } else {
+ val |= mask;
+ }
+ pca9554_write(s, PCA9554_OUTPUT, val);
+
+ /* Then, clear the config register bit for output mode */
+ val = pca9554_read(s, PCA9554_CONFIG);
+ val &= ~mask;
+ pca9554_write(s, PCA9554_CONFIG, val);
+}
+
+static const VMStateDescription pca9554_vmstate = {
+ .name = "PCA9554",
+ .version_id = 0,
+ .minimum_version_id = 0,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT8(len, PCA9554State),
+ VMSTATE_UINT8(pointer, PCA9554State),
+ VMSTATE_UINT8_ARRAY(regs, PCA9554State, PCA9554_NR_REGS),
+ VMSTATE_UINT8_ARRAY(ext_state, PCA9554State, PCA9554_PIN_COUNT),
+ VMSTATE_I2C_SLAVE(i2c, PCA9554State),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static void pca9554_reset(DeviceState *dev)
+{
+ PCA9554State *s = PCA9554(dev);
+
+ s->regs[PCA9554_INPUT] = 0xFF;
+ s->regs[PCA9554_OUTPUT] = 0xFF;
+ s->regs[PCA9554_POLARITY] = 0x0; /* No pins are inverted */
+ s->regs[PCA9554_CONFIG] = 0xFF; /* All pins are inputs */
+
+ memset(s->ext_state, PCA9554_PIN_HIZ, PCA9554_PIN_COUNT);
+ pca9554_update_pin_input(s);
+
+ s->pointer = 0x0;
+ s->len = 0;
+}
+
+static void pca9554_initfn(Object *obj)
+{
+ int pin;
+
+ for (pin = 0; pin < PCA9554_PIN_COUNT; pin++) {
+ char *name;
+
+ name = g_strdup_printf("pin%d", pin);
+ object_property_add(obj, name, "bool", pca9554_get_pin, pca9554_set_pin,
+ NULL, NULL);
+ g_free(name);
+ }
+}
+
+static void pca9554_set_ext_state(PCA9554State *s, int pin, int level)
+{
+ if (s->ext_state[pin] != level) {
+ s->ext_state[pin] = level;
+ pca9554_update_pin_input(s);
+ }
+}
+
+static void pca9554_gpio_in_handler(void *opaque, int pin, int level)
+{
+
+ PCA9554State *s = PCA9554(opaque);
+
+ assert((pin >= 0) && (pin < PCA9554_PIN_COUNT));
+ pca9554_set_ext_state(s, pin, level);
+}
+
+static void pca9554_realize(DeviceState *dev, Error **errp)
+{
+ PCA9554State *s = PCA9554(dev);
+
+ if (!s->description) {
+ s->description = g_strdup("pca9554");
+ }
+
+ qdev_init_gpio_out(dev, s->gpio_out, PCA9554_PIN_COUNT);
+ qdev_init_gpio_in(dev, pca9554_gpio_in_handler, PCA9554_PIN_COUNT);
+}
+
+static Property pca9554_properties[] = {
+ DEFINE_PROP_STRING("description", PCA9554State, description),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void pca9554_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
+
+ k->event = pca9554_event;
+ k->recv = pca9554_recv;
+ k->send = pca9554_send;
+ dc->realize = pca9554_realize;
+ dc->reset = pca9554_reset;
+ dc->vmsd = &pca9554_vmstate;
+ device_class_set_props(dc, pca9554_properties);
+}
+
+static const TypeInfo pca9554_info = {
+ .name = TYPE_PCA9554,
+ .parent = TYPE_I2C_SLAVE,
+ .instance_init = pca9554_initfn,
+ .instance_size = sizeof(PCA9554State),
+ .class_init = pca9554_class_init,
+ .class_size = sizeof(PCA9554Class),
+ .abstract = false,
+};
+
+static void pca9554_register_types(void)
+{
+ type_register_static(&pca9554_info);
+}
+
+type_init(pca9554_register_types)
diff --git a/include/hw/misc/pca9554.h b/include/hw/misc/pca9554.h
new file mode 100644
index 0000000000..54bfc4c4c7
--- /dev/null
+++ b/include/hw/misc/pca9554.h
@@ -0,0 +1,36 @@
+/*
+ * PCA9554 I/O port
+ *
+ * Copyright (c) 2023, IBM Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#ifndef PCA9554_H
+#define PCA9554_H
+
+#include "hw/i2c/i2c.h"
+#include "qom/object.h"
+
+#define TYPE_PCA9554 "pca9554"
+typedef struct PCA9554State PCA9554State;
+DECLARE_INSTANCE_CHECKER(PCA9554State, PCA9554,
+ TYPE_PCA9554)
+
+#define PCA9554_NR_REGS 4
+#define PCA9554_PIN_COUNT 8
+
+struct PCA9554State {
+ /*< private >*/
+ I2CSlave i2c;
+ /*< public >*/
+
+ uint8_t len;
+ uint8_t pointer;
+
+ uint8_t regs[PCA9554_NR_REGS];
+ qemu_irq gpio_out[PCA9554_PIN_COUNT];
+ uint8_t ext_state[PCA9554_PIN_COUNT];
+ char *description; /* For debugging purpose only */
+};
+
+#endif
diff --git a/include/hw/misc/pca9554_regs.h b/include/hw/misc/pca9554_regs.h
new file mode 100644
index 0000000000..602c4a90e0
--- /dev/null
+++ b/include/hw/misc/pca9554_regs.h
@@ -0,0 +1,19 @@
+/*
+ * PCA9554 I/O port registers
+ *
+ * Copyright (c) 2023, IBM Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#ifndef PCA9554_REGS_H
+#define PCA9554_REGS_H
+
+/*
+ * Bits [0:1] are used to address a specific register.
+ */
+#define PCA9554_INPUT 0 /* read only input register */
+#define PCA9554_OUTPUT 1 /* read/write pin output state */
+#define PCA9554_POLARITY 2 /* Set polarity of input register */
+#define PCA9554_CONFIG 3 /* Set pins as inputs our ouputs */
+
+#endif
--
2.31.1© 2016 - 2024 Red Hat, Inc.