The PCA9552 exposes its LED channels as led%d QOM string properties, but
the GPIO variants (PCA9535/PCA9555) inherited the same led%d interface,
which drives the LED selector registers and is meaningless for a plain
I/O expander.
Add pin%d string properties ("low"/"high") for the GPIO variants,
mirroring the standalone pca9555 model:
- reading returns the raw pin logic level from the INPUT register;
- writing drives the external input level, but only for pins the guest
has configured as inputs (writes to output pins are ignored with a
LOG_UNIMP message).
The LED variant keeps its led%d properties.
Signed-off-by: Emmanuel Blot <[email protected]>
---
hw/gpio/pca9552.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 86 insertions(+), 5 deletions(-)
diff --git a/hw/gpio/pca9552.c b/hw/gpio/pca9552.c
index 54a5945d92..719149b717 100644
--- a/hw/gpio/pca9552.c
+++ b/hw/gpio/pca9552.c
@@ -68,6 +68,7 @@ struct PCA955xClass {
#define PCA9552_PIN_HIZ 0x1
static const char *led_state[] = {"on", "off", "pwm0", "pwm1"};
+static const char *pin_state[] = {"low", "high"};
static uint8_t pca955x_pin_get_config(PCA955xState *s, int pin)
{
@@ -428,6 +429,79 @@ static void pca955x_set_led(Object *obj, Visitor *v, const
char *name,
pca955x_write(s, reg, val);
}
+static void pca955x_set_ext_state(PCA955xState *s, int pin, int level);
+
+static void pca955x_get_pin(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ PCA955xClass *k = PCA955X_GET_CLASS(obj);
+ PCA955xState *s = PCA955X(obj);
+ int pin, rc;
+ uint8_t input_reg, state;
+
+ rc = sscanf(name, "pin%2d", &pin);
+ if (rc != 1) {
+ error_setg(errp, "%s: error reading %s", __func__, name);
+ return;
+ }
+ if (pin < 0 || pin >= k->pin_count) {
+ error_setg(errp, "%s invalid pin %s", __func__, name);
+ return;
+ }
+
+ /*
+ * Report the raw pin logic level; polarity inversion is a read-time
+ * transform applied to the INPUT register, not to the pin state itself.
+ */
+ input_reg = PCA9535_INPUT0 + (pin / 8);
+ state = (s->regs[input_reg] >> (pin % 8)) & 0x1;
+ visit_type_str(v, name, (char **)&pin_state[state], errp);
+}
+
+static void pca955x_set_pin(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ PCA955xClass *k = PCA955X_GET_CLASS(obj);
+ PCA955xState *s = PCA955X(obj);
+ int pin, rc;
+ uint8_t state, config_reg;
+ g_autofree char *state_str = NULL;
+
+ 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 >= k->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;
+ }
+
+ /* Only input-configured pins can be driven by an external device. */
+ config_reg = PCA9535_CONFIG0 + (pin / 8);
+ if (!((s->regs[config_reg] >> (pin % 8)) & 0x1)) {
+ qemu_log_mask(LOG_UNIMP,
+ "%s: pin %d is configured as output, ignoring set\n",
+ s->description, pin);
+ return;
+ }
+
+ pca955x_set_ext_state(s, pin, state != PCA9552_PIN_LOW);
+}
+
static const VMStateDescription pca9552_vmstate = {
.name = "PCA9552",
.version_id = 0,
@@ -485,15 +559,22 @@ static void pca9535_reset_hold(Object *obj, ResetType
type)
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++) {
+ for (int ix = 0; ix < k->pin_count; ix++) {
char *name;
- name = g_strdup_printf("led%d", led);
- object_property_add(obj, name, "bool", pca955x_get_led,
pca955x_set_led,
- NULL, NULL);
+ if (k->has_led_support) {
+ /* LED variant: expose the LED selector state as led%d. */
+ name = g_strdup_printf("led%d", ix);
+ object_property_add(obj, name, "bool",
+ pca955x_get_led, pca955x_set_led, NULL, NULL);
+ } else {
+ /* GPIO variant: expose the pin logic level as pin%d. */
+ name = g_strdup_printf("pin%d", ix);
+ object_property_add(obj, name, "str",
+ pca955x_get_pin, pca955x_set_pin, NULL, NULL);
+ }
g_free(name);
}
}
--
2.50.1
