Re: [PATCH v7 50/65] hw/gpio/pca955x: convert pin/led property to QAPI-aware enum

[Miles Glenn <milesg@linux.ibm.com>]

On Tue, 2026-10-20 at 14:46 +0400, Marc-André Lureau wrote:
> Replaces the runtime-parsed visitor-based QOM property accessors with
> compile-time per-pin/per-LED accessor functions using QEMU_REPEAT.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  hw/gpio/pca9552.c | 205 +++++++++++++++++++++---------------------------------
>  hw/gpio/pca9554.c | 136 ++++++++++++++----------------------
>  2 files changed, 131 insertions(+), 210 deletions(-)
> 
> diff --git a/hw/gpio/pca9552.c b/hw/gpio/pca9552.c
> index 16741c22dea3..0a007bbbe4ac 100644
> --- a/hw/gpio/pca9552.c
> +++ b/hw/gpio/pca9552.c
> @@ -25,6 +25,7 @@
>  #include "qapi/error.h"
>  #include "qapi/qapi-types-machine.h"
>  #include "qapi/qapi-visit-machine.h"

Do you still need to include qapi/qapi-visit-machine.h?

> +#include "qapi/qapi-type-infos-machine.h"
>  #include "trace.h"
>  #include "qom/object.h"
>  
> @@ -354,33 +355,6 @@ static int pca955x_event(I2CSlave *i2c, enum i2c_event event)
>      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;
> -    Pca9552LedState 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 % 4) * 2)) & 0x3;
> -    visit_type_Pca9552LedState(v, name, &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).
> @@ -391,97 +365,8 @@ static inline uint8_t pca955x_ledsel(uint8_t oldval, int led_num, int state)
>                  ((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;
> -    Pca9552LedState state;
> -
> -    if (!visit_type_Pca9552LedState(v, name, &state, 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;
> -    }
> -
> -    reg = PCA9552_LS0 + led / 4;
> -    val = pca955x_read(s, reg);
> -    val = pca955x_ledsel(val, led % 4, state);
> -    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;
> -    Pca9552PinState 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_Pca9552PinState(v, name, &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;
> -    Pca9552PinState state;
> -    uint8_t config_reg;
> -
> -    if (!visit_type_Pca9552PinState(v, name, &state, 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;
> -    }
> -
> -    /* 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_STATE_LOW);
> -}
> -
>  static const VMStateDescription pca9552_vmstate = {
>      .name = "PCA9552",
>      .version_id = 0,
> @@ -536,26 +421,92 @@ static void pca9535_reset_hold(Object *obj, ResetType type)
>      s->len = 0;
>  }
>  
> +/*
> + * 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
> + */
> +#define DEFINE_LED_ACCESSORS(n)                                              \
> +static int prop_get_led##n(Object *obj, Error **errp)                        \
> +{                                                                            \
> +    PCA955xState *s = PCA955X(obj);                                          \
> +    uint8_t reg = PCA9552_LS0 + (n) / 4;                                     \
> +    return (pca955x_read(s, reg) >> (((n) % 4) * 2)) & 0x3;                  \
> +}                                                                            \
> +static void prop_set_led##n(Object *obj, int val, Error **errp)              \
> +{                                                                            \
> +    PCA955xState *s = PCA955X(obj);                                          \
> +    uint8_t reg = PCA9552_LS0 + (n) / 4;                                     \
> +    uint8_t old = pca955x_read(s, reg);                                      \
> +    pca955x_write(s, reg, pca955x_ledsel(old, (n) % 4, val));                \
> +}
> +
> +QEMU_REPEAT(PCA955X_PIN_COUNT_MAX, DEFINE_LED_ACCESSORS)
> +
> +#define LED_ENUM_PROP(n) {                                              \
> +    .name = "led" #n,                                                   \
> +    .default_value = -1,                                                \
> +    .qapi_type = &Pca9552LedState_type_info,                            \
> +    .get = prop_get_led##n,                                             \
> +    .set = prop_set_led##n,                                             \
> +},
> +
> +static const QapiEnumProp led_enum_props[] = {
> +    QEMU_REPEAT(PCA955X_PIN_COUNT_MAX, LED_ENUM_PROP)
> +};
> +
> +/*
> + * Report the raw pin logic level; polarity inversion is a read-time
> + * transform applied to the INPUT register, not to the pin state
> + * itself.
> + */
> +#define DEFINE_PIN_ACCESSORS(n)                                              \
> +static int prop_get_pin##n(Object *obj, Error **errp)                        \
> +{                                                                            \
> +    PCA955xState *s = PCA955X(obj);                                          \
> +    uint8_t input_reg = PCA9535_INPUT0 + (n) / 8;                            \
> +    return (s->regs[input_reg] >> ((n) % 8)) & 0x1;                          \
> +}                                                                            \
> +static void prop_set_pin##n(Object *obj, int val, Error **errp)              \
> +{                                                                            \
> +    PCA955xState *s = PCA955X(obj);                                          \
> +    uint8_t config_reg = PCA9535_CONFIG0 + (n) / 8;                          \
> +    /* Only input-configured pins can be driven by an external device */     \
> +    if (!((s->regs[config_reg] >> ((n) % 8)) & 0x1)) {                       \
> +        qemu_log_mask(LOG_UNIMP,                                             \
> +                      "%s: pin %d configured as output, ignoring set\n",     \
> +                      s->description, (n));                                  \
> +        return;                                                              \
> +    }                                                                        \
> +    pca955x_set_ext_state(s, (n), val != PCA9552_PIN_STATE_LOW);             \
> +}
> +
> +QEMU_REPEAT(PCA955X_PIN_COUNT_MAX, DEFINE_PIN_ACCESSORS)
> +
> +#define PIN_ENUM_PROP(n) {                                              \
> +    .name = "pin" #n,                                                   \
> +    .default_value = -1,                                                \
> +    .qapi_type = &Pca9552PinState_type_info,                            \
> +    .get = prop_get_pin##n,                                             \
> +    .set = prop_set_pin##n,                                             \
> +},
> +
> +static const QapiEnumProp pin_enum_props[] = {
> +    QEMU_REPEAT(PCA955X_PIN_COUNT_MAX, PIN_ENUM_PROP)
> +};
> +
>  static void pca955x_initfn(Object *obj)
>  {
>      PCA955xClass *k = PCA955X_GET_CLASS(obj);
>  
>      assert(k->pin_count <= PCA955X_PIN_COUNT_MAX);
> +    /* TODO: use array/list instead of individual QAPI enum properties */
>      for (int ix = 0; ix < k->pin_count; ix++) {
> -        char *name;
> -
>          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, "Pca9552LedState",
> -                                pca955x_get_led, pca955x_set_led, NULL, NULL);
> +            object_property_add_qapi_enum(obj, &led_enum_props[ix]);
>          } else {
> -            /* GPIO variant: expose the pin logic level as pin%d. */
> -            name = g_strdup_printf("pin%d", ix);
> -            object_property_add(obj, name, "Pca9552PinState",
> -                                pca955x_get_pin, pca955x_set_pin, NULL, NULL);
> +            object_property_add_qapi_enum(obj, &pin_enum_props[ix]);
>          }
> -        g_free(name);
>      }
>  }
>  
> diff --git a/hw/gpio/pca9554.c b/hw/gpio/pca9554.c
> index e4eddc829ef7..f2a5b94a36d8 100644
> --- a/hw/gpio/pca9554.c
> +++ b/hw/gpio/pca9554.c
> @@ -18,7 +18,7 @@
>  #include "qapi/error.h"
>  #include "qapi/qapi-types-machine.h"
>  #include "qapi/qapi-visit-machine.h"

Do you still need qapi/qapi-visit-machine.h?


> -#include "qapi/visitor.h"
> +#include "qapi/qapi-type-infos-machine.h"
>  #include "trace.h"
>  #include "qom/object.h"
>  
> @@ -151,83 +151,60 @@ static void pca9554_set_ext_state(PCA9554State *s, int pin, int level)
>      }
>  }
>  
> -static void pca9554_get_pin(Object *obj, Visitor *v, const char *name,
> -                            void *opaque, Error **errp)
> -{
> -    PCA9554State *s = PCA9554(obj);
> -    int pin, rc;
> -    Pca9554PinState 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_GET_CLASS(s)->pin_count) {
> -        error_setg(errp, "%s invalid pin %s", __func__, name);
> -        return;
> -    }
> -
> -    /*
> -     * Report the physical pin level. The input register is kept in sync by
> -     * pca9554_update_pin_input(): output pins mirror the OUTPUT register and
> -     * input pins reflect the externally driven (or pulled-up) level, so it
> -     * holds the wire level regardless of the configured direction.
> -     */
> -    state = (s->regs[PCA9554_INPUT] >> pin) & 0x1;
> -    visit_type_Pca9554PinState(v, name, &state, errp);
> +/*
> + * Report the physical pin level. The input register is kept in sync
> + * by pca9554_update_pin_input(): output pins mirror the OUTPUT
> + * register and input pins reflect the externally driven (or
> + * pulled-up) level, so it holds the wire level regardless of the
> + * configured direction.
> + */
> +#define DEFINE_PIN_ACCESSORS(n)                                              \
> +static int prop_get_pin##n(Object *obj, Error **errp)                        \
> +{                                                                            \
> +    PCA9554State *s = PCA9554(obj);                                          \
> +    return (s->regs[PCA9554_INPUT] >> (n)) & 0x1;                            \
> +}                                                                            \
> +static void prop_set_pin##n(Object *obj, int val, Error **errp)              \
> +{                                                                            \
> +    PCA9554State *s = PCA9554(obj);                                          \
> +    if (s->hw_dir) {                                                         \
> +        if (!((s->regs[PCA9554_CONFIG] >> (n)) & 0x1)) {                     \
> +            qemu_log_mask(LOG_UNIMP,                                         \
> +                          "%s: pin %d configured as output,"                 \
> +                          " ignoring set\n",                                 \
> +                          s->description, (n));                              \
> +            return;                                                          \
> +        }                                                                    \
> +        pca9554_set_ext_state(s, (n), val != PCA9554_PIN_STATE_LOW);         \
> +    } else {                                                                 \
> +        /* Legacy behavior: force output mode and drive */                   \
> +        uint8_t mask = 0x1 << (n);                                           \
> +        int v = pca9554_read(s, PCA9554_OUTPUT);                             \
> +        if (val == PCA9554_PIN_STATE_LOW) {                                  \
> +            v &= ~mask;                                                      \
> +        } else {                                                             \
> +            v |= mask;                                                       \
> +        }                                                                    \
> +        pca9554_write(s, PCA9554_OUTPUT, v);                                 \
> +        v = pca9554_read(s, PCA9554_CONFIG);                                 \
> +        v &= ~mask;                                                          \
> +        pca9554_write(s, PCA9554_CONFIG, v);                                 \
> +    }                                                                        \
>  }
>  
> -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 mask;
> -    Pca9554PinState state;
> +QEMU_REPEAT(PCA9554_PIN_COUNT, DEFINE_PIN_ACCESSORS)
>  
> -    if (!visit_type_Pca9554PinState(v, name, &state, 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_GET_CLASS(s)->pin_count) {
> -        error_setg(errp, "%s invalid pin %s", __func__, name);
> -        return;
> -    }
> +#define PIN_ENUM_PROP(n) {                                              \
> +    .name = "pin" #n,                                                   \
> +    .default_value = -1,                                                \
> +    .qapi_type = &Pca9554PinState_type_info,                            \
> +    .get = prop_get_pin##n,                                             \
> +    .set = prop_set_pin##n,                                             \
> +},
>  
> -    if (s->hw_dir) {
> -        /* Warn and ignore if the guest has configured this pin as output */
> -        if (!((s->regs[PCA9554_CONFIG] >> pin) & 0x1)) {
> -            qemu_log_mask(LOG_UNIMP,
> -                          "%s: pin %d is configured as output, "
> -                          "ignoring external set\n",
> -                          s->description, pin);
> -            return;
> -        }
> -        /* Drive the external input level */
> -        pca9554_set_ext_state(s, pin, state != PCA9554_PIN_STATE_LOW);
> -    } else {
> -        /* Legacy behavior: force output mode and drive */
> -        /* First, modify the output register bit */
> -        val = pca9554_read(s, PCA9554_OUTPUT);
> -        mask = 0x1 << pin;
> -        if (state == PCA9554_PIN_STATE_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 QapiEnumProp pin_enum_props[] = {
> +    QEMU_REPEAT(PCA9554_PIN_COUNT, PIN_ENUM_PROP)
> +};
>  
>  static const VMStateDescription pca9554_vmstate = {
>      .name = "PCA9554",
> @@ -264,16 +241,9 @@ static void pca9554_reset(DeviceState *dev)
>  static void pca9554_initfn(Object *obj)
>  {
>      PCA9554Class *pc = PCA9554_GET_CLASS(obj);
> -    int pin;
>  
> -    for (pin = 0; pin < pc->pin_count; pin++) {
> -        char *name;
> -
> -        name = g_strdup_printf("pin%d", pin);
> -        object_property_add(obj, name, "Pca9554PinState",
> -                            pca9554_get_pin, pca9554_set_pin,
> -                            NULL, NULL);
> -        g_free(name);

Should we have the same TODO comment here as with the 9552 code?

Thanks,

Glenn

> +    for (int pin = 0; pin < pc->pin_count; pin++) {
> +        object_property_add_qapi_enum(obj, &pin_enum_props[pin]);
>      }
>  }
>  
>