Looks good. Reviewed-by: Glenn Miles <[email protected]>
Thanks, Glenn On Wed, 2026-01-21 at 13:17 -0500, Patrick Williams wrote: > Extend the 16-bit PCA9552 model to support non-LED devices such as > the PCA9535[1]. > > [1]: https://www.ti.com/lit/ds/symlink/pca9535.pdf > > Signed-off-by: Patrick Williams <[email protected]> > --- > hw/gpio/pca9552.c | 176 > ++++++++++++++++++++++++++++------------- > include/hw/gpio/pca9552.h | 1 + > include/hw/gpio/pca9552_regs.h | 10 +++ > 3 files changed, 133 insertions(+), 54 deletions(-) > > diff --git a/hw/gpio/pca9552.c b/hw/gpio/pca9552.c > index dd3c795e49..dd3f1536b6 100644 > --- a/hw/gpio/pca9552.c > +++ b/hw/gpio/pca9552.c > @@ -31,6 +31,7 @@ struct PCA955xClass { > > uint8_t pin_count; > uint8_t max_reg; > + bool has_led_support; > }; > typedef struct PCA955xClass PCA955xClass; > > @@ -113,32 +114,59 @@ static void pca955x_update_pin_input(PCA955xState *s) > for (i = 0; i < k->pin_count; i++) { > uint8_t input_reg = PCA9552_INPUT0 + (i / 8); > uint8_t bit_mask = 1 << (i % 8); > - uint8_t config = pca955x_pin_get_config(s, i); > uint8_t old_value = s->regs[input_reg] & bit_mask; > uint8_t new_value; > > - switch (config) { > - case PCA9552_LED_ON: > - /* Pin is set to 0V to turn on LED */ > - s->regs[input_reg] &= ~bit_mask; > - break; > - case PCA9552_LED_OFF: > - /* > - * Pin is set to Hi-Z to turn off LED and > - * pullup sets it to a logical 1 unless > - * external device drives it low. > - */ > - if (s->ext_state[i] == PCA9552_PIN_LOW) { > + if (k->has_led_support) { > + /* PCA9552: LED control behavior */ > + uint8_t config = pca955x_pin_get_config(s, i); > + > + switch (config) { > + case PCA9552_LED_ON: > + /* Pin is set to 0V to turn on LED */ > s->regs[input_reg] &= ~bit_mask; > + break; > + case PCA9552_LED_OFF: > + /* > + * Pin is set to Hi-Z to turn off LED and > + * pullup sets it to a logical 1 unless > + * external device drives it low. > + */ > + if (s->ext_state[i] == PCA9552_PIN_LOW) { > + s->regs[input_reg] &= ~bit_mask; > + } else { > + s->regs[input_reg] |= bit_mask; > + } > + break; > + case PCA9552_LED_PWM0: > + case PCA9552_LED_PWM1: > + /* TODO */ > + default: > + break; > + } > + } else { > + /* PCA9535: Simple GPIO behavior */ > + uint8_t config_reg = PCA9535_CONFIG0 + (i / 8); > + uint8_t output_reg = PCA9535_OUTPUT0 + (i / 8); > + uint8_t polarity_reg = PCA9535_POLARITY0 + (i / 8); > + > + /* Check if pin is configured as input */ > + if (s->regs[config_reg] & bit_mask) { > + /* Input mode - reflect external state */ > + if (s->ext_state[i] == PCA9552_PIN_LOW) { > + s->regs[input_reg] &= ~bit_mask; > + } else { > + s->regs[input_reg] |= bit_mask; > + } > } else { > - s->regs[input_reg] |= bit_mask; > + /* Output mode - reflect output register value */ > + uint8_t output_bit = s->regs[output_reg] & bit_mask; > + uint8_t polarity_bit = s->regs[polarity_reg] & bit_mask; > + > + /* Apply polarity inversion if set */ > + s->regs[input_reg] = (s->regs[input_reg] & ~bit_mask) | > + ((output_bit ^ polarity_bit) & bit_mask); > } > - break; > - case PCA9552_LED_PWM0: > - case PCA9552_LED_PWM1: > - /* TODO */ > - default: > - break; > } > > /* update irq state only if pin state changed */ > @@ -151,52 +179,52 @@ static void pca955x_update_pin_input(PCA955xState *s) > > 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: > + PCA955xClass *k = PCA955X_GET_CLASS(s); > + > + if (reg > k->max_reg) { > qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected read to register > %d\n", > __func__, reg); > return 0xFF; > } > + > + return s->regs[reg]; > } > > static void pca955x_write(PCA955xState *s, uint8_t reg, uint8_t data) > { > + PCA955xClass *k = PCA955X_GET_CLASS(s); > 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: > + if (reg > k->max_reg) { > qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected write to register > %d\n", > __func__, reg); > + return; > + } > + > + /* Handle read-only registers */ > + if (reg == PCA9552_INPUT0 || reg == PCA9552_INPUT1) { > + qemu_log_mask(LOG_GUEST_ERROR, > + "%s: unexpected write to read-only register %d\n", > + __func__, reg); > + return; > + } > + > + pins_status = pca955x_pins_get_status(s); > + s->regs[reg] = data; > + > + /* Update GPIO state if this register affects outputs */ > + if (k->has_led_support) { > + /* PCA9552: Update on LED selector register writes */ > + if (reg >= PCA9552_LS0 && reg <= PCA9552_LS3) { > + pca955x_update_pin_input(s); > + pca955x_display_pins_status(s, pins_status); > + } > + } else { > + /* PCA9535: Update on OUTPUT, POLARITY, or CONFIG register writes */ > + if (reg >= PCA9535_OUTPUT0 && reg <= PCA9535_CONFIG1) { > + pca955x_update_pin_input(s); > + pca955x_display_pins_status(s, pins_status); > + } > } > } > > @@ -379,6 +407,26 @@ static void pca9552_reset(DeviceState *dev) > s->len = 0; > } > > +static void pca9535_reset(DeviceState *dev) > +{ > + PCA955xState *s = PCA955X(dev); > + > + s->regs[PCA9535_INPUT0] = 0xFF; /* All inputs high (pull-ups) */ > + s->regs[PCA9535_INPUT1] = 0xFF; /* All inputs high (pull-ups) */ > + s->regs[PCA9535_OUTPUT0] = 0xFF; /* All outputs high */ > + s->regs[PCA9535_OUTPUT1] = 0xFF; /* All outputs high */ > + s->regs[PCA9535_POLARITY0] = 0x00; /* No polarity inversion */ > + s->regs[PCA9535_POLARITY1] = 0x00; /* No polarity inversion */ > + s->regs[PCA9535_CONFIG0] = 0xFF; /* All pins as inputs */ > + s->regs[PCA9535_CONFIG1] = 0xFF; /* All pins as inputs */ > + > + memset(s->ext_state, PCA9552_PIN_HIZ, PCA955X_PIN_COUNT_MAX); > + pca955x_update_pin_input(s); > + > + s->pointer = 0xFF; > + s->len = 0; > +} > + > static void pca955x_initfn(Object *obj) > { > PCA955xClass *k = PCA955X_GET_CLASS(obj); > @@ -463,6 +511,19 @@ static void pca9552_class_init(ObjectClass *oc, const > void *data) > dc->vmsd = &pca9552_vmstate; > pc->max_reg = PCA9552_LS3; > pc->pin_count = 16; > + pc->has_led_support = true; > +} > + > +static void pca9535_class_init(ObjectClass *oc, const void *data) > +{ > + DeviceClass *dc = DEVICE_CLASS(oc); > + PCA955xClass *pc = PCA955X_CLASS(oc); > + > + device_class_set_legacy_reset(dc, pca9535_reset); > + dc->vmsd = &pca9552_vmstate; > + pc->max_reg = PCA9535_CONFIG1; > + pc->pin_count = 16; > + pc->has_led_support = false; > } > > static const TypeInfo pca9552_info = { > @@ -471,10 +532,17 @@ static const TypeInfo pca9552_info = { > .class_init = pca9552_class_init, > }; > > +static const TypeInfo pca9535_info = { > + .name = TYPE_PCA9535, > + .parent = TYPE_PCA955X, > + .class_init = pca9535_class_init, > +}; > + > static void pca955x_register_types(void) > { > type_register_static(&pca955x_info); > type_register_static(&pca9552_info); > + type_register_static(&pca9535_info); > } > > type_init(pca955x_register_types) > diff --git a/include/hw/gpio/pca9552.h b/include/hw/gpio/pca9552.h > index c36525f0c3..43b175235d 100644 > --- a/include/hw/gpio/pca9552.h > +++ b/include/hw/gpio/pca9552.h > @@ -14,6 +14,7 @@ > > #define TYPE_PCA9552 "pca9552" > #define TYPE_PCA955X "pca955x" > +#define TYPE_PCA9535 "pca9535" > typedef struct PCA955xState PCA955xState; > DECLARE_INSTANCE_CHECKER(PCA955xState, PCA955X, > TYPE_PCA955X) > diff --git a/include/hw/gpio/pca9552_regs.h b/include/hw/gpio/pca9552_regs.h > index d8051cfbd6..5a6bb03396 100644 > --- a/include/hw/gpio/pca9552_regs.h > +++ b/include/hw/gpio/pca9552_regs.h > @@ -29,4 +29,14 @@ > */ > #define PCA9552_AUTOINC (1 << 4) > > +/* PCA9535 Registers (same addresses, different semantics) */ > +#define PCA9535_INPUT0 0 /* read only input register 0 */ > +#define PCA9535_INPUT1 1 /* read only input register 1 */ > +#define PCA9535_OUTPUT0 2 /* read/write output register 0 */ > +#define PCA9535_OUTPUT1 3 /* read/write output register 1 */ > +#define PCA9535_POLARITY0 4 /* read/write polarity inversion register 0 */ > +#define PCA9535_POLARITY1 5 /* read/write polarity inversion register 1 */ > +#define PCA9535_CONFIG0 6 /* read/write configuration register 0 */ > +#define PCA9535_CONFIG1 7 /* read/write configuration register 1 */ > + > #endif >
