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 -- 2.51.2
