diff options
Diffstat (limited to 'hw/gpio/pca9552.c')
| -rw-r--r-- | hw/gpio/pca9552.c | 481 |
1 files changed, 481 insertions, 0 deletions
diff --git a/hw/gpio/pca9552.c b/hw/gpio/pca9552.c new file mode 100644 index 0000000000..27d4db0680 --- /dev/null +++ b/hw/gpio/pca9552.c @@ -0,0 +1,481 @@ +/* + * PCA9552 I2C LED blinker + * + * https://www.nxp.com/docs/en/application-note/AN264.pdf + * + * Copyright (c) 2017-2018, IBM Corporation. + * Copyright (c) 2020 Philippe Mathieu-Daudé + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "qemu/module.h" +#include "qemu/bitops.h" +#include "hw/qdev-properties.h" +#include "hw/gpio/pca9552.h" +#include "hw/gpio/pca9552_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 PCA955xClass { + /*< private >*/ + I2CSlaveClass parent_class; + /*< public >*/ + + uint8_t pin_count; + uint8_t max_reg; +}; +typedef struct PCA955xClass PCA955xClass; + +DECLARE_CLASS_CHECKERS(PCA955xClass, PCA955X, + TYPE_PCA955X) +/* + * Note: The LED_ON and LED_OFF configuration values for the PCA955X + * chips are the reverse of the PCA953X family of chips. + */ +#define PCA9552_LED_ON 0x0 +#define PCA9552_LED_OFF 0x1 +#define PCA9552_LED_PWM0 0x2 +#define PCA9552_LED_PWM1 0x3 +#define PCA9552_PIN_LOW 0x0 +#define PCA9552_PIN_HIZ 0x1 + +static const char *led_state[] = {"on", "off", "pwm0", "pwm1"}; + +static uint8_t pca955x_pin_get_config(PCA955xState *s, int pin) +{ + uint8_t reg = PCA9552_LS0 + (pin / 4); + uint8_t shift = (pin % 4) << 1; + + return extract32(s->regs[reg], shift, 2); +} + +/* Return INPUT status (bit #N belongs to GPIO #N) */ +static uint16_t pca955x_pins_get_status(PCA955xState *s) +{ + return (s->regs[PCA9552_INPUT1] << 8) | s->regs[PCA9552_INPUT0]; +} + +static void pca955x_display_pins_status(PCA955xState *s, + uint16_t previous_pins_status) +{ + PCA955xClass *k = PCA955X_GET_CLASS(s); + uint16_t pins_status, pins_changed; + int i; + + pins_status = pca955x_pins_get_status(s); + pins_changed = previous_pins_status ^ pins_status; + if (!pins_changed) { + return; + } + if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_STATUS)) { + char *buf = g_newa(char, k->pin_count + 1); + + for (i = 0; i < k->pin_count; i++) { + if (extract32(pins_status, i, 1)) { + buf[i] = '*'; + } else { + buf[i] = '.'; + } + } + buf[i] = '\0'; + trace_pca955x_gpio_status(s->description, buf); + } + if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_CHANGE)) { + for (i = 0; i < k->pin_count; i++) { + if (extract32(pins_changed, i, 1)) { + unsigned new_state = extract32(pins_status, i, 1); + + /* + * We display the state using the PCA logic ("active-high"). + * This is not the state of the LED, which signal might be + * wired "active-low" on the board. + */ + trace_pca955x_gpio_change(s->description, i, + !new_state, new_state); + } + } + } +} + +static void pca955x_update_pin_input(PCA955xState *s) +{ + PCA955xClass *k = PCA955X_GET_CLASS(s); + int i; + + 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) { + 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; + } + + /* update irq state only if pin state changed */ + new_value = s->regs[input_reg] & bit_mask; + if (new_value != old_value) { + qemu_set_irq(s->gpio_out[i], !!new_value); + } + } +} + +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: + qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected read to register %d\n", + __func__, reg); + return 0xFF; + } +} + +static void pca955x_write(PCA955xState *s, uint8_t reg, uint8_t data) +{ + 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: + qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected write to register %d\n", + __func__, reg); + } +} + +/* + * When Auto-Increment is on, the register address is incremented + * after each byte is sent to or received by the device. The index + * rollovers to 0 when the maximum register address is reached. + */ +static void pca955x_autoinc(PCA955xState *s) +{ + PCA955xClass *k = PCA955X_GET_CLASS(s); + + if (s->pointer != 0xFF && s->pointer & PCA9552_AUTOINC) { + uint8_t reg = s->pointer & 0xf; + + reg = (reg + 1) % (k->max_reg + 1); + s->pointer = reg | PCA9552_AUTOINC; + } +} + +static uint8_t pca955x_recv(I2CSlave *i2c) +{ + PCA955xState *s = PCA955X(i2c); + uint8_t ret; + + ret = pca955x_read(s, s->pointer & 0xf); + + /* + * From the Specs: + * + * Important Note: When a Read sequence is initiated and the + * AI bit is set to Logic Level 1, the Read Sequence MUST + * start by a register different from 0. + * + * I don't know what should be done in this case, so throw an + * error. + */ + if (s->pointer == PCA9552_AUTOINC) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Autoincrement read starting with register 0\n", + __func__); + } + + pca955x_autoinc(s); + + return ret; +} + +static int pca955x_send(I2CSlave *i2c, uint8_t data) +{ + PCA955xState *s = PCA955X(i2c); + + /* First byte sent by is the register address */ + if (s->len == 0) { + s->pointer = data; + s->len++; + } else { + pca955x_write(s, s->pointer & 0xf, data); + + pca955x_autoinc(s); + } + + return 0; +} + +static int pca955x_event(I2CSlave *i2c, enum i2c_event event) +{ + PCA955xState *s = PCA955X(i2c); + + s->len = 0; + 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; + uint8_t 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_str(v, name, (char **)&led_state[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). + */ +static inline uint8_t pca955x_ledsel(uint8_t oldval, int led_num, int state) +{ + return (oldval & (~(0x3 << (led_num << 1)))) | + ((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; + uint8_t state; + char *state_str; + + if (!visit_type_str(v, name, &state_str, 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; + } + + for (state = 0; state < ARRAY_SIZE(led_state); state++) { + if (!strcmp(state_str, led_state[state])) { + break; + } + } + if (state >= ARRAY_SIZE(led_state)) { + error_setg(errp, "%s invalid led state %s", __func__, state_str); + return; + } + + reg = PCA9552_LS0 + led / 4; + val = pca955x_read(s, reg); + val = pca955x_ledsel(val, led % 4, state); + pca955x_write(s, reg, val); +} + +static const VMStateDescription pca9552_vmstate = { + .name = "PCA9552", + .version_id = 0, + .minimum_version_id = 0, + .fields = (const VMStateField[]) { + VMSTATE_UINT8(len, PCA955xState), + VMSTATE_UINT8(pointer, PCA955xState), + VMSTATE_UINT8_ARRAY(regs, PCA955xState, PCA955X_NR_REGS), + VMSTATE_UINT8_ARRAY(ext_state, PCA955xState, PCA955X_PIN_COUNT_MAX), + VMSTATE_I2C_SLAVE(i2c, PCA955xState), + VMSTATE_END_OF_LIST() + } +}; + +static void pca9552_reset(DeviceState *dev) +{ + PCA955xState *s = PCA955X(dev); + + s->regs[PCA9552_PSC0] = 0xFF; + s->regs[PCA9552_PWM0] = 0x80; + s->regs[PCA9552_PSC1] = 0xFF; + s->regs[PCA9552_PWM1] = 0x80; + s->regs[PCA9552_LS0] = 0x55; /* all OFF */ + s->regs[PCA9552_LS1] = 0x55; + s->regs[PCA9552_LS2] = 0x55; + s->regs[PCA9552_LS3] = 0x55; + + 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); + int led; + + assert(k->pin_count <= PCA955X_PIN_COUNT_MAX); + for (led = 0; led < k->pin_count; led++) { + char *name; + + name = g_strdup_printf("led%d", led); + object_property_add(obj, name, "bool", pca955x_get_led, pca955x_set_led, + NULL, NULL); + g_free(name); + } +} + +static void pca955x_set_ext_state(PCA955xState *s, int pin, int level) +{ + if (s->ext_state[pin] != level) { + uint16_t pins_status = pca955x_pins_get_status(s); + s->ext_state[pin] = level; + pca955x_update_pin_input(s); + pca955x_display_pins_status(s, pins_status); + } +} + +static void pca955x_gpio_in_handler(void *opaque, int pin, int level) +{ + + PCA955xState *s = PCA955X(opaque); + PCA955xClass *k = PCA955X_GET_CLASS(s); + + assert((pin >= 0) && (pin < k->pin_count)); + pca955x_set_ext_state(s, pin, level); +} + +static void pca955x_realize(DeviceState *dev, Error **errp) +{ + PCA955xClass *k = PCA955X_GET_CLASS(dev); + PCA955xState *s = PCA955X(dev); + + if (!s->description) { + s->description = g_strdup("pca-unspecified"); + } + + qdev_init_gpio_out(dev, s->gpio_out, k->pin_count); + qdev_init_gpio_in(dev, pca955x_gpio_in_handler, k->pin_count); +} + +static Property pca955x_properties[] = { + DEFINE_PROP_STRING("description", PCA955xState, description), + DEFINE_PROP_END_OF_LIST(), +}; + +static void pca955x_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); + + k->event = pca955x_event; + k->recv = pca955x_recv; + k->send = pca955x_send; + dc->realize = pca955x_realize; + device_class_set_props(dc, pca955x_properties); +} + +static const TypeInfo pca955x_info = { + .name = TYPE_PCA955X, + .parent = TYPE_I2C_SLAVE, + .instance_init = pca955x_initfn, + .instance_size = sizeof(PCA955xState), + .class_init = pca955x_class_init, + .class_size = sizeof(PCA955xClass), + .abstract = true, +}; + +static void pca9552_class_init(ObjectClass *oc, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(oc); + PCA955xClass *pc = PCA955X_CLASS(oc); + + dc->reset = pca9552_reset; + dc->vmsd = &pca9552_vmstate; + pc->max_reg = PCA9552_LS3; + pc->pin_count = 16; +} + +static const TypeInfo pca9552_info = { + .name = TYPE_PCA9552, + .parent = TYPE_PCA955X, + .class_init = pca9552_class_init, +}; + +static void pca955x_register_types(void) +{ + type_register_static(&pca955x_info); + type_register_static(&pca9552_info); +} + +type_init(pca955x_register_types) |