/* * 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 "hw/misc/pca9552.h" #include "hw/misc/pca9552_regs.h" #include "migration/vmstate.h" #include "qapi/error.h" #include "qapi/visitor.h" typedef struct PCA955xClass { /*< private >*/ I2CSlaveClass parent_class; /*< public >*/ uint8_t pin_count; uint8_t max_reg; } PCA955xClass; #define PCA955X_CLASS(klass) \ OBJECT_CLASS_CHECK(PCA955xClass, (klass), TYPE_PCA955X) #define PCA955X_GET_CLASS(obj) \ OBJECT_GET_CLASS(PCA955xClass, (obj), TYPE_PCA955X) #define PCA9552_LED_ON 0x0 #define PCA9552_LED_OFF 0x1 #define PCA9552_LED_PWM0 0x2 #define PCA9552_LED_PWM1 0x3 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); } 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 input_shift = (i % 8); uint8_t config = pca955x_pin_get_config(s, i); switch (config) { case PCA9552_LED_ON: s->regs[input_reg] |= 1 << input_shift; break; case PCA9552_LED_OFF: s->regs[input_reg] &= ~(1 << input_shift); break; case PCA9552_LED_PWM0: case PCA9552_LED_PWM1: /* TODO */ default: break; } } } 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) { 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: s->regs[reg] = data; pca955x_update_pin_input(s); 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 % 8)) & 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); Error *local_err = NULL; int led, rc, reg, val; uint8_t state; char *state_str; visit_type_str(v, name, &state_str, &local_err); if (local_err) { error_propagate(errp, local_err); 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 = (VMStateField[]) { VMSTATE_UINT8(len, PCA955xState), VMSTATE_UINT8(pointer, PCA955xState), VMSTATE_UINT8_ARRAY(regs, PCA955xState, PCA955X_NR_REGS), 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; 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_class_init(ObjectClass *klass, void *data) { I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); k->event = pca955x_event; k->recv = pca955x_recv; k->send = pca955x_send; } 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, .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)