Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 437 insertions, 0 deletions

diff --git a/hw/misc/pca9552.c b/hw/misc/pca9552.c
new file mode 100644
index 000000000..fff19e369
--- /dev/null
+++ b/hw/misc/pca9552.c
@@ -0,0 +1,437 @@
+/*
+ * 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/misc/pca9552.h"
+#include "hw/misc/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)
+
+#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);
+}
+
+/* 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 input_shift = (i % 8);
+        uint8_t config = pca955x_pin_get_config(s, i);
+
+        switch (config) {
+        case PCA9552_LED_ON:
+            qemu_set_irq(s->gpio[i], 1);
+            s->regs[input_reg] |= 1 << input_shift;
+            break;
+        case PCA9552_LED_OFF:
+            qemu_set_irq(s->gpio[i], 0);
+            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)
+{
+    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 = (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_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, 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)