On Mon, Jun 15, 2015 at 8:15 AM, <fred.kon...@greensocs.com> wrote:
From: KONRAD Frederic <fred.kon...@greensocs.com>
This does a write to every slaves when the I2C bus get a write to address 0.
Signed-off-by: KONRAD Frederic <fred.kon...@greensocs.com>
---
hw/i2c/core.c | 46 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/hw/i2c/core.c b/hw/i2c/core.c
index 5a64026..db1cbdd 100644
--- a/hw/i2c/core.c
+++ b/hw/i2c/core.c
@@ -15,6 +15,7 @@ struct I2CBus
I2CSlave *current_dev;
I2CSlave *dev;
uint8_t saved_address;
+ bool broadcast;
};
static Property i2c_props[] = {
@@ -67,6 +68,8 @@ I2CBus *i2c_init_bus(DeviceState *parent, const char *name)
bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name));
vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
+
+ bus->broadcast = false;
0 initialiser should not be needed for new QOM object.
return bus;
}
@@ -89,6 +92,21 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int
recv)
I2CSlave *slave = NULL;
I2CSlaveClass *sc;
+ if (address == 0x00) {
+ /*
+ * This is a broadcast.
+ */
One line comment.
+ QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
+ I2CSlave *dev = I2C_SLAVE(kid->child);
+ sc = I2C_SLAVE_GET_CLASS(dev);
+ bus->broadcast = true;
Move outside loop.
+ if (sc->event) {
+ sc->event(dev, recv ? I2C_START_RECV : I2C_START_SEND);
+ }
+ }
+ return 0;
+ }
+
QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
DeviceState *qdev = kid->child;
I2CSlave *candidate = I2C_SLAVE(qdev);
@@ -114,9 +132,21 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int
recv)
void i2c_end_transfer(I2CBus *bus)
{
+ BusChild *kid;
I2CSlave *dev = bus->current_dev;
I2CSlaveClass *sc;
+ if (bus->broadcast) {
+ QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
+ I2CSlave *dev = I2C_SLAVE(kid->child);
+ sc = I2C_SLAVE_GET_CLASS(dev);
+ if (sc->event) {
+ sc->event(dev, I2C_FINISH);
+ }
+ }
+ bus->broadcast = false;
+ }
+
if (!dev) {
return;
}
@@ -131,8 +161,22 @@ void i2c_end_transfer(I2CBus *bus)
int i2c_send(I2CBus *bus, uint8_t data)
{
+ BusChild *kid;
I2CSlave *dev = bus->current_dev;
I2CSlaveClass *sc;
+ int ret = 0;
+
+ if (bus->broadcast) {
+ QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
+ I2CSlave *dev = I2C_SLAVE(kid->child);
+ sc = I2C_SLAVE_GET_CLASS(dev);
+ bus->broadcast = true;
+ if (sc->send) {
+ ret |= sc->send(dev, data);
+ }
+ }
Still not sure about the duped core functionality of each of these
APIs. That is, the same code is needed in both a looped form and a 1
form. Can this be solved by listifying current_dev? That is, ->current
dev is turned into a list which in the normal case will be populated
with 1 element by start_transfer() for the current dev. In the
broadcast case, all qbus.children are added to the list. The broadcast
bool is then removed. start() send() and end_transfer() then just loop
through the list unconditionally.
