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.
Regards,
Peter
> + return ret;
> + }
>
> if (!dev) {
> return -1;
> @@ -151,7 +195,7 @@ int i2c_recv(I2CBus *bus)
> I2CSlave *dev = bus->current_dev;
> I2CSlaveClass *sc;
>
> - if (!dev) {
> + if ((!dev) || (bus->broadcast)) {
> return -1;
> }
>
> --
> 1.9.0
>
>
