On Wed, Apr 13, 2016 at 11:36 AM, Andrea Merello <andrea.merello@xxxxxxxxx> wrote: > According to Documentation/i2c/smbus-protocol, a smbus controller driver > that wants to hook-in smbus extensions support, can call > i2c_setup_smbus_alert(). There are very few drivers that are currently > doing this. > > However the i2c-smbus module can also work with any > smbus-extensions-unaware I2C controller, as long as we provide an extra > IRQ line connected to the I2C bus ALARM signal. > > This patch makes it possible to go this way via DT. Note that the DT node > will indeed describe a (little) piece of HW, that is the routing of the > ALARM signal to an IRQ line (so it seems a fair DT use to me, but RFC). > > Note that AFAICT, by design, i2c-smbus module pretends to be an I2C slave > with address 0x0C (that is the alarm response address), and IMHO this is > quite consistent with usage in the DT as a I2C child node. > --- a/drivers/i2c/i2c-smbus.c > +++ b/drivers/i2c/i2c-smbus.c > @@ -137,20 +138,29 @@ static int smbalert_probe(struct i2c_client *ara, > struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev); > struct i2c_smbus_alert *alert; > struct i2c_adapter *adapter = ara->adapter; > + struct device_node *of_node = ara->dev.of_node; Perhaps fwnode_handle ? > int res; > + int irq_type; > > alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert), > GFP_KERNEL); > if (!alert) > return -ENOMEM; > > - alert->alert_edge_triggered = setup->alert_edge_triggered; > - alert->irq = setup->irq; > + if (setup) { > + alert->alert_edge_triggered = setup->alert_edge_triggered; > + alert->irq = setup->irq; > + } else if (of_node) { > + alert->irq = irq_of_parse_and_map(of_node, 0); > + irq_type = irq_get_trigger_type(alert->irq); > + alert->alert_edge_triggered = (irq_type & IRQ_TYPE_EDGE_BOTH); > + } -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html