On 17/07/2023 12:06:37+0800, Matt Johnston wrote:
> From: Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx>
>
> This allows other drivers to be notified when new i3c busses are
> attached, referring to a whole i3c bus as opposed to individual
> devices.
>
> Signed-off-by: Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Matt Johnston <matt@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> ---
> drivers/i3c/master.c | 35 +++++++++++++++++++++++++++++++++++
> include/linux/i3c/master.h | 11 +++++++++++
> 2 files changed, 46 insertions(+)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 08aeb69a7800..2276abe38bdc 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -22,6 +22,7 @@
> static DEFINE_IDR(i3c_bus_idr);
> static DEFINE_MUTEX(i3c_core_lock);
> static int __i3c_first_dynamic_bus_num;
> +static BLOCKING_NOTIFIER_HEAD(i3c_bus_notifier);
>
> /**
> * i3c_bus_maintenance_lock - Lock the bus for a maintenance operation
> @@ -453,6 +454,36 @@ static int i3c_bus_init(struct i3c_bus *i3cbus, struct device_node *np)
> return 0;
> }
>
> +void i3c_for_each_bus_locked(int (*fn)(struct i3c_bus *bus, void *data),
> + void *data)
> +{
> + struct i3c_bus *bus;
> + int id;
> +
> + mutex_lock(&i3c_core_lock);
> + idr_for_each_entry(&i3c_bus_idr, bus, id)
> + fn(bus, data);
> + mutex_unlock(&i3c_core_lock);
> +}
> +EXPORT_SYMBOL_GPL(i3c_for_each_bus_locked);
> +
> +int i3c_register_notifier(struct notifier_block *nb)
> +{
> + return blocking_notifier_chain_register(&i3c_bus_notifier, nb);
> +}
> +EXPORT_SYMBOL_GPL(i3c_register_notifier);
> +
> +int i3c_unregister_notifier(struct notifier_block *nb)
> +{
> + return blocking_notifier_chain_unregister(&i3c_bus_notifier, nb);
> +}
> +EXPORT_SYMBOL_GPL(i3c_unregister_notifier);
> +
> +static void i3c_bus_notify(struct i3c_bus *bus, unsigned int action)
> +{
> + blocking_notifier_call_chain(&i3c_bus_notifier, action, bus);
> +}
> +
> static const char * const i3c_bus_mode_strings[] = {
> [I3C_BUS_MODE_PURE] = "pure",
> [I3C_BUS_MODE_MIXED_FAST] = "mixed-fast",
> @@ -2678,6 +2709,8 @@ int i3c_master_register(struct i3c_master_controller *master,
> if (ret)
> goto err_del_dev;
>
> + i3c_bus_notify(i3cbus, I3C_NOTIFY_BUS_ADD);
> +
> /*
> * We're done initializing the bus and the controller, we can now
> * register I3C devices discovered during the initial DAA.
> @@ -2710,6 +2743,8 @@ EXPORT_SYMBOL_GPL(i3c_master_register);
> */
> void i3c_master_unregister(struct i3c_master_controller *master)
> {
> + i3c_bus_notify(&master->bus, I3C_NOTIFY_BUS_REMOVE);
> +
> i3c_master_i2c_adapter_cleanup(master);
> i3c_master_unregister_i3c_devs(master);
> i3c_master_bus_cleanup(master);
> diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
> index 0b52da4f2346..db909ef79be4 100644
> --- a/include/linux/i3c/master.h
> +++ b/include/linux/i3c/master.h
> @@ -24,6 +24,12 @@
>
> struct i2c_client;
>
> +/* notifier actions. notifier call data is the struct i3c_bus */
> +enum {
> + I3C_NOTIFY_BUS_ADD,
> + I3C_NOTIFY_BUS_REMOVE,
> +};
> +
> struct i3c_master_controller;
> struct i3c_bus;
> struct i3c_device;
> @@ -652,4 +658,9 @@ void i3c_master_queue_ibi(struct i3c_dev_desc *dev, struct i3c_ibi_slot *slot);
>
> struct i3c_ibi_slot *i3c_master_get_free_ibi_slot(struct i3c_dev_desc *dev);
>
> +void i3c_for_each_bus_locked(int (*fn)(struct i3c_bus *bus, void *data),
> + void *data);
> +int i3c_register_notifier(struct notifier_block *nb);
> +int i3c_unregister_notifier(struct notifier_block *nb);
> +
> #endif /* I3C_MASTER_H */
> --
> 2.37.2
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
