mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-27 21:03:32 +00:00
Code Issues Releases Wiki Activity

i3c: Allow OF-alias-based persistent bus numbering

Browse source 
Parse the /aliases node to assign any fixed bus numbers, as is done with
the i2c subsystem. Numbering for non-aliased busses will start after the
highest fixed bus number.

This allows an alias node such as:

    aliases {
        i3c0 = &bus_a,
	i3c4 = &bus_b,
    };

to set the numbering for a set of i3c controllers:

    /* fixed-numbered bus, assigned "i3c-0" */
    bus_a: i3c-master {
    };

    /* another fixed-numbered bus, assigned "i3c-4" */
    bus_b: i3c-master {
    };

    /* dynamic-numbered bus, likely assigned "i3c-5" */
    bus_c: i3c-master {
    };

If no i3c device aliases are present, the numbering will stay as-is,
starting from 0.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://lore.kernel.org/r/20230405094149.1513209-1-jk@codeconstruct.com.au
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Jeremy Kerr 2023-04-05 17:41:49 +08:00 committed by Alexandre Belloni
parent 5844564143
commit 7dc2e0a875
1 changed files with 25 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
drivers/i3c/master.c
View file

@ -21,6 +21,7 @@
static DEFINE_IDR(i3c_bus_idr);
static DEFINE_MUTEX(i3c_core_lock);
static int __i3c_first_dynamic_bus_num;
/**
* i3c_bus_maintenance_lock - Lock the bus for a maintenance operation
@ -419,9 +420,9 @@ static void i3c_bus_cleanup(struct i3c_bus *i3cbus)
mutex_unlock(&i3c_core_lock);
}
static int i3c_bus_init(struct i3c_bus *i3cbus)
static int i3c_bus_init(struct i3c_bus *i3cbus, struct device_node *np)
{
int ret;
int ret, start, end, id = -1;
init_rwsem(&i3cbus->lock);
INIT_LIST_HEAD(&i3cbus->devs.i2c);
@ -429,8 +430,19 @@ static int i3c_bus_init(struct i3c_bus *i3cbus)
i3c_bus_init_addrslots(i3cbus);
i3cbus->mode = I3C_BUS_MODE_PURE;
if (np)
id = of_alias_get_id(np, "i3c");
mutex_lock(&i3c_core_lock);
ret = idr_alloc(&i3c_bus_idr, i3cbus, 0, 0, GFP_KERNEL);
if (id >= 0) {
start = id;
end = start + 1;
} else {
start = __i3c_first_dynamic_bus_num;
end = 0;
}
ret = idr_alloc(&i3c_bus_idr, i3cbus, start, end, GFP_KERNEL);
mutex_unlock(&i3c_core_lock);
if (ret < 0)
@ -2606,7 +2618,7 @@ int i3c_master_register(struct i3c_master_controller *master,
INIT_LIST_HEAD(&master->boardinfo.i2c);
INIT_LIST_HEAD(&master->boardinfo.i3c);
ret = i3c_bus_init(i3cbus);
ret = i3c_bus_init(i3cbus, master->dev.of_node);
if (ret)
return ret;
@ -2830,8 +2842,16 @@ void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev)
static int __init i3c_init(void)
{
int res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
int res;
res = of_alias_get_highest_id("i3c");
if (res >= 0) {
mutex_lock(&i3c_core_lock);
__i3c_first_dynamic_bus_num = res + 1;
mutex_unlock(&i3c_core_lock);
}
res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
if (res)
return res;