diff options
| author | Romain Gantois <romain.gantois@bootlin.com> | 2025-03-06 17:23:28 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2025-04-18 23:34:19 +0200 |
| commit | 328a106ce0e8d0596d2b020b6f83efd0c859b084 (patch) | |
| tree | 242d7c5a6bbcba1e6c3c5a7e9f66c2a1a3d64fcd /include/linux | |
| parent | db1962c94dab207e5db5eeb7fdaa8e5f9c60d00e (diff) | |
i2c: support per-channel ATR alias pools
Some I2C address translators (ATRs) assign each of their remote peripheral
aliases to a specific channel. To properly handle these devices, add
support for having separate alias pools for each ATR channel.
This is achieved by allowing callers of i2c_atr_add_adapter to pass an
optional alias list. If present, this list will be used to populate the
channel's alias pool. Otherwise, the common alias pool will be used.
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/i2c-atr.h | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/include/linux/i2c-atr.h b/include/linux/i2c-atr.h index 14c1f9175c0d..1c3a5bcd939f 100644 --- a/include/linux/i2c-atr.h +++ b/include/linux/i2c-atr.h @@ -37,6 +37,29 @@ struct i2c_atr_ops { }; /** + * struct i2c_atr_adap_desc - An ATR downstream bus descriptor + * @chan_id: Index of the new adapter (0 .. max_adapters-1). This value is + * passed to the callbacks in `struct i2c_atr_ops`. + * @parent: The device used as the parent of the new i2c adapter, or NULL + * to use the i2c-atr device as the parent. + * @bus_handle: The fwnode handle that points to the adapter's i2c + * peripherals, or NULL. + * @num_aliases: The number of aliases in this adapter's private alias pool. Set + * to zero if this adapter uses the ATR's global alias pool. + * @aliases: An optional array of private aliases used by the adapter + * instead of the ATR's global pool of aliases. Must contain + * exactly num_aliases entries if num_aliases > 0, is ignored + * otherwise. + */ +struct i2c_atr_adap_desc { + u32 chan_id; + struct device *parent; + struct fwnode_handle *bus_handle; + size_t num_aliases; + u16 *aliases; +}; + +/** * i2c_atr_new() - Allocate and initialize an I2C ATR helper. * @parent: The parent (upstream) adapter * @dev: The device acting as an ATR @@ -65,12 +88,7 @@ void i2c_atr_delete(struct i2c_atr *atr); /** * i2c_atr_add_adapter - Create a child ("downstream") I2C bus. * @atr: The I2C ATR - * @chan_id: Index of the new adapter (0 .. max_adapters-1). This value is - * passed to the callbacks in `struct i2c_atr_ops`. - * @adapter_parent: The device used as the parent of the new i2c adapter, or NULL - * to use the i2c-atr device as the parent. - * @bus_handle: The fwnode handle that points to the adapter's i2c - * peripherals, or NULL. + * @desc: An ATR adapter descriptor * * After calling this function a new i2c bus will appear. Adding and removing * devices on the downstream bus will result in calls to the @@ -85,9 +103,7 @@ void i2c_atr_delete(struct i2c_atr *atr); * * Return: 0 on success, a negative error code otherwise. */ -int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, - struct device *adapter_parent, - struct fwnode_handle *bus_handle); +int i2c_atr_add_adapter(struct i2c_atr *atr, struct i2c_atr_adap_desc *desc); /** * i2c_atr_del_adapter - Remove a child ("downstream") I2C bus added by |