On 2018-09-27 15:38, Luca Ceresoli wrote:
> From: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
>
> i2c-mux instantiates one i2c_algorithm for each downstream adapter.
> However these algorithms are all identical, depending only on the
> parent adapter.
>
> Avoid duplication by hoisting the i2c_algorithm from the adapters to
> the i2c_mux_core object, and reuse it in all the adapters.
Looks about right to me, just a couple of nit-picks. See below.
>
> Signed-off-by: Luca Ceresoli <luca@xxxxxxxxxxxxxxxx>
>
> ---
>
> Changes v1 -> v2:
> - include i2c.h (fixes build failure on i2c-mux-ltc4306)
> ---
> drivers/i2c/i2c-mux.c | 37 ++++++++++++++++++-------------------
> include/linux/i2c-mux.h | 2 ++
> 2 files changed, 20 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
> index f330690b4125..2b0cc2ad0a17 100644
> --- a/drivers/i2c/i2c-mux.c
> +++ b/drivers/i2c/i2c-mux.c
> @@ -30,7 +30,6 @@
> /* multiplexer per channel data */
> struct i2c_mux_priv {
> struct i2c_adapter adap;
> - struct i2c_algorithm algo;
> struct i2c_mux_core *muxc;
> u32 chan_id;
> };
> @@ -263,6 +262,23 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
> muxc->deselect = deselect;
> muxc->max_adapters = max_adapters;
>
> + /* Need to do algo dynamically because we don't know ahead
> + * of time what sort of physical adapter we'll be dealing with.
> + */
Multiline comments should start with a /* on a line of its own. Yes,
I know you just moved it, but please fix it up as you do so.
> + if (parent->algo->master_xfer) {
> + if (muxc->mux_locked)
> + muxc->algo.master_xfer = i2c_mux_master_xfer;
> + else
> + muxc->algo.master_xfer = __i2c_mux_master_xfer;
> + }
> + if (parent->algo->smbus_xfer) {
> + if (muxc->mux_locked)
> + muxc->algo.smbus_xfer = i2c_mux_smbus_xfer;
> + else
> + muxc->algo.smbus_xfer = __i2c_mux_smbus_xfer;
> + }
> + muxc->algo.functionality = i2c_mux_functionality;
> +
> return muxc;
> }
> EXPORT_SYMBOL_GPL(i2c_mux_alloc);
> @@ -301,28 +317,11 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
> priv->muxc = muxc;
> priv->chan_id = chan_id;
>
> - /* Need to do algo dynamically because we don't know ahead
> - * of time what sort of physical adapter we'll be dealing with.
> - */
> - if (parent->algo->master_xfer) {
> - if (muxc->mux_locked)
> - priv->algo.master_xfer = i2c_mux_master_xfer;
> - else
> - priv->algo.master_xfer = __i2c_mux_master_xfer;
> - }
> - if (parent->algo->smbus_xfer) {
> - if (muxc->mux_locked)
> - priv->algo.smbus_xfer = i2c_mux_smbus_xfer;
> - else
> - priv->algo.smbus_xfer = __i2c_mux_smbus_xfer;
> - }
> - priv->algo.functionality = i2c_mux_functionality;
> -
> /* Now fill out new adapter structure */
> snprintf(priv->adap.name, sizeof(priv->adap.name),
> "i2c-%d-mux (chan_id %d)", i2c_adapter_id(parent), chan_id);
> priv->adap.owner = THIS_MODULE;
> - priv->adap.algo = &priv->algo;
> + priv->adap.algo = &muxc->algo;
> priv->adap.algo_data = priv;
> priv->adap.dev.parent = &parent->dev;
> priv->adap.retries = parent->retries;
> diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
> index bd74d5706f3b..5a4ffca99f5d 100644
> --- a/include/linux/i2c-mux.h
> +++ b/include/linux/i2c-mux.h
> @@ -28,6 +28,7 @@
> #ifdef __KERNEL__
>
> #include <linux/bitops.h>
> +#include <linux/i2c.h>
>
> struct i2c_mux_core {
> struct i2c_adapter *parent;
> @@ -36,6 +37,7 @@ struct i2c_mux_core {
> unsigned int arbitrator:1;
> unsigned int gate:1;
>
> + struct i2c_algorithm algo;
> void *priv;
I want the algo member further up, and certainly not "grouped" with
priv. Between parent and dev seems fine to me.
Cheers,
Peter
>
> int (*select)(struct i2c_mux_core *, u32 chan_id);
>
