On 2019-10-14 13:25, Biwen Li wrote:
> This replaces property i2c-mux-idle-disconnect with idle-state
> 
> Signed-off-by: Biwen Li <biwen...@nxp.com>
> ---
>  drivers/i2c/muxes/i2c-mux-pca954x.c | 44 ++++++++++++++++++++---------
>  1 file changed, 31 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c 
> b/drivers/i2c/muxes/i2c-mux-pca954x.c
> index 923aa3a5a3dc..a330929c4d67 100644
> --- a/drivers/i2c/muxes/i2c-mux-pca954x.c
> +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
> @@ -86,7 +86,7 @@ struct pca954x {
>  
>       u8 last_chan;           /* last register value */
>       /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */
> -     s8 idle_state;
> +     s32 idle_state;
>  
>       struct i2c_client *client;
>  
> @@ -256,7 +256,7 @@ static int pca954x_deselect_mux(struct i2c_mux_core 
> *muxc, u32 chan)
>  {
>       struct pca954x *data = i2c_mux_priv(muxc);
>       struct i2c_client *client = data->client;
> -     s8 idle_state;
> +     s32 idle_state;
>  
>       idle_state = READ_ONCE(data->idle_state);
>       if (idle_state >= 0)
> @@ -411,7 +411,6 @@ static int pca954x_probe(struct i2c_client *client,
>       struct i2c_adapter *adap = client->adapter;
>       struct device *dev = &client->dev;
>       struct device_node *np = dev->of_node;
> -     bool idle_disconnect_dt;
>       struct gpio_desc *gpio;
>       struct i2c_mux_core *muxc;
>       struct pca954x *data;
> @@ -462,22 +461,31 @@ static int pca954x_probe(struct i2c_client *client,
>               }
>       }
>  
> +     if (of_property_read_u32(np, "idle-state", &data->idle_state))
> +             data->idle_state = MUX_IDLE_AS_IS;
> +
>       /* Write the mux register at addr to verify
>        * that the mux is in fact present. This also
>        * initializes the mux to disconnected state.
>        */
> -     if (i2c_smbus_write_byte(client, 0) < 0) {
> +     if (data->idle_state >= 0){

Space before {

> +             data->last_chan = data->idle_state;

data->last_chan should have the actual register value, i.e. (untested)

                if (data->chip->muxtype == pca954x_ismux)
                        data->last_chan = data->idle_state | data->chip->enable;
                else
                        data->last_chan = 1 << data->idle_state;

                ret = i2c_smbus_write_byte(client, data->last_chan);

But since this regval calculation is now needed in three places, it should
be moved to a helper function.

> +             /* Always enable multiplexer */
> +             ret = i2c_smbus_write_byte(client, data->last_chan |
> +                             (data->chip->muxtype == pca954x_ismux ?
> +                              data->chip->enable : 0));
> +     }
> +     else{

Space before {

Naturally, you have the exact same issues in the pca954x_resume hunk, below.

> +             data->last_chan = 0;               /* force the first selection 
> */
> +             /* Disconnect multiplexer */
> +             ret = i2c_smbus_write_byte(client, data->last_chan);
> +     }
> +
> +     if (ret < 0) {
>               dev_warn(dev, "probe failed\n");
>               return -ENODEV;
>       }
>  
> -     data->last_chan = 0;               /* force the first selection */
> -     data->idle_state = MUX_IDLE_AS_IS;
> -
> -     idle_disconnect_dt = np &&
> -             of_property_read_bool(np, "i2c-mux-idle-disconnect");
> -     if (idle_disconnect_dt)
> -             data->idle_state = MUX_IDLE_DISCONNECT;

In case the idle-state property is missing, you need to fall back to the
old behavior and handle i2c-mux-idle-disconnect as before.

Cheers,
Peter

>  
>       ret = pca954x_irq_setup(muxc);
>       if (ret)
> @@ -531,8 +539,18 @@ static int pca954x_resume(struct device *dev)
>       struct i2c_mux_core *muxc = i2c_get_clientdata(client);
>       struct pca954x *data = i2c_mux_priv(muxc);
>  
> -     data->last_chan = 0;
> -     return i2c_smbus_write_byte(client, 0);
> +     if (data->idle_state >= 0){
> +             data->last_chan = data->idle_state;
> +             /* Always enable multiplexer */
> +             return i2c_smbus_write_byte(client, data->last_chan |
> +                             (data->chip->muxtype == pca954x_ismux ?
> +                              data->chip->enable : 0));
> +     }
> +     else{
> +             data->last_chan = 0;
> +             /* Disconnect multiplexer */
> +             return i2c_smbus_write_byte(client, data->last_chan);
> +     }
>  }
>  #endif
>  
> 

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