[PATCH 1/2] dt-bindings: i2c: replace property i2c-mux-idle-disconnect

[PATCH 1/2] dt-bindings: i2c: replace property i2c-mux-idle-disconnect

[Biwen Li]

This replaces property i2c-mux-idle-disconnect with idle-state

Signed-off-by: Biwen Li <biwen.li@nxp.com>
---
 Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
index 30ac6a60f041..f2db517b1635 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
@@ -25,9 +25,7 @@ Required Properties:
 Optional Properties:
 
   - reset-gpios: Reference to the GPIO connected to the reset input.
-  - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect all
-    children in idle state. This is necessary for example, if there are several
-    multiplexers on the bus and the devices behind them use same I2C addresses.
+  - idle-state: Please refer to Documentation/devicetree/bindings/mux/mux-controller.txt
   - interrupts: Interrupt mapping for IRQ.
   - interrupt-controller: Marks the device node as an interrupt controller.
   - #interrupt-cells : Should be two.
-- 
2.17.1

[PATCH 2/2] i2c: mux: pca954x: replace property i2c-mux-idle-disconnect

[Biwen Li]

This replaces property i2c-mux-idle-disconnect with idle-state

Signed-off-by: Biwen Li <biwen.li@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){
+		data->last_chan = data->idle_state;
+		/* Always enable multiplexer */
+		ret = i2c_smbus_write_byte(client, data->last_chan |
+				(data->chip->muxtype == pca954x_ismux ?
+				 data->chip->enable : 0));
+	}
+	else{
+		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;
 
 	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
 
-- 
2.17.1

Re: [PATCH 2/2] i2c: mux: pca954x: replace property i2c-mux-idle-disconnect

[Peter Rosin]

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.li@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
>  
> 

RE: [EXT] Re: [PATCH 2/2] i2c: mux: pca954x: replace property i2c-mux-idle-disconnect

[Biwen Li]

> 
> Caution: EXT Email
> 
> 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.li@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 {
Okay, got it, I will add it in v2.
> 
> > +             data->last_chan = data->idle_state;
> 
> data->last_chan should have the actual register value, i.e. (untested)
Okay, got it, I will adjust it in v2.
> 
>                 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.
You are right, I will add a helper function in v2.
> 
> > +             /* Always enable multiplexer */
> > +             ret = i2c_smbus_write_byte(client, data->last_chan |
> > +                             (data->chip->muxtype ==
> pca954x_ismux ?
> > +                              data->chip->enable : 0));
> > +     }
> > +     else{
> 
> Space before {
Got it, I will add it in v2.
> 
> Naturally, you have the exact same issues in the pca954x_resume hunk,
> below.
Got it
> 
> > +             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.
Okay, got it, I will add it in v2.
> 
> 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
> >
> >

RE: [PATCH 1/2] dt-bindings: i2c: replace property i2c-mux-idle-disconnect

[Biwen Li]

Hi Peter, Rob

This patch is a new method for https://lore.kernel.org/patchwork/patch/1132445/

Best Regards,
Biwen Li
> 
> This replaces property i2c-mux-idle-disconnect with idle-state
> 
> Signed-off-by: Biwen Li <biwen.li@nxp.com>
> ---
>  Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> index 30ac6a60f041..f2db517b1635 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> @@ -25,9 +25,7 @@ Required Properties:
>  Optional Properties:
> 
>    - reset-gpios: Reference to the GPIO connected to the reset input.
> -  - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect
> all
> -    children in idle state. This is necessary for example, if there are several
> -    multiplexers on the bus and the devices behind them use same I2C
> addresses.
> +  - idle-state: Please refer to
> Documentation/devicetree/bindings/mux/mux-controller.txt
>    - interrupts: Interrupt mapping for IRQ.
>    - interrupt-controller: Marks the device node as an interrupt controller.
>    - #interrupt-cells : Should be two.
> --
> 2.17.1

Re: [PATCH 1/2] dt-bindings: i2c: replace property i2c-mux-idle-disconnect

[Peter Rosin]

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.li@nxp.com>
> ---
>  Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> index 30ac6a60f041..f2db517b1635 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> @@ -25,9 +25,7 @@ Required Properties:
>  Optional Properties:
>  
>    - reset-gpios: Reference to the GPIO connected to the reset input.
> -  - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect all
> -    children in idle state. This is necessary for example, if there are several
> -    multiplexers on the bus and the devices behind them use same I2C addresses.
> +  - idle-state: Please refer to Documentation/devicetree/bindings/mux/mux-controller.txt
>    - interrupts: Interrupt mapping for IRQ.
>    - interrupt-controller: Marks the device node as an interrupt controller.
>    - #interrupt-cells : Should be two.
> 

You can't just remove i2c-mux-idle-disconnect. It needs to remain, and the
driver needs to maintain support for this in case a new kernel is running
with an old devicetree.

Cheers,
Peter

RE: [EXT] Re: [PATCH 1/2] dt-bindings: i2c: replace property i2c-mux-idle-disconnect

[Biwen Li]

> Caution: EXT Email
> 
> 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.li@nxp.com>
> > ---
> >  Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> > b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> > index 30ac6a60f041..f2db517b1635 100644
> > --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> > +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> > @@ -25,9 +25,7 @@ Required Properties:
> >  Optional Properties:
> >
> >    - reset-gpios: Reference to the GPIO connected to the reset input.
> > -  - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect
> all
> > -    children in idle state. This is necessary for example, if there are several
> > -    multiplexers on the bus and the devices behind them use same I2C
> addresses.
> > +  - idle-state: Please refer to
> > + Documentation/devicetree/bindings/mux/mux-controller.txt
> >    - interrupts: Interrupt mapping for IRQ.
> >    - interrupt-controller: Marks the device node as an interrupt controller.
> >    - #interrupt-cells : Should be two.
> >
> 
> You can't just remove i2c-mux-idle-disconnect. It needs to remain, and the
> driver needs to maintain support for this in case a new kernel is running
> with an old devicetree.
You are right, I will add it in v2.
> 
> Cheers,
> Peter