[PATCH] checks: Remove warning for I2C_OWN_SLAVE_ADDRESS

[PATCH] checks: Remove warning for I2C_OWN_SLAVE_ADDRESS

[Joel Stanley]

dtc does a sanity check on reg properties that they are within the 10
bit address range for i2c slave addresses. In the case of multi-master
buses the binding may describe an address that the bus will listen on as
a device. Do not warn when this flag is set.

This fixes the following build warnings reported by Stephen:

arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:126.11-130.4:
  Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:
    I2C bus unit address format error, expected "40000010"
arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:128.3-30:
  Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:reg:
    I2C address must be less than 10-bits, got "0x40000010"

Reported-by: Stephen Rothwell <sfr-3FnU+UHB4dNDw9hX6IcOSA@public.gmane.org>
Signed-off-by: Joel Stanley <joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org>
---
 checks.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/checks.c b/checks.c
index a8213c0e13a8..2c23dd4f7778 100644
--- a/checks.c
+++ b/checks.c
@@ -1022,6 +1022,8 @@ static void check_i2c_bus_bridge(struct check *c, struct dt_info *dti, struct no
 }
 WARNING(i2c_bus_bridge, check_i2c_bus_bridge, NULL, &addr_size_cells);
 
+#define I2C_OWN_SLAVE_ADDRESS	(1 << 30)
+
 static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node *node)
 {
 	struct property *prop;
@@ -1044,6 +1046,8 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
 	}
 
 	reg = fdt32_to_cpu(*cells);
+	/* Ingore I2C_OWN_SLAVE_ADDRESS */
+	reg &= ~I2C_OWN_SLAVE_ADDRESS;
 	snprintf(unit_addr, sizeof(unit_addr), "%x", reg);
 	if (!streq(unitname, unit_addr))
 		FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"",
@@ -1051,6 +1055,8 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
 
 	for (len = prop->val.len; len > 0; len -= 4) {
 		reg = fdt32_to_cpu(*(cells++));
+		/* Ingore I2C_OWN_SLAVE_ADDRESS */
+		reg &= ~I2C_OWN_SLAVE_ADDRESS;
 		if (reg > 0x3ff)
 			FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"",
 				  reg);
-- 
2.26.2

Re: [PATCH] checks: Remove warning for I2C_OWN_SLAVE_ADDRESS

[David Gibson]

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On Wed, May 20, 2020 at 05:21:34PM +0930, Joel Stanley wrote:
> dtc does a sanity check on reg properties that they are within the 10
> bit address range for i2c slave addresses. In the case of multi-master
> buses the binding may describe an address that the bus will listen on as
> a device. Do not warn when this flag is set.
> 
> This fixes the following build warnings reported by Stephen:
> 
> arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:126.11-130.4:
>   Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:
>     I2C bus unit address format error, expected "40000010"
> arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:128.3-30:
>   Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:reg:
>     I2C address must be less than 10-bits, got "0x40000010"
> 
> Reported-by: Stephen Rothwell <sfr-3FnU+UHB4dNDw9hX6IcOSA@public.gmane.org>
> Signed-off-by: Joel Stanley <joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org>

Any document you can give a pointer two explaining the special meaning
of this bit?

> ---
>  checks.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/checks.c b/checks.c
> index a8213c0e13a8..2c23dd4f7778 100644
> --- a/checks.c
> +++ b/checks.c
> @@ -1022,6 +1022,8 @@ static void check_i2c_bus_bridge(struct check *c, struct dt_info *dti, struct no
>  }
>  WARNING(i2c_bus_bridge, check_i2c_bus_bridge, NULL, &addr_size_cells);
>  
> +#define I2C_OWN_SLAVE_ADDRESS	(1 << 30)
> +
>  static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node *node)
>  {
>  	struct property *prop;
> @@ -1044,6 +1046,8 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
>  	}
>  
>  	reg = fdt32_to_cpu(*cells);
> +	/* Ingore I2C_OWN_SLAVE_ADDRESS */

Also, s/Ingore/Ignore/g

> +	reg &= ~I2C_OWN_SLAVE_ADDRESS;
>  	snprintf(unit_addr, sizeof(unit_addr), "%x", reg);
>  	if (!streq(unitname, unit_addr))
>  		FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"",
> @@ -1051,6 +1055,8 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
>  
>  	for (len = prop->val.len; len > 0; len -= 4) {
>  		reg = fdt32_to_cpu(*(cells++));
> +		/* Ingore I2C_OWN_SLAVE_ADDRESS */
> +		reg &= ~I2C_OWN_SLAVE_ADDRESS;
>  		if (reg > 0x3ff)
>  			FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"",
>  				  reg);

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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Re: [PATCH] checks: Remove warning for I2C_OWN_SLAVE_ADDRESS

[Stephen Rothwell]

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Hi David,

On Thu, 21 May 2020 15:09:14 +1000 David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6iEOx6SR5NKn@public.gmane.orgu> wrote:
>
> On Wed, May 20, 2020 at 05:21:34PM +0930, Joel Stanley wrote:
> > dtc does a sanity check on reg properties that they are within the 10
> > bit address range for i2c slave addresses. In the case of multi-master
> > buses the binding may describe an address that the bus will listen on as
> > a device. Do not warn when this flag is set.
> > 
> > This fixes the following build warnings reported by Stephen:
> > 
> > arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:126.11-130.4:
> >   Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:
> >     I2C bus unit address format error, expected "40000010"
> > arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:128.3-30:
> >   Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:reg:
> >     I2C address must be less than 10-bits, got "0x40000010"
> > 
> > Reported-by: Stephen Rothwell <sfr-3FnU+UHB4dNDw9hX6IcOSA@public.gmane.org>
> > Signed-off-by: Joel Stanley <joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org>  
> 
> Any document you can give a pointer two explaining the special meaning
> of this bit?
include/dt-bindings/i2c/i2c.h
Is Documentation/devicetree/bindings/i2c/i2c.txt in the kernel tree
sufficient? I2C_OWN_SLAVE_ADDRESS has been in there since the file was
introduced in August 2015.  The actual value has been in
include/dt-bindings/i2c/i2c.h since the same time.

-- 
Cheers,
Stephen Rothwell

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Re: [PATCH] checks: Remove warning for I2C_OWN_SLAVE_ADDRESS

[David Gibson]

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On Thu, May 21, 2020 at 04:50:09PM +1000, Stephen Rothwell wrote:
> Hi David,
> 
> On Thu, 21 May 2020 15:09:14 +1000 David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6ryscVyMRj84@public.gmane.org.au> wrote:
> >
> > On Wed, May 20, 2020 at 05:21:34PM +0930, Joel Stanley wrote:
> > > dtc does a sanity check on reg properties that they are within the 10
> > > bit address range for i2c slave addresses. In the case of multi-master
> > > buses the binding may describe an address that the bus will listen on as
> > > a device. Do not warn when this flag is set.
> > > 
> > > This fixes the following build warnings reported by Stephen:
> > > 
> > > arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:126.11-130.4:
> > >   Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:
> > >     I2C bus unit address format error, expected "40000010"
> > > arch/arm/boot/dts/aspeed-bmc-facebook-yosemitev2.dts:128.3-30:
> > >   Warning (i2c_bus_reg): /ahb/apb/bus@1e78a000/i2c-bus@80/ipmb1@10:reg:
> > >     I2C address must be less than 10-bits, got "0x40000010"
> > > 
> > > Reported-by: Stephen Rothwell <sfr-3FnU+UHB4dNDw9hX6IcOSA@public.gmane.org>
> > > Signed-off-by: Joel Stanley <joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org>  
> > 
> > Any document you can give a pointer two explaining the special meaning
> > of this bit?
> include/dt-bindings/i2c/i2c.h
> Is Documentation/devicetree/bindings/i2c/i2c.txt in the kernel tree
> sufficient?

Good enough.

> I2C_OWN_SLAVE_ADDRESS has been in there since the file was
> introduced in August 2015.  The actual value has been in
> include/dt-bindings/i2c/i2c.h since the same time.

Looking at that, though, it seems like we should also ignore the
I2C_TEN_BIT_ADDRESS flag.  Or better yet, not ignore it but validate
the base addres is under 7 bits unless its set.

Can we refine that a bit, and fix the spelling errors?

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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