Patchwork i2c: mpc: Define unique I2C adapter names

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Submitter Guenter Roeck
Date July 10, 2013, 7:03 p.m.
Message ID <1373483001-24951-1-git-send-email-linux@roeck-us.net>
Download mbox | patch
Permalink /patch/258222/
State Accepted
Headers show

Comments

Guenter Roeck - July 10, 2013, 7:03 p.m.
The I2C adapters on Freescale MPC107/824x/85xx/512x/52xx/83xx/86xx all
have the same name "MPC adapter". Since I2C adapter numbers can change
across reboots and even after loading/unloading an I2C bus master driver,
adapter names have to be used to identify adapters and thus should be
unique and well defined. Since this is not the case with this driver,
it is difficult if not impossible to identify a specific adapter from
user space on affected platforms.

To remedy the problem, use the adapter memory address as part of the
adapter name.

With this patch, adapter names are:
On P2020:
MPC adapter at 0xfff703000
MPC adapter at 0xfff703100

On P5040:
MPC adapter at 0xffe118000
MPC adapter at 0xffe118100
MPC adapter at 0xffe119000
MPC adapter at 0xffe119100

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/i2c/busses/i2c-mpc.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
Jean Delvare - July 10, 2013, 7:30 p.m.
Hi Guenter,

On Wed, 10 Jul 2013 12:03:21 -0700, Guenter Roeck wrote:
> The I2C adapters on Freescale MPC107/824x/85xx/512x/52xx/83xx/86xx all
> have the same name "MPC adapter". Since I2C adapter numbers can change
> across reboots and even after loading/unloading an I2C bus master driver,
> adapter names have to be used to identify adapters and thus should be
> unique and well defined. Since this is not the case with this driver,
> it is difficult if not impossible to identify a specific adapter from
> user space on affected platforms.
> 
> To remedy the problem, use the adapter memory address as part of the
> adapter name.
> 
> With this patch, adapter names are:
> On P2020:
> MPC adapter at 0xfff703000
> MPC adapter at 0xfff703100
> 
> On P5040:
> MPC adapter at 0xffe118000
> MPC adapter at 0xffe118100
> MPC adapter at 0xffe119000
> MPC adapter at 0xffe119100
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  drivers/i2c/busses/i2c-mpc.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
> index 7607dc0..99acf63 100644
> --- a/drivers/i2c/busses/i2c-mpc.c
> +++ b/drivers/i2c/busses/i2c-mpc.c
> @@ -609,7 +609,6 @@ static const struct i2c_algorithm mpc_algo = {
>  
>  static struct i2c_adapter mpc_ops = {
>  	.owner = THIS_MODULE,
> -	.name = "MPC adapter",
>  	.algo = &mpc_algo,
>  	.timeout = HZ,
>  };
> @@ -623,6 +622,7 @@ static int fsl_i2c_probe(struct platform_device *op)
>  	u32 clock = MPC_I2C_CLOCK_LEGACY;
>  	int result = 0;
>  	int plen;
> +	struct resource res;
>  
>  	match = of_match_device(mpc_i2c_of_match, &op->dev);
>  	if (!match)
> @@ -682,6 +682,9 @@ static int fsl_i2c_probe(struct platform_device *op)
>  	platform_set_drvdata(op, i2c);
>  
>  	i2c->adap = mpc_ops;
> +	of_address_to_resource(op->dev.of_node, 0, &res);
> +	scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
> +		  "MPC adapter at 0x%llx", (unsigned long long)res.start);
>  	i2c_set_adapdata(&i2c->adap, i2c);
>  	i2c->adap.dev.parent = &op->dev;
>  	i2c->adap.dev.of_node = of_node_get(op->dev.of_node);

I'm not familiar with the i2c-mpc driver but the fix looks good to me.

Acked-by: Jean Delvare <khali@linux-fr.org>
Guenter Roeck - July 18, 2013, 9:34 p.m.
On Wed, Jul 10, 2013 at 12:03:21PM -0700, Guenter Roeck wrote:
> The I2C adapters on Freescale MPC107/824x/85xx/512x/52xx/83xx/86xx all
> have the same name "MPC adapter". Since I2C adapter numbers can change
> across reboots and even after loading/unloading an I2C bus master driver,
> adapter names have to be used to identify adapters and thus should be
> unique and well defined. Since this is not the case with this driver,
> it is difficult if not impossible to identify a specific adapter from
> user space on affected platforms.
> 
> To remedy the problem, use the adapter memory address as part of the
> adapter name.
> 
ping ... any comments on this patch ?

Thanks,
Guenter

> With this patch, adapter names are:
> On P2020:
> MPC adapter at 0xfff703000
> MPC adapter at 0xfff703100
> 
> On P5040:
> MPC adapter at 0xffe118000
> MPC adapter at 0xffe118100
> MPC adapter at 0xffe119000
> MPC adapter at 0xffe119100
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  drivers/i2c/busses/i2c-mpc.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
> index 7607dc0..99acf63 100644
> --- a/drivers/i2c/busses/i2c-mpc.c
> +++ b/drivers/i2c/busses/i2c-mpc.c
> @@ -609,7 +609,6 @@ static const struct i2c_algorithm mpc_algo = {
>  
>  static struct i2c_adapter mpc_ops = {
>  	.owner = THIS_MODULE,
> -	.name = "MPC adapter",
>  	.algo = &mpc_algo,
>  	.timeout = HZ,
>  };
> @@ -623,6 +622,7 @@ static int fsl_i2c_probe(struct platform_device *op)
>  	u32 clock = MPC_I2C_CLOCK_LEGACY;
>  	int result = 0;
>  	int plen;
> +	struct resource res;
>  
>  	match = of_match_device(mpc_i2c_of_match, &op->dev);
>  	if (!match)
> @@ -682,6 +682,9 @@ static int fsl_i2c_probe(struct platform_device *op)
>  	platform_set_drvdata(op, i2c);
>  
>  	i2c->adap = mpc_ops;
> +	of_address_to_resource(op->dev.of_node, 0, &res);
> +	scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
> +		  "MPC adapter at 0x%llx", (unsigned long long)res.start);
>  	i2c_set_adapdata(&i2c->adap, i2c);
>  	i2c->adap.dev.parent = &op->dev;
>  	i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
> -- 
> 1.7.9.7
> 
> 
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Guenter Roeck - Aug. 3, 2013, 2:31 p.m.
ping ... any comments/feedback on this patch ?

Thanks,
Guenter

On 07/10/2013 12:03 PM, Guenter Roeck wrote:
> The I2C adapters on Freescale MPC107/824x/85xx/512x/52xx/83xx/86xx all
> have the same name "MPC adapter". Since I2C adapter numbers can change
> across reboots and even after loading/unloading an I2C bus master driver,
> adapter names have to be used to identify adapters and thus should be
> unique and well defined. Since this is not the case with this driver,
> it is difficult if not impossible to identify a specific adapter from
> user space on affected platforms.
>
> To remedy the problem, use the adapter memory address as part of the
> adapter name.
>
> With this patch, adapter names are:
> On P2020:
> MPC adapter at 0xfff703000
> MPC adapter at 0xfff703100
>
> On P5040:
> MPC adapter at 0xffe118000
> MPC adapter at 0xffe118100
> MPC adapter at 0xffe119000
> MPC adapter at 0xffe119100
>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>   drivers/i2c/busses/i2c-mpc.c |    5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
> index 7607dc0..99acf63 100644
> --- a/drivers/i2c/busses/i2c-mpc.c
> +++ b/drivers/i2c/busses/i2c-mpc.c
> @@ -609,7 +609,6 @@ static const struct i2c_algorithm mpc_algo = {
>
>   static struct i2c_adapter mpc_ops = {
>   	.owner = THIS_MODULE,
> -	.name = "MPC adapter",
>   	.algo = &mpc_algo,
>   	.timeout = HZ,
>   };
> @@ -623,6 +622,7 @@ static int fsl_i2c_probe(struct platform_device *op)
>   	u32 clock = MPC_I2C_CLOCK_LEGACY;
>   	int result = 0;
>   	int plen;
> +	struct resource res;
>
>   	match = of_match_device(mpc_i2c_of_match, &op->dev);
>   	if (!match)
> @@ -682,6 +682,9 @@ static int fsl_i2c_probe(struct platform_device *op)
>   	platform_set_drvdata(op, i2c);
>
>   	i2c->adap = mpc_ops;
> +	of_address_to_resource(op->dev.of_node, 0, &res);
> +	scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
> +		  "MPC adapter at 0x%llx", (unsigned long long)res.start);
>   	i2c_set_adapdata(&i2c->adap, i2c);
>   	i2c->adap.dev.parent = &op->dev;
>   	i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
>

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Wolfram Sang - Aug. 7, 2013, 3:34 p.m.
On Wed, Jul 10, 2013 at 12:03:21PM -0700, Guenter Roeck wrote:
> The I2C adapters on Freescale MPC107/824x/85xx/512x/52xx/83xx/86xx all
> have the same name "MPC adapter". Since I2C adapter numbers can change
> across reboots and even after loading/unloading an I2C bus master driver,
> adapter names have to be used to identify adapters and thus should be
> unique and well defined. Since this is not the case with this driver,
> it is difficult if not impossible to identify a specific adapter from
> user space on affected platforms.
> 
> To remedy the problem, use the adapter memory address as part of the
> adapter name.
> 
> With this patch, adapter names are:
> On P2020:
> MPC adapter at 0xfff703000
> MPC adapter at 0xfff703100
> 
> On P5040:
> MPC adapter at 0xffe118000
> MPC adapter at 0xffe118100
> MPC adapter at 0xffe119000
> MPC adapter at 0xffe119100
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Applied to for-next, thanks!

Patch

diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 7607dc0..99acf63 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -609,7 +609,6 @@  static const struct i2c_algorithm mpc_algo = {
 
 static struct i2c_adapter mpc_ops = {
 	.owner = THIS_MODULE,
-	.name = "MPC adapter",
 	.algo = &mpc_algo,
 	.timeout = HZ,
 };
@@ -623,6 +622,7 @@  static int fsl_i2c_probe(struct platform_device *op)
 	u32 clock = MPC_I2C_CLOCK_LEGACY;
 	int result = 0;
 	int plen;
+	struct resource res;
 
 	match = of_match_device(mpc_i2c_of_match, &op->dev);
 	if (!match)
@@ -682,6 +682,9 @@  static int fsl_i2c_probe(struct platform_device *op)
 	platform_set_drvdata(op, i2c);
 
 	i2c->adap = mpc_ops;
+	of_address_to_resource(op->dev.of_node, 0, &res);
+	scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
+		  "MPC adapter at 0x%llx", (unsigned long long)res.start);
 	i2c_set_adapdata(&i2c->adap, i2c);
 	i2c->adap.dev.parent = &op->dev;
 	i2c->adap.dev.of_node = of_node_get(op->dev.of_node);