[PATCH 1/1] iio: light: vcnl4035: fixed chip ID check

[PATCH 1/1] iio: light: vcnl4035: fixed chip ID check

[Frank Li]

VCNL4035 register(0xE) ID_L and ID_M define as:

 ID_L: 0x80
 ID_H: 7:6 (0:0)
       5:4 (0:0) slave address = 0x60 (7-bit)
           (0:1) slave address = 0x51 (7-bit)
           (1:0) slave address = 0x40 (7-bit)
           (1:0) slave address = 0x41 (7-bit)
       3:0 Version code default	(0:0:0:0)

So just check ID_L.

Fixes: 55707294c4eb ("iio: light: Add support for vishay vcnl4035")

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/iio/light/vcnl4035.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/light/vcnl4035.c b/drivers/iio/light/vcnl4035.c
index 3ed37f6057fb..8b7769930f3b 100644
--- a/drivers/iio/light/vcnl4035.c
+++ b/drivers/iio/light/vcnl4035.c
@@ -413,7 +413,7 @@ static int vcnl4035_init(struct vcnl4035_data *data)
 		return ret;
 	}
 
-	if (id != VCNL4035_DEV_ID_VAL) {
+	if ((id & 0xff) != VCNL4035_DEV_ID_VAL) {
 		dev_err(&data->client->dev, "Wrong id, got %x, expected %x\n",
 			id, VCNL4035_DEV_ID_VAL);
 		return -ENODEV;
-- 
2.34.1

Re: [PATCH 1/1] iio: light: vcnl4035: fixed chip ID check

[Jonathan Cameron]

On Thu, 27 Apr 2023 17:30:37 -0400
Frank Li <Frank.Li@nxp.com> wrote:

> VCNL4035 register(0xE) ID_L and ID_M define as:
> 
>  ID_L: 0x80
>  ID_H: 7:6 (0:0)
>        5:4 (0:0) slave address = 0x60 (7-bit)
>            (0:1) slave address = 0x51 (7-bit)
>            (1:0) slave address = 0x40 (7-bit)
>            (1:0) slave address = 0x41 (7-bit)
>        3:0 Version code default	(0:0:0:0)
> 
> So just check ID_L.

Hi Frank,

Thanks for the fix. A few minor things inline.

> 
> Fixes: 55707294c4eb ("iio: light: Add support for vishay vcnl4035")
> 

No blank line here as the Fixes tag is part of the main tag block.

> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Just to check, the result of this bug is that the driver probe fails
if the slave address isn't 0x60?

> ---
>  drivers/iio/light/vcnl4035.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/light/vcnl4035.c b/drivers/iio/light/vcnl4035.c
> index 3ed37f6057fb..8b7769930f3b 100644
> --- a/drivers/iio/light/vcnl4035.c
> +++ b/drivers/iio/light/vcnl4035.c
> @@ -413,7 +413,7 @@ static int vcnl4035_init(struct vcnl4035_data *data)
>  		return ret;
>  	}
>  
> -	if (id != VCNL4035_DEV_ID_VAL) {
> +	if ((id & 0xff) != VCNL4035_DEV_ID_VAL) {

Please add a define for that 0xff mask and perhaps also use
FIELD_GET() to extract the field for comparison with VCNL4035_DEV_ID_VAL.
Whilst that isn't being done elsewhere in this driver, the heavy use
of set bits means it isn't appropriate anywhere else that I can quickly
identify. You'll also need to include linux/bitfield.h if making that change.

Thanks,

Jonathan

>  		dev_err(&data->client->dev, "Wrong id, got %x, expected %x\n",
>  			id, VCNL4035_DEV_ID_VAL);
>  		return -ENODEV;

RE: [EXT] Re: [PATCH 1/1] iio: light: vcnl4035: fixed chip ID check

[Frank Li]

> -----Original Message-----
> From: Jonathan Cameron <jic23@kernel.org>
> Sent: Sunday, April 30, 2023 12:23 PM
> To: Frank Li <frank.li@nxp.com>
> Cc: Lars-Peter Clausen <lars@metafoo.de>; Uwe Kleine-König <u.kleine-
> koenig@pengutronix.de>; Petr Machata <petrm@nvidia.com>; Heikki
> Krogerus <heikki.krogerus@linux.intel.com>; Jean Delvare
> <jdelvare@suse.de>; Andy Shevchenko
> <andriy.shevchenko@linux.intel.com>; Parthiban Nallathambi
> <pn@denx.de>; open list:IIO SUBSYSTEM AND DRIVERS <linux-
> iio@vger.kernel.org>; open list <linux-kernel@vger.kernel.org>;
> imx@lists.linux.dev
> Subject: [EXT] Re: [PATCH 1/1] iio: light: vcnl4035: fixed chip ID check
> 
> Caution: This is an external email. Please take care when clicking links or
> opening attachments. When in doubt, report the message using the 'Report
> this email' button
> 
> 
> On Thu, 27 Apr 2023 17:30:37 -0400
> Frank Li <Frank.Li@nxp.com> wrote:
> 
> > VCNL4035 register(0xE) ID_L and ID_M define as:
> >
> >  ID_L: 0x80
> >  ID_H: 7:6 (0:0)
> >        5:4 (0:0) slave address = 0x60 (7-bit)
> >            (0:1) slave address = 0x51 (7-bit)
> >            (1:0) slave address = 0x40 (7-bit)
> >            (1:0) slave address = 0x41 (7-bit)
> >        3:0 Version code default       (0:0:0:0)
> >
> > So just check ID_L.
> 
> Hi Frank,
> 
> Thanks for the fix. A few minor things inline.
> 
> >
> > Fixes: 55707294c4eb ("iio: light: Add support for vishay vcnl4035")
> >
> 
> No blank line here as the Fixes tag is part of the main tag block.
> 
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> 
> Just to check, the result of this bug is that the driver probe fails
> if the slave address isn't 0x60?

Yes, I get chip which slave address = 0x51. 
I will update patch soon.

> 
> > ---
> >  drivers/iio/light/vcnl4035.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/iio/light/vcnl4035.c b/drivers/iio/light/vcnl4035.c
> > index 3ed37f6057fb..8b7769930f3b 100644
> > --- a/drivers/iio/light/vcnl4035.c
> > +++ b/drivers/iio/light/vcnl4035.c
> > @@ -413,7 +413,7 @@ static int vcnl4035_init(struct vcnl4035_data *data)
> >               return ret;
> >       }
> >
> > -     if (id != VCNL4035_DEV_ID_VAL) {
> > +     if ((id & 0xff) != VCNL4035_DEV_ID_VAL) {
> 
> Please add a define for that 0xff mask and perhaps also use
> FIELD_GET() to extract the field for comparison with VCNL4035_DEV_ID_VAL.
> Whilst that isn't being done elsewhere in this driver, the heavy use
> of set bits means it isn't appropriate anywhere else that I can quickly
> identify. You'll also need to include linux/bitfield.h if making that change.
> 
> Thanks,
> 
> Jonathan
> 
> >               dev_err(&data->client->dev, "Wrong id, got %x, expected %x\n",
> >                       id, VCNL4035_DEV_ID_VAL);
> >               return -ENODEV;

Re: [PATCH 1/1] iio: light: vcnl4035: fixed chip ID check

[Christophe JAILLET]

Le 27/04/2023 à 23:30, Frank Li a écrit :
> VCNL4035 register(0xE) ID_L and ID_M define as:
> 
>   ID_L: 0x80
>   ID_H: 7:6 (0:0)
>         5:4 (0:0) slave address = 0x60 (7-bit)
>             (0:1) slave address = 0x51 (7-bit)
>             (1:0) slave address = 0x40 (7-bit)
>             (1:0) slave address = 0x41 (7-bit)
>         3:0 Version code default	(0:0:0:0)
> 
> So just check ID_L.
> 
> Fixes: 55707294c4eb ("iio: light: Add support for vishay vcnl4035")
> 
> Signed-off-by: Frank Li <Frank.Li-3arQi8VN3Tc@public.gmane.org>
> ---
>   drivers/iio/light/vcnl4035.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/light/vcnl4035.c b/drivers/iio/light/vcnl4035.c
> index 3ed37f6057fb..8b7769930f3b 100644
> --- a/drivers/iio/light/vcnl4035.c
> +++ b/drivers/iio/light/vcnl4035.c
> @@ -413,7 +413,7 @@ static int vcnl4035_init(struct vcnl4035_data *data)
>   		return ret;
>   	}
>   
> -	if (id != VCNL4035_DEV_ID_VAL) {
> +	if ((id & 0xff) != VCNL4035_DEV_ID_VAL) {
>   		dev_err(&data->client->dev, "Wrong id, got %x, expected %x\n",
>   			id, VCNL4035_DEV_ID_VAL);

Hi,
should the error message be updated as well?

Cj

>   		return -ENODEV;