diff mbox series

[v4,2/5] iio: temperature: tmp117: improve fallback capabilities

Message ID 20230220122552.925216-3-m.felsch@pengutronix.de (mailing list archive)
State Changes Requested
Headers show
Series Add TI TMP116 Support | expand

Commit Message

Marco Felsch Feb. 20, 2023, 12:25 p.m. UTC
Don't error if the device-id found don't match the device-id for the
TMP117 sensor since other TMPxxx might be compatible to the TMP117. The
fallback mechanism tries to gather the required information from the
of_device_id or from the i2c_client information.

The commit also prepares the driver for adding new devices more easily
by making use of switch-case at the relevant parts.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
v4:
- new patch to implement possible fallback (Jonathan)

 drivers/iio/temperature/tmp117.c | 67 +++++++++++++++++++++-----------
 1 file changed, 44 insertions(+), 23 deletions(-)

Comments

Jonathan Cameron Feb. 26, 2023, 1:07 p.m. UTC | #1
On Mon, 20 Feb 2023 13:25:49 +0100
Marco Felsch <m.felsch@pengutronix.de> wrote:

> Don't error if the device-id found don't match the device-id for the
> TMP117 sensor since other TMPxxx might be compatible to the TMP117. The
> fallback mechanism tries to gather the required information from the
> of_device_id or from the i2c_client information.
> 
> The commit also prepares the driver for adding new devices more easily
> by making use of switch-case at the relevant parts.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Hi Marco,

Thanks for doing this.  A small things inline.

> ---
> v4:
> - new patch to implement possible fallback (Jonathan)
> 
>  drivers/iio/temperature/tmp117.c | 67 +++++++++++++++++++++-----------
>  1 file changed, 44 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c
> index f9b8f2b570f6b..4ddb8cf9a29ab 100644
> --- a/drivers/iio/temperature/tmp117.c
> +++ b/drivers/iio/temperature/tmp117.c
> @@ -16,6 +16,7 @@
>  #include <linux/types.h>
>  #include <linux/kernel.h>
>  #include <linux/limits.h>
> +#include <linux/property.h>
>  
>  #include <linux/iio/iio.h>
>  
> @@ -113,32 +114,60 @@ static const struct iio_info tmp117_info = {
>  	.write_raw = tmp117_write_raw,
>  };
>  
> +static const struct of_device_id tmp117_of_match[] = {
> +	{ .compatible = "ti,tmp117", .data = (void *)TMP117_DEVICE_ID },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, tmp117_of_match);
> +
> +static const struct i2c_device_id tmp117_id[] = {
> +	{ "tmp117", TMP117_DEVICE_ID },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, tmp117_id);

As below.  There is an easy way to avoid having to move these.

> +
>  static int tmp117_identify(struct i2c_client *client)
>  {
> +	unsigned long match_data;
>  	int dev_id;
>  
>  	dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
>  	if (dev_id < 0)
>  		return dev_id;
> -	if (dev_id != TMP117_DEVICE_ID) {
> -		dev_err(&client->dev, "TMP117 not found\n");
> -		return -ENODEV;
> +
> +	switch (dev_id) {
> +	case TMP117_DEVICE_ID:
> +		return dev_id;
>  	}
> -	return 0;
> +
> +	dev_info(&client->dev, "Unknown device id (0x%x), use fallback compatible\n",
> +		 dev_id);
> +
> +	match_data = (uintptr_t)device_get_match_data(&client->dev);
> +	if (match_data)
> +		return match_data;
> +
> +	match_data = i2c_match_id(tmp117_id, client)->driver_data;

Whilst correct, i2c_client_get_device_id() avoids the need
to move tmp117_id up to where you have by getting to that table via
the driver structure. That will simplify this patch a fair bit.

> +	if (match_data)
> +		return match_data;
> +
> +	dev_err(&client->dev, "error: No valid fallback found\n");

This is a little misleading as fallback only applies to the device tree
path.  Also, not a lot of point in putting error in the text of
a dev_err.  Perhaps just "Unsupported device".


> +
> +	return -ENODEV;
>  }
>  
>  static int tmp117_probe(struct i2c_client *client)
>  {
>  	struct tmp117_data *data;
>  	struct iio_dev *indio_dev;
> -	int ret;
> +	int dev_id;
>  
>  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
>  		return -EOPNOTSUPP;
>  
> -	ret = tmp117_identify(client);
> -	if (ret < 0)
> -		return ret;
> +	dev_id = tmp117_identify(client);
> +	if (dev_id < 0)
> +		return dev_id;

I'd keep it in ret until you know it's good.  Reduces churn and is nicer
code in general, though one more line.

	dev_id = ret;

>  
>  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>  	if (!indio_dev)
> @@ -148,28 +177,20 @@ static int tmp117_probe(struct i2c_client *client)
>  	data->client = client;
>  	data->calibbias = 0;
>  
> -	indio_dev->name = "tmp117";
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->info = &tmp117_info;
>  
> -	indio_dev->channels = tmp117_channels;
> -	indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> +	switch (dev_id) {
> +	case TMP117_DEVICE_ID:
> +		indio_dev->channels = tmp117_channels;
> +		indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> +		indio_dev->name = "tmp117";
> +		break;
> +	}
>  
>  	return devm_iio_device_register(&client->dev, indio_dev);
>  }
>  
> -static const struct of_device_id tmp117_of_match[] = {
> -	{ .compatible = "ti,tmp117", },
> -	{ }
> -};
> -MODULE_DEVICE_TABLE(of, tmp117_of_match);
> -
> -static const struct i2c_device_id tmp117_id[] = {
> -	{ "tmp117", 0 },
> -	{ }
> -};
> -MODULE_DEVICE_TABLE(i2c, tmp117_id);
> -
>  static struct i2c_driver tmp117_driver = {
>  	.driver = {
>  		.name	= "tmp117",
Marco Felsch Feb. 27, 2023, 6:44 p.m. UTC | #2
Hi Jonathan,

On 23-02-26, Jonathan Cameron wrote:
> On Mon, 20 Feb 2023 13:25:49 +0100
> Marco Felsch <m.felsch@pengutronix.de> wrote:
> 
> > Don't error if the device-id found don't match the device-id for the
> > TMP117 sensor since other TMPxxx might be compatible to the TMP117. The
> > fallback mechanism tries to gather the required information from the
> > of_device_id or from the i2c_client information.
> > 
> > The commit also prepares the driver for adding new devices more easily
> > by making use of switch-case at the relevant parts.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> Hi Marco,
> 
> Thanks for doing this.  A small things inline.

please see my comments below.

> > ---
> > v4:
> > - new patch to implement possible fallback (Jonathan)
> > 
> >  drivers/iio/temperature/tmp117.c | 67 +++++++++++++++++++++-----------
> >  1 file changed, 44 insertions(+), 23 deletions(-)
> > 
> > diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c
> > index f9b8f2b570f6b..4ddb8cf9a29ab 100644
> > --- a/drivers/iio/temperature/tmp117.c
> > +++ b/drivers/iio/temperature/tmp117.c
> > @@ -16,6 +16,7 @@
> >  #include <linux/types.h>
> >  #include <linux/kernel.h>
> >  #include <linux/limits.h>
> > +#include <linux/property.h>
> >  
> >  #include <linux/iio/iio.h>
> >  
> > @@ -113,32 +114,60 @@ static const struct iio_info tmp117_info = {
> >  	.write_raw = tmp117_write_raw,
> >  };
> >  
> > +static const struct of_device_id tmp117_of_match[] = {
> > +	{ .compatible = "ti,tmp117", .data = (void *)TMP117_DEVICE_ID },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, tmp117_of_match);
> > +
> > +static const struct i2c_device_id tmp117_id[] = {
> > +	{ "tmp117", TMP117_DEVICE_ID },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, tmp117_id);
> 
> As below.  There is an easy way to avoid having to move these.
> 
> > +
> >  static int tmp117_identify(struct i2c_client *client)
> >  {
> > +	unsigned long match_data;
> >  	int dev_id;
> >  
> >  	dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
> >  	if (dev_id < 0)
> >  		return dev_id;
> > -	if (dev_id != TMP117_DEVICE_ID) {
> > -		dev_err(&client->dev, "TMP117 not found\n");
> > -		return -ENODEV;
> > +
> > +	switch (dev_id) {
> > +	case TMP117_DEVICE_ID:
> > +		return dev_id;
> >  	}
> > -	return 0;
> > +
> > +	dev_info(&client->dev, "Unknown device id (0x%x), use fallback compatible\n",
> > +		 dev_id);
> > +
> > +	match_data = (uintptr_t)device_get_match_data(&client->dev);
> > +	if (match_data)
> > +		return match_data;
> > +
> > +	match_data = i2c_match_id(tmp117_id, client)->driver_data;
> 
> Whilst correct, i2c_client_get_device_id() avoids the need
> to move tmp117_id up to where you have by getting to that table via
> the driver structure. That will simplify this patch a fair bit.
> 
> > +	if (match_data)
> > +		return match_data;
> > +
> > +	dev_err(&client->dev, "error: No valid fallback found\n");
> 
> This is a little misleading as fallback only applies to the device tree
> path. 

Since we support the i2c_device_id table as well, this is not 100% true.

> Also, not a lot of point in putting error in the text of
> a dev_err.  Perhaps just "Unsupported device".

dev_err() does not print a error on the commandline. If something went
wrong I tend to "dmesg|grep -i err" or "dmesg|grep -i fail". Therefore I
added the error keyword here. But I can change the message to "Error:
unsupported device" if this is okay for you.

Regards,
  Marco

> > +
> > +	return -ENODEV;
> >  }
> >  
> >  static int tmp117_probe(struct i2c_client *client)
> >  {
> >  	struct tmp117_data *data;
> >  	struct iio_dev *indio_dev;
> > -	int ret;
> > +	int dev_id;
> >  
> >  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
> >  		return -EOPNOTSUPP;
> >  
> > -	ret = tmp117_identify(client);
> > -	if (ret < 0)
> > -		return ret;
> > +	dev_id = tmp117_identify(client);
> > +	if (dev_id < 0)
> > +		return dev_id;
> 
> I'd keep it in ret until you know it's good.  Reduces churn and is nicer
> code in general, though one more line.
> 
> 	dev_id = ret;
> 
> >  
> >  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> >  	if (!indio_dev)
> > @@ -148,28 +177,20 @@ static int tmp117_probe(struct i2c_client *client)
> >  	data->client = client;
> >  	data->calibbias = 0;
> >  
> > -	indio_dev->name = "tmp117";
> >  	indio_dev->modes = INDIO_DIRECT_MODE;
> >  	indio_dev->info = &tmp117_info;
> >  
> > -	indio_dev->channels = tmp117_channels;
> > -	indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> > +	switch (dev_id) {
> > +	case TMP117_DEVICE_ID:
> > +		indio_dev->channels = tmp117_channels;
> > +		indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> > +		indio_dev->name = "tmp117";
> > +		break;
> > +	}
> >  
> >  	return devm_iio_device_register(&client->dev, indio_dev);
> >  }
> >  
> > -static const struct of_device_id tmp117_of_match[] = {
> > -	{ .compatible = "ti,tmp117", },
> > -	{ }
> > -};
> > -MODULE_DEVICE_TABLE(of, tmp117_of_match);
> > -
> > -static const struct i2c_device_id tmp117_id[] = {
> > -	{ "tmp117", 0 },
> > -	{ }
> > -};
> > -MODULE_DEVICE_TABLE(i2c, tmp117_id);
> > -
> >  static struct i2c_driver tmp117_driver = {
> >  	.driver = {
> >  		.name	= "tmp117",
> 
>
Jonathan Cameron March 4, 2023, 1:13 p.m. UTC | #3
On Mon, 27 Feb 2023 19:44:57 +0100
Marco Felsch <m.felsch@pengutronix.de> wrote:

> Hi Jonathan,
> 
> On 23-02-26, Jonathan Cameron wrote:
> > On Mon, 20 Feb 2023 13:25:49 +0100
> > Marco Felsch <m.felsch@pengutronix.de> wrote:
> >   
> > > Don't error if the device-id found don't match the device-id for the
> > > TMP117 sensor since other TMPxxx might be compatible to the TMP117. The
> > > fallback mechanism tries to gather the required information from the
> > > of_device_id or from the i2c_client information.
> > > 
> > > The commit also prepares the driver for adding new devices more easily
> > > by making use of switch-case at the relevant parts.
> > > 
> > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>  
> > Hi Marco,
> > 
> > Thanks for doing this.  A small things inline.  
> 
> please see my comments below.
> 
> > > ---
> > > v4:
> > > - new patch to implement possible fallback (Jonathan)
> > > 
> > >  drivers/iio/temperature/tmp117.c | 67 +++++++++++++++++++++-----------
> > >  1 file changed, 44 insertions(+), 23 deletions(-)
> > > 
> > > diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c
> > > index f9b8f2b570f6b..4ddb8cf9a29ab 100644
> > > --- a/drivers/iio/temperature/tmp117.c
> > > +++ b/drivers/iio/temperature/tmp117.c
> > > @@ -16,6 +16,7 @@
> > >  #include <linux/types.h>
> > >  #include <linux/kernel.h>
> > >  #include <linux/limits.h>
> > > +#include <linux/property.h>
> > >  
> > >  #include <linux/iio/iio.h>
> > >  
> > > @@ -113,32 +114,60 @@ static const struct iio_info tmp117_info = {
> > >  	.write_raw = tmp117_write_raw,
> > >  };
> > >  
> > > +static const struct of_device_id tmp117_of_match[] = {
> > > +	{ .compatible = "ti,tmp117", .data = (void *)TMP117_DEVICE_ID },
> > > +	{ }
> > > +};
> > > +MODULE_DEVICE_TABLE(of, tmp117_of_match);
> > > +
> > > +static const struct i2c_device_id tmp117_id[] = {
> > > +	{ "tmp117", TMP117_DEVICE_ID },
> > > +	{ }
> > > +};
> > > +MODULE_DEVICE_TABLE(i2c, tmp117_id);  
> > 
> > As below.  There is an easy way to avoid having to move these.
> >   
> > > +
> > >  static int tmp117_identify(struct i2c_client *client)
> > >  {
> > > +	unsigned long match_data;
> > >  	int dev_id;
> > >  
> > >  	dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
> > >  	if (dev_id < 0)
> > >  		return dev_id;
> > > -	if (dev_id != TMP117_DEVICE_ID) {
> > > -		dev_err(&client->dev, "TMP117 not found\n");
> > > -		return -ENODEV;
> > > +
> > > +	switch (dev_id) {
> > > +	case TMP117_DEVICE_ID:
> > > +		return dev_id;
> > >  	}
> > > -	return 0;
> > > +
> > > +	dev_info(&client->dev, "Unknown device id (0x%x), use fallback compatible\n",
> > > +		 dev_id);
> > > +
> > > +	match_data = (uintptr_t)device_get_match_data(&client->dev);
> > > +	if (match_data)
> > > +		return match_data;
> > > +
> > > +	match_data = i2c_match_id(tmp117_id, client)->driver_data;  
> > 
> > Whilst correct, i2c_client_get_device_id() avoids the need
> > to move tmp117_id up to where you have by getting to that table via
> > the driver structure. That will simplify this patch a fair bit.
> >   
> > > +	if (match_data)
> > > +		return match_data;
> > > +
> > > +	dev_err(&client->dev, "error: No valid fallback found\n");  
> > 
> > This is a little misleading as fallback only applies to the device tree
> > path.   
> 
> Since we support the i2c_device_id table as well, this is not 100% true.

I guess it's semantics, but the error message implies that a fallback is
possible.  That only exists for one of the possible paths, all of which
failed to get to here.  Hence suggestion of more generic message.

> 
> > Also, not a lot of point in putting error in the text of
> > a dev_err.  Perhaps just "Unsupported device".  
> 
> dev_err() does not print a error on the commandline. If something went
> wrong I tend to "dmesg|grep -i err" or "dmesg|grep -i fail". Therefore I
> added the error keyword here. But I can change the message to "Error:
> unsupported device" if this is okay for you.

Ok. I guess I was assuming some parsing that used the log level.

> 
> Regards,
>   Marco
> 
> > > +
> > > +	return -ENODEV;
> > >  }
> > >  
> > >  static int tmp117_probe(struct i2c_client *client)
> > >  {
> > >  	struct tmp117_data *data;
> > >  	struct iio_dev *indio_dev;
> > > -	int ret;
> > > +	int dev_id;
> > >  
> > >  	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
> > >  		return -EOPNOTSUPP;
> > >  
> > > -	ret = tmp117_identify(client);
> > > -	if (ret < 0)
> > > -		return ret;
> > > +	dev_id = tmp117_identify(client);
> > > +	if (dev_id < 0)
> > > +		return dev_id;  
> > 
> > I'd keep it in ret until you know it's good.  Reduces churn and is nicer
> > code in general, though one more line.
> > 
> > 	dev_id = ret;
> >   
> > >  
> > >  	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> > >  	if (!indio_dev)
> > > @@ -148,28 +177,20 @@ static int tmp117_probe(struct i2c_client *client)
> > >  	data->client = client;
> > >  	data->calibbias = 0;
> > >  
> > > -	indio_dev->name = "tmp117";
> > >  	indio_dev->modes = INDIO_DIRECT_MODE;
> > >  	indio_dev->info = &tmp117_info;
> > >  
> > > -	indio_dev->channels = tmp117_channels;
> > > -	indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> > > +	switch (dev_id) {
> > > +	case TMP117_DEVICE_ID:
> > > +		indio_dev->channels = tmp117_channels;
> > > +		indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
> > > +		indio_dev->name = "tmp117";
> > > +		break;
> > > +	}
> > >  
> > >  	return devm_iio_device_register(&client->dev, indio_dev);
> > >  }
> > >  
> > > -static const struct of_device_id tmp117_of_match[] = {
> > > -	{ .compatible = "ti,tmp117", },
> > > -	{ }
> > > -};
> > > -MODULE_DEVICE_TABLE(of, tmp117_of_match);
> > > -
> > > -static const struct i2c_device_id tmp117_id[] = {
> > > -	{ "tmp117", 0 },
> > > -	{ }
> > > -};
> > > -MODULE_DEVICE_TABLE(i2c, tmp117_id);
> > > -
> > >  static struct i2c_driver tmp117_driver = {
> > >  	.driver = {
> > >  		.name	= "tmp117",  
> > 
> >
diff mbox series

Patch

diff --git a/drivers/iio/temperature/tmp117.c b/drivers/iio/temperature/tmp117.c
index f9b8f2b570f6b..4ddb8cf9a29ab 100644
--- a/drivers/iio/temperature/tmp117.c
+++ b/drivers/iio/temperature/tmp117.c
@@ -16,6 +16,7 @@ 
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/limits.h>
+#include <linux/property.h>
 
 #include <linux/iio/iio.h>
 
@@ -113,32 +114,60 @@  static const struct iio_info tmp117_info = {
 	.write_raw = tmp117_write_raw,
 };
 
+static const struct of_device_id tmp117_of_match[] = {
+	{ .compatible = "ti,tmp117", .data = (void *)TMP117_DEVICE_ID },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tmp117_of_match);
+
+static const struct i2c_device_id tmp117_id[] = {
+	{ "tmp117", TMP117_DEVICE_ID },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tmp117_id);
+
 static int tmp117_identify(struct i2c_client *client)
 {
+	unsigned long match_data;
 	int dev_id;
 
 	dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
 	if (dev_id < 0)
 		return dev_id;
-	if (dev_id != TMP117_DEVICE_ID) {
-		dev_err(&client->dev, "TMP117 not found\n");
-		return -ENODEV;
+
+	switch (dev_id) {
+	case TMP117_DEVICE_ID:
+		return dev_id;
 	}
-	return 0;
+
+	dev_info(&client->dev, "Unknown device id (0x%x), use fallback compatible\n",
+		 dev_id);
+
+	match_data = (uintptr_t)device_get_match_data(&client->dev);
+	if (match_data)
+		return match_data;
+
+	match_data = i2c_match_id(tmp117_id, client)->driver_data;
+	if (match_data)
+		return match_data;
+
+	dev_err(&client->dev, "error: No valid fallback found\n");
+
+	return -ENODEV;
 }
 
 static int tmp117_probe(struct i2c_client *client)
 {
 	struct tmp117_data *data;
 	struct iio_dev *indio_dev;
-	int ret;
+	int dev_id;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 		return -EOPNOTSUPP;
 
-	ret = tmp117_identify(client);
-	if (ret < 0)
-		return ret;
+	dev_id = tmp117_identify(client);
+	if (dev_id < 0)
+		return dev_id;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev)
@@ -148,28 +177,20 @@  static int tmp117_probe(struct i2c_client *client)
 	data->client = client;
 	data->calibbias = 0;
 
-	indio_dev->name = "tmp117";
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &tmp117_info;
 
-	indio_dev->channels = tmp117_channels;
-	indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
+	switch (dev_id) {
+	case TMP117_DEVICE_ID:
+		indio_dev->channels = tmp117_channels;
+		indio_dev->num_channels = ARRAY_SIZE(tmp117_channels);
+		indio_dev->name = "tmp117";
+		break;
+	}
 
 	return devm_iio_device_register(&client->dev, indio_dev);
 }
 
-static const struct of_device_id tmp117_of_match[] = {
-	{ .compatible = "ti,tmp117", },
-	{ }
-};
-MODULE_DEVICE_TABLE(of, tmp117_of_match);
-
-static const struct i2c_device_id tmp117_id[] = {
-	{ "tmp117", 0 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, tmp117_id);
-
 static struct i2c_driver tmp117_driver = {
 	.driver = {
 		.name	= "tmp117",