Re: [PATCH v2 1/6] iio: imu: inv_mpu6050: cleanup of/acpi support

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Thu, 6 Feb 2020 11:51:55 +0000
Jonathan Cameron <jic23@kernel.org> wrote:

> On Thu,  6 Feb 2020 11:31:00 +0100
> Jean-Baptiste Maneyrol <jmaneyrol@invensense.com> wrote:
> 
> > Use device_get_match_data for using of and acpi tables.
> > In spi support add missing mpu6515 and of match table.
> > Reorganize Kconfig to display chips grouped by generations.
> > 
> > Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>  
> Great.
> 
> Applied to the togreg branch of iio.git.  Clearly I took this
> one very quickly after posting, but note it's not in a non rebasing
> tree so I can still change that if anyone else has comments!
> 

I happened to be looking at the code this affects for an entirely
different reason and realized there is a problem...

> Thanks
> 
> Jonathan
> 
> > ---
> >  drivers/iio/imu/inv_mpu6050/Kconfig       |  8 ++---
> >  drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c | 26 +++-----------
> >  drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c | 44 +++++++++++++++++++++--
> >  3 files changed, 50 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/iio/imu/inv_mpu6050/Kconfig b/drivers/iio/imu/inv_mpu6050/Kconfig
> > index 017bc0fcc365..003134734646 100644
> > --- a/drivers/iio/imu/inv_mpu6050/Kconfig
> > +++ b/drivers/iio/imu/inv_mpu6050/Kconfig
> > @@ -15,8 +15,8 @@ config INV_MPU6050_I2C
> >  	select INV_MPU6050_IIO
> >  	select REGMAP_I2C
> >  	help
> > -	  This driver supports the Invensense MPU6050/6500/6515,
> > -	  MPU9150/9250/9255 and ICM20608/20602 motion tracking devices
> > +	  This driver supports the Invensense MPU6050/9150,
> > +	  MPU6500/6515/9250/9255, ICM20608 and ICM20602 motion tracking devices
> >  	  over I2C.
> >  	  This driver can be built as a module. The module will be called
> >  	  inv-mpu6050-i2c.
> > @@ -27,8 +27,8 @@ config INV_MPU6050_SPI
> >  	select INV_MPU6050_IIO
> >  	select REGMAP_SPI
> >  	help
> > -	  This driver supports the Invensense MPU6000/6500/6515,
> > -	  MPU9250/9255 and ICM20608/20602 motion tracking devices
> > +	  This driver supports the Invensense MPU6000,
> > +	  MPU6500/6515/9250/9255, ICM20608 and ICM20602 motion tracking devices
> >  	  over SPI.
> >  	  This driver can be built as a module. The module will be called
> >  	  inv-mpu6050-spi.
> > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c
> > index f47a28b4be23..49e9aa777ba4 100644
> > --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c
> > +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c
> > @@ -10,6 +10,7 @@
> >  #include <linux/iio/iio.h>
> >  #include <linux/module.h>
> >  #include <linux/of_device.h>
> > +#include <linux/property.h>
> >  #include "inv_mpu_iio.h"
> >  
> >  static const struct regmap_config inv_mpu_regmap_config = {
> > @@ -54,20 +55,6 @@ static int inv_mpu6050_deselect_bypass(struct i2c_mux_core *muxc, u32 chan_id)
> >  	return 0;
> >  }
> >  
> > -static const char *inv_mpu_match_acpi_device(struct device *dev,
> > -					     enum inv_devices *chip_id)
> > -{
> > -	const struct acpi_device_id *id;
> > -
> > -	id = acpi_match_device(dev->driver->acpi_match_table, dev);
> > -	if (!id)
> > -		return NULL;
> > -
> > -	*chip_id = (int)id->driver_data;
> > -
> > -	return dev_name(dev);
> > -}
> > -
> >  static bool inv_mpu_i2c_aux_bus(struct device *dev)
> >  {
> >  	struct inv_mpu6050_state *st = iio_priv(dev_get_drvdata(dev));
> > @@ -130,6 +117,7 @@ static int inv_mpu_magn_disable(struct iio_dev *indio_dev)
> >  static int inv_mpu_probe(struct i2c_client *client,
> >  			 const struct i2c_device_id *id)
> >  {
> > +	const void *match;
> >  	struct inv_mpu6050_state *st;
> >  	int result;
> >  	enum inv_devices chip_type;
> > @@ -140,18 +128,14 @@ static int inv_mpu_probe(struct i2c_client *client,
> >  				     I2C_FUNC_SMBUS_I2C_BLOCK))
> >  		return -EOPNOTSUPP;
> >  
> > -	if (client->dev.of_node) {
> > -		chip_type = (enum inv_devices)
> > -			of_device_get_match_data(&client->dev);
> > +	match = device_get_match_data(&client->dev);
> > +	if (match) {

Unfortunately, chip_type == 0 and hence match == NULL doesn't 
necessarily mean no match... It might mean the enum value was
0 which is the case for INV_MPU6050

For the of case, we probably get away with it because
id->driver_data will be set anyway but I don't think that was what
was intended.

Fixes are all a bit mess.  Simplest might be to add a check of
dev_fwnode() to verify if there is a firmware node or not and
then use the match value form device_get_match_data without checking
it against 0.

Jonathan
> > +		chip_type = (enum inv_devices)match;
> >  		name = client->name;
> >  	} else if (id) {
> >  		chip_type = (enum inv_devices)
> >  			id->driver_data;
> >  		name = id->name;
> > -	} else if (ACPI_HANDLE(&client->dev)) {
> > -		name = inv_mpu_match_acpi_device(&client->dev, &chip_type);
> > -		if (!name)
> > -			return -ENODEV;
> >  	} else {
> >  		return -ENOSYS;
> >  	}
> > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c
> > index ec102d5a5c77..834bfa8e8684 100644
> > --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c
> > +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c
> > @@ -4,6 +4,8 @@
> >  */
> >  #include <linux/module.h>
> >  #include <linux/acpi.h>
> > +#include <linux/of.h>
> > +#include <linux/property.h>
> >  #include <linux/spi/spi.h>
> >  #include <linux/regmap.h>
> >  #include <linux/iio/iio.h>
> > @@ -41,17 +43,18 @@ static int inv_mpu_i2c_disable(struct iio_dev *indio_dev)
> >  
> >  static int inv_mpu_probe(struct spi_device *spi)
> >  {
> > +	const void *match;
> >  	struct regmap *regmap;
> >  	const struct spi_device_id *spi_id;
> > -	const struct acpi_device_id *acpi_id;
> >  	const char *name = NULL;
> >  	enum inv_devices chip_type;
> >  
> >  	if ((spi_id = spi_get_device_id(spi))) {
> >  		chip_type = (enum inv_devices)spi_id->driver_data;
> >  		name = spi_id->name;
> > -	} else if ((acpi_id = acpi_match_device(spi->dev.driver->acpi_match_table, &spi->dev))) {
> > -		chip_type = (enum inv_devices)acpi_id->driver_data;
> > +	} else if ((match = device_get_match_data(&spi->dev))) {
> > +		chip_type = (enum inv_devices)match;
> > +		name = dev_name(&spi->dev);
> >  	} else {
> >  		return -ENODEV;
> >  	}
> > @@ -74,6 +77,7 @@ static int inv_mpu_probe(struct spi_device *spi)
> >  static const struct spi_device_id inv_mpu_id[] = {
> >  	{"mpu6000", INV_MPU6000},
> >  	{"mpu6500", INV_MPU6500},
> > +	{"mpu6515", INV_MPU6515},
> >  	{"mpu9250", INV_MPU9250},
> >  	{"mpu9255", INV_MPU9255},
> >  	{"icm20608", INV_ICM20608},
> > @@ -83,6 +87,39 @@ static const struct spi_device_id inv_mpu_id[] = {
> >  
> >  MODULE_DEVICE_TABLE(spi, inv_mpu_id);
> >  
> > +static const struct of_device_id inv_of_match[] = {
> > +	{
> > +		.compatible = "invensense,mpu6000",
> > +		.data = (void *)INV_MPU6000
> > +	},
> > +	{
> > +		.compatible = "invensense,mpu6500",
> > +		.data = (void *)INV_MPU6500
> > +	},
> > +	{
> > +		.compatible = "invensense,mpu6515",
> > +		.data = (void *)INV_MPU6515
> > +	},
> > +	{
> > +		.compatible = "invensense,mpu9250",
> > +		.data = (void *)INV_MPU9250
> > +	},
> > +	{
> > +		.compatible = "invensense,mpu9255",
> > +		.data = (void *)INV_MPU9255
> > +	},
> > +	{
> > +		.compatible = "invensense,icm20608",
> > +		.data = (void *)INV_ICM20608
> > +	},
> > +	{
> > +		.compatible = "invensense,icm20602",
> > +		.data = (void *)INV_ICM20602
> > +	},
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, inv_of_match);
> > +
> >  static const struct acpi_device_id inv_acpi_match[] = {
> >  	{"INVN6000", INV_MPU6000},
> >  	{ },
> > @@ -93,6 +130,7 @@ static struct spi_driver inv_mpu_driver = {
> >  	.probe		=	inv_mpu_probe,
> >  	.id_table	=	inv_mpu_id,
> >  	.driver = {
> > +		.of_match_table = inv_of_match,
> >  		.acpi_match_table = ACPI_PTR(inv_acpi_match),
> >  		.name	=	"inv-mpu6000-spi",
> >  		.pm     =       &inv_mpu_pmops,  
> 
>