| Message ID | 20241213222310.189443-1-Frank.Li@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/1] input: mma8450: Add chip ID check in probe | expand |
Hello Frank, On Fri, Dec 13, 2024 at 05:23:09PM -0500, Frank Li wrote: > From: Luwei Zhou <b45643@freescale.com> > > Prevent continuous polling error logs by adding a chip ID check in the > probe function. This ensures the driver only proceeds when the mma8450 is > present, avoiding issues in scenarios like missing add-on cards. > > Signed-off-by: Luwei Zhou <b45643@freescale.com> > Signed-off-by: Fugang Duan <B38611@freescale.com> > Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com> > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> > Signed-off-by: Frank Li <Frank.Li@nxp.com> > --- > drivers/input/misc/mma8450.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c > index 08412239b8e69..da941748ed29b 100644 > --- a/drivers/input/misc/mma8450.c > +++ b/drivers/input/misc/mma8450.c > @@ -38,6 +38,8 @@ > > #define MMA8450_CTRL_REG1 0x38 > #define MMA8450_CTRL_REG2 0x39 > +#define MMA8450_ID 0xc6 > +#define MMA8450_WHO_AM_I 0x0f > > static int mma8450_read(struct i2c_client *c, unsigned int off) > { > @@ -148,8 +150,20 @@ static void mma8450_close(struct input_dev *input) > */ > static int mma8450_probe(struct i2c_client *c) > { > + struct i2c_adapter *adapter = to_i2c_adapter(c->dev.parent); + struct i2c_adapter *adapter = c->adapter; > struct input_dev *input; > - int err; > + int err, client_id; > + > + err = i2c_check_functionality(adapter, > + I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA); > + if (!err) > + return err; How unusual. I would have expected no ! here. > + client_id = i2c_smbus_read_byte_data(c, MMA8450_WHO_AM_I); > + if (client_id != MMA8450_ID) > + return dev_err_probe(&c->dev, -EINVAL, > + "read chip ID 0x%x is not equal to 0x%x!\n", > + client_id, MMA8450_ID); Given that here you emit an error message, maybe add an error message above, too? > input = devm_input_allocate_device(&c->dev); > if (!input) Best regards Uwe
On Sat, Dec 14, 2024 at 12:02:56AM +0100, Uwe Kleine-König wrote: > Hello Frank, > > On Fri, Dec 13, 2024 at 05:23:09PM -0500, Frank Li wrote: > > From: Luwei Zhou <b45643@freescale.com> > > > > Prevent continuous polling error logs by adding a chip ID check in the > > probe function. This ensures the driver only proceeds when the mma8450 is > > present, avoiding issues in scenarios like missing add-on cards. > > > > Signed-off-by: Luwei Zhou <b45643@freescale.com> > > Signed-off-by: Fugang Duan <B38611@freescale.com> > > Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com> > > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> > > Signed-off-by: Frank Li <Frank.Li@nxp.com> > > --- > > drivers/input/misc/mma8450.c | 16 +++++++++++++++- > > 1 file changed, 15 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c > > index 08412239b8e69..da941748ed29b 100644 > > --- a/drivers/input/misc/mma8450.c > > +++ b/drivers/input/misc/mma8450.c > > @@ -38,6 +38,8 @@ > > > > #define MMA8450_CTRL_REG1 0x38 > > #define MMA8450_CTRL_REG2 0x39 > > +#define MMA8450_ID 0xc6 > > +#define MMA8450_WHO_AM_I 0x0f > > > > static int mma8450_read(struct i2c_client *c, unsigned int off) > > { > > @@ -148,8 +150,20 @@ static void mma8450_close(struct input_dev *input) > > */ > > static int mma8450_probe(struct i2c_client *c) > > { > > + struct i2c_adapter *adapter = to_i2c_adapter(c->dev.parent); > > + struct i2c_adapter *adapter = c->adapter; > > > struct input_dev *input; > > - int err; > > + int err, client_id; > > + > > + err = i2c_check_functionality(adapter, > > + I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA); > > + if (!err) > > + return err; > > How unusual. I would have expected no ! here. yes, it should be better if (!i2c_check_functionality()) .... i2c_check_functionality() return 1 if adapter supports everything we need. Frank > > > + client_id = i2c_smbus_read_byte_data(c, MMA8450_WHO_AM_I); > > + if (client_id != MMA8450_ID) > > + return dev_err_probe(&c->dev, -EINVAL, > > + "read chip ID 0x%x is not equal to 0x%x!\n", > > + client_id, MMA8450_ID); > > Given that here you emit an error message, maybe add an error message > above, too? > > > input = devm_input_allocate_device(&c->dev); > > if (!input) > > Best regards > Uwe
On Mon, Dec 16, 2024 at 11:30:15AM -0500, Frank Li wrote: > On Sat, Dec 14, 2024 at 12:02:56AM +0100, Uwe Kleine-König wrote: > > Hello Frank, > > > > On Fri, Dec 13, 2024 at 05:23:09PM -0500, Frank Li wrote: > > > From: Luwei Zhou <b45643@freescale.com> > > > > > > Prevent continuous polling error logs by adding a chip ID check in the > > > probe function. This ensures the driver only proceeds when the mma8450 is > > > present, avoiding issues in scenarios like missing add-on cards. > > > > > > Signed-off-by: Luwei Zhou <b45643@freescale.com> > > > Signed-off-by: Fugang Duan <B38611@freescale.com> > > > Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com> > > > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> > > > Signed-off-by: Frank Li <Frank.Li@nxp.com> > > > --- > > > drivers/input/misc/mma8450.c | 16 +++++++++++++++- > > > 1 file changed, 15 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c > > > index 08412239b8e69..da941748ed29b 100644 > > > --- a/drivers/input/misc/mma8450.c > > > +++ b/drivers/input/misc/mma8450.c > > > @@ -38,6 +38,8 @@ > > > > > > #define MMA8450_CTRL_REG1 0x38 > > > #define MMA8450_CTRL_REG2 0x39 > > > +#define MMA8450_ID 0xc6 > > > +#define MMA8450_WHO_AM_I 0x0f > > > > > > static int mma8450_read(struct i2c_client *c, unsigned int off) > > > { > > > @@ -148,8 +150,20 @@ static void mma8450_close(struct input_dev *input) > > > */ > > > static int mma8450_probe(struct i2c_client *c) > > > { > > > + struct i2c_adapter *adapter = to_i2c_adapter(c->dev.parent); > > > > + struct i2c_adapter *adapter = c->adapter; > > > > > struct input_dev *input; > > > - int err; > > > + int err, client_id; > > > + > > > + err = i2c_check_functionality(adapter, > > > + I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA); > > > + if (!err) > > > + return err; > > > > How unusual. I would have expected no ! here. > > yes, it should be better > > if (!i2c_check_functionality()) > .... > > i2c_check_functionality() return 1 if adapter supports everything we need. Yes, it would be much better, otherwise in the case when an adapter does not support the required functionality your code returns 0 which signals successful probing. Thanks.
diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c index 08412239b8e69..da941748ed29b 100644 --- a/drivers/input/misc/mma8450.c +++ b/drivers/input/misc/mma8450.c @@ -38,6 +38,8 @@ #define MMA8450_CTRL_REG1 0x38 #define MMA8450_CTRL_REG2 0x39 +#define MMA8450_ID 0xc6 +#define MMA8450_WHO_AM_I 0x0f static int mma8450_read(struct i2c_client *c, unsigned int off) { @@ -148,8 +150,20 @@ static void mma8450_close(struct input_dev *input) */ static int mma8450_probe(struct i2c_client *c) { + struct i2c_adapter *adapter = to_i2c_adapter(c->dev.parent); struct input_dev *input; - int err; + int err, client_id; + + err = i2c_check_functionality(adapter, + I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA); + if (!err) + return err; + + client_id = i2c_smbus_read_byte_data(c, MMA8450_WHO_AM_I); + if (client_id != MMA8450_ID) + return dev_err_probe(&c->dev, -EINVAL, + "read chip ID 0x%x is not equal to 0x%x!\n", + client_id, MMA8450_ID); input = devm_input_allocate_device(&c->dev); if (!input)