| Message ID | 20241216173205.211058-1-Frank.Li@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/1] input: mma8450: Add chip ID check in probe | expand |
Hello, On Mon, Dec 16, 2024 at 12:32:04PM -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> > --- > change from v1 to v2 > - Use *adapter = c->adapter > - Use if (!i2c_check_functionality()) > --- > drivers/input/misc/mma8450.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c > index 08412239b8e69..a1adb49fb5f33 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 +150,17 @@ static void mma8450_close(struct input_dev *input) > */ > static int mma8450_probe(struct i2c_client *c) > { > + struct i2c_adapter *adapter = c->adapter; > struct input_dev *input; > - int err; > + int err, client_id; > + > + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) > + return dev_err_probe(&c->dev, -EINVAL, "I2C adapter can't support SMBUS BYTE"); > + > + 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); i2c_smbus_read_byte_data() might return a negative errno. So the right handling is: client_id = i2c_smbus_read_byte_data(c, MMA8450_WHO_AM_I); if (client_id < 0) return dev_err_probe(&c->dev, client_id, "Failed to read chip ID\n"); 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); Best regards Uwe
diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c index 08412239b8e69..a1adb49fb5f33 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 +150,17 @@ static void mma8450_close(struct input_dev *input) */ static int mma8450_probe(struct i2c_client *c) { + struct i2c_adapter *adapter = c->adapter; struct input_dev *input; - int err; + int err, client_id; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA)) + return dev_err_probe(&c->dev, -EINVAL, "I2C adapter can't support SMBUS BYTE"); + + 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)