Messages in this thread | | | Date | Tue, 31 May 2011 17:23:20 +0100 | From | Alan Cox <> | Subject | Re: [PATCH] input: add driver for Bosch Sensortec's BMA150 accelerometer |
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See the driver I posted some time ago. It's in rather better state than this one and as it's been through most of the review process and also handles the BMA023 and SMB380 so I think would be a better place to start from. I'll report that driver in a moment.
Alan
Some of the first immediately obvious questions though - in particular the lack of clear locking ...
> +struct bma150acc { > + s16 x, > + y, > + z; > +};
Why does this need to be a struct ?
> + if ((mode != BMA150_MODE_NORMAL) && > + (mode != BMA150_MODE_SLEEP) && > + (mode != BMA150_MODE_WAKE_UP)) > + return -EINVAL;
How can any other mode get passed ?
> + > + data1 = i2c_smbus_read_byte_data(client, BMA150_WAKE_UP_REG); > + if (data1 < 0) > + return ret; > + > + data1 = (data1 & ~BMA150_WAKE_UP_MSK) | > + ((mode << BMA150_WAKE_UP_POS) & BMA150_WAKE_UP_MSK); > + > + data2 = i2c_smbus_read_byte_data(client, BMA150_SLEEP_REG); > + if (data2 < 0) > + return ret; > + > + data2 = (data2 & ~BMA150_SLEEP_MSK) | > + (((mode>>1) << BMA150_SLEEP_POS) & BMA150_SLEEP_MSK); > + > + ret = i2c_smbus_write_byte_data(client, BMA150_WAKE_UP_REG, data1); > + if (ret < 0) > + return ret; > + > + ret = i2c_smbus_write_byte_data(client, BMA150_SLEEP_REG, data2); > + if (ret < 0) > + return ret;
What locks this SMBUS transaction against others
> +static int bma150_set_range(struct i2c_client *client, unsigned char range) > +{ > + int ret; > + unsigned char data; > + > + if (range > BMA150_RANGE_8G) > + return -EINVAL;
This should be actual values not a register range
> + > + data = i2c_smbus_read_byte_data(client, BMA150_RANGE_REG); > + if (data < 0) > + return ret; > + > + data = (data & ~BMA150_RANGE_MSK) | > + ((range << BMA150_RANGE_POS) & BMA150_RANGE_MSK); > + > + ret = i2c_smbus_write_byte_data(client, BMA150_RANGE_REG, data);
What locks this ?
> + if (ret < 0) > + return ret; > + > + return 0;
Why this pointless if ?
> +} > + > +static int bma150_get_range(struct i2c_client *client, unsigned char *range) > +{ > + int ret; > + unsigned char data; > + > + data = i2c_smbus_read_byte_data(client, BMA150_RANGE_REG); > + if (data < 0) > + return ret; > + > + *range = (data & BMA150_RANGE_MSK) >> BMA150_RANGE_POS; > + return 0;
See comments above
> +} > + > +static int bma150_set_bandwidth(struct i2c_client *client, unsigned char bw)
Similar problem
> +static int bma150_read_accel_xyz(struct i2c_client *client, > + struct bma150acc *acc) > +{ > + unsigned char data[6]; > + int ret = i2c_smbus_read_i2c_block_data(client, > + BMA150_ACC_X_LSB_REG, 6, data); > + if (ret != 6) > + return -EIO; > + > + acc->x = ((0xC0 & data[0]) >> 6) | (data[1] << 2); > + acc->y = ((0xC0 & data[2]) >> 6) | (data[3] << 2); > + acc->z = ((0xC0 & data[4]) >> 6) | (data[5] << 2); > + > + /* sign extension */ > + acc->x = (s16) (acc->x << 6) >> 6; > + acc->y = (s16) (acc->y << 6) >> 6; > + acc->z = (s16) (acc->z << 6) >> 6; > + > + return 0;
Why the separate function and struct
> +} > + > +static void bma150_work_func(struct work_struct *work) > +{
Threaded IRQ ?
> +static ssize_t bma150_mode_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct bma150_data *bma150 = i2c_get_clientdata(client); > + > + return sprintf(buf, "%d\n", bma150->mode);
API definition ?
> + schedule_delayed_work(&data->work, > + msecs_to_jiffies(atomic_read(&data->delay))); > +
Why the atomic read ?
And there are a ton more issues unfixed in this driver
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