Messages in this thread | | | Date | Thu, 23 Jun 2011 16:36:31 +0100 | From | Alan Cox <> | Subject | Re: [PATCH v2 1/1] input: add driver for Bosch Sensortec's BMA150 accelerometer |
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> +Description: This is used to select the full scale acceleration range. The > + values represent the range given as +/- G. > + Possible values are: 2, 4, 8. > + > + Reading: returns the current acceleration range. > + > + Writing: sets a new acceleration range.
As there is no way to know the valid values I suspect it ought to pick nearest inclusive for others <=8 ?
Similarly for the others
> + normal - Sets the sensor in full running mode. > + sleep - Sets the sensor in deep sleep. > + wakeup - Sets the sensor to low-power mode using > + sequential sleep period. > + > + Reading: returns the current operational mode. > + > + Writing: sets a new operational mode.
We have runtime_pm for this (and in fact to switch from the bma023 driver I posted to yours we'd need runtime pm)
> + > + > +What: /sys/bus/i2c/devices/<busnum>-<devaddr>/value > +Date: May 2011 > +Contact: Eric Andersson <eric.andersson@unixphere.com> > +Description: This is used to get the current acceleration values for each > + axis. The values are represented as (x,y,z), where each axis can > + hold a value between -512 and 511. > + > + Reading: returns the current acceleration values.
This was nacked in the bma023 driver by the IIO folks - and Dmitry pointed out you can do this without a sysfs hack. The trick is to do an initial poll in input_open at which point the ioctl query for the position will have data that is current and open/ioctl/close works and providing we go nail that into other drivers that need that kind of use the API is generic and input event based.
> + > + > +What: /sys/bus/i2c/devices/<busnum>-<devaddr>/delay > +Date: May 2011 > +Contact: Eric Andersson <eric.andersson@unixphere.com> > +Description: This is used to select the polling rate of the driver. The > + value is represented in ms and can be between 0 and 200. Any
0-200 whats ?
> +What: /sys/bus/i2c/devices/<busnum>-<devaddr>/enable > +Date: May 2011 > +Contact: Eric Andersson <eric.andersson@unixphere.com> > +Description: This is used to enable and disable the chip. The chip will only > + be disabled if there are no input device users.
How does this differ from the power one and why is it needed, why doesn't it disable when not in use ? How does this interact with runtime pm
> > +static int bma150_set_bandwidth(struct i2c_client *client, unsigned char bw) > +{ > + s32 ret; > + unsigned char data; > + struct bma150_data *bma150 = i2c_get_clientdata(client); > + > + mutex_lock(&bma150->mutex); > + ret = i2c_smbus_read_byte_data(client, BMA150_BANDWIDTH_REG); > + if (ret < 0) > + goto error; > + > + data = (ret & ~BMA150_BANDWIDTH_MSK) | > + ((bw << BMA150_BANDWIDTH_POS) & BMA150_BANDWIDTH_MSK); > + > + ret = i2c_smbus_write_byte_data(client, BMA150_BANDWIDTH_REG, data); > +error: > + mutex_unlock(&bma150->mutex); > + return ret; > +}
A lot of remarkably similar functions
> + mutex_lock(&bma150->mutex); > + bma150->x = x; > + bma150->y = y; > + bma150->z = z; > + mutex_unlock(&bma150->mutex);
This locking would go away if you dropped the un-needed sysfs node
> > +static int bma150_open(struct input_dev *inputdev) > +{ > + struct bma150_data *dev = input_get_drvdata(inputdev); > + > + if (!dev->sysfs_enable) > + return bma150_start_polling(inputdev); > + > + return 0; > +}
Most bma023 users will be IRQ based, so this driver would need chunks extracting from the other bma023 driver submission for that to be handled.
> + > +static void bma150_close(struct input_dev *inputdev) > +{ > + struct bma150_data *dev = input_get_drvdata(inputdev); > + > + if (!dev->sysfs_enable) > + bma150_stop_polling(inputdev);
What locks sysfs_enable ?
From the Intel side to use your driver instead of bma023 we'd need IRQ support and runtime pm but otherwise it looks basically ok. I really don't see how to reconcile proper power management with all your sysfs enables and power bits though ?
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