Re: [PATCH 1/3] toshiba_acpi: Add IIO interface for accelerometer axis data
From: Azael Avalos
Date: Sun Jun 19 2016 - 19:30:07 EST
Hi,
Thanks for the feedback, I just did a respin of the series with the
changes you mentioned.
Cheers
Azael
2016-06-19 14:16 GMT-06:00 Jonathan Cameron <jic23@xxxxxxxxxx>:
> On 11/06/16 19:57, Azael Avalos wrote:
>> This patch adds the accelerometer axis data to the IIO subsystem.
>>
>> Currently reporting the X, Y and Z values, as no other data can be
>> queried given the fact that the accelerometer chip itself is hidden
>> behind the Toshiba proprietary interface.
>>
>> Signed-off-by: Azael Avalos <coproscefalo@xxxxxxxxx>
> Looks pretty good and simple to me. A few bits and bobs inline.
>
> Jonathan
>> ---
>> All:
>> This is my first attempt with the IIO subsysem, I'll be looking
>> forward for your valuable input on this.
>>
>> Darren:
>> There's a warning about more than 80 columns on this patch, once
>> I get feedback from the IIO guys I'll respin this with that issue
>> corrected.
>>
>> drivers/platform/x86/toshiba_acpi.c | 130 ++++++++++++++++++++++++++++++++++--
>> 1 file changed, 126 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
>> index 01e12d2..85014a3 100644
>> --- a/drivers/platform/x86/toshiba_acpi.c
>> +++ b/drivers/platform/x86/toshiba_acpi.c
>> @@ -53,6 +53,7 @@
>> #include <linux/uaccess.h>
>> #include <linux/miscdevice.h>
>> #include <linux/rfkill.h>
>> +#include <linux/iio/iio.h>
>> #include <linux/toshiba.h>
>> #include <acpi/video.h>
>>
>> @@ -134,6 +135,7 @@ MODULE_LICENSE("GPL");
>>
>> /* Field definitions */
>> #define HCI_ACCEL_MASK 0x7fff
>> +#define HCI_ACCEL_DIRECTION_MASK 0x8000
>> #define HCI_HOTKEY_DISABLE 0x0b
>> #define HCI_HOTKEY_ENABLE 0x09
>> #define HCI_HOTKEY_SPECIAL_FUNCTIONS 0x10
>> @@ -178,6 +180,7 @@ struct toshiba_acpi_dev {
>> struct led_classdev eco_led;
>> struct miscdevice miscdev;
>> struct rfkill *wwan_rfk;
>> + struct iio_dev *indio_dev;
>>
>> int force_fan;
>> int last_key_event;
>> @@ -1962,8 +1965,8 @@ static ssize_t position_show(struct device *dev,
>> struct device_attribute *attr, char *buf)
>> {
>> struct toshiba_acpi_dev *toshiba = dev_get_drvdata(dev);
>> - u32 xyval, zval, tmp;
>> - u16 x, y, z;
>> + u32 xyval, zval;
>> + int x, y, z;
>> int ret;
>>
>> xyval = zval = 0;
>> @@ -1971,10 +1974,14 @@ static ssize_t position_show(struct device *dev,
>> if (ret < 0)
>> return ret;
>>
>> + /* Accelerometer values */
>> x = xyval & HCI_ACCEL_MASK;
>> - tmp = xyval >> HCI_MISC_SHIFT;
>> - y = tmp & HCI_ACCEL_MASK;
>> + y = (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_MASK;
>> z = zval & HCI_ACCEL_MASK;
>> + /* Movement direction */
>> + x *= xyval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
>> + y *= (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
>> + z *= zval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
> This lot is really an unrelated change - do it as a separate precursor patch
> to the IIO support.
>>
>> return sprintf(buf, "%d %d %d\n", x, y, z);
>> }
>> @@ -2420,6 +2427,94 @@ static void toshiba_acpi_kbd_bl_work(struct work_struct *work)
>> }
>>
>> /*
>> + * IIO device
>> + */
>> +
>> +enum toshiba_accel_chan {
>> + AXIS_X,
>> + AXIS_Y,
>> + AXIS_Z
>> +};
>> +
>> +static int toshiba_accel_get_axis(enum toshiba_accel_chan chan)
>> +{
>> + u32 xyval, zval;
>> + int x, y, z;
>> + int ret;
>> +
>> + xyval = zval = 0;
>> + ret = toshiba_accelerometer_get(toshiba_acpi, &xyval, &zval);
>> + if (ret < 0)
>> + return ret;
>> +
>> + /* Accelerometer values */
>> + x = xyval & HCI_ACCEL_MASK;
>> + y = (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_MASK;
>> + z = zval & HCI_ACCEL_MASK;
>> + /* Movement direction */
>> + x *= xyval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
>> + y *= (xyval >> HCI_MISC_SHIFT) & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
>> + z *= zval & HCI_ACCEL_DIRECTION_MASK ? -1 : 1;
> Wow, that's hideous ;)
>> +
>> + switch (chan) {
>> + case AXIS_X:
>> + ret = x;
>> + break;
>> + case AXIS_Y:
>> + ret = y;
>> + break;
>> + case AXIS_Z:
>> + ret = z;
>> + break;
> Just compute the one you are returning perhaps?
> case AXIS_X:
> return xyval & HCI_ACCEL_DIRECTION_MASK ?
> -(xyval & HCI_ACCEL_MASK) :
> xyval & HCI_ACCEL_MASK;
> etc?
> Brings all the 'mess' into one location.
> Or break it out into steps which is fine, but only compute the one
> we care about.
>
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int toshiba_accel_read_raw(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan,
>> + int *val, int *val2, long mask)
>> +{
>> + int ret;
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_RAW:
>> + if (iio_buffer_enabled(indio_dev))
>> + return -EBUSY;
> Couple of things here.
> * you aren't supporting buffered reads (pushed data flows) so
> very unlikely the buffer would be enabled.
> * if you were you'd need to be holding indio_dev->mlock to
> avoid races around entering buffered mode mid way through this
> function. Note we have the claim_direct functions to handle this
> case cleanly if you ever do need them!
>
> Right now just drop this check.
>
>> +
>> + ret = toshiba_accel_get_axis(chan->scan_index);
> For this use chan->address as it's not the 'scan_index' as such.
>
>> + if (ret == -EIO || ret == -ENODEV)
>> + return ret;
>> +
>> + *val = ret;
>> +
>> + return IIO_VAL_INT;
>> + }
>> +
>> + return -EINVAL;
>> +}
>> +
>> +#define TOSHIBA_ACCEL_CHANNEL(axis, chan) { \
>> + .type = IIO_ACCEL, \
>> + .modified = 1, \
>> + .channel2 = IIO_MOD_##axis, \
>> + .output = 1, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> + .scan_index = chan, \
> You don't need scan index unless you are supporting pushed data
> flow (rather than polled ones that you have here).
>> +}
>> +
>> +static const struct iio_chan_spec toshiba_accel_channels[] = {
>> + TOSHIBA_ACCEL_CHANNEL(X, AXIS_X),
>> + TOSHIBA_ACCEL_CHANNEL(Y, AXIS_Y),
>> + TOSHIBA_ACCEL_CHANNEL(Z, AXIS_Z),
>> +};
>> +
>> +static const struct iio_info toshiba_accel_info = {
>> + .driver_module = THIS_MODULE,
>> + .read_raw = &toshiba_accel_read_raw,
>> +};
>> +
>> +/*
>> * Misc device
>> */
>> static int toshiba_acpi_smm_bridge(SMMRegisters *regs)
>> @@ -2903,6 +2998,11 @@ static int toshiba_acpi_remove(struct acpi_device *acpi_dev)
>> misc_deregister(&dev->miscdev);
>>
>> remove_toshiba_proc_entries(dev);
>> +
>> + if (dev->accelerometer_supported) {
>> + iio_device_unregister(dev->indio_dev);
>> + iio_device_free(dev->indio_dev);
>> + }
>>
>> if (dev->sysfs_created)
>> sysfs_remove_group(&dev->acpi_dev->dev.kobj,
>> @@ -3051,6 +3151,28 @@ static int toshiba_acpi_add(struct acpi_device *acpi_dev)
>> dev->touchpad_supported = !ret;
>>
>> toshiba_accelerometer_available(dev);
>> + if (dev->accelerometer_supported) {
>> + dev->indio_dev = iio_device_alloc(sizeof(*dev));
>> + if (!dev->indio_dev)
>> + return -ENOMEM;
>> +
>> + pr_info("Registering Toshiba accelerometer iio device\n");
>> +
>> + dev->indio_dev->info = &toshiba_accel_info;
>> + dev->indio_dev->name = "Toshiba accelerometer";
>> + dev->indio_dev->dev.parent = &acpi_dev->dev;
>> + dev->indio_dev->modes = INDIO_DIRECT_MODE;
>> + dev->indio_dev->channels = toshiba_accel_channels;
>> + dev->indio_dev->num_channels = ARRAY_SIZE(toshiba_accel_channels);
>> +
>> + ret = iio_device_register(dev->indio_dev);
>> + if (ret < 0) {
>> + pr_err("Unable to register iio device\n");
>> + iio_device_free(dev->indio_dev);
> I'm wondering if we want to be a little 'ruder' if this occurs and drop out
> hard as it indicates something very nasty happened... Here we are papering
> over any failures and users may never notice. I guess it depends on what
> is happening in other similar locations in this driver.
>
> You already drop out if you get a memory allocation failure, so best
> to be consistent I think.
>> + }
>> +
>> + iio_device_set_drvdata(dev->indio_dev, dev);
> There should be no real advantage in setting this as you can always get
> to dev via iio_priv(indio_dev)
>> + }
>>
>> toshiba_usb_sleep_charge_available(dev);
>>
>>
>
--
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