> > Many of the hardware configuration registers may only be modified while the
> > device is inactive.
> >
> > Currently the probe code first activates the device and then modifies the
> > registers (eg to set the scale). This doesn't actually work but is not
> > noticed since the scale used is the default value.
> >
> > While at it also issue a hardware reset command at probe time.
> >
> > Signed-off-by: Martin Fuzzey <mfuzzey@xxxxxxxxxxx>
> Looks fine to me but I'd like an OK from Peter for this series.
looks good, no objection, I haven't test yet however
patch 1/8 is a bug fix but not worth for -stable
in patch 2, the local variable ret could be dropped and replaced with
returns
patch 3, what is the local variable supported_interrupts good for?
patch 6/8 still has wrong subject: io -> iio
> > drivers/iio/accel/mma8452.c | 39 ++++++++++++++++++++++++++++++++++-----
> > 1 file changed, 34 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> > index 3c12d49..04a4f34 100644
> > --- a/drivers/iio/accel/mma8452.c
> > +++ b/drivers/iio/accel/mma8452.c
> > @@ -32,6 +32,7 @@
> > #define MMA8452_OFF_Z 0x31
> > #define MMA8452_CTRL_REG1 0x2a
> > #define MMA8452_CTRL_REG2 0x2b
> > +#define MMA8452_CTRL_REG2_RST BIT(6)
> >
> > #define MMA8452_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
> >
> > @@ -111,7 +112,7 @@ static const int mma8452_samp_freq[8][2] = {
> > {6, 250000}, {1, 560000}
> > };
> >
> > -/*
> > +/*
> This ought to be in a separate cleanup patch. Just adds noise to the important
> stuff in here! Not important though so don't bother rerolling the series for this.
>
> > * Hardware has fullscale of -2G, -4G, -8G corresponding to raw value -2048
> > * The userspace interface uses m/s^2 and we declare micro units
> > * So scale factor is given by:
> > @@ -335,6 +336,30 @@ static const struct iio_info mma8452_info = {
> >
> > static const unsigned long mma8452_scan_masks[] = {0x7, 0};
> >
> > +static int mma8452_reset(struct i2c_client *client)
> > +{
> > + int i;
> > + int ret;
> > +
> > + ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG2,
> > + MMA8452_CTRL_REG2_RST);
> > + if (ret)
> > + return ret;
> > +
> > + for (i = 0; i < 10; i++) {
> > + udelay(100);
> > + ret = i2c_smbus_read_byte_data(client, MMA8452_CTRL_REG2);
> > + if (ret == -EIO)
> > + continue; /* I2C comm reset */
> > + if (ret < 0)
> > + return ret;
> > + if (!(ret & MMA8452_CTRL_REG2_RST))
> > + return 0;
> > + }
> > +
> > + return -ETIMEDOUT;
> > +}
> > +
> > static int mma8452_probe(struct i2c_client *client,
> > const struct i2c_device_id *id)
> > {
> > @@ -365,10 +390,7 @@ static int mma8452_probe(struct i2c_client *client,
> > indio_dev->num_channels = ARRAY_SIZE(mma8452_channels);
> > indio_dev->available_scan_masks = mma8452_scan_masks;
> >
> > - data->ctrl_reg1 = MMA8452_CTRL_ACTIVE |
> > - (MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT);
> > - ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1,
> > - data->ctrl_reg1);
> > + ret = mma8452_reset(client);
> > if (ret < 0)
> > return ret;
> >
> > @@ -378,6 +400,13 @@ static int mma8452_probe(struct i2c_client *client,
> > if (ret < 0)
> > return ret;
> >
> > + data->ctrl_reg1 = MMA8452_CTRL_ACTIVE |
> > + (MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT);
> > + ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1,
> > + data->ctrl_reg1);
> > + if (ret < 0)
> > + return ret;
> > +
> > ret = iio_triggered_buffer_setup(indio_dev, NULL,
> > mma8452_trigger_handler, NULL);
> > if (ret < 0)
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> > the body of a message to majordomo@xxxxxxxxxxxxxxx
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
>
--
Peter Meerwald
+43-664-2444418 (mobile)
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