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    SubjectRe: [PATCH v2 1/5] iio: light: vcnl4000 use word writes instead of byte writes
    Hi Angus,

    On Wed, 20 Mar 2019 13:21:58 -0700
    Angus Ainslie <angus@akkea.ca> wrote:

    > Hi Tomas,
    >
    > On 2019-03-20 07:53, Tomas Novotny wrote:
    > > Hi Angus,
    > >
    > > On Sun, 17 Mar 2019 08:47:58 -0700
    > > "Angus Ainslie (Purism)" <angus@akkea.ca> wrote:
    > >
    > >> The VCNL4200 datasheet says that word read and writes should be used
    > >> to access the registers.
    > >>
    > >> Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>
    > >> ---
    > >> drivers/iio/light/vcnl4000.c | 4 ++--
    > >> 1 file changed, 2 insertions(+), 2 deletions(-)
    > >>
    > >> diff --git a/drivers/iio/light/vcnl4000.c
    > >> b/drivers/iio/light/vcnl4000.c
    > >> index 04fd0d4b6f19..5295330b65e2 100644
    > >> --- a/drivers/iio/light/vcnl4000.c
    > >> +++ b/drivers/iio/light/vcnl4000.c
    > >> @@ -140,10 +140,10 @@ static int vcnl4200_init(struct vcnl4000_data
    > >> *data)
    > >> data->rev = (ret >> 8) & 0xf;
    > >>
    > >> /* Set defaults and enable both channels */
    > >> - ret = i2c_smbus_write_byte_data(data->client, VCNL4200_AL_CONF,
    > >> 0x00);
    > >> + ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF,
    > >> 0x00);
    > >
    > > minor note: the 0x00 looks like a byte. 0 or 0x0000 would be slightly
    > > better?
    > > The same below.
    > >
    > >> if (ret < 0)
    > >> return ret;
    > >> - ret = i2c_smbus_write_byte_data(data->client, VCNL4200_PS_CONF1,
    > >> 0x00);
    > >> + ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1,
    > >> 0x00);
    > >
    > > The VCNL4200_PS_CONF1 definition is a bit misleading with word write.
    > > Because
    > > PS_CONF1 is only a low byte of command code 0x03. The high byte of 0x03
    > > is
    > > PS_CONF2. I would rename it.
    > >
    >
    > As far as a base address for the register that is correct based on the
    > names in the datasheet. I suppose I could add something like:
    >
    > #define VCNL4200_PS_CONF VCNL4200_PS_CONF1
    >
    > and change the reference here if you think that would be more clear.

    to be honest, I don't know the best practice. As there is also PS_CONF3, I
    was thinking about PS_CONF1_2, but thinking again, your current name is good
    enough maybe.

    Tomas

    > >> if (ret < 0)
    > >> return ret;
    > >
    > > Anyway, the main point is that I've tested this patch on VCNL4200 and
    > > it
    > > works, so:
    > > Tested-by: Tomas Novotny <tomas@novotny.cz>
    > >
    > > T.
    >
    > Thanks for testing it
    > Angus
    >

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