| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <Zw116IDMKFZ-MKIi@vamoirid-laptop>
Date: Mon, 14 Oct 2024 21:50:00 +0200
From: Vasileios Amoiridis <vassilisamir@...il.com>
To: Jonathan Cameron <jic23@...nel.org>
Cc: lars@...afoo.de, robh@...nel.org, krzk+dt@...nel.org,
conor+dt@...nel.org, andriy.shevchenko@...ux.intel.com,
ang.iglesiasg@...il.com, linus.walleij@...aro.org,
biju.das.jz@...renesas.com, javier.carrasco.cruz@...il.com,
semen.protsenko@...aro.org, 579lpy@...il.com, ak@...klinger.de,
linux-iio@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, christophe.jaillet@...adoo.fr
Subject: Re: [PATCH v8 1/4] iio: pressure: bmp280: Use sleep and forced mode
for oneshot captures
On Sat, Oct 12, 2024 at 05:03:33PM +0100, Jonathan Cameron wrote:
> On Mon, 7 Oct 2024 21:49:42 +0200
> Vasileios Amoiridis <vassilisamir@...il.com> wrote:
>
> > Add forced mode support in sensors BMP28x, BME28x, BMP3xx and BMP58x.
> > Sensors BMP18x and BMP085 are old and do not support this feature so
> > their operation is not affected at all.
> >
> > Essentially, up to now, the rest of the sensors were used in normal mode
> > all the time. This means that they are continuously doing measurements
> > even though these measurements are not used. Even though the sensor does
> > provide PM support, to cover all the possible use cases, the sensor needs
> > to go into sleep mode and wake up whenever necessary.
> >
> > The idea is that the sensor is by default in sleep mode, wakes up in
> > forced mode when a oneshot capture is requested, or in normal mode
> > when the buffer is enabled. The difference lays in the fact that in
> > forced mode, the sensor does only one conversion and goes back to sleep
> > while in normal mode, the sensor does continuous measurements with the
> > frequency that was set in the ODR registers.
> >
> > The bmpX_chip_config() functions which are responsible for applying
> > the requested configuration to the sensor, are modified accordingly
> > in order to set the sensor by default in sleep mode.
> >
> > DEEP STANDBY, Low Power NORMAL and CONTINUOUS modes, supported only by
> > the BMP58x version, are not added.
> >
> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> > Signed-off-by: Vasileios Amoiridis <vassilisamir@...il.com>
> Hi Vasilieos
>
> Given it looks like you'll be doing a v9 anyway, a few comments inline
> on some minor simplifications and potential readability improvements.
>
> Thanks,
>
> Jonathan
>
Hi Jonathan,
>
> > ---
> > drivers/iio/pressure/bmp280-core.c | 296 +++++++++++++++++++++++++++--
> > drivers/iio/pressure/bmp280.h | 21 ++
> > 2 files changed, 296 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> > index 6811619c6f11..9ad29cf4c2ac 100644
> > --- a/drivers/iio/pressure/bmp280-core.c
> > +++ b/drivers/iio/pressure/bmp280-core.c
> > @@ -16,6 +16,11 @@
>
>
> > @@ -1522,6 +1610,71 @@ static int bmp380_preinit(struct bmp280_data *data)
> > return bmp380_cmd(data, BMP380_CMD_SOFT_RESET);
> > }
> >
> > +static const u8 bmp380_operation_mode[] = {
> > + BMP380_MODE_SLEEP, BMP380_MODE_FORCED, BMP380_MODE_NORMAL,
> > +};
>
> As below - I'd assign these to specific entries to make the fairly obvious association
> even more obvious!
>
ACK! Makes total sense. Thanks for your time!
Cheers,
Vasilis
> > +
> > +static int bmp380_set_mode(struct bmp280_data *data, enum bmp280_op_mode mode)
> > +{
> > + int ret;
> > +
> > + switch (mode) {
> > + case BMP280_SLEEP:
> > + case BMP280_FORCED:
> > + case BMP280_NORMAL:
> > + break;
> > + default:
> > + return -EINVAL;
>
> Currently there aren't others. So the compiler should shout if you try to pass
> something else. Hence this check shouldn't be needed.
>
> > + }
> > +
> > + ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
> > + BMP380_MODE_MASK,
> > + FIELD_PREP(BMP380_MODE_MASK,
> > + bmp380_operation_mode[mode]));
> > + if (ret) {
> > + dev_err(data->dev, "failed to write power control register.\n");
> > + return ret;
> > + }
> > +
> > + data->op_mode = mode;
> > +
> > + return 0;
> > +}
> >
>
> > return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
> > }
> >
> > +static const u8 bmp580_operation_mode[] = {
> > + BMP580_MODE_SLEEP, BMP580_MODE_FORCED, BMP580_MODE_NORMAL,
>
> For these, explicit setting will make it more obvious.
> [BMP280_SLEEP] = BMP580_MODE_SLEEP,
> etc
>
> > +};
> > +
> > +static int bmp580_set_mode(struct bmp280_data *data, enum bmp280_op_mode mode)
> > +{
> > + struct device *dev = data->dev;
> > + int ret;
> > +
> > + switch (mode) {
> > + case BMP280_SLEEP:
> > + case BMP280_NORMAL:
> > + break;
> > + case BMP280_FORCED:
> > + ret = regmap_set_bits(data->regmap, BMP580_REG_DSP_CONFIG,
> > + BMP580_DSP_IIR_FORCED_FLUSH);
> > + if (ret) {
> > + dev_err(dev, "Could not flush IIR filter constants.\n");
> > + return ret;
> > + }
> > + break;
> > + default:
> There are only the values above, and we should hopefully be able to rely
> on compiler warnings to shout at us if a future modification adds more.
>
> So should be able to drop the default here.
>
> > + return -EINVAL;
> > + }
> > +
> > + ret = regmap_write_bits(data->regmap, BMP580_REG_ODR_CONFIG,
> > + BMP580_MODE_MASK,
> > + FIELD_PREP(BMP580_MODE_MASK,
> > + bmp580_operation_mode[mode]));
> > + if (ret) {
> > + dev_err(dev, "failed to write power control register.\n");
> > + return ret;
> > + }
> > +
> > + data->op_mode = mode;
> > +
> > + return 0;
> > +}
>
Powered by blists - more mailing lists