From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Reichel Subject: Re: [PATCH v5 05/11] power: bq24257: Add SW-based approach for Power Good determination Date: Tue, 22 Sep 2015 21:37:20 +0200 Message-ID: <20150922193719.GD9949@earth> References: <1442612399-341-1-git-send-email-dannenberg@ti.com> <1442612399-341-6-git-send-email-dannenberg@ti.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="+B+y8wtTXqdUj1xM" Return-path: Content-Disposition: inline In-Reply-To: <1442612399-341-6-git-send-email-dannenberg@ti.com> Sender: linux-pm-owner@vger.kernel.org To: Andreas Dannenberg Cc: Dmitry Eremin-Solenikov , David Woodhouse , Laurentiu Palcu , Krzysztof Kozlowski , Ramakrishna Pallala , linux-pm@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org --+B+y8wtTXqdUj1xM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Fri, Sep 18, 2015 at 04:39:53PM -0500, Andreas Dannenberg wrote: > A software-based approach for determining the charger's input voltage > "Power Good" state is introduced for devices like the bq24250 which > don't have a dedicated hardware pin for that purpose. This SW-based > approach is also used for other devices (with dedicated PG pin) as a > fall back solution if that pin is not configured to be used through > "pg-gpios". >=20 > Signed-off-by: Andreas Dannenberg > --- > drivers/power/bq24257_charger.c | 49 +++++++++++++++++++++++++++++++++++= +----- > 1 file changed, 43 insertions(+), 6 deletions(-) >=20 > diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_char= ger.c > index 502dd8a5..135cfd4 100644 > --- a/drivers/power/bq24257_charger.c > +++ b/drivers/power/bq24257_charger.c > @@ -107,6 +107,7 @@ struct bq24257_device { > struct mutex lock; /* protect state data */ > =20 > bool iilimit_autoset_enable; > + bool pg_gpio_disable; I don't think this is required. > }; > =20 > static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg) > @@ -360,7 +361,26 @@ static int bq24257_get_chip_state(struct bq24257_dev= ice *bq, > =20 > state->fault =3D ret; > =20 > - state->power_good =3D !gpiod_get_value_cansleep(bq->pg); > + if (bq->pg_gpio_disable) > + /* > + * If we have a chip without a dedicated power-good GPIO or > + * some other explicit bit that would provide this information > + * assume the power is good if there is no supply related > + * fault - and not good otherwise. There is a possibility for > + * other errors to mask that power in fact is not good but this > + * is probably the best we can do here. > + */ > + switch (state->fault) { > + case FAULT_INPUT_OVP: > + case FAULT_INPUT_UVLO: > + case FAULT_INPUT_LDO_LOW: > + state->power_good =3D false; > + break; > + default: > + state->power_good =3D true; > + } > + else > + state->power_good =3D !gpiod_get_value_cansleep(bq->pg); I guess you can just handle this like an optional gpio if(bq->pg) state->power_good =3D !gpiod_get_value_cansleep(bq->pg); else ... > =20 > return 0; > } > @@ -680,7 +700,7 @@ static int bq24257_pg_gpio_probe(struct bq24257_devic= e *bq) > { > bq->pg =3D devm_gpiod_get_index(bq->dev, BQ24257_PG_GPIO, 0, GPIOD_IN); > if (IS_ERR(bq->pg)) { > - dev_err(bq->dev, "could not probe PG pin\n"); > + dev_info(bq->dev, "could not probe PG pin\n"); > return PTR_ERR(bq->pg); > } > =20 > @@ -814,10 +834,27 @@ static int bq24257_probe(struct i2c_client *client, > INIT_DELAYED_WORK(&bq->iilimit_setup_work, > bq24257_iilimit_setup_work); > =20 > - /* we can only check Power Good status by probing the PG pin */ > - ret =3D bq24257_pg_gpio_probe(bq); > - if (ret < 0) > - return ret; > + /* > + * The BQ24250 doesn't have a dedicated Power Good (PG) pin so we > + * explicitly disable this feature for this device and instead use > + * a SW-based approach to determine the PG state. > + */ > + if (bq->chip =3D=3D BQ24250) > + bq->pg_gpio_disable =3D true; > + > + /* > + * For devices that do have a dedicated PG pin go ahead and probe it, > + * using the SW-based approach as a fall back solution. Note that the > + * use of the dedicated pin is preferred. > + */ > + if (!bq->pg_gpio_disable) { > + ret =3D bq24257_pg_gpio_probe(bq); > + if (ret < 0) { > + dev_info(bq->dev, > + "using SW-based power-good detection\n"); > + bq->pg_gpio_disable =3D true; > + } > + } > =20 > /* reset all registers to defaults */ > ret =3D bq24257_field_write(bq, F_RESET, 1); -- Sebastian --+B+y8wtTXqdUj1xM Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCgAGBQJWAa3vAAoJENju1/PIO/qaY9cP/RzSB9IKYjECpXQlLKbuWQDV N5klZf8ZbcvKfoHqMR3acD1FvJIqrFlPHSZlgXehMV9EMBkIIwM8+NBBCJNFsYEJ zwBg1s3wwhPcNRtD/L45JXkksuSw4glKBYo1ZDqVCFMD9YNy11PHXfRyNyXuYplm znid4t4dbtjt+g4LcfXf8G0t8/KvzjQ4wFzHhvgyZQBK1983HlBS+jJYC3fK7P+M zC15AKQHtMqWQQztZ7VKAaNgzo6Qixase8T/gNI1ZjP9OJz6LSb9SZ2fDfVkWhAb 3T1+QNDo1CN3YuKDUsvS76L6NtQ87Omn7wIeJU6MdvVzi1D/XZswk5n09hhB+HqK t2cJY5dGo5LR16xnFsYTJ2ZT4jKKrY7bemgOqS/Iq6OAOiukicFTdpxFVAHlyb1h Ey/wtL3aEVgi6iiwqozKmg3lCNuC4xF/BiVeT2SM5O9cT7bEE8ln6Sx88l4y/e07 tKaXF+IS3dHA12C4UmmmrWFUVy58oM7iRt30JrLXMj/NXnxv1L+HuS//MhYmMDfs EHFzHDVq1fXUeODGe/QEUVVk+Vsld8LF2dj7Uzwi2Bwt9Q+HSgOeFiTtBc2SH8ey ZLxNtxv2dFHa4iv7g0vxZ+TrzqRoIU8WY09ba8lKbqqpx8Nu3u52ZVQ6LUPgE6vN 2QPBWgssUEi9VnzUpuix =hQ0Y -----END PGP SIGNATURE----- --+B+y8wtTXqdUj1xM--