Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754797AbaJMTOT (ORCPT ); Mon, 13 Oct 2014 15:14:19 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:47637 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754236AbaJMTOS (ORCPT ); Mon, 13 Oct 2014 15:14:18 -0400 Date: Mon, 13 Oct 2014 14:14:05 -0500 From: Felipe Balbi To: David Cohen CC: , , , Subject: Re: [PATCH] pinctrl: baytrail: show output gpio state correctly on Intel Baytrail Message-ID: <20141013191405.GB29810@saruman> Reply-To: References: <1412355319-18946-1-git-send-email-david.a.cohen@linux.intel.com> <1413224639-21552-1-git-send-email-david.a.cohen@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="XOIedfhf+7KOe/yw" Content-Disposition: inline In-Reply-To: <1413224639-21552-1-git-send-email-david.a.cohen@linux.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --XOIedfhf+7KOe/yw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Oct 13, 2014 at 11:23:59AM -0700, David Cohen wrote: > Even if a gpio pin is set to output, we still need to set INPUT_EN bit here you say you're setting that bit. > to be able to read its value. Without this change, we'll always read low > level state. >=20 > Cc: # v3.14+ > Signed-off-by: David Cohen > --- >=20 > Hi, >=20 > I'm resending same v1 patch but now copying linux stable and linux gpio. > This patch is meant for all linux stable trees >=3D v3.14. >=20 > Br, David > --- >=20 > drivers/pinctrl/pinctrl-baytrail.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl= -baytrail.c > index e12e5b07f6d7..c23d8ded936d 100644 > --- a/drivers/pinctrl/pinctrl-baytrail.c > +++ b/drivers/pinctrl/pinctrl-baytrail.c > @@ -318,7 +318,7 @@ static int byt_gpio_direction_output(struct gpio_chip= *chip, > "Potential Error: Setting GPIO with direct_irq_en to output"); > =20 > reg_val =3D readl(reg) | BYT_DIR_MASK; > - reg_val &=3D ~BYT_OUTPUT_EN; > + reg_val &=3D ~(BYT_OUTPUT_EN | BYT_INPUT_EN); but code is clearing it. Also, you're not patching byt_gpio_get(), so you can't be 'reading its value' either. Quite frankly, this looks very fishy to me. Comments on BYT_OUTPUT_EN and BYT_INPUT_EN states that those bits are active low, meaning that clearing them enables that particular feature. How can you enable a pin to be both OUTPUT and INPUT ? Look like what you really want is: diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-b= aytrail.c index e12e5b0..69f882d 100644 --- a/drivers/pinctrl/pinctrl-baytrail.c +++ b/drivers/pinctrl/pinctrl-baytrail.c @@ -290,6 +290,7 @@ static int byt_gpio_direction_input(struct gpio_chip *c= hip, unsigned offset) =20 value =3D readl(reg) | BYT_DIR_MASK; value &=3D ~BYT_INPUT_EN; /* active low */ + value |=3D BYT_OUTPUT_EN; /* disable output */ writel(value, reg); =20 spin_unlock_irqrestore(&vg->lock, flags); @@ -319,6 +320,7 @@ static int byt_gpio_direction_output(struct gpio_chip *= chip, =20 reg_val =3D readl(reg) | BYT_DIR_MASK; reg_val &=3D ~BYT_OUTPUT_EN; + value |=3D BYT_INPUT_EN; /* disable input */ =20 if (value) writel(reg_val | BYT_LEVEL, reg); completely untested however. Care to further explain why clearing both bits - thus enabling both INPUT and OUTPUT - is correct ? --=20 balbi --XOIedfhf+7KOe/yw Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUPCR9AAoJEIaOsuA1yqREhbUP/218r1tB0ToV/u23D6ex4tcS xXP80QOhH77OibNz2ngUBN/z2zvrsIFiVvjdPA2GobtT5/28Am95yRa44c++k0Su Fl0VZ12ApLw4XTjLBhcB22U/b+OcK4ivHIVKnsb8qfOGfuWU0MJPURGJ7mPMk+6K AZgOI5Ga0wFO7f2OP+6ysMvtawd8DKvoir01u8d9GXJvoCMLo8PggkIoCwIs44cL bc0ebHQMjZwuqP8LbHI8FECnpzOEOjN3NcR2oAGYK7HuRfFVZAXbngHKijURT/dy Kge1eurm7fMEsdpQC2Ho37PQskcB/XMz8Tw529EzIi1YeyHDKqlp33WnvGyOjuYk Cjt2G1r/rCupxtbKZYMyAFinux5A7CsNrqFlIJYeYPBJ07Vy8whSCf4s6HnJWcm0 o18ifAcjKs7KdNBcEQhY6ubTDxtBg5xNrCHpP4DpPN9y0NtDoIjgTxK85BepfdbP /zDISI0yDgwxsZggsqhgHvFicMdL96bpCAtaFYo54XoK5RG4FrBcJf2r9RRfIw3y r4pd1B0In0XMBJy39lENoerCT9lpWMLGwqXxZjHTqM9vXQMADh6ZKg4Ql7V6Wuuf Pjikw8FrKBM+w9UtTq9E9XNXyNjq55PhcxLsP/I39LnxDOORvr2UFG/OTRpKdmJt 3VROP+Eow4syCXJKprdW =u+Fe -----END PGP SIGNATURE----- --XOIedfhf+7KOe/yw-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/