From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [RCF PATCH,v2,2/2] pwm: imx: Configure output to GPIO in disabled state Date: Mon, 26 Nov 2018 12:51:23 +0100 Message-ID: <20181126115123.GA15164@ulmo> References: <20181114215120.vddykljqyavm64wj@pengutronix.de> <20181115152545.GA8611@ulmo> <20181115203733.qvonika6yhn2bsnb@pengutronix.de> <20181116083430.7f1d8452@ipc1.ka-ro> <20181116082557.l2ljgu3hsu7tvdci@pengutronix.de> <91640f9b-d219-553e-043a-c6151f2f68d7@ysoft.com> <20181122162359.ufngpgxkenlmgqni@pengutronix.de> <20181122190321.ktqegs7kpvhcemvi@pengutronix.de> <9da8c6d9-d97c-200c-d8e4-2eb9f73eedc5@ysoft.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="y0ulUmNC+osPPQO6" Return-path: Content-Disposition: inline In-Reply-To: <9da8c6d9-d97c-200c-d8e4-2eb9f73eedc5@ysoft.com> Sender: linux-kernel-owner@vger.kernel.org To: =?utf-8?B?Vm9rw6HEjQ==?= Michal Cc: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , Lothar =?utf-8?Q?Wa=C3=9Fmann?= , Mark Rutland , "devicetree@vger.kernel.org" , "linux-pwm@vger.kernel.org" , Lukasz Majewski , "linux-kernel@vger.kernel.org" , Rob Herring , "kernel@pengutronix.de" , Fabio Estevam , Linus Walleij , viresh kumar List-Id: devicetree@vger.kernel.org --y0ulUmNC+osPPQO6 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Nov 23, 2018 at 03:15:11PM +0000, Vok=C3=A1=C4=8D Michal wrote: > On 22.11.2018 20:03, Uwe Kleine-K=C3=B6nig wrote: > > On Thu, Nov 22, 2018 at 04:46:39PM +0000, Vok=C3=A1=C4=8D Michal wrote: > >> On 22.11.2018 17:23, Uwe Kleine-K=C3=B6nig wrote: > >>> On Thu, Nov 22, 2018 at 03:42:14PM +0000, Vok=C3=A1=C4=8D Michal wrot= e: > >>>> On 16.11.2018 09:25, Uwe Kleine-K=C3=B6nig wrote: > >>>>> On Fri, Nov 16, 2018 at 08:34:30AM +0100, Lothar Wa=C3=9Fmann wrote: > >>>>>> No. You can disable the output driver via pinctrl, so that only the > >>>>>> selected pull-up/down is relevant. The pin function and GPIO regis= ter > >>>>>> settings don't matter at all in this case. > >>>> > >>>> Lothar, please can you be more specific how would you do that? IFAIK= the > >>>> pull-up/down internal resistors have effect only if the pin is confi= gured > >>>> as GPIO *input* (on i.MX6 at least). See the TRM, 29.4.2.2 Output dr= iver: > >>>> > >>>> "Internal pull-up, pull-down resistors, and pad keeper are disab= led in > >>>> output mode." > >=20 > > This would mean you'd have to rely on an external pull up for your use > > case. I wouldn't be surprised however if DSE=3D0 wouldn't count as "out= put > > mode". Given the reliability of NXP documentation I wouldn't bet neither > > on one nor the other possibility. >=20 > Yeah, the NXP documentation sometimes does not really match reality. > My use case is based on the fact that I configure the pin as input in > the driver. Then it works just fine. >=20 > >>> So I'd expect this to really work on i.MX6 but not the earlier SoCs > >>> without a gpio specifier. > >> > >> Maybe you would expect it to work but I already tested and measured > >> that weeks ago ;) It did not work. > >=20 > > Which pin/gpio do we talk about? Which i.MX6 variant did you test this > > on? (Assuming i.MX6D or i.MX6Q and PAD_DISP0_DATA09, did you try setting > >=20 > > IOMUXC_SW_MUX_CTL_PAD_DISP0_DATA09 (0x020E0194) =3D 0x00000005 > > IOMUXC_SW_PAD_CTL_PAD_DISP0_DATA09 (0x020E04A8) =3D 0x0000b080 > >=20 > > and then play with GPIO 4.30 direction and output value?) >=20 > My test setup is as follows: > - SoC is i.MX6DL or i.MX6S - I have three board variants in total. > - Pin used for PWM/GPIO is PAD_GPIO9. > - The pin is not connected to any circuit. Just a test point. > - pinctrl setup in DT: > - for "pwm": > - fsl,pins =3D > - IOMUXC_SW_MUX_CTL_PAD_GPIO09 =3D 0x00000004 > - IOMUXC_SW_PAD_CTL_PAD_GPIO09 =3D 0x00000008 >=20 > - for "gpio": > - fsl,pins =3D > - IOMUXC_SW_MUX_CTL_PAD_GPIO09 =3D 0x00000005 > - IOMUXC_SW_PAD_CTL_PAD_GPIO09 =3D 0x0000b000 Does it help if you additionally set the ODE bit (bit 11) here? Thierry --y0ulUmNC+osPPQO6 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAlv73jgACgkQ3SOs138+ s6Eo/hAAiZDZS/s4dgLSQLvuZolBku1IUFAPtT68E1MuS8GLBsO3HsTImJ3/+v9C QcohCQ4B1ymoOU8x5WcF5kDy928tpvZ7y+u1YG9QUt+jkmZ1tOIUPuSQbjwZsirU jDJxmLWMZfOuEydNIRM4CPKSyO6l/XD1QMdtV51LkCJLhvCSUv+bFVDwR+EBpXCw 0kBlLPuyjVFmp7Lg2oBIgIY2a56TwgpXJViAWRWxY1ugQaS9qrMj70gxlAjGkY0T Dz7ZxPTJU7YpggVHF09eO7ReYOFPikSc8hP/2fNIL0O2DbSc04mmbR6sXLY0al5A opadlDPtRvMli/5ECp0+jneaQStdThmB3DKfFCxG5rNpwb2dlnm//waFahM6Y9cY Kw+C9AJly3hiG1a2uQnmL5ijaBqyLXPlUAqMr5vtU2CHRNZRiHSmZzASSGObIkcn 4XHYWEkLkxvkxh0Av1Y3vBOX/6+WeZdKWBxNSISDFjG+G74SCKGQpxIRYrLXj+2S fAUHHZQSvL1RohhEmm9AICTcaQOuJz4aFV+ew4lo82zKhpbS/J7KvCHredi7tzuf pZI363JxqpalfLZQl7cfzYckbFHSnOb3LaYWiVnKgURt45y9Gd2giHqbrKqGJEmU SPWgv4bFPRfhnsOb+soBxbZNsOWCUfYPlStImQC+9toyDaIUkM0= =ImQK -----END PGP SIGNATURE----- --y0ulUmNC+osPPQO6--