From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH 4/5] regulator: pwm: Add support for voltage linear equal steps Date: Mon, 14 Mar 2016 16:28:43 +0000 Message-ID: <20160314162843.GC2566@sirena.org.uk> References: <1457434405-30372-1-git-send-email-ldewangan@nvidia.com> <1457434405-30372-5-git-send-email-ldewangan@nvidia.com> <20160312060925.GW3898@sirena.org.uk> <56E565BE.5010703@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="wxDdMuZNg1r63Hyj" Return-path: Content-Disposition: inline In-Reply-To: <56E565BE.5010703-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Laxman Dewangan Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, lgirdwood-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org --wxDdMuZNg1r63Hyj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Mar 13, 2016 at 06:36:06PM +0530, Laxman Dewangan wrote: > On Saturday 12 March 2016 11:39 AM, Mark Brown wrote: > >I can't see any reason why this would ever be preferable to just using > >the flat linear range (you certainly haven't articulated one, you're > >just stating it). This seems like you are bodging around a limited > >consumer driver, you should fix the consumer to cope with regulators > >with lots of voltages - PWM regulators aren't the only ones with high > >resolution steps. > The requirement is to have perfect linear steps interms of the period/pulse > time of PWM without loosing any voltage. > Continuous mode is pretty much near to what you said but here we are loosing > the perfect step as this divides the periods to 100 parts and then set > voltage. Could you be more specific about what the issue is? We've hopefully got errors of less than 1% in the values here... > If new mode is not accpetable then need to enhance the existing continuous > mode like before scaling for 100% of period, first look if we get the > perfect pulse time of of PWM period and if it is there then use this direct > instead of converting required voltage to 100% scale and then back > calculating duty time. That seems a lot better, what you're proposing is changing the ABI to fudge things for a client specific requirement where both the client requirement and the change you're proposing are specific to the current Linux implementation. That doesn't sound like a DT thing. --wxDdMuZNg1r63Hyj Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJW5ua6AAoJECTWi3JdVIfQqw0H/RQktJyRcNuIDmbziylrXQ5v czCa7zha6uSDIIizkU0pvwBI8tmrbgAUloRiACb8MlgEk1dsGShRjMjbShPeMLp8 rNe5FN5b3zRQQrOUzF40UzMwhiy+PuJhwPfMbE4GVwtE3nS5svbaonGD9SVjMiCB az0XrE1T28oef4tyhfbSxqq8C3w1JYgiNzbje09JLieMmFjYMaV5PKSId00eHGFg uMgNdUZ9Q4nhmA0zQPMUdMTUz8qu3XduLY0vHlICzY/Yc78mg3M/U3k8uNjztvRi r7zRGVt5bGfdkEdTeRbjJozx1sM6NGrBTCf0KqzUg9cv40fktFOqoJ3cY8G1zVM= =GJ61 -----END PGP SIGNATURE----- --wxDdMuZNg1r63Hyj-- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html