Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753450AbbBSVOv (ORCPT ); Thu, 19 Feb 2015 16:14:51 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:40080 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752427AbbBSVOu (ORCPT ); Thu, 19 Feb 2015 16:14:50 -0500 Date: Thu, 19 Feb 2015 15:14:24 -0600 From: Felipe Balbi To: , , , Linux Kernel Mailing List , Linux OMAP Mailing List Subject: "advanced" LED controllers Message-ID: <20150219211424.GN13603@saruman.tx.rr.com> Reply-To: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="JQ29orswtRjjfiJM" Content-Disposition: inline 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 Content-Length: 2724 Lines: 69 --JQ29orswtRjjfiJM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, Do we have support for LED controllers which can handle patterns of different kinds ? I mean, currently, if we have an LED controller such as TPIC2810 [1] which can control 8 different leds and each LED corresponds to one bit on register 0x44, we could control leds by just "playing" a wave file on the controller and create easy patterns with that. AFAICT, in linux today we would have to register each of the 8 LEDs as a different LED and have driver magic to write the proper bits on register 0x44, that seems a bit overkill, specially when we want to make patterns: instead of writing 0xff we would have to write 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 separately and have the driver cache the previous results so we don't end up switching off other LEDs. IOW, what could be handled with a single write, currently needs 8. I wonder if there's any work happening to support these slightly more inteligent LED engines. regards [1] http://www.ti.com/product/tpic2810 ps: tpic2810 is probably the simplest example, lp551, lp5523 and others have even more advanced pattern engines which can even handle RGB leds. Currently the driver loads patterns as if it was a firmware blob and registers each of R, G and B components as separate LEDs. Each component also has its own brightness controls (something tpic2810 doesn't have, it's either on or off). --=20 balbi --JQ29orswtRjjfiJM Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJU5lIwAAoJEIaOsuA1yqRErsQP/A3HDxA/MYW6vxuwP7h8v46c j6Kinanz8MutZqx+6FcJLCq9DY4dRpDqyeRucI4TdLsyaSulAZQadAcxVjsFRPUk 6h7i4KwNofwhCXeXrG5fXNUOyjHtWWPGefU9S63+Z6umTc2xyKzxVi0IxFhPs9rd w9GUgmNmd/f1JeJym4IwQGOw2IivPlTp+MYKUI+4Z9NI+MWYM3lPCKcVZ7qc2wA8 Tdcmn9nLUJ0/hMkm88lU9FattyRZ6qJfGvSLGZJGhh1v0dNNojbXz1PcUzCoJENY rsF3N57wj5GNbd8pPGJyMSKiyw3U8TWu/6hV5JUerG4ZP1HoOip3H2K8iFiVjFkz Jc76czwqj73vIOY8ZBM85qCtnIuX1evWDlqU5a3W2GNNiNckKhSrq5qygbwkneNB Xg3TOxkFSWG8/0wZvFF+ziJjr4jQO6emRWYGESZpnzRMDobuLh9aS76uPtqvidr+ 8tJeFqQf/6F/z7m4QkYxMZvmzE3S72aQlwMNkUX/5+aOXuDRzbJzgpN9BVYsoy9S H9uJWF2P4HrSKUQowWHQnRjcJ9MxJ1ADbSYjNfqglUNoEX85BudTkv9jvGCUiRxR HsMi4oe1U7NUU2AcCSfdbV+Rby+u2HXAiAamPtR7xKD0CYwbckw6gNknYj/k8SZl +7BAnVQqzWbpaFzk2O9P =+tXS -----END PGP SIGNATURE----- --JQ29orswtRjjfiJM-- -- 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/