From patchwork Tue Feb 24 04:33:51 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 5869681 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id EBAA9BF440 for ; Tue, 24 Feb 2015 04:36:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2DF732063C for ; Tue, 24 Feb 2015 04:36:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 490CC20634 for ; Tue, 24 Feb 2015 04:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752848AbbBXEgJ (ORCPT ); Mon, 23 Feb 2015 23:36:09 -0500 Received: from cantor2.suse.de ([195.135.220.15]:34437 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752364AbbBXEgE (ORCPT ); Mon, 23 Feb 2015 23:36:04 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 20A74ACA9; Tue, 24 Feb 2015 04:36:03 +0000 (UTC) From: NeilBrown To: Samuel Ortiz , Tony Lindgren , Lee Jones , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse Date: Tue, 24 Feb 2015 15:33:51 +1100 Subject: [PATCH 06/15] twl4030_charger: split uA calculation into a function. Cc: GTA04 owners , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Message-ID: <20150224043351.4243.86053.stgit@notabene.brown> In-Reply-To: <20150224043341.4243.23291.stgit@notabene.brown> References: <20150224043341.4243.23291.stgit@notabene.brown> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We will need this calculation in other places, so create functions to map between register value and uA value. Signed-off-by: NeilBrown Acked-by: Pavel Machek --- drivers/power/twl4030_charger.c | 48 ++++++++++++++++++++++++++++----------- 1 file changed, 35 insertions(+), 13 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/power/twl4030_charger.c b/drivers/power/twl4030_charger.c index db8931a17541..0b6fb06a0c01 100644 --- a/drivers/power/twl4030_charger.c +++ b/drivers/power/twl4030_charger.c @@ -178,6 +178,40 @@ static int twl4030_is_battery_present(struct twl4030_bci *bci) } /* + * TI provided formulas: + * CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85 + * CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7 + * Here we use integer approximation of: + * CGAIN == 0: val * 1.6618 - 0.85 * 1000 + * CGAIN == 1: (val * 1.6618 - 0.85 * 1000) * 2 + */ +/* + * convert twl register value for currents into uA + */ +static int regval2ua(int regval, bool cgain) +{ + if (cgain) + return (regval * 16618 - 8500 * 1000) / 5; + else + return (regval * 16618 - 8500 * 1000) / 10; +} + +/* + * convert uA currents into twl register value + */ +static int ua2regval(int ua, bool cgain) +{ + int ret; + if (cgain) + ua /= 2; + ret = (ua * 10 + 8500 * 1000) / 16618; + /* rounding problems */ + if (ret < 512) + ret = 512; + return ret; +} + +/* * Enable/Disable USB Charge functionality. */ static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable) @@ -366,14 +400,6 @@ static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val, return NOTIFY_OK; } -/* - * TI provided formulas: - * CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85 - * CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7 - * Here we use integer approximation of: - * CGAIN == 0: val * 1.6618 - 0.85 - * CGAIN == 1: (val * 1.6618 - 0.85) * 2 - */ static int twl4030_charger_get_current(void) { int curr; @@ -388,11 +414,7 @@ static int twl4030_charger_get_current(void) if (ret) return ret; - ret = (curr * 16618 - 850 * 10000) / 10; - if (bcictl1 & TWL4030_CGAIN) - ret *= 2; - - return ret; + return regval2ua(curr, bcictl1 & TWL4030_CGAIN); } /*