From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765121Ab3DJGq1 (ORCPT ); Wed, 10 Apr 2013 02:46:27 -0400 Received: from mail-pb0-f47.google.com ([209.85.160.47]:48096 "EHLO mail-pb0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752063Ab3DJGqZ (ORCPT ); Wed, 10 Apr 2013 02:46:25 -0400 Message-ID: <1365576380.4283.5.camel@phoenix> Subject: [PATCH RFT 2/2] regulator: ab8500: Optimize ab8540_aux3_regulator_get_voltage_sel From: Axel Lin To: Mark Brown Cc: Bengt Jonsson , Lee Jones , Yvan FILLION , Liam Girdwood , linux-kernel@vger.kernel.org Date: Wed, 10 Apr 2013 14:46:20 +0800 In-Reply-To: <1365576052.4283.2.camel@phoenix> References: <1365576052.4283.2.camel@phoenix> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.2-0ubuntu0.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can save a register read operation in some case if read expand_register first. If info->expand_register.voltage_mask bit is set, no need to read voltage_reg. Signed-off-by: Axel Lin --- drivers/regulator/ab8500.c | 42 ++++++++++++++++++------------------------ 1 file changed, 18 insertions(+), 24 deletions(-) diff --git a/drivers/regulator/ab8500.c b/drivers/regulator/ab8500.c index 222a63e..7a86fe6 100644 --- a/drivers/regulator/ab8500.c +++ b/drivers/regulator/ab8500.c @@ -521,7 +521,7 @@ static int ab8500_regulator_get_voltage_sel(struct regulator_dev *rdev) static int ab8540_aux3_regulator_get_voltage_sel(struct regulator_dev *rdev) { - int ret, val; + int ret; struct ab8500_regulator_info *info = rdev_get_drvdata(rdev); u8 regval, regval_expand; @@ -531,18 +531,25 @@ static int ab8540_aux3_regulator_get_voltage_sel(struct regulator_dev *rdev) } ret = abx500_get_register_interruptible(info->dev, - info->voltage_bank, info->voltage_reg, ®val); - + info->expand_register.voltage_bank, + info->expand_register.voltage_reg, ®val_expand); if (ret < 0) { dev_err(rdev_get_dev(rdev), - "couldn't read voltage reg for regulator\n"); + "couldn't read voltage expand reg for regulator\n"); return ret; } - ret = abx500_get_register_interruptible(info->dev, - info->expand_register.voltage_bank, - info->expand_register.voltage_reg, ®val_expand); + dev_vdbg(rdev_get_dev(rdev), + "%s-get_voltage expand (bank, reg, mask, value): 0x%x, 0x%x, 0x%x, 0x%x\n", + info->desc.name, info->expand_register.voltage_bank, + info->expand_register.voltage_reg, + info->expand_register.voltage_mask, regval_expand); + + if (regval_expand & info->expand_register.voltage_mask) + return info->expand_register.voltage_limit; + ret = abx500_get_register_interruptible(info->dev, + info->voltage_bank, info->voltage_reg, ®val); if (ret < 0) { dev_err(rdev_get_dev(rdev), "couldn't read voltage reg for regulator\n"); @@ -550,24 +557,11 @@ static int ab8540_aux3_regulator_get_voltage_sel(struct regulator_dev *rdev) } dev_vdbg(rdev_get_dev(rdev), - "%s-get_voltage (bank, reg, mask, value): 0x%x, 0x%x, 0x%x," - " 0x%x\n", - info->desc.name, info->voltage_bank, info->voltage_reg, - info->voltage_mask, regval); - dev_vdbg(rdev_get_dev(rdev), - "%s-get_voltage expand (bank, reg, mask, value): 0x%x, 0x%x, 0x%x," - " 0x%x\n", - info->desc.name, info->expand_register.voltage_bank, - info->expand_register.voltage_reg, - info->expand_register.voltage_mask, regval_expand); - - if (regval_expand&(info->expand_register.voltage_mask)) - /* Vaux3 has a different layout */ - val = info->expand_register.voltage_limit; - else - val = (regval & info->voltage_mask) >> info->voltage_shift; + "%s-get_voltage (bank, reg, mask, value): 0x%x, 0x%x, 0x%x, 0x%x\n", + info->desc.name, info->voltage_bank, info->voltage_reg, + info->voltage_mask, regval); - return val; + return (regval & info->voltage_mask) >> info->voltage_shift; } static int ab8500_regulator_set_voltage_sel(struct regulator_dev *rdev, -- 1.7.10.4