Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751642AbdGYL1s (ORCPT ); Tue, 25 Jul 2017 07:27:48 -0400 Received: from mail.izt-labs.de ([82.135.25.162]:51330 "EHLO mail.izt-labs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751582AbdGYL1p (ORCPT ); Tue, 25 Jul 2017 07:27:45 -0400 From: Johannes Poehlmann To: linux-kernel@vger.kernel.org Cc: Johannes Poehlmann , Evgeniy Polyakov , Greg Kroah-Hartman Subject: [PATCH v4 1/5] w1: ds1wm: fix register offset (bus shift) calculation Date: Tue, 25 Jul 2017 13:27:11 +0200 Message-Id: <1500982035-28838-2-git-send-email-johannes.poehlmann@izt-labs.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1500982035-28838-1-git-send-email-johannes.poehlmann@izt-labs.de> References: <1500982035-28838-1-git-send-email-johannes.poehlmann@izt-labs.de> In-Reply-To: <20170718141502.GA18857@kroah.com> References: <20170718141502.GA18857@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3244 Lines: 98 Replace incorrect register offsett calculation by direct configuration of bus_shift in mfd-cell. Indirect definition of address-shift by resource size was unobvious and was wrong (should have used a binary log). Signed-off-by: Johannes Poehlmann Acked-by: Evgeniy Polyakov --- drivers/w1/masters/ds1wm.c | 23 +++++++++++++++++++---- include/linux/mfd/ds1wm.h | 24 +++++++++++++++++------- 2 files changed, 36 insertions(+), 11 deletions(-) diff --git a/drivers/w1/masters/ds1wm.c b/drivers/w1/masters/ds1wm.c index fd2e9da..401e53e 100644 --- a/drivers/w1/masters/ds1wm.c +++ b/drivers/w1/masters/ds1wm.c @@ -95,7 +95,7 @@ static struct { struct ds1wm_data { void __iomem *map; - int bus_shift; /* # of shifts to calc register offsets */ + unsigned int bus_shift; /* # of shifts to calc register offsets */ struct platform_device *pdev; const struct mfd_cell *cell; int irq; @@ -473,9 +473,6 @@ static int ds1wm_probe(struct platform_device *pdev) if (!ds1wm_data->map) return -ENOMEM; - /* calculate bus shift from mem resource */ - ds1wm_data->bus_shift = resource_size(res) >> 3; - ds1wm_data->pdev = pdev; ds1wm_data->cell = mfd_get_cell(pdev); if (!ds1wm_data->cell) @@ -484,6 +481,24 @@ static int ds1wm_probe(struct platform_device *pdev) if (!plat) return -ENODEV; + /* how many bits to shift register number to get register offset */ + if (plat->bus_shift > 2) { + dev_err(&ds1wm_data->pdev->dev, + "illegal bus shift %d, not written", + ds1wm_data->bus_shift); + return -EINVAL; + } + + ds1wm_data->bus_shift = plat->bus_shift; + /* make sure resource has space for 8 registers */ + if ((8 << ds1wm_data->bus_shift) > resource_size(res)) { + dev_err(&ds1wm_data->pdev->dev, + "memory resource size %d to small, should be %d\n", + (int)resource_size(res), + 8 << ds1wm_data->bus_shift); + return -EINVAL; + } + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (!res) return -ENXIO; diff --git a/include/linux/mfd/ds1wm.h b/include/linux/mfd/ds1wm.h index 38a372a..79a01e8 100644 --- a/include/linux/mfd/ds1wm.h +++ b/include/linux/mfd/ds1wm.h @@ -1,13 +1,23 @@ -/* MFD cell driver data for the DS1WM driver */ +/* MFD cell driver data for the DS1WM driver + * + * to be defined in the MFD device that is + * using this driver for one of his sub devices + */ struct ds1wm_driver_data { int active_high; int clock_rate; - /* in milliseconds, the amount of time to */ - /* sleep following a reset pulse. Zero */ - /* should work if your bus devices recover*/ - /* time respects the 1-wire spec since the*/ - /* ds1wm implements the precise timings of*/ - /* a reset pulse/presence detect sequence.*/ + /* in milliseconds, the amount of time to + * sleep following a reset pulse. Zero + * should work if your bus devices recover + * time respects the 1-wire spec since the + * ds1wm implements the precise timings of + * a reset pulse/presence detect sequence. + */ unsigned int reset_recover_delay; + + /* left shift of register number to get register address offsett. + * Only 0,1,2 allowed for 8,16 or 32 bit bus width respectively + */ + unsigned int bus_shift; }; -- 2.1.4