From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262904AbUCPBiy (ORCPT ); Mon, 15 Mar 2004 20:38:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263363AbUCPB1V (ORCPT ); Mon, 15 Mar 2004 20:27:21 -0500 Received: from mail.kroah.org ([65.200.24.183]:34735 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S262910AbUCPACm convert rfc822-to-8bit (ORCPT ); Mon, 15 Mar 2004 19:02:42 -0500 Subject: Re: [PATCH] i2c driver fixes for 2.6.4 In-Reply-To: <1079391394926@kroah.com> X-Mailer: gregkh_patchbomb Date: Mon, 15 Mar 2004 14:56:35 -0800 Message-Id: <10793913953583@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII To: linux-kernel@vger.kernel.org, sensors@stimpy.netroedge.com Content-Transfer-Encoding: 7BIT From: Greg KH Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org ChangeSet 1.1608.74.16, 2004/03/15 13:09:19-08:00, khali@linux-fr.org [PATCH] I2C: Setting w83781d fan_div preserves fan_min This patch makes the w83781d driver preserve fan_min settings when the user changes fan_divs. This isn't done "by default" because the actual fan min value (in RPMs) depends on both the fan_min register and the fan_div register. Only two drivers handle it properly at the moment as far as I know (lm78 and asb100). Several other drivers would need to be fixed the same way, but well, once at a time ;) Tested on my AS99127F rev.1. Credits go to Philip Pokorny, since I think I remember he is the one who introduced the method in the lm78 driver in the first place. This tends to increase the size of the three set_store_regs_fan_div functions, and I am considering refactoring them at some point. Later though. drivers/i2c/chips/w83781d.c | 37 ++++++++++++++++++++++++++++++++++--- 1 files changed, 34 insertions(+), 3 deletions(-) diff -Nru a/drivers/i2c/chips/w83781d.c b/drivers/i2c/chips/w83781d.c --- a/drivers/i2c/chips/w83781d.c Mon Mar 15 14:33:59 2004 +++ b/drivers/i2c/chips/w83781d.c Mon Mar 15 14:33:59 2004 @@ -615,12 +615,21 @@ (long) DIV_FROM_REG(data->fan_div[nr - 1])); } +/* Note: we save and restore the fan minimum here, because its value is + determined in part by the fan divisor. This follows the principle of + least suprise; the user doesn't expect the fan minimum to change just + because the divisor changed. */ static ssize_t store_regs_fan_div_1(struct device *dev, const char *buf, size_t count) { struct i2c_client *client = to_i2c_client(dev); struct w83781d_data *data = i2c_get_clientdata(client); - u32 reg; + unsigned long min; + u8 reg; + + /* Save fan_min */ + min = FAN_FROM_REG(data->fan_min[0], + DIV_FROM_REG(data->fan_div[0])); data->fan_div[0] = DIV_TO_REG(simple_strtoul(buf, NULL, 10), data->type); @@ -636,6 +645,10 @@ w83781d_write_value(client, W83781D_REG_VBAT, reg); } + /* Restore fan_min */ + data->fan_min[0] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[0])); + w83781d_write_value(client, W83781D_REG_FAN_MIN(1), data->fan_min[0]); + return count; } @@ -644,7 +657,12 @@ { struct i2c_client *client = to_i2c_client(dev); struct w83781d_data *data = i2c_get_clientdata(client); - u32 reg; + unsigned long min; + u8 reg; + + /* Save fan_min */ + min = FAN_FROM_REG(data->fan_min[1], + DIV_FROM_REG(data->fan_div[1])); data->fan_div[1] = DIV_TO_REG(simple_strtoul(buf, NULL, 10), data->type); @@ -660,6 +678,10 @@ w83781d_write_value(client, W83781D_REG_VBAT, reg); } + /* Restore fan_min */ + data->fan_min[1] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[1])); + w83781d_write_value(client, W83781D_REG_FAN_MIN(2), data->fan_min[1]); + return count; } @@ -668,7 +690,12 @@ { struct i2c_client *client = to_i2c_client(dev); struct w83781d_data *data = i2c_get_clientdata(client); - u32 reg; + unsigned long min; + u8 reg; + + /* Save fan_min */ + min = FAN_FROM_REG(data->fan_min[2], + DIV_FROM_REG(data->fan_div[2])); data->fan_div[2] = DIV_TO_REG(simple_strtoul(buf, NULL, 10), data->type); @@ -683,6 +710,10 @@ reg |= (data->fan_div[2] & 0x04) << 5; w83781d_write_value(client, W83781D_REG_VBAT, reg); } + + /* Restore fan_min */ + data->fan_min[2] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[2])); + w83781d_write_value(client, W83781D_REG_FAN_MIN(3), data->fan_min[2]); return count; }