From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752771AbcKITcO (ORCPT ); Wed, 9 Nov 2016 14:32:14 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:46755 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751688AbcKITcM (ORCPT ); Wed, 9 Nov 2016 14:32:12 -0500 Date: Wed, 9 Nov 2016 11:32:06 -0800 From: Guenter Roeck To: Clemens Gruber Cc: linux-hwmon@vger.kernel.org, Jean Delvare , linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/3] hwmon: (mcp3021) add devicetree support Message-ID: <20161109193206.GB22665@roeck-us.net> References: <20161109171614.9730-1-clemens.gruber@pqgruber.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161109171614.9730-1-clemens.gruber@pqgruber.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 09, 2016 at 06:16:13PM +0100, Clemens Gruber wrote: > Support setting the reference voltage from the device tree. > > Signed-off-by: Clemens Gruber > --- > drivers/hwmon/mcp3021.c | 46 ++++++++++++++++++++++++++++++++++++---------- > 1 file changed, 36 insertions(+), 10 deletions(-) > > diff --git a/drivers/hwmon/mcp3021.c b/drivers/hwmon/mcp3021.c > index 972444a..81f4b7f 100644 > --- a/drivers/hwmon/mcp3021.c > +++ b/drivers/hwmon/mcp3021.c > @@ -4,6 +4,7 @@ > * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc. > * Author: Mingkai Hu > * Reworked by Sven Schuchmann > + * Copyright (C) 2016 Clemens Gruber Sorry, I can't accept that for such a minor change. Feel free to add something like "devicetree support added by ...", if you like. > * > * This driver export the value of analog input voltage to sysfs, the > * voltage unit is mV. Through the sysfs interface, lm-sensors tool > @@ -22,11 +23,13 @@ > #include > #include > #include > +#include > +#include > > -/* Vdd info */ > +/* Vdd / reference voltage in millivolt */ > #define MCP3021_VDD_MAX 5500 > #define MCP3021_VDD_MIN 2700 > -#define MCP3021_VDD_REF 3300 > +#define MCP3021_VDD_DEFAULT 3300 I don't really see the value of changing this, but if it makes you feel better at least make it MCP3021_VDD_REF_DEFAULT. > > /* output format */ > #define MCP3021_SAR_SHIFT 2 > @@ -47,7 +50,7 @@ enum chips { > */ > struct mcp3021_data { > struct device *hwmon_dev; > - u32 vdd; /* device power supply */ > + u32 vdd; /* supply and reference voltage in millivolt */ > u16 sar_shift; > u16 sar_mask; > u8 output_res; > @@ -106,6 +109,7 @@ static int mcp3021_probe(struct i2c_client *client, > { > int err; > struct mcp3021_data *data = NULL; > + struct device_node *np = client->dev.of_node; > > if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) > return -ENODEV; > @@ -117,6 +121,21 @@ static int mcp3021_probe(struct i2c_client *client, > > i2c_set_clientdata(client, data); > > + if (np) { > + if (of_property_read_u32(np, "reference-voltage-microvolt", > + &data->vdd)) > + data->vdd = MCP3021_VDD_DEFAULT; > + else > + data->vdd /= 1000; It would be slightly better to reverse the logic here to make the code easier to read. if (!of_property_read_u32(np, "reference-voltage-microvolt", &data->vdd)) data->vdd /= 1000; else data->vdd = MCP3021_VDD_DEFAULT; Not worth arguing about it, though, so feel free to keep it as is. > + } else { > + u32 *pdata = dev_get_platdata(&client->dev); > + > + if (pdata) > + data->vdd = *pdata; > + else > + data->vdd = MCP3021_VDD_DEFAULT; > + } > + > switch (id->driver_data) { > case mcp3021: > data->sar_shift = MCP3021_SAR_SHIFT; > @@ -129,15 +148,12 @@ static int mcp3021_probe(struct i2c_client *client, > data->sar_mask = MCP3221_SAR_MASK; > data->output_res = MCP3221_OUTPUT_RES; > break; > + default: > + return -ENODEV; Hmm ... that is really an unrelated change (nor is it really needed unless there is a bug in the code). Not worth arguing about it either, but please keep in mind that this is one of the things making life hard for maintainers. > } > > - if (dev_get_platdata(&client->dev)) { > - data->vdd = *(u32 *)dev_get_platdata(&client->dev); > - if (data->vdd > MCP3021_VDD_MAX || data->vdd < MCP3021_VDD_MIN) > - return -EINVAL; > - } else { > - data->vdd = MCP3021_VDD_REF; > - } > + if (data->vdd > MCP3021_VDD_MAX || data->vdd < MCP3021_VDD_MIN) > + return -EINVAL; > > err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr); > if (err) > @@ -173,9 +189,19 @@ static const struct i2c_device_id mcp3021_id[] = { > }; > MODULE_DEVICE_TABLE(i2c, mcp3021_id); > > +#ifdef CONFIG_OF > +static const struct of_device_id of_mcp3021_match[] = { > + { .compatible = "microchip,mcp3021", .data = (void *)mcp3021 }, > + { .compatible = "microchip,mcp3221", .data = (void *)mcp3221 }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, of_mcp3021_match); > +#endif > + > static struct i2c_driver mcp3021_driver = { > .driver = { > .name = "mcp3021", > + .of_match_table = of_match_ptr(of_mcp3021_match), > }, > .probe = mcp3021_probe, > .remove = mcp3021_remove, > -- > 2.10.2 >