From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A46CC25B0C for ; Sat, 6 Aug 2022 14:33:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231772AbiHFOd5 (ORCPT ); Sat, 6 Aug 2022 10:33:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231322AbiHFOd4 (ORCPT ); Sat, 6 Aug 2022 10:33:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 202C0DF4B; Sat, 6 Aug 2022 07:33:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B1F7F61083; Sat, 6 Aug 2022 14:33:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BE48C433C1; Sat, 6 Aug 2022 14:33:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659796434; bh=9fiTg8lNS3hGnstVONUZi+Slu960suCrCuosPk+E2AU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=S8e5yiA1cR3Zawf/MhHO7jIauSbmWf66F6USk1BCRwR5BtpVeBzqv4bM0e5vfE5YY MZwLHxqSG1Tqmh/Qnxe8WRgimUcsabbspvOxjXnvhe0WHlyk7Qwf4nHFQJl7U81Knx g+XdXx4quEhLjbi/TZ8JtB2Io/Bd/qzKGvLD65qPPPTkyiRp3o21/hR8rbgTS7TJC/ Wx9Glu+jqJWWO2RV/O8H0ElvVaEKl0eg+l8OyTU/8tIeaPH5POgbx0Zlct+sRshMdz n8KeCNQLruMU509tXoZH+4CBlZDSeN1RwsQqgE4uhfne9KWpb7lWTcCXPvbo9hywuf yhcHxp7Plj7MQ== Date: Sat, 6 Aug 2022 15:44:12 +0100 From: Jonathan Cameron To: Jason Gerecke Cc: linux-i2c@vger.kernel.org, linux-iio , Lars-Peter Clausen , Wolfram Sang , Andy Shevchenko , LKML , Ping Cheng , "Tobita, Tatsunosuke" , Jason Gerecke , Ping Cheng Subject: Re: [PATCH v2] i2c: Use u8 type in i2c transfer calls Message-ID: <20220806154412.581a4f83@jic23-huawei> In-Reply-To: <20220803145937.698603-1-jason.gerecke@wacom.com> References: <20220718153448.173652-1-jason.gerecke@wacom.com> <20220803145937.698603-1-jason.gerecke@wacom.com> X-Mailer: Claws Mail 4.1.0 (GTK 3.24.34; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On Wed, 3 Aug 2022 07:59:37 -0700 Jason Gerecke wrote: > The 'i2c_transfer_buffer_flags' function (and related inlines) defines its > 'buf' argument to be of type 'char*'. This is a poor choice of type given > that most callers actually pass a 'u8*' and that the function itself ends > up just storing the variable to a 'u8*'-typed member of 'struct i2c_msg' > anyway. > > Changing the type of the 'buf' argument to 'u8*' vastly reduces the number > of (admittedly usually-silent) Wpointer-sign warnings that are generated > as the types get needlessly juggled back and forth. > > At the same time, update the max1363 driver to match the new interface so > we don't introduce a new Wincompatible-function-pointer-types warning. > > Signed-off-by: Jason Gerecke > Reviewed-by: Ping Cheng With the minor stuff Andy raised tidied up I'm fine with this change. Acked-by: Jonathan Cameron I'd forgotten all about the oddities of the max1363 :) That brings back some memories! Jonathan > --- > Changes in v2: > - Added modifications to the max1363 driver required to avoid warnings > > drivers/i2c/i2c-core-base.c | 2 +- > drivers/iio/adc/max1363.c | 8 ++++---- > include/linux/i2c.h | 14 +++++++------- > 3 files changed, 12 insertions(+), 12 deletions(-) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 10f35f942066a..2925507e8626d 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -2184,7 +2184,7 @@ EXPORT_SYMBOL(i2c_transfer); > * > * Returns negative errno, or else the number of bytes transferred. > */ > -int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, > +int i2c_transfer_buffer_flags(const struct i2c_client *client, u8 *buf, > int count, u16 flags) > { > int ret; > diff --git a/drivers/iio/adc/max1363.c b/drivers/iio/adc/max1363.c > index eef55ed4814a6..ebe6eb99583da 100644 > --- a/drivers/iio/adc/max1363.c > +++ b/drivers/iio/adc/max1363.c > @@ -184,9 +184,9 @@ struct max1363_state { > struct regulator *vref; > u32 vref_uv; > int (*send)(const struct i2c_client *client, > - const char *buf, int count); > + const u8 *buf, int count); > int (*recv)(const struct i2c_client *client, > - char *buf, int count); > + u8 *buf, int count); > }; > > #define MAX1363_MODE_SINGLE(_num, _mask) { \ > @@ -312,7 +312,7 @@ static const struct max1363_mode > return NULL; > } > > -static int max1363_smbus_send(const struct i2c_client *client, const char *buf, > +static int max1363_smbus_send(const struct i2c_client *client, const u8 *buf, > int count) > { > int i, err; > @@ -323,7 +323,7 @@ static int max1363_smbus_send(const struct i2c_client *client, const char *buf, > return err ? err : count; > } > > -static int max1363_smbus_recv(const struct i2c_client *client, char *buf, > +static int max1363_smbus_recv(const struct i2c_client *client, u8 *buf, > int count) > { > int i, ret; > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index 8eab5017bff30..3a94385f4642c 100644 > --- a/include/linux/i2c.h > +++ b/include/linux/i2c.h > @@ -64,7 +64,7 @@ const char *i2c_freq_mode_string(u32 bus_freq_hz); > * @count must be less than 64k since msg.len is u16. > */ > int i2c_transfer_buffer_flags(const struct i2c_client *client, > - char *buf, int count, u16 flags); > + u8 *buf, int count, u16 flags); > > /** > * i2c_master_recv - issue a single I2C message in master receive mode > @@ -75,7 +75,7 @@ int i2c_transfer_buffer_flags(const struct i2c_client *client, > * Returns negative errno, or else the number of bytes read. > */ > static inline int i2c_master_recv(const struct i2c_client *client, > - char *buf, int count) > + u8 *buf, int count) > { > return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); > }; > @@ -90,7 +90,7 @@ static inline int i2c_master_recv(const struct i2c_client *client, > * Returns negative errno, or else the number of bytes read. > */ > static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, > - char *buf, int count) > + u8 *buf, int count) > { > return i2c_transfer_buffer_flags(client, buf, count, > I2C_M_RD | I2C_M_DMA_SAFE); > @@ -105,9 +105,9 @@ static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, > * Returns negative errno, or else the number of bytes written. > */ > static inline int i2c_master_send(const struct i2c_client *client, > - const char *buf, int count) > + const u8 *buf, int count) > { > - return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); > + return i2c_transfer_buffer_flags(client, (u8 *)buf, count, 0); > }; > > /** > @@ -120,9 +120,9 @@ static inline int i2c_master_send(const struct i2c_client *client, > * Returns negative errno, or else the number of bytes written. > */ > static inline int i2c_master_send_dmasafe(const struct i2c_client *client, > - const char *buf, int count) > + const u8 *buf, int count) > { > - return i2c_transfer_buffer_flags(client, (char *)buf, count, > + return i2c_transfer_buffer_flags(client, (u8 *)buf, count, > I2C_M_DMA_SAFE); > }; >