From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Cameron Subject: Re: [PATCH v6 5/9] i2c: add i2c_master_{send|recv}_dmasafe Date: Sat, 11 Nov 2017 00:08:50 +0000 Message-ID: <20171111000850.00003b44@huawei.com> References: <20171104202009.3818-1-wsa+renesas@sang-engineering.com> <20171104202009.3818-6-wsa+renesas@sang-engineering.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171104202009.3818-6-wsa+renesas@sang-engineering.com> Sender: linux-input-owner@vger.kernel.org To: Wolfram Sang Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-iio@vger.kernel.org, linux-input@vger.kernel.org, linux-media@vger.kernel.org, Mark Brown List-Id: linux-i2c@vger.kernel.org On Sat, 4 Nov 2017 21:20:05 +0100 Wolfram Sang wrote: > Use the new helper to create variants of i2c_master_{send|recv} which > mark their buffers as DMA safe. > > Signed-off-by: Wolfram Sang Can't really argue with such a simple patch ;) Acked-by: Jonathan Cameron > --- > include/linux/i2c.h | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index ef1a8791c1ae24..8c144e3cbfb261 100644 > --- a/include/linux/i2c.h > +++ b/include/linux/i2c.h > @@ -81,6 +81,22 @@ static inline int i2c_master_recv(const struct i2c_client *client, > }; > > /** > + * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode > + * using a DMA safe buffer > + * @client: Handle to slave device > + * @buf: Where to store data read from slave, must be safe to use with DMA > + * @count: How many bytes to read, must be less than 64k since msg.len is u16 > + * > + * 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) > +{ > + return i2c_transfer_buffer_flags(client, buf, count, > + I2C_M_RD | I2C_M_DMA_SAFE); > +}; > + > +/** > * i2c_master_send - issue a single I2C message in master transmit mode > * @client: Handle to slave device > * @buf: Data that will be written to the slave > @@ -93,6 +109,21 @@ static inline int i2c_master_send(const struct i2c_client *client, > { > return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); > }; > +/** > + * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode > + * using a DMA safe buffer > + * @client: Handle to slave device > + * @buf: Data that will be written to the slave, must be safe to use with DMA > + * @count: How many bytes to write, must be less than 64k since msg.len is u16 > + * > + * 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) > +{ > + return i2c_transfer_buffer_flags(client, (char *)buf, count, > + I2C_M_DMA_SAFE); > +}; > > /* Transfer num messages. > */