| Message ID | 20171104202009.3818-6-wsa+renesas@sang-engineering.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 4 Nov 2017 21:20:05 +0100 Wolfram Sang <wsa+renesas@sang-engineering.com> 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 <wsa+renesas@sang-engineering.com> Can't really argue with such a simple patch ;) Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > 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. > */
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. */
Use the new helper to create variants of i2c_master_{send|recv} which mark their buffers as DMA safe. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- include/linux/i2c.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)