From: Jonathan Cameron <Jonathan.Cameron@huawei.com> To: Wolfram Sang <wsa+renesas@sang-engineering.com> 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 <broonie@kernel.org> Subject: Re: [PATCH v6 4/9] i2c: refactor i2c_master_{send_recv} Date: Sat, 11 Nov 2017 00:03:38 +0000 [thread overview] Message-ID: <20171111000338.00003f67@huawei.com> (raw) In-Reply-To: <20171104202009.3818-5-wsa+renesas@sang-engineering.com> On Sat, 4 Nov 2017 21:20:04 +0100 Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > Those two functions are very similar, the only differences are that one > needs the I2C_M_RD flag for its message while the other one needs the > buffer casted to drop the const. Introduce a generic helper which > allows to specify the flags (also needed later for DMA safe variants of > these calls) and let the casting be done in the inlining fuctions which > are now calling the new helper function. The casting away of the const is a bit nasty, but short of making this whole thing a macro, I can't see a better way. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > drivers/i2c/i2c-core-base.c | 64 +++++++++++++-------------------------------- > include/linux/i2c.h | 34 +++++++++++++++++++++--- > 2 files changed, 48 insertions(+), 50 deletions(-) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index de1850bd440659..206c47c85c98c5 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -1972,63 +1972,35 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > EXPORT_SYMBOL(i2c_transfer); > > /** > - * i2c_master_send - issue a single I2C message in master transmit mode > + * i2c_transfer_buffer_flags - issue a single I2C message transferring data > + * to/from a buffer > * @client: Handle to slave device > - * @buf: Data that will be written to the slave > - * @count: How many bytes to write, must be less than 64k since msg.len is u16 > + * @buf: Where the data is stored > + * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 > + * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads > * > - * Returns negative errno, or else the number of bytes written. > + * Returns negative errno, or else the number of bytes transferred. > */ > -int i2c_master_send(const struct i2c_client *client, const char *buf, int count) > +int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, > + int count, u16 flags) > { > int ret; > - struct i2c_adapter *adap = client->adapter; > - struct i2c_msg msg; > - > - msg.addr = client->addr; > - msg.flags = client->flags & I2C_M_TEN; > - msg.len = count; > - msg.buf = (char *)buf; > - > - ret = i2c_transfer(adap, &msg, 1); > - > - /* > - * If everything went ok (i.e. 1 msg transmitted), return #bytes > - * transmitted, else error code. > - */ > - return (ret == 1) ? count : ret; > -} > -EXPORT_SYMBOL(i2c_master_send); > - > -/** > - * i2c_master_recv - issue a single I2C message in master receive mode > - * @client: Handle to slave device > - * @buf: Where to store data read from slave > - * @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. > - */ > -int i2c_master_recv(const struct i2c_client *client, char *buf, int count) > -{ > - struct i2c_adapter *adap = client->adapter; > - struct i2c_msg msg; > - int ret; > - > - msg.addr = client->addr; > - msg.flags = client->flags & I2C_M_TEN; > - msg.flags |= I2C_M_RD; > - msg.len = count; > - msg.buf = buf; > + struct i2c_msg msg = { > + .addr = client->addr, > + .flags = flags | (client->flags & I2C_M_TEN), > + .len = count, > + .buf = buf, > + }; > > - ret = i2c_transfer(adap, &msg, 1); > + ret = i2c_transfer(client->adapter, &msg, 1); > > /* > - * If everything went ok (i.e. 1 msg received), return #bytes received, > - * else error code. > + * If everything went ok (i.e. 1 msg transferred), return #bytes > + * transferred, else error code. > */ > return (ret == 1) ? count : ret; > } > -EXPORT_SYMBOL(i2c_master_recv); > +EXPORT_SYMBOL(i2c_transfer_buffer_flags); > > /* ---------------------------------------------------- > * the i2c address scanning function > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index a0b57de91e21d3..ef1a8791c1ae24 100644 > --- a/include/linux/i2c.h > +++ b/include/linux/i2c.h > @@ -63,10 +63,36 @@ struct property_entry; > * transmit an arbitrary number of messages without interruption. > * @count must be be less than 64k since msg.len is u16. > */ > -extern int i2c_master_send(const struct i2c_client *client, const char *buf, > - int count); > -extern int i2c_master_recv(const struct i2c_client *client, char *buf, > - int count); > +extern int i2c_transfer_buffer_flags(const struct i2c_client *client, > + char *buf, int count, u16 flags); > + > +/** > + * i2c_master_recv - issue a single I2C message in master receive mode > + * @client: Handle to slave device > + * @buf: Where to store data read from slave > + * @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(const struct i2c_client *client, > + char *buf, int count) > +{ > + return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); > +}; > + > +/** > + * 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 > + * @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(const struct i2c_client *client, > + const char *buf, int count) > +{ > + return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); > +}; > > /* Transfer num messages. > */
WARNING: multiple messages have this Message-ID (diff)
From: Jonathan Cameron <Jonathan.Cameron@huawei.com> To: Wolfram Sang <wsa+renesas@sang-engineering.com> 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 <broonie@kernel.org> Subject: Re: [PATCH v6 4/9] i2c: refactor i2c_master_{send_recv} Date: Sat, 11 Nov 2017 00:03:38 +0000 [thread overview] Message-ID: <20171111000338.00003f67@huawei.com> (raw) In-Reply-To: <20171104202009.3818-5-wsa+renesas@sang-engineering.com> On Sat, 4 Nov 2017 21:20:04 +0100 Wolfram Sang <wsa+renesas@sang-engineering.com> wrote: > Those two functions are very similar, the only differences are that one > needs the I2C_M_RD flag for its message while the other one needs the > buffer casted to drop the const. Introduce a generic helper which > allows to specify the flags (also needed later for DMA safe variants of > these calls) and let the casting be done in the inlining fuctions which > are now calling the new helper function. The casting away of the const is a bit nasty, but short of making this whole thing a macro, I can't see a better way. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > drivers/i2c/i2c-core-base.c | 64 +++++++++++++-------------------------------- > include/linux/i2c.h | 34 +++++++++++++++++++++--- > 2 files changed, 48 insertions(+), 50 deletions(-) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index de1850bd440659..206c47c85c98c5 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -1972,63 +1972,35 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > EXPORT_SYMBOL(i2c_transfer); > > /** > - * i2c_master_send - issue a single I2C message in master transmit mode > + * i2c_transfer_buffer_flags - issue a single I2C message transferring data > + * to/from a buffer > * @client: Handle to slave device > - * @buf: Data that will be written to the slave > - * @count: How many bytes to write, must be less than 64k since msg.len is u16 > + * @buf: Where the data is stored > + * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 > + * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads > * > - * Returns negative errno, or else the number of bytes written. > + * Returns negative errno, or else the number of bytes transferred. > */ > -int i2c_master_send(const struct i2c_client *client, const char *buf, int count) > +int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, > + int count, u16 flags) > { > int ret; > - struct i2c_adapter *adap = client->adapter; > - struct i2c_msg msg; > - > - msg.addr = client->addr; > - msg.flags = client->flags & I2C_M_TEN; > - msg.len = count; > - msg.buf = (char *)buf; > - > - ret = i2c_transfer(adap, &msg, 1); > - > - /* > - * If everything went ok (i.e. 1 msg transmitted), return #bytes > - * transmitted, else error code. > - */ > - return (ret == 1) ? count : ret; > -} > -EXPORT_SYMBOL(i2c_master_send); > - > -/** > - * i2c_master_recv - issue a single I2C message in master receive mode > - * @client: Handle to slave device > - * @buf: Where to store data read from slave > - * @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. > - */ > -int i2c_master_recv(const struct i2c_client *client, char *buf, int count) > -{ > - struct i2c_adapter *adap = client->adapter; > - struct i2c_msg msg; > - int ret; > - > - msg.addr = client->addr; > - msg.flags = client->flags & I2C_M_TEN; > - msg.flags |= I2C_M_RD; > - msg.len = count; > - msg.buf = buf; > + struct i2c_msg msg = { > + .addr = client->addr, > + .flags = flags | (client->flags & I2C_M_TEN), > + .len = count, > + .buf = buf, > + }; > > - ret = i2c_transfer(adap, &msg, 1); > + ret = i2c_transfer(client->adapter, &msg, 1); > > /* > - * If everything went ok (i.e. 1 msg received), return #bytes received, > - * else error code. > + * If everything went ok (i.e. 1 msg transferred), return #bytes > + * transferred, else error code. > */ > return (ret == 1) ? count : ret; > } > -EXPORT_SYMBOL(i2c_master_recv); > +EXPORT_SYMBOL(i2c_transfer_buffer_flags); > > /* ---------------------------------------------------- > * the i2c address scanning function > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index a0b57de91e21d3..ef1a8791c1ae24 100644 > --- a/include/linux/i2c.h > +++ b/include/linux/i2c.h > @@ -63,10 +63,36 @@ struct property_entry; > * transmit an arbitrary number of messages without interruption. > * @count must be be less than 64k since msg.len is u16. > */ > -extern int i2c_master_send(const struct i2c_client *client, const char *buf, > - int count); > -extern int i2c_master_recv(const struct i2c_client *client, char *buf, > - int count); > +extern int i2c_transfer_buffer_flags(const struct i2c_client *client, > + char *buf, int count, u16 flags); > + > +/** > + * i2c_master_recv - issue a single I2C message in master receive mode > + * @client: Handle to slave device > + * @buf: Where to store data read from slave > + * @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(const struct i2c_client *client, > + char *buf, int count) > +{ > + return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); > +}; > + > +/** > + * 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 > + * @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(const struct i2c_client *client, > + const char *buf, int count) > +{ > + return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); > +}; > > /* Transfer num messages. > */
next prev parent reply other threads:[~2017-11-11 0:03 UTC|newest] Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-11-04 20:20 [PATCH v6 0/9] i2c: document DMA handling and add helpers for it Wolfram Sang 2017-11-04 20:20 ` Wolfram Sang 2017-11-04 20:20 ` [PATCH v6 1/9] i2c: add a message flag for DMA safe buffers Wolfram Sang 2017-11-04 20:20 ` [PATCH v6 2/9] i2c: add helpers to ease DMA handling Wolfram Sang 2017-11-04 20:20 ` Wolfram Sang 2017-11-04 20:20 ` [PATCH v6 3/9] i2c: dev: mark RDWR buffers as DMA_SAFE Wolfram Sang 2017-11-04 20:20 ` Wolfram Sang 2017-11-04 20:20 ` [PATCH v6 4/9] i2c: refactor i2c_master_{send_recv} Wolfram Sang 2017-11-11 0:03 ` Jonathan Cameron [this message] 2017-11-11 0:03 ` Jonathan Cameron 2017-11-04 20:20 ` [PATCH v6 5/9] i2c: add i2c_master_{send|recv}_dmasafe Wolfram Sang 2017-11-11 0:08 ` Jonathan Cameron 2017-11-11 0:08 ` Jonathan Cameron 2017-11-04 20:20 ` [PATCH v6 6/9] i2c: smbus: use DMA safe buffers for emulated SMBus transactions Wolfram Sang 2017-11-11 0:13 ` Jonathan Cameron 2017-11-11 0:13 ` Jonathan Cameron 2017-11-04 20:20 ` [PATCH v6 7/9] i2c: add docs to clarify DMA handling Wolfram Sang 2017-11-04 20:20 ` [PATCH v6 8/9] i2c: sh_mobile: use core helper to decide when to use DMA Wolfram Sang 2017-11-04 20:20 ` [PATCH v6 9/9] i2c: rcar: skip DMA if buffer is not safe Wolfram Sang 2017-11-08 22:50 ` [PATCH v6 0/9] i2c: document DMA handling and add helpers for it Mark Brown 2017-11-27 18:51 ` Wolfram Sang 2017-11-28 15:34 ` Mark Brown 2017-12-03 19:43 ` Wolfram Sang 2017-12-04 22:05 ` Mark Brown 2017-12-04 22:05 ` Mark Brown 2017-12-05 11:00 ` Jonathan Cameron 2017-12-05 11:00 ` Jonathan Cameron 2017-12-04 21:25 ` Wolfram Sang
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