| Message ID | 1398695268-28645-6-git-send-email-tianyu.lan@intel.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On Mon, Apr 28, 2014 at 10:27:44PM +0800, Lan Tianyu wrote: > Add i2c_smbus_quick_write/read() helper function. These will be used > in the implementation of i2c ACPI address space handler. > > Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> > Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> We had such a function once but removed because of no users. Please check 67c2e66571c383404a5acd08189194da660da942 what it takes to bring them back. Especially missing are documentation updates... > +s32 i2c_smbus_quick_write(const struct i2c_client *client) ... and I like the original function much better. 1) It is named *_write_quick which follows other function name patterns 2) It uses a parameter for the r/w bit. Make sense to me, since this bit is the information we send to the device. quick_read doesn't make sense to me. We don't receive a bit from the device.
On 05/17/2014 05:41 PM, Wolfram Sang wrote: > On Mon, Apr 28, 2014 at 10:27:44PM +0800, Lan Tianyu wrote: >> Add i2c_smbus_quick_write/read() helper function. These will be used >> in the implementation of i2c ACPI address space handler. >> >> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> >> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> > > We had such a function once but removed because of no users. Please > check 67c2e66571c383404a5acd08189194da660da942 what it takes to bring > them back. Especially missing are documentation updates... > >> +s32 i2c_smbus_quick_write(const struct i2c_client *client) > > ... and I like the original function much better. > > 1) It is named *_write_quick which follows other function name patterns > 2) It uses a parameter for the r/w bit. Make sense to me, since this bit > is the information we send to the device. quick_read doesn't make sense > to me. We don't receive a bit from the device. > Hi Wolfram: Great thanks for your review. Ok. I will follow commit 67c2e665 to bring i2c_smbus_write_quick(struct i2c_client *client, u8 value) back. BTW, how about i2c_probe_func_quick_read()? Should we replace it with the original i2c_smbus_write_quick()? -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> >2) It uses a parameter for the r/w bit. Make sense to me, since this bit > >is the information we send to the device. quick_read doesn't make sense > >to me. We don't receive a bit from the device. > > > > Hi Wolfram: > Great thanks for your review. Ok. I will follow commit 67c2e665 to > bring i2c_smbus_write_quick(struct i2c_client *client, u8 value) > back. > > BTW, how about i2c_probe_func_quick_read()? Should we replace it > with the original i2c_smbus_write_quick()? As said above "quick_read doesn't make sense to me. We don't receive a bit from the device." Start implementing and you will see why we don't need it :)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 7c7f4b8..3bf0048 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -2162,6 +2162,36 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) } /** + * i2c_smbus_quick_write - SMBus "quick write" protocol + * @client: Handle to slave device + * + * This executes the SMBus "quick write" protocol, returning negative errno + * else zero on success. + */ +s32 i2c_smbus_quick_write(const struct i2c_client *client) +{ + return i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, 0, + I2C_SMBUS_QUICK, NULL); +} +EXPORT_SYMBOL_GPL(i2c_smbus_quick_write); + +/** + * i2c_smbus_quick_read - SMBus "quick read" protocol + * @client: Handle to slave device + * + * This executes the SMBus "quick read" protocol, returning negative errno + * else zero on success. + */ +s32 i2c_smbus_quick_read(const struct i2c_client *client) +{ + return i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, 0, + I2C_SMBUS_QUICK, NULL); +} +EXPORT_SYMBOL_GPL(i2c_smbus_quick_read); + +/** * i2c_smbus_read_byte - SMBus "receive byte" protocol * @client: Handle to slave device * diff --git a/include/linux/i2c.h b/include/linux/i2c.h index b556e0a..3e6ea90 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -82,6 +82,8 @@ extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, /* Now follow the 'nice' access routines. These also document the calling conventions of i2c_smbus_xfer. */ +extern s32 i2c_smbus_quick_write(const struct i2c_client *client); +extern s32 i2c_smbus_quick_read(const struct i2c_client *client); extern s32 i2c_smbus_read_byte(const struct i2c_client *client); extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,