[RESEND PATCH 1/3] i2c: added FUNC flag for unsupported clock stretching

[RESEND PATCH 1/3] i2c: added FUNC flag for unsupported clock stretching

[Nicola Corna]

Added I2C_FUNC_NO_CLK_STRETCH, to be used when clock stretching is not
supported.

Signed-off-by: Nicola Corna <nicola-V0pQiMyom5mh6J55Ss3d3w@public.gmane.org>
---
 Documentation/i2c/functionality | 1 +
 include/uapi/linux/i2c.h        | 1 +
 2 files changed, 2 insertions(+)

diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality
index 4aae8ed..f53807e 100644
--- a/Documentation/i2c/functionality
+++ b/Documentation/i2c/functionality
@@ -21,6 +21,7 @@ For the most up-to-date list of functionality constants, please check
                                   I2C_M_REV_DIR_ADDR and I2C_M_NO_RD_ACK
                                   flags (which modify the I2C protocol!)
   I2C_FUNC_NOSTART                Can skip repeated start sequence
+  I2C_FUNC_NO_CLK_STRETCH         Does NOT support clock stretching
   I2C_FUNC_SMBUS_QUICK            Handles the SMBus write_quick command
   I2C_FUNC_SMBUS_READ_BYTE        Handles the SMBus read_byte command
   I2C_FUNC_SMBUS_WRITE_BYTE       Handles the SMBus write_byte command
diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h
index b0a7dd6..59e4b43 100644
--- a/include/uapi/linux/i2c.h
+++ b/include/uapi/linux/i2c.h
@@ -88,6 +88,7 @@ struct i2c_msg {
 #define I2C_FUNC_SMBUS_PEC		0x00000008
 #define I2C_FUNC_NOSTART		0x00000010 /* I2C_M_NOSTART */
 #define I2C_FUNC_SLAVE			0x00000020
+#define I2C_FUNC_NO_CLK_STRETCH		0x00000040 /* No check for SCL low */
 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
 #define I2C_FUNC_SMBUS_QUICK		0x00010000
 #define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
-- 
2.5.1

Re: [RESEND PATCH 1/3] i2c: added FUNC flag for unsupported clock stretching

[Wolfram Sang]

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On Wed, Sep 16, 2015 at 03:32:01PM +0200, Nicola Corna wrote:
> Added I2C_FUNC_NO_CLK_STRETCH, to be used when clock stretching is not
> supported.
> 
> Signed-off-by: Nicola Corna <nicola@corna.info>

I think this should be rather a quirk than a functionality, i.e.
I2C_AQ_NO_CLK_STRETCH. Agree?

> ---
>  Documentation/i2c/functionality | 1 +
>  include/uapi/linux/i2c.h        | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality
> index 4aae8ed..f53807e 100644
> --- a/Documentation/i2c/functionality
> +++ b/Documentation/i2c/functionality
> @@ -21,6 +21,7 @@ For the most up-to-date list of functionality constants, please check
>                                    I2C_M_REV_DIR_ADDR and I2C_M_NO_RD_ACK
>                                    flags (which modify the I2C protocol!)
>    I2C_FUNC_NOSTART                Can skip repeated start sequence
> +  I2C_FUNC_NO_CLK_STRETCH         Does NOT support clock stretching
>    I2C_FUNC_SMBUS_QUICK            Handles the SMBus write_quick command
>    I2C_FUNC_SMBUS_READ_BYTE        Handles the SMBus read_byte command
>    I2C_FUNC_SMBUS_WRITE_BYTE       Handles the SMBus write_byte command
> diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h
> index b0a7dd6..59e4b43 100644
> --- a/include/uapi/linux/i2c.h
> +++ b/include/uapi/linux/i2c.h
> @@ -88,6 +88,7 @@ struct i2c_msg {
>  #define I2C_FUNC_SMBUS_PEC		0x00000008
>  #define I2C_FUNC_NOSTART		0x00000010 /* I2C_M_NOSTART */
>  #define I2C_FUNC_SLAVE			0x00000020
> +#define I2C_FUNC_NO_CLK_STRETCH		0x00000040 /* No check for SCL low */
>  #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
>  #define I2C_FUNC_SMBUS_QUICK		0x00010000
>  #define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
> -- 
> 2.5.1
> 

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Re: [RESEND PATCH 1/3] i2c: added FUNC flag for unsupported clock stretching

[Nicola Corna]

October 20 2015 5:35 PM, "Wolfram Sang" <wsa@the-dreams.de> wrote:
> On Wed, Sep 16, 2015 at 03:32:01PM +0200, Nicola Corna wrote:
> 
>> Added I2C_FUNC_NO_CLK_STRETCH, to be used when clock stretching is not
>> supported.
>> 
>> Signed-off-by: Nicola Corna <nicola@corna.info>
> 
> I think this should be rather a quirk than a functionality, i.e.
> I2C_AQ_NO_CLK_STRETCH. Agree?
> 
I didn't know about these quirks, thanks. I'll update the patches, please review them.

Nicola Corna
>> ---
>> Documentation/i2c/functionality | 1 +
>> include/uapi/linux/i2c.h | 1 +
>> 2 files changed, 2 insertions(+)
>> 
>> diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality
>> index 4aae8ed..f53807e 100644
>> --- a/Documentation/i2c/functionality
>> +++ b/Documentation/i2c/functionality
>> @@ -21,6 +21,7 @@ For the most up-to-date list of functionality constants, please check
>> I2C_M_REV_DIR_ADDR and I2C_M_NO_RD_ACK
>> flags (which modify the I2C protocol!)
>> I2C_FUNC_NOSTART Can skip repeated start sequence
>> + I2C_FUNC_NO_CLK_STRETCH Does NOT support clock stretching
>> I2C_FUNC_SMBUS_QUICK Handles the SMBus write_quick command
>> I2C_FUNC_SMBUS_READ_BYTE Handles the SMBus read_byte command
>> I2C_FUNC_SMBUS_WRITE_BYTE Handles the SMBus write_byte command
>> diff --git a/include/uapi/linux/i2c.h b/include/uapi/linux/i2c.h
>> index b0a7dd6..59e4b43 100644
>> --- a/include/uapi/linux/i2c.h
>> +++ b/include/uapi/linux/i2c.h
>> @@ -88,6 +88,7 @@ struct i2c_msg {
>> #define I2C_FUNC_SMBUS_PEC 0x00000008
>> #define I2C_FUNC_NOSTART 0x00000010 /* I2C_M_NOSTART */
>> #define I2C_FUNC_SLAVE 0x00000020
>> +#define I2C_FUNC_NO_CLK_STRETCH 0x00000040 /* No check for SCL low */
>> #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
>> #define I2C_FUNC_SMBUS_QUICK 0x00010000
>> #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
>> --
>> 2.5.1