Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-10 Thread Wolfram Sang
> I still have to examine in depth all of the problems in the i2c-mux > documented in Documentation/i2c/i2c-topology (thanks for having written > those docs!), but at first sight it looks like the ATR is not going to > introduce big problems because of how it works. Assuming we are using the

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-10 Thread Luca Ceresoli
Hi Vladimir, On 09/09/19 05:56, Vladimir Zapolskiy wrote: > Hi Luca, Jacopo, Wolfram, Peter, > > On 09/08/2019 11:45 PM, Vladimir Zapolskiy wrote: >> Hi Luca, Jacopo, Wolfram, Peter, >> >> On 09/01/2019 05:31 PM, jacopo mondi wrote: >>> Hi Luca, >>>thanks for keep pushing this series! I hope

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-10 Thread Wolfram Sang
> Here i2c-0 is the "local" bus, i2c-4 and i2c-5 are the remote busses on > ports 0 and 1. As you can see the eeproms are accessed using a name like > "4-0050", meaning physical slave address 0x50 on bus 4. No alias is needed. > > Should you want to know the alias, perhaps for debugging (it's

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-09 Thread Luca Ceresoli
Hi Vladimir, On 09/09/19 16:10, Vladimir Zapolskiy wrote: > Hi Wolfram, > > On 09/09/2019 10:22 AM, Wolfram Sang wrote: >> Hi Vladimir, >> >>> I won't attend the LPC, however I would appreciate if you book some >> >> A pity. I would have liked to have you in the room. Let's see if we can >> get

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-09 Thread Vladimir Zapolskiy
Hi Wolfram, On 09/09/2019 10:22 AM, Wolfram Sang wrote: > Hi Vladimir, > >> I won't attend the LPC, however I would appreciate if you book some > > A pity. I would have liked to have you in the room. Let's see if we can > get enough input from you via mail here. > if it might help, I'll

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-09 Thread Wolfram Sang
Hi Vladimir, > I won't attend the LPC, however I would appreciate if you book some A pity. I would have liked to have you in the room. Let's see if we can get enough input from you via mail here. > time to review my original / alternative implementation of the TI > DS90Ux9xx I2C bridge device

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-08 Thread Vladimir Zapolskiy
Hi Luca, Jacopo, Wolfram, Peter, On 09/08/2019 11:45 PM, Vladimir Zapolskiy wrote: > Hi Luca, Jacopo, Wolfram, Peter, > > On 09/01/2019 05:31 PM, jacopo mondi wrote: >> Hi Luca, >>thanks for keep pushing this series! I hope we can use part of this >> for the (long time) on-going GMSL work...

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-08 Thread Vladimir Zapolskiy
Hi Luca, Jacopo, Wolfram, Peter, On 09/01/2019 05:31 PM, jacopo mondi wrote: > Hi Luca, >thanks for keep pushing this series! I hope we can use part of this > for the (long time) on-going GMSL work... > > I hope you will be patient enough to provide (another :) overview > of this work during

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-08 Thread Luca Ceresoli
Hi Peter, On 04/09/19 10:09, Peter Rosin wrote:> Hi! > > [ Sorry about my absence. I've been meaning to comment on this series > for a long time, but work and family keep interfering... ] No problem, thanks for your comments. See below my reply. > > On 2019-09-03 09:31, Luca Ceresoli wrote:

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-04 Thread Peter Rosin
Hi! [ Sorry about my absence. I've been meaning to comment on this series for a long time, but work and family keep interfering... ] On 2019-09-03 09:31, Luca Ceresoli wrote: > Hi Jacopo, > > thanks for your feedback. > > On 01/09/19 16:31, jacopo mondi wrote: >> Hi Luca, >>thanks for

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-03 Thread Wolfram Sang
> > One huge drawback for me is the attach/detach callbacks. One year ago, I > > removed a similar callback from the I2C core ("[PATCH 0/2] i2c: remove > > deprecated attach_adapter callback") because some drivers did a lot of > > crazy things there. It took years to remove all that. > > Oh

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-03 Thread Luca Ceresoli
Hi Wolfram, On 02/09/19 22:42, Wolfram Sang wrote: > Hi Luca, > >> + * Topology: >> + * >> + * Slave X @ 0x10 >> + * .-. | >> + * .-. | |---+ B >> + * | CPU |--A--| ATR | >> + * `-' | |---+ C >> + *

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-03 Thread Wolfram Sang
> Adding the ATR features to i2c-mux.c was very tricky and error-prone due > to all of this code, that's why I have moved ATR to its own file in RFCv2. I forgot to say that I like this. signature.asc Description: PGP signature

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-03 Thread Luca Ceresoli
Hi Jacopo, thanks for your feedback. On 01/09/19 16:31, jacopo mondi wrote: > Hi Luca, >thanks for keep pushing this series! I hope we can use part of this > for the (long time) on-going GMSL work... > > I hope you will be patient enough to provide (another :) overview > of this work during

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-02 Thread Wolfram Sang
Hi Luca, > + * Topology: > + * > + * Slave X @ 0x10 > + * .-. | > + * .-. | |---+ B > + * | CPU |--A--| ATR | > + * `-' | |---+ C > + * `-' | > + * Slave Y @ 0x10 > + * > + *

Re: [RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-09-01 Thread jacopo mondi
Hi Luca, thanks for keep pushing this series! I hope we can use part of this for the (long time) on-going GMSL work... I hope you will be patient enough to provide (another :) overview of this work during the BoF Wolfram has organized at LPC for the next week. In the meantime I would have

[RFC,v2 2/6] i2c: add I2C Address Translator (ATR) support

2019-07-23 Thread Luca Ceresoli
An ATR is a device that looks similar to an i2c-mux: it has an I2C slave "upstream" port and N master "downstream" ports, and forwards transactions from upstream to the appropriate downstream port. But is is different in that the forwarded transaction has a different slave address. The address