Hi, On 07/10/2015 07:02 PM, Sekhar Nori wrote: > On Friday 10 July 2015 01:23 AM, Wolfram Sang wrote: >> On Thu, Jun 18, 2015 at 12:22:33PM -0400, Murali Karicheri wrote: >>> On 06/18/2015 05:00 AM, Sekhar Nori wrote: >>>> On Thursday 18 June 2015 02:23 PM, Alexander Sverdlin wrote: >>>>> According to KeyStone Architecture I2C User Guide, >>>>> >>>>> module clock frequency >>>>> master clock frequency = ---------------------- >>>>> (ICCL + 6) + (ICCH + 6) >>>>> >>>>> i.e. "d" in i2c_davinci_calc_clk_dividers() should be fixed and >>>>> not dependent from module clock prescaler PSC on these SoCs. >>>>> >>>>> Signed-off-by: Alexander Sverdlin <[email protected]> >>>>> --- >>>>> >>>>> RFC: If someone from TI has an idea how to improve the coverage of future >>>>> Keystone >>>>> revisions -- hints/patches are welcome. The current ID check is based on >>>>> Davinci/Keystone datasheets and is at least working on real Keystone II. >>>> >>>> + Murali who works on Keystone devices in TI. >>> >>> + Grygorii >>> >>> + Grygorii has been involved in the Keystone related enhancement and >>> reviewing prior patches. Need to have his ack for this change >> >> Any news? > > Fixing Grygorii's e-mail id. > > Grygorii, let me know if you don't have the thread. I can forward.
Thanks Sekhar. My opinion - it's time for compatible string :) "ti,keystone-i2c". Especially taking int account two things: 1) In Datasheet SPRS893B TCI6630K2L Multicore DSP+ARM KeyStone II System-on-Chip (SoC) (Rev. E) values for those registers specified as: 0x0034 ICPID1 I2C Peripheral Identification Register 1 [value: 0x0000 0105] 0x0038 ICPID2 I2C Peripheral Identification Register 2 [value: 0x0000 0005] (actually the same is in k2h, k2e Datasheets). 2) This is not the first time such discussion has been raised. >> > This is not really critical fix. Currently bus rate is lower than expected >> > because of these >> > calculation errors. The fix maximizes the bus rate. So newer SoCs will run >> > little bit slower >> > until support is added to this part of the code. Not really critical. Regarding the patch itself: - Seems the "d" value is fixed to 6 as per User Guide SPRUGV3 "KeyStone Architecture 2 Inter-IC Control Bus (I2C)" and this change is correct. It would be nice to have ref on document in commit message as above. - I think, it will be very useful to have same real digits/calculation mentioned in commit message which can show how valuable is the improvement. -- regards, -grygorii -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
