On 2015-06-24 11:56, Stefan Wahren wrote: > Hi Sanchayan, > > Am 24.06.2015 um 07:19 schrieb [email protected]: >> On 15-06-23 21:31:41, Stefan Wahren wrote: >>> Hi Sanchayan, >>> >>>> Sanchayan Maity <[email protected]> hat am 23. Juni 2015 um 15:44 >>>> geschrieben: >>>> >>>> >>>> The patch adds support for the On Chip One Time Programmable Peripheral >>>> (OCOTP) and On Chip ROM (OCROM) support. >>>> >>>> On Vybrid OCOTP contain data like SoC ID, MAC address and OCROM has the >>>> revision ID. >>>> >>>> Signed-off-by: Sanchayan Maity <[email protected]> >>>> --- >>>> drivers/nvmem/Kconfig | 11 +++++++++ >>>> drivers/nvmem/Makefile | 2 ++ >>>> drivers/nvmem/vf610-ocotp.c | 60 >>>> +++++++++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 73 insertions(+) >>>> create mode 100644 drivers/nvmem/vf610-ocotp.c >>>> >>>> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig >>>> index 17f1a57..557c1e0 100644 >>>> --- a/drivers/nvmem/Kconfig >>>> +++ b/drivers/nvmem/Kconfig >>>> @@ -33,4 +33,15 @@ config NVMEM_SUNXI_SID >>>> This driver can also be built as a module. If so, the module >>>> will be called eeprom-sunxi-sid. >>>> >>>> +config NVMEM_VF610_OCOTP >>>> + tristate "VF610 SoCs OCOTP support" >>>> + depends on SOC_VF610 >>>> + select REGMAP_MMIO >>> how do you come to the conclusion that Vybrid On-Chip OTP is accessable via >>> MMIO? >> Frankly speaking I just changed the naming conventions and followed the qfrom >> and sunxi sid examples in Srinivas's patches. >> >> I just tested it without the "select REGMAP_MMIO" and it works just fine. >> >> - Sanchayan. > > sorry for the confusion. My question refers to the whole driver > implementation not only to the REGMAP_MMIO. > > According to > > Vybrid Reference Manual F-Series > Document Number: VYBRIDRM > Rev 7, 06/2014 > > 35.5 OCOTP memory map/register definition > > the memory region is organized in control and shadow registers. I'm very > sceptical that using REGMAP_MMIO is the right way for accessing the OCOTP. > > It possible that it works in your case. But in the case the lock bits > are set the driver won't work correctly.
The OCOTP represents fuses, starting from 0x400A5400 one can access the shadowed registers containing the fuses values. The reference manual also says: "All shadow registers are always readable through the APB bus except some secret key" The driver does not need write access. I guess it is fine to use only reads through regmap...? -- Stefan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
