On 18/06/15 08:05, Stefan Wahren wrote: > Hi Srinivas, > > Am 16.06.2015 um 12:54 schrieb Srinivas Kandagatla: >> >> >> On 16/06/15 11:06, Caesar Wang wrote: >>> Hi Srinivas, >>> >>> ? 2015?06?16? 17:21, Srinivas Kandagatla ??: >>>> Hi Stefan, >>>> >>>> >>>> On 16/06/15 09:52, Stefan Wahren wrote: >>>>> Hi Caesar, >>>>> >>>>> [add Maxime and Srinivas] >>>>> >>>>> Am 16.06.2015 um 09:27 schrieb Caesar Wang: >>>>>> The original driver is uploaded by Jianqun. >>>>>> Here is his patchs: >>>>>> https://patchwork.kernel.org/patch/5410341/ >>>>>> https://patchwork.kernel.org/patch/5410351/ >>>>>> >>>>>> Jianqun, nevermind! >>>>>> I check-pick it and re-upload the driver for the upstream. >>>>>> e.g.: >>>>>> Tested by on minnie board.(kernel-4.1-rc8) >>>>>> cd /sys/devices/platform/ffb40000.efuse >>>>>> localhost ffb40000.efuse # cat cpu_leakage_show >>>>>> cpu_version_show >>>>>> The results: >>>>>> 19 >>>>>> 2 >>>>>> >>>>>> Changes in v2: >>>>>> - Change the document decription. >>>>>> - Move the efuse driver into driver/soc/vendor. >>>>>> - update the efuse driver. >>>>>> - Add the dts node on RK3288. >>>>>> >>>>>> >>>>> >>>>> i want to mention that there is a upcoming new framework suitable for >>>>> efuse drivers: >>>>> >>>>> https://lkml.org/lkml/2015/5/21/643 >>>>> >>>>> Unfortunately i don't know the current development state. >>>>> >>>> >>>> Currently this framework is used by atleast 3 drivers(qcom-tsens, >>>> qcom-cpr, begel-bone-cape manager) which are still floating in the >>>> mailing list. >>>> >>>> I was hoping that these 3 users would getback with tested-by.. which >>>> did not happen for last 3-4 weeks. >>>> >>>> I would appreciate, If you could try framework too, and let me know. >>> > > yes i work on OCOTP driver for MXS platform and i will try ... > >> >> int rockchip_efuse_reg_read(void *context, unsigned int reg, unsigned >> int *val) >> { >> /* efuse specific read sequence */ >> ... >> } > > I will need a specific read sequence too. You can have a look at https://git.linaro.org/people/srinivas.kandagatla/linux.git/blob/b4c3ad253747767511233687436f20144e850d67:/drivers/nvmem/rockchip-efuse.c I did modify the rockchip driver, which I guess should be very much similar to what OCOTP driver would need. > > Sorry for these newbie questions: > > What data structure does context points to for this reg_read opteration? > > Do we need range checking of reg or is it handled by the framework? > We already have that in place. > Are there any limitation for reg_read regarding sleeping or locking > operations? There are no limitaions as such from nvmem framework, regmap might have limitations w.r.t to sleeping and fast_io, as fast_io would take spinlocks, AFAIK the providers would not have fast_io, as they not IO devices. > > In case of a read only driver, is everything handle by devicetree or do > we need an empty write operation? Yes, if you pass read-only flag in the provider, the framework would not attempt to even write. You will find answers to most of your question in the rochip-efuse.c file. --srini > > Best regards > Stefan >
