? 2015?06?18? 16:29, Srinivas Kandagatla ??: > > > 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. That rockchip-efuse.c driver shouldn't be work. An entire 8-bit word of data can be read in one read operation with STROBE being high and a proper address selected (address signals A5~A7 are ?don?t cares?). That's great if we can get the content from the .reg_read when the consumer driver callback the nvmem_cell_read(). e.g.: static struct regmap_config rockchip_efuse_regmap_config = { .reg_bits = 32, .val_bits = 8, .reg_stride = 1, .reg_read = rockchip_efuse_reg_read, }; ... / * consumer driver */ nvmem_cell_get()/nvmem_cell_put(); nvmem_cell_read()/nvmem_cell_write(); ........ > > >> >> 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 >> > > > -- Thanks, - Caesar
