在 2015年06月18日 16:29, Srinivas Kandagatla 写道:
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,
在 2015年06月16日 17:21, Srinivas Kandagatla 写道:
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
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