Re: [PATCH] soc: qcom: provide mechanism for drivers to access L2 registers

Christopher Covington
2016-05-23T22:26:31Z

On 05/23/2016 02:22 PM, Neil Leeder wrote:
>
> On 5/23/2016 01:25 PM, Mark Rutland wrote:
>> On Fri, May 20, 2016 at 03:13:07PM -0400, Neil Leeder wrote:
>>> L2 registers are accessed using a select register and data
>>> register pair. To prevent multiple concurrent writes to the
>>> select register by independent drivers, the write to the
>>> select register and the associated access of the data register
>>> are protected with a lock. All drivers accessing the L2
>>> registers use the set and get functions provided by
>>> l2-accessors to ensure correct reads and writes to L2 registers.
>>
>> What will this be used for? (i.e. which drivers want to touch the L2
>> registers?).
>>
>> Generally we expect FW to configure the caches and interconnect
>> appropriately.
>
> The primary use is in the L2 PMU driver, which will be posted shortly.
>
>>
>>> Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
>>> ---
>>> drivers/soc/qcom/Kconfig | 9 +++++
>>> drivers/soc/qcom/Makefile | 1 +
>>> drivers/soc/qcom/l2-accessors.c | 66 +++++++++++++++++++++++++++++++++++
>>> include/linux/soc/qcom/l2-accessors.h | 27 ++++++++++++++
>>> 4 files changed, 103 insertions(+)
>>> create mode 100644 drivers/soc/qcom/l2-accessors.c
>>> create mode 100644 include/linux/soc/qcom/l2-accessors.h
>>
>> These are awfully generic file names (and function names). Which SoCs
>> does this apply to?
>>
>> It would be good to give these more specific names.
>
> It's under soc/qcom, and dependent on ARCH_QCOM and (in v2) also on ARM64. It applies to all QCOM ARM64 SoCs.
> Given that it can only be used in a QCOM driver, and the include path has qcom in it, I'd
> prefer not to add redundancy by adding another qcom in there.

They ended up calling the pinctrl file qcom/pinctrl/qdf2xxx.c.

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8f1338cd80648adf5434798f5393ad7c55d10848

Regards,
Cov

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