| Message ID | 20240829092418.2863659-1-quic_msavaliy@quicinc.com |
|---|---|
| Headers | show |
| Series | Enable shared SE support over I2C | expand |
Hi, On 29/08/2024 11:24, Mukesh Kumar Savaliya wrote: > This Series adds support to share QUP based I2C SE between subsystems. > Each subsystem should have its own GPII which interacts between SE and > GSI DMA HW engine. > > Subsystem must acquire Lock over the SE on GPII channel so that it > gets uninterrupted control till it unlocks the SE. It also makes sure > the commonly shared TLMM GPIOs are not touched which can impact other > subsystem or cause any interruption. Generally, GPIOs are being > unconfigured during suspend time. > > GSI DMA engine is capable to perform requested transfer operations > from any of the SE in a seamless way and its transparent to the > subsystems. Make sure to enable “qcom,shared-se” flag only while > enabling this feature. I2C client should add in its respective parent > node. > > --- > Mukesh Kumar Savaliya (4): > dt-bindindgs: i2c: qcom,i2c-geni: Document shared flag > dma: gpi: Add Lock and Unlock TRE support to access SE exclusively > soc: qcom: geni-se: Export function geni_se_clks_off() > i2c: i2c-qcom-geni: Enable i2c controller sharing between two > subsystems > > .../bindings/i2c/qcom,i2c-geni-qcom.yaml | 4 ++ > drivers/dma/qcom/gpi.c | 37 ++++++++++++++++++- > drivers/i2c/busses/i2c-qcom-geni.c | 29 +++++++++++---- > drivers/soc/qcom/qcom-geni-se.c | 4 +- > include/linux/dma/qcom-gpi-dma.h | 6 +++ > include/linux/soc/qcom/geni-se.h | 3 ++ > 6 files changed, 74 insertions(+), 9 deletions(-) > I see in downstream that this flag is used on the SM8650 qupv3_se6_i2c, and that on the SM8650-HDK this i2c is shared between the aDSP battmgr and the linux to access the HDMI controller. Is this is the target use-case ? We have some issues on this platform that crashes the system when Linux does some I2C transfers while battmgr does some access at the same time, the problem is that on the Linux side the i2c uses the SE DMA and not GPI because fifo_disable=0 so by default this bypasses GPI. A temporary fix has been merged: https://lore.kernel.org/all/20240605-topic-sm8650-upstream-hdk-iommu-fix-v1-1-9fd7233725fa@linaro.org/ but it's clearly not a real solution What would be the solution to use the shared i2c with on one side battmgr using GPI and the kernel using SE DMA ? In this case, shouldn't we force using GPI on linux with: ==============><===================================================================== diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index ee2e431601a6..a15825ea56de 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -885,7 +885,7 @@ static int geni_i2c_probe(struct platform_device *pdev) else fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE; - if (fifo_disable) { + if (gi2c->is_shared || fifo_disable) { /* FIFO is disabled, so we can only use GPI DMA */ gi2c->gpi_mode = true; ret = setup_gpi_dma(gi2c); ==============><===================================================================== Neil
On 29/08/2024 11:24, Mukesh Kumar Savaliya wrote: > Adds qcom,shared-se flag usage. Use this when particular I2C serial > controller needs to be shared between two subsystems. > > Signed-off-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com> > --- > Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml | 4 ++++ > 1 file changed, 4 insertions(+) <form letter> Please use scripts/get_maintainers.pl to get a list of necessary people and lists to CC. It might happen, that command when run on an older kernel, gives you outdated entries. Therefore please be sure you base your patches on recent Linux kernel. Tools like b4 or scripts/get_maintainer.pl provide you proper list of people, so fix your workflow. Tools might also fail if you work on some ancient tree (don't, instead use mainline) or work on fork of kernel (don't, instead use mainline). Just use b4 and everything should be fine, although remember about `b4 prep --auto-to-cc` if you added new patches to the patchset. You missed at least devicetree list (maybe more), so this won't be tested by automated tooling. Performing review on untested code might be a waste of time. Please kindly resend and include all necessary To/Cc entries. </form letter> Best regards, Krzysztof
This Series adds support to share QUP based I2C SE between subsystems. Each subsystem should have its own GPII which interacts between SE and GSI DMA HW engine. Subsystem must acquire Lock over the SE on GPII channel so that it gets uninterrupted control till it unlocks the SE. It also makes sure the commonly shared TLMM GPIOs are not touched which can impact other subsystem or cause any interruption. Generally, GPIOs are being unconfigured during suspend time. GSI DMA engine is capable to perform requested transfer operations from any of the SE in a seamless way and its transparent to the subsystems. Make sure to enable “qcom,shared-se” flag only while enabling this feature. I2C client should add in its respective parent node. --- Mukesh Kumar Savaliya (4): dt-bindindgs: i2c: qcom,i2c-geni: Document shared flag dma: gpi: Add Lock and Unlock TRE support to access SE exclusively soc: qcom: geni-se: Export function geni_se_clks_off() i2c: i2c-qcom-geni: Enable i2c controller sharing between two subsystems .../bindings/i2c/qcom,i2c-geni-qcom.yaml | 4 ++ drivers/dma/qcom/gpi.c | 37 ++++++++++++++++++- drivers/i2c/busses/i2c-qcom-geni.c | 29 +++++++++++---- drivers/soc/qcom/qcom-geni-se.c | 4 +- include/linux/dma/qcom-gpi-dma.h | 6 +++ include/linux/soc/qcom/geni-se.h | 3 ++ 6 files changed, 74 insertions(+), 9 deletions(-)