| Message ID | 1617047583-12104-2-git-send-email-bbhatt@codeaurora.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Polling for MHI ready | expand |
On Mon, Mar 29, 2021 at 12:53:02PM -0700, Bhaumik Bhatt wrote: > Introduce helper function to allow MHI core driver to poll for > a value in a register field. This helps reach a common path to > read and poll register values along with a retry time interval. > > Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org> > --- > drivers/bus/mhi/core/internal.h | 3 +++ > drivers/bus/mhi/core/main.c | 23 +++++++++++++++++++++++ > 2 files changed, 26 insertions(+) > > diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h > index 6f80ec3..005286b 100644 > --- a/drivers/bus/mhi/core/internal.h > +++ b/drivers/bus/mhi/core/internal.h > @@ -643,6 +643,9 @@ int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl, > int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl, > void __iomem *base, u32 offset, u32 mask, > u32 shift, u32 *out); > +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, > + void __iomem *base, u32 offset, u32 mask, > + u32 shift, u32 val, u32 delayus); > void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base, > u32 offset, u32 val); > void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base, > diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c > index 4e0131b..6f4b630 100644 > --- a/drivers/bus/mhi/core/main.c > +++ b/drivers/bus/mhi/core/main.c > @@ -4,6 +4,7 @@ > * > */ > > +#include <linux/delay.h> > #include <linux/device.h> > #include <linux/dma-direction.h> > #include <linux/dma-mapping.h> > @@ -37,6 +38,28 @@ int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl, > return 0; > } > > +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, > + void __iomem *base, u32 offset, > + u32 mask, u32 shift, u32 val, u32 delayus) > +{ > + int ret; > + u32 out, retry = (mhi_cntrl->timeout_ms * 1000) / delayus; > + > + while (retry--) { > + ret = mhi_read_reg_field(mhi_cntrl, base, offset, mask, shift, > + &out); > + if (ret) > + return ret; > + > + if (out == val) > + return 0; > + > + fsleep(delayus); > + } > + > + return -ENOENT; Maybe I'm too late on this one, but I don't think -ENOENT is the correct error code here. The error code will be returned only when the reg field value didn't change as expected, so in that case it should be -EINVAL or -ETIMEDOUT, no? Thanks, Mani > +} > + > void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base, > u32 offset, u32 val) > { > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
Hi Mani, On 2021-03-31 06:03 AM, Manivannan Sadhasivam wrote: > On Mon, Mar 29, 2021 at 12:53:02PM -0700, Bhaumik Bhatt wrote: >> Introduce helper function to allow MHI core driver to poll for >> a value in a register field. This helps reach a common path to >> read and poll register values along with a retry time interval. >> >> Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org> >> --- >> drivers/bus/mhi/core/internal.h | 3 +++ >> drivers/bus/mhi/core/main.c | 23 +++++++++++++++++++++++ >> 2 files changed, 26 insertions(+) >> >> diff --git a/drivers/bus/mhi/core/internal.h >> b/drivers/bus/mhi/core/internal.h >> index 6f80ec3..005286b 100644 >> --- a/drivers/bus/mhi/core/internal.h >> +++ b/drivers/bus/mhi/core/internal.h >> @@ -643,6 +643,9 @@ int __must_check mhi_read_reg(struct >> mhi_controller *mhi_cntrl, >> int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl, >> void __iomem *base, u32 offset, u32 mask, >> u32 shift, u32 *out); >> +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, >> + void __iomem *base, u32 offset, u32 mask, >> + u32 shift, u32 val, u32 delayus); >> void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem >> *base, >> u32 offset, u32 val); >> void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void >> __iomem *base, >> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c >> index 4e0131b..6f4b630 100644 >> --- a/drivers/bus/mhi/core/main.c >> +++ b/drivers/bus/mhi/core/main.c >> @@ -4,6 +4,7 @@ >> * >> */ >> >> +#include <linux/delay.h> >> #include <linux/device.h> >> #include <linux/dma-direction.h> >> #include <linux/dma-mapping.h> >> @@ -37,6 +38,28 @@ int __must_check mhi_read_reg_field(struct >> mhi_controller *mhi_cntrl, >> return 0; >> } >> >> +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, >> + void __iomem *base, u32 offset, >> + u32 mask, u32 shift, u32 val, u32 delayus) >> +{ >> + int ret; >> + u32 out, retry = (mhi_cntrl->timeout_ms * 1000) / delayus; >> + >> + while (retry--) { >> + ret = mhi_read_reg_field(mhi_cntrl, base, offset, mask, shift, >> + &out); >> + if (ret) >> + return ret; >> + >> + if (out == val) >> + return 0; >> + >> + fsleep(delayus); >> + } >> + >> + return -ENOENT; > > Maybe I'm too late on this one, but I don't think -ENOENT is the > correct > error code here. The error code will be returned only when the reg > field > value didn't change as expected, so in that case it should be -EINVAL > or > -ETIMEDOUT, no? > > Thanks, > Mani > Thanks for pointing that out. The intention of the error code was despite polling for whatever time period, we were unable to see the value changing as expected. I think the -ETIMEDOUT error code would be appropriate. Will upload a v6. >> +} >> + >> void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem >> *base, >> u32 offset, u32 val) >> { >> -- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> Forum, >> a Linux Foundation Collaborative Project >> Thanks, Bhaumik --- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h index 6f80ec3..005286b 100644 --- a/drivers/bus/mhi/core/internal.h +++ b/drivers/bus/mhi/core/internal.h @@ -643,6 +643,9 @@ int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl, int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base, u32 offset, u32 mask, u32 shift, u32 *out); +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, + void __iomem *base, u32 offset, u32 mask, + u32 shift, u32 val, u32 delayus); void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base, u32 offset, u32 val); void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base, diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index 4e0131b..6f4b630 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -4,6 +4,7 @@ * */ +#include <linux/delay.h> #include <linux/device.h> #include <linux/dma-direction.h> #include <linux/dma-mapping.h> @@ -37,6 +38,28 @@ int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl, return 0; } +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, + void __iomem *base, u32 offset, + u32 mask, u32 shift, u32 val, u32 delayus) +{ + int ret; + u32 out, retry = (mhi_cntrl->timeout_ms * 1000) / delayus; + + while (retry--) { + ret = mhi_read_reg_field(mhi_cntrl, base, offset, mask, shift, + &out); + if (ret) + return ret; + + if (out == val) + return 0; + + fsleep(delayus); + } + + return -ENOENT; +} + void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base, u32 offset, u32 val) {
Introduce helper function to allow MHI core driver to poll for a value in a register field. This helps reach a common path to read and poll register values along with a retry time interval. Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org> --- drivers/bus/mhi/core/internal.h | 3 +++ drivers/bus/mhi/core/main.c | 23 +++++++++++++++++++++++ 2 files changed, 26 insertions(+)