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bus: mhi: core: Introduce internal register poll helper function 

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>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1617215665-19593-2-git-send-email-bbhatt@codeaurora.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit is contained in:
Bhaumik Bhatt 2021-03-31 11:34:24 -07:00 committed by Manivannan Sadhasivam
parent 19e60d6e88
commit 1a42aef258
2 changed files with 26 additions and 0 deletions
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3
drivers/bus/mhi/core/internal.h
View File

@ -646,6 +646,9 @@ 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,

23
drivers/bus/mhi/core/main.c
View File

@ -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 -ETIMEDOUT;
}
void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
u32 offset, u32 val)
{