[RESEND PATCH v2] soc: mediatek: PMIC wrap: Clear the vldclr if state machine stay on FSM_VLDCLR state.

On 08/01/16 03:43, Ricky Liang wrote:

On Mon, Jan 4, 2016 at 8:02 PM, Henry Chen [off-list ref] wrote:

quoted

Sometimes PMIC is too busy to send data in time to cause pmic wrap timeout,
because pmic wrap is waiting for FSM_VLDCLR after finishing WACS2_CMD. It
just return error when issue happened, so the state machine will stay on
FSM_VLDCLR state when data send back later by PMIC and timeout again in next
time because pmic wrap waiting for FSM_IDLE state at the beginning of the
read/write function.

Clear the vldclr when timeout if state machine stay on FSM_VLDCLR.

Signed-off-by: Henry Chen <redacted>
---
Changes since v1:
Encapsulated the code in a inline function, and add a descriptive comment.
---
  drivers/soc/mediatek/mtk-pmic-wrap.c | 30 ++++++++++++++++++++++++++++--
  1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
index 105597a..af919b1 100644
--- a/drivers/soc/mediatek/mtk-pmic-wrap.c
+++ b/drivers/soc/mediatek/mtk-pmic-wrap.c

@@ -412,6 +412,12 @@ static bool pwrap_is_fsm_vldclr(struct pmic_wrapper *wrp)
         return PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR;
  }

+static inline void pwrap_leave_fsm_vldclr(struct pmic_wrapper *wrp)
+{
+       if (pwrap_is_fsm_vldclr(wrp))
+               pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
+}
+
  static bool pwrap_is_sync_idle(struct pmic_wrapper *wrp)
  {
         return pwrap_readl(wrp, PWRAP_WACS2_RDATA) & PWRAP_STATE_SYNC_IDLE0;

@@ -445,8 +451,18 @@ static int pwrap_write(struct pmic_wrapper *wrp, u32 adr, u32 wdata)
         int ret;

         ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
-       if (ret)
+       if (ret) {
+               /*
+                * Timeout issue sometimes caused by the last read command
+                * failed because pmic wrap could not got the FSM_VLDCLR
+                * in time after finishing WACS2_CMD. It made state machine
+                * still on FSM_VLDCLR and timeout next time.
+                * Check the status of FSM and clear the vldclr to recovery the
+                * error.
+                */
+               pwrap_leave_fsm_vldclr(wrp);
                 return ret;
+       }

         pwrap_writel(wrp, (1 << 31) | ((adr >> 1) << 16) | wdata,
                         PWRAP_WACS2_CMD);

@@ -459,8 +475,18 @@ static int pwrap_read(struct pmic_wrapper *wrp, u32 adr, u32 *rdata)
         int ret;

         ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
-       if (ret)
+       if (ret) {
+               /*
+                * Timeout issue sometimes caused by the last read command
+                * failed because pmic wrap could not got the FSM_VLDCLR
+                * in time after finishing WACS2_CMD. It made state machine
+                * still on FSM_VLDCLR and timeout next time.
+                * Check the status of FSM and clear the vldclr to recovery the
+                * error.
+                */
+               pwrap_leave_fsm_vldclr(wrp);
                 return ret;
+       }

         pwrap_writel(wrp, (adr >> 1) << 16, PWRAP_WACS2_CMD);

--

1.9.1

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Tested-by: Ricky Liang <redacted>

On our test platform this patch fixes PMIC communication erros.

I put the comment above the function declaration.

Applied to v4.5-next/soc

Thanks.