From: Henry Chen <henryc.chen@mediatek.com>
To: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
Henry Chen <henryc.chen@mediatek.com>
Subject: [PATCH] soc: mediatek: PMIC wrap: Clear the vldclr if state machine stay on FSM_VLDCLR state.
Date: Mon, 4 Jan 2016 19:59:35 +0800 [thread overview]
Message-ID: <1451908775-21527-1-git-send-email-henryc.chen@mediatek.com> (raw)
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 <henryc.chen@mediatek.com>
---
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
reply other threads:[~2016-01-04 11:59 UTC|newest]
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