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

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 is stay on FSM_VLDCLR state.
Date: Tue, 22 Dec 2015 15:51:17 +0800	[thread overview]
Message-ID: <1450770677-13557-1-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 begining of the
read/write function.

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

Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
---
 drivers/soc/mediatek/mtk-pmic-wrap.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
index 105597a..ccd5337 100644
--- a/drivers/soc/mediatek/mtk-pmic-wrap.c
+++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
@@ -443,10 +443,16 @@ static int pwrap_wait_for_state(struct pmic_wrapper *wrp,
 static int pwrap_write(struct pmic_wrapper *wrp, u32 adr, u32 wdata)
 {
 	int ret;
+	u32 val;
 
 	ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
-	if (ret)
+	if (ret) {
+		/* Clear vldclr bit if state is on the WACS_FSM_WFVLDCLR */
+		val = pwrap_readl(wrp, PWRAP_WACS2_RDATA);
+		if (PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR)
+			pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
 		return ret;
+	}
 
 	pwrap_writel(wrp, (1 << 31) | ((adr >> 1) << 16) | wdata,
 			PWRAP_WACS2_CMD);
@@ -457,10 +463,16 @@ static int pwrap_write(struct pmic_wrapper *wrp, u32 adr, u32 wdata)
 static int pwrap_read(struct pmic_wrapper *wrp, u32 adr, u32 *rdata)
 {
 	int ret;
+	u32 val;
 
 	ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
-	if (ret)
+	if (ret) {
+		/* Clear vldclr bit if state is on the WACS_FSM_WFVLDCLR */
+		val = pwrap_readl(wrp, PWRAP_WACS2_RDATA);
+		if (PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR)
+			pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
 		return ret;
+	}
 
 	pwrap_writel(wrp, (adr >> 1) << 16, PWRAP_WACS2_CMD);
 
-- 
1.9.1

