netdev - [PATCH V3 4/6] can: flexcan: change the way of stop mode acknowledgment

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Date:   Wed, 4 Dec 2019 11:36:14 +0000
From:   Joakim Zhang <qiangqing.zhang@....com>
To:     "mkl@...gutronix.de" <mkl@...gutronix.de>,
        "sean@...nix.com" <sean@...nix.com>,
        "linux-can@...r.kernel.org" <linux-can@...r.kernel.org>
CC:     dl-linux-imx <linux-imx@....com>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        Joakim Zhang <qiangqing.zhang@....com>
Subject: [PATCH V3 4/6] can: flexcan: change the way of stop mode
 acknowledgment

Stop mode is entered when Stop mode is requested at chip level and
MCR[LPM_ACK] is asserted by the FlexCAN.

Double check with IP owner, should poll MCR[LPM_ACK] for stop mode
acknowledgment, not the acknowledgment from chip level which is used
to gate flexcan clocks.

Fixes: 5f186c257fa4 (can: flexcan: fix stop mode acknowledgment)
Tested-by: Sean Nyekjaer <sean@...nix.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@....com>
-----
ChangeLog:
	V1->V2: * no change.

	V2->V3: * spilt the patch.
---
 drivers/net/can/flexcan.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 6c4f1bab7042..19602b77907f 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -434,7 +434,6 @@ static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable)
 static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
 {
 	struct flexcan_regs __iomem *regs = priv->regs;
-	unsigned int ackval;
 	u32 reg_mcr;
 
 	reg_mcr = priv->read(&regs->mcr);
@@ -445,36 +444,24 @@ static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
 	regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
 			   1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
 
-	/* get stop acknowledgment */
-	if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr,
-				     ackval, ackval & (1 << priv->stm.ack_bit),
-				     0, FLEXCAN_TIMEOUT_US))
-		return -ETIMEDOUT;
-
-	return 0;
+	return flexcan_low_power_enter_ack(priv);
 }
 
 static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
 {
 	struct flexcan_regs __iomem *regs = priv->regs;
-	unsigned int ackval;
 	u32 reg_mcr;
 
 	/* remove stop request */
 	regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
 			   1 << priv->stm.req_bit, 0);
 
-	/* get stop acknowledgment */
-	if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr,
-				     ackval, !(ackval & (1 << priv->stm.ack_bit)),
-				     0, FLEXCAN_TIMEOUT_US))
-		return -ETIMEDOUT;
 
 	reg_mcr = priv->read(&regs->mcr);
 	reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
 	priv->write(reg_mcr, &regs->mcr);
 
-	return 0;
+	return flexcan_low_power_exit_ack(priv);
 }
 
 static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
-- 
2.17.1