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can: flexcan: poll MCR_LPM_ACK instead of GPR ACK for stop mode acknowledgment

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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, the MCR[LPM_ACK] bit should be polled for
stop mode acknowledgment, not the acknowledgment from chip level which
is used to gate flexcan clocks.

This patch depends on:

    b7603d080f ("can: flexcan: add low power enter/exit acknowledgment helper")

Fixes: 5f186c257f (can: flexcan: fix stop mode acknowledgment)
Tested-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v5.0
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Joakim Zhang 2019-12-04 11:36:14 +00:00 committed by Marc Kleine-Budde
parent b7603d080f
commit 048e3a34a2
1 changed files with 2 additions and 15 deletions
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17
drivers/net/can/flexcan.c
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@ -435,7 +435,6 @@ static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable)
static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv) static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
{ {
struct flexcan_regs __iomem *regs = priv->regs; struct flexcan_regs __iomem *regs = priv->regs;
unsigned int ackval;
u32 reg_mcr; u32 reg_mcr;
reg_mcr = priv->read(&regs->mcr); reg_mcr = priv->read(&regs->mcr);
@ -446,36 +445,24 @@ static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr, regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
1 << priv->stm.req_bit, 1 << priv->stm.req_bit); 1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
/* get stop acknowledgment */ return flexcan_low_power_enter_ack(priv);
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;
} }
static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv) static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
{ {
struct flexcan_regs __iomem *regs = priv->regs; struct flexcan_regs __iomem *regs = priv->regs;
unsigned int ackval;
u32 reg_mcr; u32 reg_mcr;
/* remove stop request */ /* remove stop request */
regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr, regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
1 << priv->stm.req_bit, 0); 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 = priv->read(&regs->mcr);
reg_mcr &= ~FLEXCAN_MCR_SLF_WAK; reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
priv->write(reg_mcr, &regs->mcr); 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) static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)