From b7603d080ffcf8689ec91ca300caf84d8dbed317 Mon Sep 17 00:00:00 2001 From: Joakim Zhang Date: Wed, 4 Dec 2019 11:36:11 +0000 Subject: [PATCH] can: flexcan: add low power enter/exit acknowledgment helper The MCR[LPMACK] read-only bit indicates that FlexCAN is in a lower-power mode (Disabled mode, Doze mode, Stop mode). The CPU can poll this bit to know when FlexCAN has actually entered low power mode. The low power enter/exit acknowledgment helper will reduce code duplication for disabled mode, doze mode and stop mode. Tested-by: Sean Nyekjaer Signed-off-by: Joakim Zhang Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 46 ++++++++++++++++++++++++++++++---------------- 1 file changed, 30 insertions(+), 16 deletions(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index b6f675a..9f3a5e5 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -389,6 +389,34 @@ static struct flexcan_mb __iomem *flexcan_get_mb(const struct flexcan_priv *priv (&priv->regs->mb[bank][priv->mb_size * mb_index]); } +static int flexcan_low_power_enter_ack(struct flexcan_priv *priv) +{ + struct flexcan_regs __iomem *regs = priv->regs; + unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; + + while (timeout-- && !(priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) + udelay(10); + + if (!(priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) + return -ETIMEDOUT; + + return 0; +} + +static int flexcan_low_power_exit_ack(struct flexcan_priv *priv) +{ + struct flexcan_regs __iomem *regs = priv->regs; + unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; + + while (timeout-- && (priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) + udelay(10); + + if (priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK) + return -ETIMEDOUT; + + return 0; +} + static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable) { struct flexcan_regs __iomem *regs = priv->regs; @@ -506,39 +534,25 @@ static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv) static int flexcan_chip_enable(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->regs; - unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; u32 reg; reg = priv->read(®s->mcr); reg &= ~FLEXCAN_MCR_MDIS; priv->write(reg, ®s->mcr); - while (timeout-- && (priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) - udelay(10); - - if (priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK) - return -ETIMEDOUT; - - return 0; + return flexcan_low_power_exit_ack(priv); } static int flexcan_chip_disable(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->regs; - unsigned int timeout = FLEXCAN_TIMEOUT_US / 10; u32 reg; reg = priv->read(®s->mcr); reg |= FLEXCAN_MCR_MDIS; priv->write(reg, ®s->mcr); - while (timeout-- && !(priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) - udelay(10); - - if (!(priv->read(®s->mcr) & FLEXCAN_MCR_LPM_ACK)) - return -ETIMEDOUT; - - return 0; + return flexcan_low_power_enter_ack(priv); } static int flexcan_chip_freeze(struct flexcan_priv *priv) -- 2.7.4