diff options
| author |   Joakim Zhang <qiangqing.zhang@nxp.com> | 2019-12-04 11:36:11 +0000 |
|---|---|---|
| committer |   Marc Kleine-Budde <mkl@pengutronix.de> | 2019-12-08 11:52:02 +0100 |
| commit | b7603d080ffcf8689ec91ca300caf84d8dbed317 (patch) | |
| tree | ee96d615a5e33aa2b877f2aa2d5456ca06e821d5 /drivers/net/can | |
| parent | can: flexcan: fix possible deadlock and out-of-order reception after wakeup (diff) | |
| download | linux-dev-b7603d080ffcf8689ec91ca300caf84d8dbed317.tar.xz linux-dev-b7603d080ffcf8689ec91ca300caf84d8dbed317.zip | |
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 <sean@geanix.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
| -rw-r--r-- | drivers/net/can/flexcan.c | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index b6f675a5e2d9..9f3a5e56fc37 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) |