[PATCH 5.4 388/434] can: flexcan: add low power enter/exit acknowledgment helper

From: Joakim Zhang qiangqing.zhang@nxp.com

[ Upstream commit b7603d080ffcf8689ec91ca300caf84d8dbed317 ]

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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 99b3492ea130..e5c207ad3c77 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(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)) + udelay(10); + + if (!(priv->read(&regs->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(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)) + udelay(10); + + if (priv->read(&regs->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; @@ -493,39 +521,25 @@ 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(&regs->mcr); reg &= ~FLEXCAN_MCR_MDIS; priv->write(reg, &regs->mcr);

- while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)) - udelay(10); - - if (priv->read(&regs->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(&regs->mcr); reg |= FLEXCAN_MCR_MDIS; priv->write(reg, &regs->mcr);

- while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)) - udelay(10); - - if (!(priv->read(&regs->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)