Commit b7603d08 authored by Joakim Zhang's avatar Joakim Zhang Committed by Marc Kleine-Budde
Browse files

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: default avatarSean Nyekjaer <sean@geanix.com>
Signed-off-by: default avatarJoakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent e707180a

drivers/net/can/flexcan.c

+30 −16
Original line number Diff line number Diff line
@@ -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;
@@ -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(&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)

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