can: flexcan: fix transition from and to freeze mode in chip_{,un}freeze

[mirror_ubuntu-bionic-kernel.git] / drivers / net / can / flexcan.c

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 6b0fecd0a6adc090e4e14dfd8486cb1a26882339..330b5b957a396b739739ea13e06d560068c831da 100644 (file)
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -325,6 +325,44 @@ static int flexcan_chip_disable(struct flexcan_priv *priv)
        return 0;
 }
 
+static int flexcan_chip_freeze(struct flexcan_priv *priv)
+{
+       struct flexcan_regs __iomem *regs = priv->base;
+       unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;
+       u32 reg;
+
+       reg = flexcan_read(&regs->mcr);
+       reg |= FLEXCAN_MCR_HALT;
+       flexcan_write(reg, &regs->mcr);
+
+       while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+               usleep_range(100, 200);
+
+       if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
+static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
+{
+       struct flexcan_regs __iomem *regs = priv->base;
+       unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
+       u32 reg;
+
+       reg = flexcan_read(&regs->mcr);
+       reg &= ~FLEXCAN_MCR_HALT;
+       flexcan_write(reg, &regs->mcr);
+
+       while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
+               usleep_range(10, 20);
+
+       if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
 static int flexcan_get_berr_counter(const struct net_device *dev,
                                    struct can_berr_counter *bec)
 {
@@ -756,7 +794,7 @@ static int flexcan_chip_start(struct net_device *dev)
                netdev_err(dev, "Failed to softreset can module (mcr=0x%08x)\n",
                           reg_mcr);
                err = -ENODEV;
-               goto out;
+               goto out_chip_disable;
        }
 
        flexcan_set_bittiming(dev);
@@ -826,12 +864,12 @@ static int flexcan_chip_start(struct net_device *dev)
 
        err = flexcan_transceiver_enable(priv);
        if (err)
-               goto out;
+               goto out_chip_disable;
 
        /* synchronize with the can bus */
-       reg_mcr = flexcan_read(&regs->mcr);
-       reg_mcr &= ~FLEXCAN_MCR_HALT;
-       flexcan_write(reg_mcr, &regs->mcr);
+       err = flexcan_chip_unfreeze(priv);
+       if (err)
+               goto out_transceiver_disable;
 
        priv->can.state = CAN_STATE_ERROR_ACTIVE;
 
@@ -844,7 +882,9 @@ static int flexcan_chip_start(struct net_device *dev)
 
        return 0;
 
- out:
+ out_transceiver_disable:
+       flexcan_transceiver_disable(priv);
+ out_chip_disable:
        flexcan_chip_disable(priv);
        return err;
 }
@@ -859,12 +899,10 @@ static void flexcan_chip_stop(struct net_device *dev)
 {
        struct flexcan_priv *priv = netdev_priv(dev);
        struct flexcan_regs __iomem *regs = priv->base;
-       u32 reg;
 
-       /* Disable + halt module */
-       reg = flexcan_read(&regs->mcr);
-       reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
-       flexcan_write(reg, &regs->mcr);
+       /* freeze + disable module */
+       flexcan_chip_freeze(priv);
+       flexcan_chip_disable(priv);
 
        /* Disable all interrupts */
        flexcan_write(0, &regs->imask1);