1 files changed, 44 insertions, 7 deletions

diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index d371d3868a66..5009ff294941 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -468,6 +468,39 @@ static void mcp251x_hw_sleep(struct spi_device *spi)
 	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
 }
 
+/* May only be called when device is sleeping! */
+static int mcp251x_hw_wake(struct spi_device *spi)
+{
+	unsigned long timeout;
+
+	/* Force wakeup interrupt to wake device, but don't execute IST */
+	disable_irq(spi->irq);
+	mcp251x_write_2regs(spi, CANINTE, CANINTE_WAKIE, CANINTF_WAKIF);
+
+	/* Wait for oscillator startup timer after wake up */
+	mdelay(MCP251X_OST_DELAY_MS);
+
+	/* Put device into config mode */
+	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_CONF);
+
+	/* Wait for the device to enter config mode */
+	timeout = jiffies + HZ;
+	while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) !=
+			CANCTRL_REQOP_CONF) {
+		schedule();
+		if (time_after(jiffies, timeout)) {
+			dev_err(&spi->dev, "MCP251x didn't enter in config mode\n");
+			return -EBUSY;
+		}
+	}
+
+	/* Disable and clear pending interrupts */
+	mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00);
+	enable_irq(spi->irq);
+
+	return 0;
+}
+
 static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
 					   struct net_device *net)
 {
@@ -725,8 +758,12 @@ static void mcp251x_restart_work_handler(struct work_struct *ws)
 
 	mutex_lock(&priv->mcp_lock);
 	if (priv->after_suspend) {
-		mcp251x_hw_reset(spi);
-		mcp251x_setup(net, spi);
+		if (priv->after_suspend & AFTER_SUSPEND_POWER) {
+			mcp251x_hw_reset(spi);
+			mcp251x_setup(net, spi);
+		} else {
+			mcp251x_hw_wake(spi);
+		}
 		priv->force_quit = 0;
 		if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
 			mcp251x_set_normal_mode(spi);
@@ -923,7 +960,7 @@ static int mcp251x_open(struct net_device *net)
 	INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
 	INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
 
-	ret = mcp251x_hw_reset(spi);
+	ret = mcp251x_hw_wake(spi);
 	if (ret)
 		goto out_free_wq;
 	ret = mcp251x_setup(net, spi);
@@ -1165,13 +1202,13 @@ static int __maybe_unused mcp251x_can_resume(struct device *dev)
 
 	if (priv->after_suspend & AFTER_SUSPEND_POWER)
 		mcp251x_power_enable(priv->power, 1);
-
-	if (priv->after_suspend & AFTER_SUSPEND_UP) {
+	if (priv->after_suspend & AFTER_SUSPEND_UP)
 		mcp251x_power_enable(priv->transceiver, 1);
+
+	if (priv->after_suspend & (AFTER_SUSPEND_POWER | AFTER_SUSPEND_UP))
 		queue_work(priv->wq, &priv->restart_work);
-	} else {
+	else
 		priv->after_suspend = 0;
-	}
 
 	priv->force_quit = 0;
 	enable_irq(spi->irq);