[PATCH v7 6/8] net: can: c_can: Disable pins when CAN interface is down
From: Roger Quadros <hidden>
Date: 2014-11-14 15:40:46
Also in:
linux-can, linux-omap
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
DRA7 CAN IP suffers from a problem which causes it to be prevented from fully turning OFF (i.e. stuck in transition) if the module was disabled while there was traffic on the CAN_RX line. To work around this issue we select the SLEEP pin state by default on probe and use the DEFAULT pin state on CAN up and back to the SLEEP pin state on CAN down. Signed-off-by: Roger Quadros <redacted> --- drivers/net/can/c_can/c_can.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 8e78bb4..f94a9fa 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c@@ -35,6 +35,7 @@ #include <linux/list.h> #include <linux/io.h> #include <linux/pm_runtime.h> +#include <linux/pinctrl/consumer.h> #include <linux/can.h> #include <linux/can/dev.h>
@@ -603,6 +604,8 @@ static int c_can_start(struct net_device *dev) priv->can.state = CAN_STATE_ERROR_ACTIVE; + /* activate pins */ + pinctrl_pm_select_default_state(dev->dev.parent); return 0; }
@@ -611,6 +614,9 @@ static void c_can_stop(struct net_device *dev) struct c_can_priv *priv = netdev_priv(dev); c_can_irq_control(priv, false); + + /* deactivate pins */ + pinctrl_pm_select_sleep_state(dev->dev.parent); priv->can.state = CAN_STATE_STOPPED; }
@@ -1244,6 +1250,13 @@ int register_c_can_dev(struct net_device *dev) struct c_can_priv *priv = netdev_priv(dev); int err; + /* Deactivate pins to prevent DRA7 DCAN IP from being + * stuck in transition when module is disabled. + * Pins are activated in c_can_start() and deactivated + * in c_can_stop() + */ + pinctrl_pm_select_sleep_state(dev->dev.parent); + c_can_pm_runtime_enable(priv); dev->flags |= IFF_ECHO; /* we support local echo */
--
1.8.3.2