can: m_can: add deep Suspend/Resume support

This adds Power Management deep Suspend/Resume support for Bosch M_CAN
chip.

When entering deep sleep, the clocks are gated, the interrupts are
disabled. When resuming from deep sleep, the chip needs to be
reinitialized, the clocks ungated and the interrupts enabled.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Quentin Schulz 2017-05-05 15:50:33 +02:00 committed by Marc Kleine-Budde
parent ef7b8aa8ca
commit d14ccea0e7

View File

@ -1668,6 +1668,8 @@ failed_ret:
return ret; return ret;
} }
/* TODO: runtime PM with power down or sleep mode */
static __maybe_unused int m_can_suspend(struct device *dev) static __maybe_unused int m_can_suspend(struct device *dev)
{ {
struct net_device *ndev = dev_get_drvdata(dev); struct net_device *ndev = dev_get_drvdata(dev);
@ -1676,10 +1678,10 @@ static __maybe_unused int m_can_suspend(struct device *dev)
if (netif_running(ndev)) { if (netif_running(ndev)) {
netif_stop_queue(ndev); netif_stop_queue(ndev);
netif_device_detach(ndev); netif_device_detach(ndev);
m_can_stop(ndev);
m_can_clk_stop(priv);
} }
/* TODO: enter low power */
priv->can.state = CAN_STATE_SLEEPING; priv->can.state = CAN_STATE_SLEEPING;
return 0; return 0;
@ -1690,11 +1692,18 @@ static __maybe_unused int m_can_resume(struct device *dev)
struct net_device *ndev = dev_get_drvdata(dev); struct net_device *ndev = dev_get_drvdata(dev);
struct m_can_priv *priv = netdev_priv(ndev); struct m_can_priv *priv = netdev_priv(ndev);
/* TODO: exit low power */ m_can_init_ram(priv);
priv->can.state = CAN_STATE_ERROR_ACTIVE; priv->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(ndev)) { if (netif_running(ndev)) {
int ret;
ret = m_can_clk_start(priv);
if (ret)
return ret;
m_can_start(ndev);
netif_device_attach(ndev); netif_device_attach(ndev);
netif_start_queue(ndev); netif_start_queue(ndev);
} }