On 05/05/2017 01:46 PM, Quentin Schulz wrote: > 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.sch...@free-electrons.com> > --- > > v3: > - do not close/reopen the can interface (which was previously done when > calling m_can_close), basically do the same routine as in probe but > it does not close/open the can device,
much better!
> - update commit log,
>
> v2:
> - fix erroneous commit log,
>
> drivers/net/can/m_can/m_can.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 3f0445440146..0a06690febe2 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -1672,10 +1672,9 @@ static __maybe_unused int m_can_suspend(struct device
> *dev)
> if (netif_running(ndev)) {
> netif_stop_queue(ndev);
> netif_device_detach(ndev);
> + m_can_stop(ndev);
> }
>
> - /* TODO: enter low power */
> -
> priv->can.state = CAN_STATE_SLEEPING;
>
> return 0;
> @@ -1686,11 +1685,23 @@ static __maybe_unused int m_can_resume(struct device
> *dev)
> struct net_device *ndev = dev_get_drvdata(dev);
> struct m_can_priv *priv = netdev_priv(ndev);
>
> - /* TODO: exit low power */
> + m_can_init_ram(priv);
>
> priv->can.state = CAN_STATE_ERROR_ACTIVE;
>
> if (netif_running(ndev)) {
> + int ret = clk_prepare_enable(priv->hclk);
> +
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(priv->cclk);
> + if (ret) {
> + clk_disable_unprepare(priv->hclk);
> + return ret;
> + }
> +
> + m_can_start(ndev);
Using m_can_stop() m_can_start() here is the way to go. However, when
looking at this hook we se, that the m_can_start/stop functions are not
symmetric (as they should be). Either move the clock handling to
completely in or out of m_can_start/stop.
> netif_device_attach(ndev);
> netif_start_queue(ndev);
> }
>
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
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