can: mcp251xfd: move chip sleep mode into runtime pm

This is a preparation patch to add GPIO support.

Up to now, the Vdd regulator and the clocks have been managed by
Runtime-PM (on systems without CONFIG_PM these remain permanently
switched on).

During the mcp251xfd_open() callback the mcp251xfd is powered,
soft-reset and configured. In mcp251xfd_stop() the chip is shut down
again. To support the on-chip GPIOs, the chip must be supplied with
power while GPIOs are being requested, even if the networking
interface is down.

To support this, move the functions mcp251xfd_chip_softreset() and
mcp251xfd_chip_clock_init() from mcp251xfd_chip_start() to
mcp251xfd_runtime_resume(). Instead of setting the controller to sleep
mode in mcp251xfd_chip_stop(), bring it into configuration mode. This
way it doesn't take part in bus activity and doesn't enter sleep mode.

Signed-off-by: Gregor Herburger <gregor.herburger@ew.tq-group.com>
Tested-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251001091006.4003841-2-viken.dadhaniya@oss.qualcomm.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index c0f9d9fed02e3b90404d52b22f3aafae3802c817..9104561e099527a266796c57d15c46517076cf3c 100644 (file)
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -767,21 +767,13 @@ static void mcp251xfd_chip_stop(struct mcp251xfd_priv *priv,
        mcp251xfd_chip_interrupts_disable(priv);
        mcp251xfd_chip_rx_int_disable(priv);
        mcp251xfd_timestamp_stop(priv);
-       mcp251xfd_chip_sleep(priv);
+       mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_CONFIG);
 }
 
 static int mcp251xfd_chip_start(struct mcp251xfd_priv *priv)
 {
        int err;
 
-       err = mcp251xfd_chip_softreset(priv);
-       if (err)
-               goto out_chip_stop;
-
-       err = mcp251xfd_chip_clock_init(priv);
-       if (err)
-               goto out_chip_stop;
-
        err = mcp251xfd_chip_timestamp_init(priv);
        if (err)
                goto out_chip_stop;
@@ -1625,8 +1617,11 @@ static int mcp251xfd_open(struct net_device *ndev)
                return err;
 
        err = pm_runtime_resume_and_get(ndev->dev.parent);
-       if (err)
+       if (err) {
+               if (err == -ETIMEDOUT || err == -ENODEV)
+                       pm_runtime_set_suspended(ndev->dev.parent);
                goto out_close_candev;
+       }
 
        err = mcp251xfd_ring_alloc(priv);
        if (err)
@@ -1907,53 +1902,53 @@ static int mcp251xfd_register(struct mcp251xfd_priv *priv)
        struct net_device *ndev = priv->ndev;
        int err;
 
+       mcp251xfd_register_quirks(priv);
+
        err = mcp251xfd_clks_and_vdd_enable(priv);
        if (err)
                return err;
 
-       pm_runtime_get_noresume(ndev->dev.parent);
-       err = pm_runtime_set_active(ndev->dev.parent);
-       if (err)
-               goto out_runtime_put_noidle;
-       pm_runtime_enable(ndev->dev.parent);
-
-       mcp251xfd_register_quirks(priv);
-
        err = mcp251xfd_chip_softreset(priv);
        if (err == -ENODEV)
-               goto out_runtime_disable;
+               goto out_clks_and_vdd_disable;
        if (err)
                goto out_chip_sleep;
 
        err = mcp251xfd_chip_clock_init(priv);
        if (err == -ENODEV)
-               goto out_runtime_disable;
+               goto out_clks_and_vdd_disable;
        if (err)
                goto out_chip_sleep;
 
+       pm_runtime_get_noresume(ndev->dev.parent);
+       err = pm_runtime_set_active(ndev->dev.parent);
+       if (err)
+               goto out_runtime_put_noidle;
+       pm_runtime_enable(ndev->dev.parent);
+
        err = mcp251xfd_register_chip_detect(priv);
        if (err)
-               goto out_chip_sleep;
+               goto out_runtime_disable;
 
        err = mcp251xfd_register_check_rx_int(priv);
        if (err)
-               goto out_chip_sleep;
+               goto out_runtime_disable;
 
        mcp251xfd_ethtool_init(priv);
 
        err = register_candev(ndev);
        if (err)
-               goto out_chip_sleep;
+               goto out_runtime_disable;
 
        err = mcp251xfd_register_done(priv);
        if (err)
                goto out_unregister_candev;
 
-       /* Put controller into sleep mode and let pm_runtime_put()
-        * disable the clocks and vdd. If CONFIG_PM is not enabled,
-        * the clocks and vdd will stay powered.
+       /* Put controller into Config mode and let pm_runtime_put()
+        * put in sleep mode, disable the clocks and vdd. If CONFIG_PM
+        * is not enabled, the clocks and vdd will stay powered.
         */
-       err = mcp251xfd_chip_sleep(priv);
+       err = mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_CONFIG);
        if (err)
                goto out_unregister_candev;
 
@@ -1963,12 +1958,13 @@ static int mcp251xfd_register(struct mcp251xfd_priv *priv)
 
 out_unregister_candev:
        unregister_candev(ndev);
-out_chip_sleep:
-       mcp251xfd_chip_sleep(priv);
 out_runtime_disable:
        pm_runtime_disable(ndev->dev.parent);
 out_runtime_put_noidle:
        pm_runtime_put_noidle(ndev->dev.parent);
+out_chip_sleep:
+       mcp251xfd_chip_sleep(priv);
+out_clks_and_vdd_disable:
        mcp251xfd_clks_and_vdd_disable(priv);
 
        return err;
@@ -1980,10 +1976,12 @@ static inline void mcp251xfd_unregister(struct mcp251xfd_priv *priv)
 
        unregister_candev(ndev);
 
-       if (pm_runtime_enabled(ndev->dev.parent))
+       if (pm_runtime_enabled(ndev->dev.parent)) {
                pm_runtime_disable(ndev->dev.parent);
-       else
+       } else {
+               mcp251xfd_chip_sleep(priv);
                mcp251xfd_clks_and_vdd_disable(priv);
+       }
 }
 
 static const struct of_device_id mcp251xfd_of_match[] = {
@@ -2206,16 +2204,41 @@ static void mcp251xfd_remove(struct spi_device *spi)
 
 static int __maybe_unused mcp251xfd_runtime_suspend(struct device *device)
 {
-       const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
+       struct mcp251xfd_priv *priv = dev_get_drvdata(device);
 
+       mcp251xfd_chip_sleep(priv);
        return mcp251xfd_clks_and_vdd_disable(priv);
 }
 
 static int __maybe_unused mcp251xfd_runtime_resume(struct device *device)
 {
-       const struct mcp251xfd_priv *priv = dev_get_drvdata(device);
+       struct mcp251xfd_priv *priv = dev_get_drvdata(device);
+       int err;
+
+       err = mcp251xfd_clks_and_vdd_enable(priv);
+       if (err)
+               return err;
 
-       return mcp251xfd_clks_and_vdd_enable(priv);
+       err = mcp251xfd_chip_softreset(priv);
+       if (err == -ENODEV)
+               goto out_clks_and_vdd_disable;
+       if (err)
+               goto out_chip_sleep;
+
+       err = mcp251xfd_chip_clock_init(priv);
+       if (err == -ENODEV)
+               goto out_clks_and_vdd_disable;
+       if (err)
+               goto out_chip_sleep;
+
+       return 0;
+
+out_chip_sleep:
+       mcp251xfd_chip_sleep(priv);
+out_clks_and_vdd_disable:
+       mcp251xfd_clks_and_vdd_disable(priv);
+
+       return err;
 }
 
 static const struct dev_pm_ops mcp251xfd_pm_ops = {