[PATCH v2 3/6] can: mcp251xfd: move chip sleep mode into runtime pm

From: Gregor Herburger
Date: Mon May 06 2024 - 02:01:16 EST


From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>

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 ist 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: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 99 ++++++++++++++++----------
1 file changed, 61 insertions(+), 38 deletions(-)

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 4ae201426a46..4739ad80ef2a 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -745,21 +745,13 @@ 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;
@@ -1602,8 +1594,11 @@ 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)
@@ -1872,53 +1867,53 @@ 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;

+ 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;
+
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;
- if (err)
- goto out_chip_sleep;
-
- err = mcp251xfd_chip_clock_init(priv);
- if (err == -ENODEV)
- goto out_runtime_disable;
- if (err)
- goto out_chip_sleep;
-
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;

@@ -1928,12 +1923,13 @@ 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;
@@ -1945,10 +1941,12 @@ 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[] = {
@@ -2175,16 +2173,41 @@ 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;

- return mcp251xfd_clks_and_vdd_enable(priv);
+ err = mcp251xfd_clks_and_vdd_enable(priv);
+ if (err)
+ return err;
+
+ 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 = {

--
2.34.1