diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2012-04-10 10:00:38 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2012-04-18 13:53:11 +0200 |
| commit | c05127c4e2c6e7d9949347a76fd05c337bcd5e84 (patch) | |
| tree | 5b23f8a116919028317f026e3f9998dce2ffb828 | |
| parent | ad8bb720c23a80233e45ed31d67458f5e5b7ab31 (diff) | |
pinctrl: implement pinctrl deferred probing
If drivers try to obtain pinctrl handles for a pin controller that
has not yet registered to the subsystem, we need to be able to
back out and retry with deferred probing. So let's return
-EPROBE_DEFER whenever this location fails. Also downgrade the
errors to info, maybe we will even set them to debug once the
deferred probing is commonplace.
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| -rw-r--r-- | Documentation/pinctrl.txt | 5 | ||||
| -rw-r--r-- | drivers/pinctrl/core.c | 9 | ||||
| -rw-r--r-- | drivers/pinctrl/devicetree.c | 6 |
3 files changed, 14 insertions, 6 deletions
diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt index eb46b1c0b07a..4431c3e727ba 100644 --- a/Documentation/pinctrl.txt +++ b/Documentation/pinctrl.txt @@ -1043,6 +1043,11 @@ quickly poking some registers. The pins are allocated for your device when you issue the pinctrl_get() call, after this you should be able to see this in the debugfs listing of all pins. +NOTE: the pinctrl system will return -EPROBE_DEFER if it cannot find the +requested pinctrl handles, for example if the pinctrl driver has not yet +registered. Thus make sure that the error path in your driver gracefully +cleans up and is ready to retry the probing later in the startup process. + System pin control hogging ========================== diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 7ff869007ba4..59027ab8347a 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -518,11 +518,14 @@ static int add_setting(struct pinctrl *p, struct pinctrl_map const *map) setting->pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name); if (setting->pctldev == NULL) { - dev_err(p->dev, "unknown pinctrl device %s in map entry", + dev_info(p->dev, "unknown pinctrl device %s in map entry, deferring probe", map->ctrl_dev_name); kfree(setting); - /* Eventually, this should trigger deferred probe */ - return -ENODEV; + /* + * OK let us guess that the driver is not there yet, and + * let's defer obtaining this pinctrl handle to later... + */ + return -EPROBE_DEFER; } switch (map->type) { diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c index 5ef2feb44395..fcb1de45473c 100644 --- a/drivers/pinctrl/devicetree.c +++ b/drivers/pinctrl/devicetree.c @@ -121,11 +121,11 @@ static int dt_to_map_one_config(struct pinctrl *p, const char *statename, for (;;) { np_pctldev = of_get_next_parent(np_pctldev); if (!np_pctldev || of_node_is_root(np_pctldev)) { - dev_err(p->dev, "could not find pctldev for node %s\n", + dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n", np_config->full_name); of_node_put(np_pctldev); - /* FIXME: This should trigger deferrered probe */ - return -ENODEV; + /* OK let's just assume this will appear later then */ + return -EPROBE_DEFER; } pctldev = find_pinctrl_by_of_node(np_pctldev); if (pctldev) |