From: Jon Hunter <jonathanh@nvidia.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: <linux-gpio@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
Jon Hunter <jonathanh@nvidia.com>
Subject: [PATCH] pinctrl: Don't create a pinctrl handle if no pinctrl entries exist
Date: Thu, 16 Jun 2016 13:39:09 +0100 [thread overview]
Message-ID: <1466080749-23567-1-git-send-email-jonathanh@nvidia.com> (raw)
When pinctrl_get() is called for a device, it will return a valid handle
even if the device itself has no pinctrl state entries defined in
device-tree. This is caused by the function pinctrl_dt_to_map() which
will return success even if the first pinctrl state, 'pinctrl-0', is not
found in the device-tree node for a device.
According to the pinctrl device-tree binding documentation, pinctrl
states must be numbered starting from 0 and so 'pinctrl-0' should always
be present if a device uses pinctrl and therefore, if 'pinctrl-0' is not
present it seems valid that we should not return a valid pinctrl handle.
Fix this by returning an error code if the property 'pinctrl-0' is not
present for a device.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
I was wondering if this meant we are creating pinctrl handles for
devices on boot that don't use pinctrl (when
calling pinctrl_bind_pins()). However, although devm_pinctrl_get()
does return successful for all devices, the subsequent call to
pinctrl_lookup_state() (to get the default state) will fail and so
we will destroy the pinctrl handle afterall.
drivers/pinctrl/devicetree.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index fe04e748dfe4..f41c16e11a11 100644
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -195,8 +195,11 @@ int pinctrl_dt_to_map(struct pinctrl *p)
propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
prop = of_find_property(np, propname, &size);
kfree(propname);
- if (!prop)
+ if (!prop) {
+ if (state == 0)
+ return -ENODEV;
break;
+ }
list = prop->value;
size /= sizeof(*list);
--
2.1.4
next reply other threads:[~2016-06-16 12:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-16 12:39 Jon Hunter [this message]
2016-06-16 15:20 ` [PATCH] pinctrl: Don't create a pinctrl handle if no pinctrl entries exist Jon Hunter
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