From: Enric Balletbo i Serra <enric.balletbo@collabora.com>
To: linux-kernel@vger.kernel.org
Cc: Collabora Kernel ML <kernel@collabora.com>,
Nicolas Boichat <drinkcat@chromium.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
Arnd Bergmann <arnd@arndb.de>, Lee Jones <lee.jones@linaro.org>
Subject: [PATCH v2] mfd: syscon: Add syscon_regmap_lookup_by_phandle_optional() function.
Date: Tue, 10 Nov 2020 17:13:37 +0100 [thread overview]
Message-ID: <20201110161338.18198-1-enric.balletbo@collabora.com> (raw)
This adds syscon_regmap_lookup_by_phandle_optional() function to get an
optional regmap.
It behaves the same as syscon_regmap_lookup_by_phandle() except where
there is no regmap phandle. In this case, instead of returning -ENODEV,
the function returns NULL. This makes error checking simpler when the
regmap phandle is optional.
Suggested-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
---
Changes in v2:
- Add Matthias r-b tag.
- Add the explanation from the patch description to the code.
- Return NULL instead of -ENOTSUPP when regmap helpers are not enabled.
drivers/mfd/syscon.c | 18 ++++++++++++++++++
include/linux/mfd/syscon.h | 11 +++++++++++
2 files changed, 29 insertions(+)
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index ca465794ea9c..c6f139b2e0c0 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -255,6 +255,24 @@ struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
+/*
+ * It behaves the same as syscon_regmap_lookup_by_phandle() except where
+ * there is no regmap phandle. In this case, instead of returning -ENODEV,
+ * the function returns NULL.
+ */
+struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
+ const char *property)
+{
+ struct regmap *regmap;
+
+ regmap = syscon_regmap_lookup_by_phandle(np, property);
+ if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
+ return NULL;
+
+ return regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
+
static int syscon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h
index 7f20e9b502a5..fecc2fa2a364 100644
--- a/include/linux/mfd/syscon.h
+++ b/include/linux/mfd/syscon.h
@@ -28,6 +28,9 @@ extern struct regmap *syscon_regmap_lookup_by_phandle_args(
const char *property,
int arg_count,
unsigned int *out_args);
+extern struct regmap *syscon_regmap_lookup_by_phandle_optional(
+ struct device_node *np,
+ const char *property);
#else
static inline struct regmap *device_node_to_regmap(struct device_node *np)
{
@@ -59,6 +62,14 @@ static inline struct regmap *syscon_regmap_lookup_by_phandle_args(
{
return ERR_PTR(-ENOTSUPP);
}
+
+static inline struct regmap *syscon_regmap_lookup_by_phandle_optional(
+ struct device_node *np,
+ const char *property)
+{
+ return NULL;
+}
+
#endif
#endif /* __LINUX_MFD_SYSCON_H__ */
--
2.28.0
next reply other threads:[~2020-11-10 16:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 16:13 Enric Balletbo i Serra [this message]
2020-11-11 10:15 ` [PATCH v2] mfd: syscon: Add syscon_regmap_lookup_by_phandle_optional() function Arnd Bergmann
2020-11-13 10:19 ` Lee Jones
2020-11-17 12:05 ` Matthias Brugger
2020-11-17 12:37 ` Lee Jones
2020-11-17 15:17 ` Matthias Brugger
2020-11-17 16:05 ` Lee Jones
2020-11-17 16:40 ` Arnd Bergmann
2020-11-18 14:56 ` Matthias Brugger
2020-11-19 8:32 ` Lee Jones
2020-11-19 16:57 ` Matthias Brugger
2020-11-19 8:33 ` [GIT PULL] Immutable branch between MFD and MediaTek due for the v5.11 merge window Lee Jones
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