From: Andrew Jeffery <andrew@aj.id.au>
To: linux-gpio@vger.kernel.org
Cc: Andrew Jeffery <andrew@aj.id.au>,
linus.walleij@linaro.org, corbet@lwn.net, joel@jms.id.au,
ryan_chen@aspeedtech.com, robh+dt@kernel.org,
frowand.list@gmail.com, ckeepax@opensource.wolfsonmicro.com,
ldewangan@nvidia.com, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, patches@opensource.cirrus.com,
devicetree@vger.kernel.org, openbmc@lists.ozlabs.org,
linux-aspeed@lists.ozlabs.org
Subject: [RFC PATCH 2/5] gpio: gpiolib: Add OF support for maintaining GPIO values on reset
Date: Fri, 20 Oct 2017 14:07:24 +1030 [thread overview]
Message-ID: <20171020033727.21557-3-andrew@aj.id.au> (raw)
In-Reply-To: <20171020033727.21557-1-andrew@aj.id.au>
Add flags and the associated flag mappings between interfaces to enable
GPIO reset tolerance to be specified via devicetree.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
drivers/gpio/gpiolib-of.c | 2 ++
drivers/gpio/gpiolib.c | 5 +++++
include/dt-bindings/gpio/gpio.h | 4 ++++
include/linux/of_gpio.h | 1 +
4 files changed, 12 insertions(+)
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index e0d59e61b52f..4a268ba52998 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -155,6 +155,8 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
if (of_flags & OF_GPIO_SLEEP_MAY_LOSE_VALUE)
*flags |= GPIO_SLEEP_MAY_LOSE_VALUE;
+ if (of_flags & OF_GPIO_RESET_TOLERANT)
+ *flags |= GPIO_RESET_TOLERANT;
return desc;
}
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d9dc7e588699..6b4c5df10e84 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3434,6 +3434,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
bool active_low = false;
bool single_ended = false;
bool open_drain = false;
+ bool reset_tolerant = false;
int ret;
if (!fwnode)
@@ -3448,6 +3449,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
active_low = flags & OF_GPIO_ACTIVE_LOW;
single_ended = flags & OF_GPIO_SINGLE_ENDED;
open_drain = flags & OF_GPIO_OPEN_DRAIN;
+ reset_tolerant = flags & OF_GPIO_RESET_TOLERANT;
}
} else if (is_acpi_node(fwnode)) {
struct acpi_gpio_info info;
@@ -3478,6 +3480,9 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
lflags |= GPIO_OPEN_SOURCE;
}
+ if (reset_tolerant)
+ lflags |= GPIO_RESET_TOLERANT;
+
ret = gpiod_configure_flags(desc, propname, lflags, dflags);
if (ret < 0) {
gpiod_put(desc);
diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h
index 70de5b7a6c9b..01c75d9e308e 100644
--- a/include/dt-bindings/gpio/gpio.h
+++ b/include/dt-bindings/gpio/gpio.h
@@ -32,4 +32,8 @@
#define GPIO_SLEEP_MAINTAIN_VALUE 0
#define GPIO_SLEEP_MAY_LOSE_VALUE 8
+/* Bit 4 express GPIO persistence on reset */
+#define GPIO_RESET_INTOLERANT 0
+#define GPIO_RESET_TOLERANT 16
+
#endif
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index 1fe205582111..9b34737706a7 100644
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -32,6 +32,7 @@ enum of_gpio_flags {
OF_GPIO_SINGLE_ENDED = 0x2,
OF_GPIO_OPEN_DRAIN = 0x4,
OF_GPIO_SLEEP_MAY_LOSE_VALUE = 0x8,
+ OF_GPIO_RESET_TOLERANT = 0x16,
};
#ifdef CONFIG_OF_GPIO
--
2.11.0
next prev parent reply other threads:[~2017-10-20 3:37 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-20 3:37 [RFC PATCH 0/5] gpio: Expose reset tolerance capability Andrew Jeffery
2017-10-20 3:37 ` [RFC PATCH 1/5] gpio: gpiolib: Add core support for maintaining GPIO values on reset Andrew Jeffery
2017-10-20 7:17 ` Linus Walleij
2017-10-20 7:43 ` Linus Walleij
2017-10-20 8:32 ` Andrew Jeffery
2017-10-25 8:11 ` Charles Keepax
2017-10-26 0:00 ` Andrew Jeffery
2017-10-20 8:24 ` Andrew Jeffery
2017-10-20 3:37 ` Andrew Jeffery [this message]
[not found] ` <20171020033727.21557-3-andrew-zrmu5oMJ5Fs@public.gmane.org>
2017-10-20 7:18 ` [RFC PATCH 2/5] gpio: gpiolib: Add OF " Linus Walleij
2017-10-20 7:29 ` Andrew Jeffery
2017-10-20 3:37 ` [RFC PATCH 3/5] gpio: gpiolib: Add chardev " Andrew Jeffery
2017-10-20 7:27 ` Linus Walleij
2017-10-20 9:02 ` Andrew Jeffery
2017-10-25 8:14 ` Charles Keepax
2017-10-26 0:05 ` Andrew Jeffery
[not found] ` <1508976339.13477.5.camel-zrmu5oMJ5Fs@public.gmane.org>
2017-10-26 9:10 ` Charles Keepax
2017-10-31 9:59 ` Linus Walleij
2017-10-20 3:37 ` [RFC PATCH 4/5] gpio: gpiolib: Add sysfs " Andrew Jeffery
[not found] ` <20171020033727.21557-5-andrew-zrmu5oMJ5Fs@public.gmane.org>
2017-10-20 7:29 ` Linus Walleij
2017-10-20 7:40 ` Andrew Jeffery
2017-10-20 3:37 ` [RFC PATCH 5/5] gpio: aspeed: Add support for reset tolerance Andrew Jeffery
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