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From: Kent Gibson <warthog618@gmail.com>
To: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
	bgolaszewski@baylibre.com, linus.walleij@linaro.org
Cc: Kent Gibson <warthog618@gmail.com>
Subject: [PATCH 14/22] gpiolib: make cdev a build option
Date: Tue, 23 Jun 2020 12:00:59 +0800	[thread overview]
Message-ID: <20200623040107.22270-15-warthog618@gmail.com> (raw)
In-Reply-To: <20200623040107.22270-1-warthog618@gmail.com>

Make the gpiolib-cdev module a build option.  This allows the CDEV
interface to be removed from the kernel to reduce kernel size in
applications where is it not required, and provides the parent for
other other CDEV interface specific build options to follow.

Suggested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>

---
 drivers/gpio/Kconfig        | 16 ++++++++++++++--
 drivers/gpio/Makefile       |  2 +-
 drivers/gpio/gpiolib-cdev.h | 15 +++++++++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index c6b5c65c8405..affc1524bc2c 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -66,8 +66,20 @@ config GPIO_SYSFS
 
 	  This ABI is deprecated. If you want to use GPIO from userspace,
 	  use the character device /dev/gpiochipN with the appropriate
-	  ioctl() operations instead. The character device is always
-	  available.
+	  ioctl() operations instead.
+
+config GPIO_CDEV
+	bool "/dev/gpiochipN (character device interface)"
+	default y
+	help
+	  Say Y here to add the character device /dev/gpiochipN interface
+	  for GPIOs. The character device allows userspace to control GPIOs
+	  using ioctl() operations.
+
+	  Only say N is you are sure that the GPIO character device is not
+	  required.
+
+	  If unsure, say Y.
 
 config GPIO_GENERIC
 	depends on HAS_IOMEM # Only for IOMEM drivers
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index ef666cfef9d0..45eb09808d12 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -7,8 +7,8 @@ obj-$(CONFIG_GPIOLIB)		+= gpiolib.o
 obj-$(CONFIG_GPIOLIB)		+= gpiolib-devres.o
 obj-$(CONFIG_GPIOLIB)		+= gpiolib-legacy.o
 obj-$(CONFIG_GPIOLIB)		+= gpiolib-devprop.o
-obj-$(CONFIG_GPIOLIB)		+= gpiolib-cdev.o
 obj-$(CONFIG_OF_GPIO)		+= gpiolib-of.o
+obj-$(CONFIG_GPIO_CDEV)		+= gpiolib-cdev.o
 obj-$(CONFIG_GPIO_SYSFS)	+= gpiolib-sysfs.o
 obj-$(CONFIG_GPIO_ACPI)		+= gpiolib-acpi.o
 
diff --git a/drivers/gpio/gpiolib-cdev.h b/drivers/gpio/gpiolib-cdev.h
index 973578e7ad10..19a4e3d57120 100644
--- a/drivers/gpio/gpiolib-cdev.h
+++ b/drivers/gpio/gpiolib-cdev.h
@@ -5,7 +5,22 @@
 
 #include <linux/device.h>
 
+#ifdef CONFIG_GPIO_CDEV
+
 int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt);
 void gpiolib_cdev_unregister(struct gpio_device *gdev);
 
+#else
+
+static inline int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
+{
+	return 0;
+}
+
+static inline void gpiolib_cdev_unregister(struct gpio_device *gdev)
+{
+}
+
+#endif /* CONFIG_GPIO_CDEV */
+
 #endif /* GPIOLIB_CDEV_H */
-- 
2.27.0


  parent reply	other threads:[~2020-06-23  4:03 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-23  4:00 [PATCH 00/22] gpio: cdev: add uAPI V2 Kent Gibson
2020-06-23  4:00 ` [PATCH 01/22] gpiolib: move gpiolib-sysfs function declarations into their own header Kent Gibson
2020-06-24 13:34   ` Bartosz Golaszewski
2020-06-24 13:38     ` Kent Gibson
2020-06-23  4:00 ` [PATCH 02/22] gpiolib: cdev: sort includes Kent Gibson
2020-06-24 13:34   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 03/22] gpiolib: cdev: minor indentation fixes Kent Gibson
2020-06-24 13:35   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 04/22] gpiolib: cdev: refactor gpiohandle_flags_to_desc_flags Kent Gibson
2020-06-24 13:51   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 05/22] gpiolib: cdev: rename 'filep' and 'filp' to 'file' to be consistent with other use Kent Gibson
2020-06-24 13:52   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 06/22] gpiolib: cdev: rename numdescs to num_descs Kent Gibson
2020-06-24 13:53   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 07/22] gpiolib: cdev: remove pointless decrement of i Kent Gibson
2020-06-24 13:53   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 08/22] gpiolib: cdev: complete the irq/thread timestamp handshake Kent Gibson
2020-06-24 14:00   ` Bartosz Golaszewski
2020-06-24 14:08     ` Kent Gibson
2020-06-25  9:44       ` Bartosz Golaszewski
2020-06-25 10:01         ` Kent Gibson
2020-06-30  9:08           ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 09/22] gpiolib: cdev: rename priv to gcdev Kent Gibson
2020-06-24 14:04   ` Bartosz Golaszewski
2020-06-24 14:19     ` Kent Gibson
2020-06-24 14:20       ` Bartosz Golaszewski
2020-06-24 23:16         ` Kent Gibson
2020-06-25 10:26           ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 10/22] gpiolib: cdev: fix minor race in GET_LINEINFO_WATCH Kent Gibson
2020-06-24 14:05   ` Bartosz Golaszewski
2020-06-24 14:46   ` Andy Shevchenko
2020-06-24 15:57     ` Kent Gibson
2020-06-24 22:58       ` Kent Gibson
2020-06-25  8:44         ` Andy Shevchenko
2020-06-25  9:13           ` Kent Gibson
2020-06-25  9:23             ` Andy Shevchenko
2020-06-25  9:36               ` Kent Gibson
2020-06-23  4:00 ` [PATCH 11/22] gpiolib: cdev: remove recalculation of offset Kent Gibson
2020-06-30  8:56   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 12/22] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes Kent Gibson
2020-06-24 14:13   ` Bartosz Golaszewski
2020-06-23  4:00 ` [PATCH 13/22] gpio: uapi: define uAPI V2 Kent Gibson
2020-06-24 14:33   ` Andy Shevchenko
2020-06-24 15:40     ` Kent Gibson
2020-06-26 14:02       ` Kent Gibson
2020-06-24 14:36   ` Bartosz Golaszewski
2020-06-24 23:58     ` Kent Gibson
2020-06-23  4:00 ` Kent Gibson [this message]
2020-06-29 14:25   ` [PATCH 14/22] gpiolib: make cdev a build option Bartosz Golaszewski
2020-06-23  4:01 ` [PATCH 15/22] gpiolib: add build option for CDEV V1 ABI Kent Gibson
2020-06-29 14:26   ` Bartosz Golaszewski
2020-06-23  4:01 ` [PATCH 16/22] gpiolib: cdev: add V2 uAPI implementation to parity with V1 Kent Gibson
2020-06-23 17:44   ` Dan Carpenter
2020-06-23 23:23     ` Kent Gibson
2020-06-23  4:01 ` [PATCH 17/22] gpiolib: cdev: report edge detection in lineinfo Kent Gibson
2020-06-23  4:01 ` [PATCH 18/22] gpiolib: cdev: support setting debounce Kent Gibson
2020-06-23  4:01 ` [PATCH 19/22] gpio: uapi: document uAPI V1 as deprecated Kent Gibson
2020-06-23  4:01 ` [PATCH 20/22] tools: gpio: switch tools to V2 uAPI Kent Gibson
2020-06-23  4:01 ` [PATCH 21/22] tools: gpio: add debounce support to gpio-event-mon Kent Gibson
2020-06-23  4:01 ` [PATCH 22/22] tools: gpio: support monitoring multiple lines Kent Gibson
2020-06-30 10:43   ` Bartosz Golaszewski

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