openwrt/target/linux/bcm27xx/patches-4.19/950-0698-regulator-gpio-Allow-nonexclusive-GPIO-access.patch
Adrian Schmutzler 7d7aa2fd92 brcm2708: rename target to bcm27xx
This change makes the names of Broadcom targets consistent by using
the common notation based on SoC/CPU ID (which is used internally
anyway), bcmXXXX instead of brcmXXXX.
This is even used for target TITLE in make menuconfig already,
only the short target name used brcm so far.

Despite, since subtargets range from bcm2708 to bcm2711, it seems
appropriate to use bcm27xx instead of bcm2708 (again, as already done
for BOARDNAME).

This also renames the packages brcm2708-userland and brcm2708-gpu-fw.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
2020-02-14 14:10:51 +01:00

80 lines
2.8 KiB
Diff

From f6d983b7bc9ae79d0eb4dea7bc30a1ad5ff428a7 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@linaro.org>
Date: Fri, 12 Oct 2018 14:54:12 +0200
Subject: [PATCH] regulator/gpio: Allow nonexclusive GPIO access
commit b0ce7b29bfcd090ddba476f45a75ec0a797b048a upstream.
[ This is a partial cherry-pick, omitting the regulator
change which isn't required ]
This allows nonexclusive (simultaneous) access to a single
GPIO line for the fixed regulator enable line. This happens
when several regulators use the same GPIO for enabling and
disabling a regulator, and all need a handle on their GPIO
descriptor.
This solution with a special flag is not entirely elegant
and should ideally be replaced by something more careful as
this makes it possible for several consumers to
enable/disable the same GPIO line to the left and right
without any consistency. The current use inside the regulator
core should however be fine as it takes special care to
handle this.
For the state of the GPIO backend, this is still the
lesser evil compared to going back to global GPIO
numbers.
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Fixes: efdfeb079cc3 ("regulator: fixed: Convert to use GPIO descriptor only")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
drivers/gpio/gpiolib.c | 19 +++++++++++++++++--
include/linux/gpio/consumer.h | 1 +
2 files changed, 18 insertions(+), 2 deletions(-)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3988,8 +3988,23 @@ struct gpio_desc *__must_check gpiod_get
* the device name as label
*/
status = gpiod_request(desc, con_id ? con_id : devname);
- if (status < 0)
- return ERR_PTR(status);
+ if (status < 0) {
+ if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
+ /*
+ * This happens when there are several consumers for
+ * the same GPIO line: we just return here without
+ * further initialization. It is a bit if a hack.
+ * This is necessary to support fixed regulators.
+ *
+ * FIXME: Make this more sane and safe.
+ */
+ dev_info(dev, "nonexclusive access to GPIO for %s\n",
+ con_id ? con_id : devname);
+ return desc;
+ } else {
+ return ERR_PTR(status);
+ }
+ }
status = gpiod_configure_flags(desc, con_id, lookupflags, flags);
if (status < 0) {
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -30,6 +30,7 @@ struct gpio_descs {
#define GPIOD_FLAGS_BIT_DIR_OUT BIT(1)
#define GPIOD_FLAGS_BIT_DIR_VAL BIT(2)
#define GPIOD_FLAGS_BIT_OPEN_DRAIN BIT(3)
+#define GPIOD_FLAGS_BIT_NONEXCLUSIVE BIT(4)
/**
* Optional flags that can be passed to one of gpiod_* to configure direction