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authorLinus Walleij <linus.walleij@linaro.org>2018-10-12 14:54:12 +0200
committerMark Brown <broonie@kernel.org>2018-10-12 18:55:02 +0200
commitb0ce7b29bfcd090ddba476f45a75ec0a797b048a (patch)
treeb689c014f8e3423d4db5a5355ec81c548eba3ae1 /drivers/regulator
parentbef9391cbec547351c6a13e52f3a26bb2d271ec7 (diff)
regulator/gpio: Allow nonexclusive GPIO access
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>
Diffstat (limited to 'drivers/regulator')
-rw-r--r--drivers/regulator/fixed.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index 7d639ad953b6..ccc29038f19a 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -170,6 +170,19 @@ static int reg_fixed_voltage_probe(struct platform_device *pdev)
gflags = GPIOD_OUT_LOW_OPEN_DRAIN;
}
+ /*
+ * Some fixed regulators share the enable line between two
+ * regulators which makes it necessary to get a handle on the
+ * same descriptor for two different consumers. This will get
+ * the GPIO descriptor, but only the first call will initialize
+ * it so any flags such as inversion or open drain will only
+ * be set up by the first caller and assumed identical on the
+ * next caller.
+ *
+ * FIXME: find a better way to deal with this.
+ */
+ gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
+
cfg.ena_gpiod = devm_gpiod_get_optional(&pdev->dev, NULL, gflags);
if (IS_ERR(cfg.ena_gpiod))
return PTR_ERR(cfg.ena_gpiod);