[PATCH v2 0/2] gpio: add gpio open-drain & open-source emulation

[PATCH v2 0/2] gpio: add gpio open-drain & open-source emulation

[Neil Armstrong]

When a line is in open-drain or open-source mode, U-Boot doesn't handle it
directly.

Let's add gpio open-drain & open-source emulation in gpio u-class to make
it transparent to driver using a gpio line from DT.

Changes since v1:
- fixed all open-drain/open source cases
- updated dm gpio test

Neil Armstrong (2):
  gpio: emulate open drain & open source in dm_gpio_set_value()
  test: dm: update test for open-drain/open-source emulation in
    gpio-uclass

 arch/sandbox/dts/test.dts  |  4 +-
 drivers/gpio/gpio-uclass.c | 15 +++++++
 test/dm/gpio.c             | 89 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+), 1 deletion(-)

-- 
2.22.0

[PATCH v2 1/2] gpio: emulate open drain & open source in dm_gpio_set_value()

[Neil Armstrong]

Handle the GPIOD_OPEN_DRAIN & GPIOD_OPEN_SOURCE flags to emulate open drain
and open source by setting the GPIO line as input depending on the
requested value.

The behaviour is taken from the Linux gpiolib.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpio/gpio-uclass.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 757ab7106e..d3cea11f76 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -526,6 +526,21 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value)
 
 	if (desc->flags & GPIOD_ACTIVE_LOW)
 		value = !value;
+
+	/*
+	 * Emulate open drain by not actively driving the line high or
+	 * Emulate open source by not actively driving the line low
+	 */
+	if ((desc->flags & GPIOD_OPEN_DRAIN && value) ||
+	    (desc->flags & GPIOD_OPEN_SOURCE && !value))
+		return gpio_get_ops(desc->dev)->direction_input(desc->dev,
+								desc->offset);
+	else if (desc->flags & GPIOD_OPEN_DRAIN ||
+		 desc->flags & GPIOD_OPEN_SOURCE)
+		return gpio_get_ops(desc->dev)->direction_output(desc->dev,
+								desc->offset,
+								value);
+
 	gpio_get_ops(desc->dev)->set_value(desc->dev, desc->offset, value);
 	return 0;
 }
-- 
2.22.0

[PATCH v2 2/2] test: dm: update test for open-drain/open-source emulation in gpio-uclass

[Neil Armstrong]

Add tests for testing open-drain/open-source emulation in gpio-uclass.
It also adds two test3-gpios configured as GPIO_ACTIVE_LOW.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 arch/sandbox/dts/test.dts |  4 +-
 test/dm/gpio.c            | 89 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 1 deletion(-)

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 4bccfbe6e1..e9b9404363 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -104,7 +104,9 @@
 			<&gpio_c 2 GPIO_OUT>,
 			<&gpio_c 3 (GPIO_IN|GPIO_PULL_UP)>,
 			<&gpio_c 4 (GPIO_IN|GPIO_PULL_DOWN)>,
-			<&gpio_c 5 GPIO_IN>;
+			<&gpio_c 5 GPIO_IN>,
+			<&gpio_c 6 (GPIO_ACTIVE_LOW|GPIO_OUT|GPIO_OPEN_DRAIN)>,
+			<&gpio_c 7 (GPIO_ACTIVE_LOW|GPIO_OUT|GPIO_OPEN_SOURCE)>;
 		int-value = <1234>;
 		uint-value = <(-1234)>;
 		int64-value = /bits/ 64 <0x1111222233334444>;
diff --git a/test/dm/gpio.c b/test/dm/gpio.c
index f5c7aaf3bc..7c18e5c411 100644
--- a/test/dm/gpio.c
+++ b/test/dm/gpio.c
@@ -112,6 +112,95 @@ static int dm_test_gpio(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_gpio, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
 
+/* Test that GPIO open-drain/open-source emulation works correctly */
+static int dm_test_gpio_opendrain_opensource(struct unit_test_state *uts)
+{
+	struct gpio_desc desc_list[8];
+	struct udevice *dev, *gpio_c;
+	char buf[80];
+
+	ut_assertok(uclass_get_device(UCLASS_TEST_FDT, 0, &dev));
+	ut_asserteq_str("a-test", dev->name);
+
+	ut_assertok(uclass_get_device(UCLASS_GPIO, 3, &gpio_c));
+	ut_asserteq_str("pinmux-gpios", gpio_c->name);
+
+	ut_asserteq(8, gpio_request_list_by_name(dev, "test3-gpios", desc_list,
+						 ARRAY_SIZE(desc_list), 0))
+
+	ut_asserteq(true, !!device_active(gpio_c));
+	ut_asserteq_ptr(gpio_c, desc_list[0].dev);
+	ut_asserteq_ptr(gpio_c, desc_list[1].dev);
+	ut_asserteq_ptr(gpio_c, desc_list[2].dev);
+	ut_asserteq_ptr(gpio_c, desc_list[3].dev);
+	ut_asserteq_ptr(gpio_c, desc_list[4].dev);
+	ut_asserteq_ptr(gpio_c, desc_list[5].dev);
+	ut_asserteq_ptr(gpio_c, desc_list[6].dev);
+	ut_asserteq_ptr(gpio_c, desc_list[7].dev);
+
+	/* GPIO 0 is (GPIO_OUT|GPIO_OPEN_DRAIN) */
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_OPEN_DRAIN,
+		    sandbox_gpio_get_dir_flags(gpio_c, 0));
+
+	/* Set it as output high, should become an input */
+	ut_assertok(dm_gpio_set_value(&desc_list[0], 1));
+	ut_assertok(gpio_get_status(gpio_c, 0, buf, sizeof(buf)));
+	ut_asserteq_str("c0: input: 0 [x] a-test.test3-gpios0", buf);
+
+	/* Set it as output low, should become output low */
+	ut_assertok(dm_gpio_set_value(&desc_list[0], 0));
+	ut_assertok(gpio_get_status(gpio_c, 0, buf, sizeof(buf)));
+	ut_asserteq_str("c0: output: 0 [x] a-test.test3-gpios0", buf);
+
+	/* GPIO 1 is (GPIO_OUT|GPIO_OPEN_SOURCE) */
+	ut_asserteq(GPIOD_IS_OUT | GPIOD_OPEN_SOURCE,
+		    sandbox_gpio_get_dir_flags(gpio_c, 1));
+
+	/* Set it as output high, should become output high */
+	ut_assertok(dm_gpio_set_value(&desc_list[1], 1));
+	ut_assertok(gpio_get_status(gpio_c, 1, buf, sizeof(buf)));
+	ut_asserteq_str("c1: output: 1 [x] a-test.test3-gpios1", buf);
+
+	/* Set it as output low, should become an input */
+	ut_assertok(dm_gpio_set_value(&desc_list[1], 0));
+	ut_assertok(gpio_get_status(gpio_c, 1, buf, sizeof(buf)));
+	ut_asserteq_str("c1: input: 1 [x] a-test.test3-gpios1", buf);
+
+	/* GPIO 6 is (GPIO_ACTIVE_LOW|GPIO_OUT|GPIO_OPEN_DRAIN) */
+	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_DRAIN,
+		    sandbox_gpio_get_dir_flags(gpio_c, 6));
+
+	/* Set it as output high, should become output low */
+	ut_assertok(dm_gpio_set_value(&desc_list[6], 1));
+	ut_assertok(gpio_get_status(gpio_c, 6, buf, sizeof(buf)));
+	ut_asserteq_str("c6: output: 0 [x] a-test.test3-gpios6", buf);
+
+	/* Set it as output low, should become an input */
+	ut_assertok(dm_gpio_set_value(&desc_list[6], 0));
+	ut_assertok(gpio_get_status(gpio_c, 6, buf, sizeof(buf)));
+	ut_asserteq_str("c6: input: 0 [x] a-test.test3-gpios6", buf);
+
+	/* GPIO 7 is (GPIO_ACTIVE_LOW|GPIO_OUT|GPIO_OPEN_SOURCE) */
+	ut_asserteq(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT | GPIOD_OPEN_SOURCE,
+		    sandbox_gpio_get_dir_flags(gpio_c, 7));
+
+	/* Set it as output high, should become an input */
+	ut_assertok(dm_gpio_set_value(&desc_list[7], 1));
+	ut_assertok(gpio_get_status(gpio_c, 7, buf, sizeof(buf)));
+	ut_asserteq_str("c7: input: 0 [x] a-test.test3-gpios7", buf);
+
+	/* Set it as output low, should become output high */
+	ut_assertok(dm_gpio_set_value(&desc_list[7], 0));
+	ut_assertok(gpio_get_status(gpio_c, 7, buf, sizeof(buf)));
+	ut_asserteq_str("c7: output: 1 [x] a-test.test3-gpios7", buf);
+
+	ut_assertok(gpio_free_list(dev, desc_list, 8));
+
+	return 0;
+}
+DM_TEST(dm_test_gpio_opendrain_opensource,
+	DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
 /* Test that sandbox anonymous GPIOs work correctly */
 static int dm_test_gpio_anon(struct unit_test_state *uts)
 {
-- 
2.22.0

[PATCH v2 2/2] test: dm: update test for open-drain/open-source emulation in gpio-uclass

[Simon Glass]

On Tue, 5 May 2020 at 02:43, Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> Add tests for testing open-drain/open-source emulation in gpio-uclass.
> It also adds two test3-gpios configured as GPIO_ACTIVE_LOW.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  arch/sandbox/dts/test.dts |  4 +-
>  test/dm/gpio.c            | 89 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 92 insertions(+), 1 deletion(-)
>

Reviewed-by: Simon Glass <sjg@chromium.org>

[PATCH v2 1/2] gpio: emulate open drain & open source in dm_gpio_set_value()

[Simon Glass]

Hi Neil,

+Tom Rini

On Tue, 5 May 2020 at 02:43, Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> Handle the GPIOD_OPEN_DRAIN & GPIOD_OPEN_SOURCE flags to emulate open drain
> and open source by setting the GPIO line as input depending on the
> requested value.
>
> The behaviour is taken from the Linux gpiolib.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/gpio/gpio-uclass.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>

Reviewed-by: Simon Glass <sjg@chromium.org>

I wonder how we should handle small increases in functionality, like
this. If a board doesn't want the code-stize hit in SPL, should we
have it behind a Kconfig, like CONFIG_GPIO_EXTRA?

Regards,
Simon

[PATCH v2 1/2] gpio: emulate open drain & open source in dm_gpio_set_value()

[Tom Rini]

On Wed, May 06, 2020 at 08:47:20AM -0600, Simon Glass wrote:
> Hi Neil,
> 
> +Tom Rini
> 
> On Tue, 5 May 2020 at 02:43, Neil Armstrong <narmstrong@baylibre.com> wrote:
> >
> > Handle the GPIOD_OPEN_DRAIN & GPIOD_OPEN_SOURCE flags to emulate open drain
> > and open source by setting the GPIO line as input depending on the
> > requested value.
> >
> > The behaviour is taken from the Linux gpiolib.
> >
> > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> > ---
> >  drivers/gpio/gpio-uclass.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> >
> 
> Reviewed-by: Simon Glass <sjg@chromium.org>
> 
> I wonder how we should handle small increases in functionality, like
> this. If a board doesn't want the code-stize hit in SPL, should we
> have it behind a Kconfig, like CONFIG_GPIO_EXTRA?

I suppose it'll come down to how much growth and where.

-- 
Tom
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[PATCH v2 0/2] gpio: add gpio open-drain & open-source emulation

[Neil Armstrong]

On 05/05/2020 10:43, Neil Armstrong wrote:
> When a line is in open-drain or open-source mode, U-Boot doesn't handle it
> directly.
> 
> Let's add gpio open-drain & open-source emulation in gpio u-class to make
> it transparent to driver using a gpio line from DT.
> 
> Changes since v1:
> - fixed all open-drain/open source cases
> - updated dm gpio test
> 
> Neil Armstrong (2):
>   gpio: emulate open drain & open source in dm_gpio_set_value()
>   test: dm: update test for open-drain/open-source emulation in
>     gpio-uclass
> 
>  arch/sandbox/dts/test.dts  |  4 +-
>  drivers/gpio/gpio-uclass.c | 15 +++++++
>  test/dm/gpio.c             | 89 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 107 insertions(+), 1 deletion(-)
> 

Applying to u-boot-amlogic

Thanks for reviewing.

Neil