[PATCH v2 0/2] gpio: add gpio open-drain & open-source emulation
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(-)
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; }
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
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.
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) {
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
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
participants (3)
-
Neil Armstrong -
Simon Glass -
Tom Rini