dm: gpio: Add better functions to request GPIOs

At present U-Boot sort-of supports the standard way of reading GPIOs from
device tree nodes, but the support is incomplete, a bit clunky and only
works for GPIO bindings where #gpio-cells is 2.

Add new functions to request GPIOs, taking full account of the device
tree binding. These permit requesting a GPIO with a simple call like:

   gpio_request_by_name(dev, "cd-gpios", 0, &desc, GPIOD_IS_IN);

This will request the GPIO, looking at the device's node which might be
this, for example:

   cd-gpios = <&gpio TEGRA_GPIO(B, 3) GPIO_ACTIVE_LOW>;

The GPIO will be set to input mode in this case and polarity will be
honoured by the GPIO calls.

It is also possible to request and free a list of GPIOs.

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

1 files changed, 68 insertions, 1 deletions

diff --git a/test/dm/gpio.c b/test/dm/gpio.c
index 94bd0d99dc0..b29daf1af4e 100644
--- a/test/dm/gpio.c
+++ b/test/dm/gpio.c
@@ -174,5 +174,72 @@ static int dm_test_gpio_leak(struct dm_test_state *dms)
 
 	return 0;
 }
-
 DM_TEST(dm_test_gpio_leak, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Test that we can find GPIOs using phandles */
+static int dm_test_gpio_phandles(struct dm_test_state *dms)
+{
+	struct gpio_desc desc, desc_list[8], desc_list2[8];
+	struct udevice *dev, *gpio_a, *gpio_b;
+
+	ut_assertok(uclass_get_device(UCLASS_TEST_FDT, 0, &dev));
+	ut_asserteq_str("a-test", dev->name);
+
+	ut_assertok(gpio_request_by_name(dev, "test-gpios", 1, &desc, 0));
+	ut_assertok(uclass_get_device(UCLASS_GPIO, 1, &gpio_a));
+	ut_assertok(uclass_get_device(UCLASS_GPIO, 2, &gpio_b));
+	ut_asserteq_str("base-gpios", gpio_a->name);
+	ut_asserteq(true, !!device_active(gpio_a));
+	ut_asserteq_ptr(gpio_a, desc.dev);
+	ut_asserteq(4, desc.offset);
+	/* GPIOF_INPUT is the sandbox GPIO driver default */
+	ut_asserteq(GPIOF_INPUT, gpio_get_function(gpio_a, 4, NULL));
+	ut_assertok(dm_gpio_free(dev, &desc));
+
+	ut_asserteq(-ENOENT, gpio_request_by_name(dev, "test-gpios", 3, &desc,
+						  0));
+	ut_asserteq_ptr(NULL, desc.dev);
+	ut_asserteq(desc.offset, 0);
+	ut_asserteq(-ENOENT, gpio_request_by_name(dev, "test-gpios", 5, &desc,
+						  0));
+
+	/* Last GPIO is ignord as it comes after <0> */
+	ut_asserteq(3, gpio_request_list_by_name(dev, "test-gpios", desc_list,
+						 ARRAY_SIZE(desc_list), 0));
+	ut_asserteq(-EBUSY, gpio_request_list_by_name(dev, "test-gpios",
+						      desc_list2,
+						      ARRAY_SIZE(desc_list2),
+						      0));
+	ut_assertok(gpio_free_list(dev, desc_list, 3));
+	ut_asserteq(3, gpio_request_list_by_name(dev,  "test-gpios", desc_list,
+						 ARRAY_SIZE(desc_list),
+						 GPIOD_IS_OUT |
+						 GPIOD_IS_OUT_ACTIVE));
+	ut_asserteq_ptr(gpio_a, desc_list[0].dev);
+	ut_asserteq(1, desc_list[0].offset);
+	ut_asserteq_ptr(gpio_a, desc_list[1].dev);
+	ut_asserteq(4, desc_list[1].offset);
+	ut_asserteq_ptr(gpio_b, desc_list[2].dev);
+	ut_asserteq(5, desc_list[2].offset);
+	ut_asserteq(1, dm_gpio_get_value(desc_list));
+	ut_assertok(gpio_free_list(dev, desc_list, 3));
+
+	ut_asserteq(6, gpio_request_list_by_name(dev, "test2-gpios", desc_list,
+						 ARRAY_SIZE(desc_list), 0));
+	/* This was set to output previously, so still will be */
+	ut_asserteq(GPIOF_OUTPUT, gpio_get_function(gpio_a, 1, NULL));
+
+	/* Active low should invert the input value */
+	ut_asserteq(GPIOF_INPUT, gpio_get_function(gpio_b, 6, NULL));
+	ut_asserteq(1, dm_gpio_get_value(&desc_list[2]));
+
+	ut_asserteq(GPIOF_INPUT, gpio_get_function(gpio_b, 7, NULL));
+	ut_asserteq(GPIOF_OUTPUT, gpio_get_function(gpio_b, 8, NULL));
+	ut_asserteq(0, dm_gpio_get_value(&desc_list[4]));
+	ut_asserteq(GPIOF_OUTPUT, gpio_get_function(gpio_b, 9, NULL));
+	ut_asserteq(1, dm_gpio_get_value(&desc_list[5]));
+
+
+	return 0;
+}
+DM_TEST(dm_test_gpio_phandles, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);