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>
This commit is contained in:
Simon Glass 2015-01-05 20:05:29 -07:00
parent 0dac4d51f5
commit 3669e0e759
5 changed files with 461 additions and 4 deletions

View file

@ -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);

View file

@ -22,6 +22,11 @@
ping-expect = <0>;
ping-add = <0>;
u-boot,dm-pre-reloc;
test-gpios = <&gpio_a 1>, <&gpio_a 4>, <&gpio_b 5 0 3 2 1>,
<0>, <&gpio_a 12>;
test2-gpios = <&gpio_a 1>, <&gpio_a 4>, <&gpio_b 6 1 3 2 1>,
<&gpio_b 7 2 3 2 1>, <&gpio_b 8 4 3 2 1>,
<&gpio_b 9 0xc 3 2 1>;
};
junk {
@ -83,12 +88,16 @@
gpio_a: base-gpios {
compatible = "sandbox,gpio";
gpio-controller;
#gpio-cells = <1>;
gpio-bank-name = "a";
num-gpios = <20>;
};
extra-gpios {
gpio_b: extra-gpios {
compatible = "sandbox,gpio";
gpio-controller;
#gpio-cells = <5>;
gpio-bank-name = "b";
num-gpios = <10>;
};