6a0388c5b1
Update the binding file for gpio, it is just an alignment
with kernel v5.3.
The U-Boot code example for gpio-hog (not directly linked
to binding) is moved in a new file doc/README.gpio.
[commit 21676b706e99 ("gpio: fixes for gpio-hog support")
& 'commit 4762a9988ede ("gpio: add gpio-hog support")']
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
43 lines
1.1 KiB
Plaintext
43 lines
1.1 KiB
Plaintext
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GPIO hog (CONFIG_GPIO_HOG)
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--------
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All the GPIO hog are initialized in gpio_hog_probe_all() function called in
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board_r.c just before board_late_init() but you can also acces directly to
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the gpio with gpio_hog_lookup_name().
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Example, for the device tree:
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tca6416@20 {
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compatible = "ti,tca6416";
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reg = <0x20>;
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#gpio-cells = <2>;
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gpio-controller;
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env_reset {
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gpio-hog;
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input;
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gpios = <6 GPIO_ACTIVE_LOW>;
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};
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boot_rescue {
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gpio-hog;
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input;
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line-name = "foo-bar-gpio";
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gpios = <7 GPIO_ACTIVE_LOW>;
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};
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};
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You can than access the gpio in your board code with:
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struct gpio_desc *desc;
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int ret;
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ret = gpio_hog_lookup_name("boot_rescue", &desc);
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if (ret)
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return;
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if (dm_gpio_get_value(desc) == 1)
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printf("\nBooting into Rescue System\n");
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else if (dm_gpio_get_value(desc) == 0)
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printf("\nBoot normal\n");
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