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Set output pin initial value based on pin's pinmux pullup/pulldown setup

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Some of FDT blobs for AM335x-based devices use pinmux pullup/pulldown
flag to setup initial GPIO ouputp value, e.g. 4DCAPE-43 sets LCD DATAEN
signal this way. It works for Linux because Linux driver does not enforce
pin direction until after it's requested by consumer. So input with pullup
flag set acts as output with GPIO_HIGH value

Reviewed by:	loos
This commit is contained in:
gonzo 2015-08-01 23:10:36 +00:00
parent 5c500bdd46
commit 8864759038
1 changed files with 8 additions and 2 deletions
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10
sys/arm/ti/ti_gpio.c
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@ -573,7 +573,7 @@ ti_gpio_bank_init(device_t dev)
{
int pin;
struct ti_gpio_softc *sc;
uint32_t flags, reg_oe, rev;
uint32_t flags, reg_oe, reg_set, rev;
clk_ident_t clk;
sc = device_get_softc(dev);
@ -607,12 +607,18 @@ ti_gpio_bank_init(device_t dev)
/* Init OE register based on pads configuration. */
reg_oe = 0xffffffff;
reg_set = 0;
for (pin = 0; pin < PINS_PER_BANK; pin++) {
TI_GPIO_GET_FLAGS(dev, pin, &flags);
if (flags & GPIO_PIN_OUTPUT)
if (flags & GPIO_PIN_OUTPUT) {
reg_oe &= ~(1UL << pin);
if (flags & GPIO_PIN_PULLUP)
reg_set |= (1UL << pin);
}
}
ti_gpio_write_4(sc, TI_GPIO_OE, reg_oe);
if (reg_set)
ti_gpio_write_4(sc, TI_GPIO_SETDATAOUT, reg_set);
return (0);
}