drivers: tegra_gpio: add early SPL functions

In some cases access to GPIOs is needed so early that DM
is not ready even nearly. These functions are exactly for
this case.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>

drivers/gpio/tegra_gpio.c

@@ -257,6 +257,56 @@ static const struct dm_gpio_ops gpio_tegra_ops = {
 	.xlate			= tegra_gpio_xlate,
 };
 
+/*
+ * SPL GPIO functions.
+ */
+int spl_gpio_output(void *regs, uint gpio, int value)
+{
+	/* Configure GPIO output value. */
+	set_level(gpio, value);
+
+	/* Configure GPIO direction as output. */
+	set_direction(gpio, DIRECTION_OUTPUT);
+
+	/* Enable the pin as a GPIO */
+	set_config(gpio, 1);
+
+	return 0;
+}
+
+int spl_gpio_input(void *regs, uint gpio)
+{
+	/* Configure GPIO direction as input. */
+	set_direction(gpio, DIRECTION_INPUT);
+
+	/* Enable the pin as a GPIO */
+	set_config(gpio, 1);
+
+	return 0;
+}
+
+int spl_gpio_get_value(void *regs, uint gpio)
+{
+	struct gpio_ctlr *ctlr = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
+	struct gpio_ctlr_bank *bank = &ctlr->gpio_bank[GPIO_BANK(gpio)];
+	int val;
+
+	if (get_direction(gpio) == DIRECTION_INPUT)
+		val = readl(&bank->gpio_in[GPIO_PORT(gpio)]);
+	else
+		val = readl(&bank->gpio_out[GPIO_PORT(gpio)]);
+
+	return (val >> GPIO_BIT(gpio)) & 1;
+}
+
+int spl_gpio_set_value(void *regs, uint gpio, int value)
+{
+	/* Configure GPIO output value. */
+	set_level(gpio, value);
+
+	return 0;
+}
+
 /**
  * Returns the name of a GPIO port
  *

include/spl_gpio.h

@@ -59,4 +59,23 @@ int spl_gpio_output(void *regs, uint gpio, int value);
  */
 int spl_gpio_input(void *regs, uint gpio);
 
+/**
+ * spl_gpio_get_value() - Get GPIO value
+ *
+ * @regs: Pointer to GPIO registers
+ * @gpio: GPIO to adjust (SoC-specific)
+ * Return: return GPIO value if OK, -ve on error
+ */
+int spl_gpio_get_value(void *regs, uint gpio);
+
+/**
+ * spl_gpio_set_value() - Set value on GPIO
+ *
+ * @regs: Pointer to GPIO registers
+ * @gpio: GPIO to adjust (SoC-specific)
+ * @value: 0 to set the output low, 1 to set it high
+ * Return: return 0 if OK, -ve on error
+ */
+int spl_gpio_set_value(void *regs, uint gpio, int value);
+
 #endif /* __SPL_GPIO_H */