fusee: merge in most of the microSD card (not fully working)

fusee/fusee-primary/src/gpio.c

@@ -0,0 +1,149 @@
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+
+#include "gpio.h"
+#include "lib/printk.h"
+
+enum tegra_gpio_shifts {
+    GPIO_BANK_SHIFT = 5,  
+    GPIO_PORT_SHIFT = 3,
+};
+
+enum tegra_gpio_masks {
+    GPIO_PORT_MASK = 0x3,
+    GPIO_PIN_MASK  = 0x7,
+};
+
+/**
+ * Returns a GPIO bank object that corresponds to the given GPIO pin,
+ * which can be created using the TEGRA_GPIO macro or passed from the name macro.
+ *
+ * @param pin The GPIO to get the bank for.
+ * @return The GPIO bank object to use for working with the given bank.
+ */
+static volatile struct tegra_gpio_bank *gpio_get_bank(enum tegra_named_gpio pin)
+{
+    volatile struct tegra_gpio *gpio = gpio_get_regs();
+    int bank_number = pin >> GPIO_BANK_SHIFT;
+
+    return &gpio->bank[bank_number];
+}
+
+
+/**
+ * @return the port number for working with the given GPIO.
+ */
+static volatile int gpio_get_port(enum tegra_named_gpio pin)
+{
+    return (pin >> GPIO_PORT_SHIFT) & GPIO_PORT_MASK;
+}
+
+
+/**
+ * @return a mask to be used to work with the given GPIO
+ */
+static volatile uint32_t gpio_get_mask(enum tegra_named_gpio pin)
+{
+    uint32_t pin_number = pin & GPIO_PIN_MASK;
+    return (1 << pin_number);
+}
+
+
+
+/**
+ * Performs a simple GPIO configuration operation.
+ *
+ * @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
+ * @param should_be_set True iff the relevant bit should be set; or false if it should be cleared.
+ * @param offset The offset into a gpio_bank structure 
+ */
+static void gpio_simple_register_set(enum tegra_named_gpio pin, bool should_be_set, size_t offset)
+{
+    // Retrieve the register set that corresponds to the given pin and offset.
+    uintptr_t cluster_addr = (uintptr_t)gpio_get_bank(pin) + offset;
+    uint32_t *cluster = (uint32_t *)cluster_addr;
+
+    // Figure out the offset into the cluster,
+    // and the mask to be used.
+    int port      = gpio_get_port(pin);
+    uint32_t mask = gpio_get_mask(pin);
+
+
+    // Set or clear the bit, as appropriate.
+    if (should_be_set)
+        cluster[port] |=  mask;
+    else
+        cluster[port] &= ~mask;
+}
+
+
+/**
+ * Performs a simple GPIO configuration operation.
+ *
+ * @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
+ * @param should_be_set True iff the relevant bit should be set; or false if it should be cleared.
+ * @param offset The offset into a gpio_bank structure 
+ */
+static bool gpio_simple_register_get(enum tegra_named_gpio pin, size_t offset)
+{
+    // Retrieve the register set that corresponds to the given pin and offset.
+    uintptr_t cluster_addr = (uintptr_t)gpio_get_bank(pin) + offset;
+    uint32_t *cluster = (uint32_t *)cluster_addr;
+
+    // Figure out the offset into the cluster,
+    // and the mask to be used.
+    int port      = gpio_get_port(pin);
+    uint32_t mask = gpio_get_mask(pin);
+
+    // Convert the given value to a boolean.
+    return !!(cluster[port] & mask);
+}
+
+
+/**
+ * Configures a given pin as either GPIO or SFIO.
+ *
+ * @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
+ * @param mode The relevant mode.
+ */
+void gpio_configure_mode(enum tegra_named_gpio pin, enum tegra_gpio_mode mode)
+{
+    gpio_simple_register_set(pin, mode == GPIO_MODE_GPIO, offsetof(struct tegra_gpio_bank, config));
+}
+
+
+/**
+ * Configures a given pin as either INPUT or OUPUT.
+ *
+ * @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
+ * @param direction The relevant direction.
+ */
+void gpio_configure_direction(enum tegra_named_gpio pin, enum tegra_gpio_direction dir)
+{
+    gpio_simple_register_set(pin, dir == GPIO_DIRECTION_OUTPUT, offsetof(struct tegra_gpio_bank, direction)); 
+}
+
+
+/**
+ * Drives a relevant GPIO pin as either HIGH or LOW.
+ *
+ * @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
+ * @param mode The relevant mode.
+ */
+void gpio_write(enum tegra_named_gpio pin, enum tegra_gpio_value value)
+{
+    gpio_simple_register_set(pin, value == GPIO_LEVEL_HIGH, offsetof(struct tegra_gpio_bank, out)); 
+}
+
+
+/**
+ * Drives a relevant GPIO pin as either HIGH or LOW.
+ *
+ * @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
+ * @param mode The relevant mode.
+ */
+enum tegra_gpio_value gpio_read(enum tegra_named_gpio pin)
+{
+    return gpio_simple_register_get(pin, offsetof(struct tegra_gpio_bank, in)); 
+}