Drivers: Added Sunxi pinctrl driver

Works well enough to set bank modes and turn on an LED

Very not complete and needs more testing

kernel/drivers/sunxi_d1_pinctrl/include/sunxi_d1_pinctrl/registers.h

@@ -0,0 +1,38 @@
+#include <stdint.h>
+
+namespace drivers {
+namespace sunxi_d1_pinctrl {
+
+struct [[gnu::aligned(4)]] Port {
+    uint32_t config[4];
+    uint32_t data;
+    uint32_t drive[4];
+    uint32_t pull[2];
+    uint32_t _;
+};
+
+struct [[gnu::aligned(4)]] PortInt {
+    uint32_t config[4];
+    uint32_t control;
+    uint32_t status;
+    uint32_t debounce;
+    uint32_t _;
+};
+
+struct [[gnu::aligned(4)]] PIO {
+    uint32_t mode;
+    uint32_t control;
+    uint32_t value;
+    uint32_t voltage_select;
+};
+
+struct [[gnu::aligned(4)]] Registers {
+    volatile Port ports[7];
+    volatile uint32_t _[0x34];
+    volatile PortInt interrupt[7];
+    volatile uint32_t __[0x10];
+    volatile PIO pio;
+};
+
+}  // End namespace sunxi_d1_pinctrl
+}  // End namespace drivers

kernel/drivers/sunxi_d1_pinctrl/include/sunxi_d1_pinctrl/sunxi_d1_pinctrl.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include "registers.h"
+#include <stdint.h>
+
+namespace drivers {
+namespace sunxi_d1_pinctrl {
+
+enum Bank {
+    PA,
+    PB,
+    PC,
+    PD,
+    PE,
+    PF,
+    PG,
+};
+
+struct SunxiD1Pinctrl {
+    SunxiD1Pinctrl(void * const addr);
+
+    void set_pin_mode(
+            const Bank bank,
+            const uint8_t pin,
+            const uint8_t mode);
+    void set_pin_state(
+            const Bank bank,
+            const uint8_t pin,
+            const bool state);
+    bool get_pin_state(
+            const Bank bank,
+            const uint8_t pin);
+
+  private:
+    Registers &m_registers;
+};
+
+}  // End namespace sunxi_d1_pinctrl
+}  // End namespace drivers

kernel/drivers/sunxi_d1_pinctrl/meson.build

@@ -0,0 +1,9 @@
+kernel_sources += [
+    files(
+        'sunxi_d1_pinctrl.cpp',
+    ),
+]
+
+kernel_includes += include_directories(
+    'include'
+)

kernel/drivers/sunxi_d1_pinctrl/sunxi_d1_pinctrl.cpp

@@ -0,0 +1,47 @@
+#include "sunxi_d1_pinctrl/sunxi_d1_pinctrl.h"
+
+namespace drivers {
+namespace sunxi_d1_pinctrl {
+
+SunxiD1Pinctrl::SunxiD1Pinctrl(void * const addr) :
+    m_registers(*reinterpret_cast<Registers *>(addr)) {}
+
+void SunxiD1Pinctrl::set_pin_mode(
+        const Bank bank,
+        const uint8_t pin,
+        const uint8_t mode) {
+    // Config banks are split up every 8 GPIO pins
+    // Each bank is 32 bits and configures up to 8 pins
+    const int config_bank = pin / 8;
+    // Each config is 4 bits per pin
+    const int shift_amount = pin % 8 * 4;
+    const uint32_t mask = 0b1111 << shift_amount;
+
+    auto config = m_registers.ports[bank].config[config_bank];
+    config &= ~mask;
+    config |= (mode & 0b1111) << shift_amount;
+    m_registers.ports[bank].config[config_bank] = config;
+}
+
+void SunxiD1Pinctrl::set_pin_state(
+        const Bank bank,
+        const uint8_t pin,
+        const bool state) {
+    const uint32_t mask = 0b1 << pin;
+
+    auto data = m_registers.ports[bank].data;
+    if(state)
+        data |= mask;
+    else
+        data &= ~mask;
+    m_registers.ports[bank].data = data;
+}
+
+bool SunxiD1Pinctrl::get_pin_state(
+        const Bank bank,
+        const uint8_t pin) {
+    return m_registers.ports[bank].data >> pin & 1;
+}
+
+}  // End namespace sunxi_d1_pinctrl
+}  // End namespace drivers

kernel/kernel.cpp

@@ -13,6 +13,7 @@
 #include <opensbi/extensions/srst.h>
 #include <opensbi/extensions/pmu.h>
 
+#include <sunxi_d1_pinctrl/sunxi_d1_pinctrl.h>
 
 void fmt(const char *f, ...) {
     namespace legacy = drivers::opensbi::legacy;
@@ -110,6 +111,12 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
     fmt("uintmax: {} bits\n", sizeof(uintmax_t) * 8);
     fmt("HART: {}, DTB: {}\n", hart, dtb);
 
+    namespace sunxi_d1_pinctrl = drivers::sunxi_d1_pinctrl;
+    sunxi_d1_pinctrl::SunxiD1Pinctrl pinctrl((void *)0x2000000);
+
+    pinctrl.set_pin_mode(sunxi_d1_pinctrl::Bank::PC, 1, 1);
+    pinctrl.set_pin_state(sunxi_d1_pinctrl::Bank::PC, 1, true);
+
     fmt("HALT\n");
     while(1);
 

kernel/meson.build

@@ -13,6 +13,7 @@ kernel_cpp_args = []
 kernel_link_args = ['-nostdlib']
 
 subdir('drivers/opensbi')
+subdir('drivers/sunxi_d1_pinctrl')
 # subdir('common/dtb')
 
 includes = [