Kernel: Make the PresentState register a bitfield in the SDHC driver

Kernel/Devices/Storage/SD/Registers.h

@@ -42,7 +42,34 @@ struct HostControlRegisterMap {
     u32 response_2;
     u32 response_3;
     u32 buffer_data_port;
-    u32 present_state;
+    union PresentState {
+        struct { // SDHC 2.2.9 Present State Register (Cat.C Offset 024h)
+            u32 command_inhibit_cmd : 1;
+            u32 command_inhibit_dat : 1;
+            u32 dat_line_active : 1;
+            u32 re_tuning_request : 1;
+            u32 dat_7_4_line_signal_level : 4;
+            u32 write_transfer_active : 1;
+            u32 read_transfer_active : 1;
+            u32 buffer_write_enable : 1;
+            u32 buffer_read_enable : 1;
+            u32 : 4;
+            u32 card_inserted : 1;
+            u32 card_state_stable : 1;
+            u32 card_detect_pin_level : 1;
+            u32 write_protect_switch_pin_level : 1;
+            u32 dat_3_0_line_signal_level : 4;
+            u32 cmd_line_signal_level : 1;
+            u32 host_regulator_voltage_stable : 1;
+            u32 : 1;
+            u32 command_not_issued_by_error : 1;
+            u32 sub_command_status : 1;
+            u32 in_dormant_state : 1;
+            u32 lane_synchronization : 1;
+            u32 uhs_2_if_detection : 1;
+        };
+        u32 raw;
+    } present_state;
     u32 host_configuration_0;
     u32 host_configuration_1;
     union InterruptStatus {

Kernel/Devices/Storage/SD/SDHostController.cpp

@@ -270,14 +270,12 @@ bool SDHostController::retry_with_timeout(Function<bool()> f, i64 delay_between_
 ErrorOr<void> SDHostController::issue_command(SD::Command const& cmd, u32 argument)
 {
     // SDHC 3.7.1: "Transaction Control without Data Transfer Using DAT Line"
-    constexpr u32 command_inhibit = 1 << 1;
 
     // 1. Check Command Inhibit (CMD) in the Present State register.
     //    Repeat this step until Command Inhibit (CMD) is 0.
     //    That is, when Command Inhibit (CMD) is 1, the Host Driver
     //    shall not issue an SD Command.
-    if (!retry_with_timeout(
-            [&]() { return !(m_registers->present_state & command_inhibit); })) {
+    if (!retry_with_timeout([&]() { return !m_registers->present_state.command_inhibit_cmd; })) {
         return EIO;
     }
 
@@ -290,8 +288,7 @@ ErrorOr<void> SDHostController::issue_command(SD::Command const& cmd, u32 argume
 
         // 4. Check Command Inhibit (DAT) in the Present State register. Repeat
         // this step until Command Inhibit (DAT) is set to 0.
-        constexpr u32 data_inhibit = 1 << 2;
-        if (!retry_with_timeout([&]() { return !(m_registers->present_state & data_inhibit); })) {
+        if (!retry_with_timeout([&]() { return !m_registers->present_state.command_inhibit_dat; })) {
             return EIO;
         }
     }

Kernel/Devices/Storage/SD/SDHostController.h

@@ -43,8 +43,7 @@ private:
 
     bool is_card_inserted() const
     {
-        constexpr u32 card_inserted = 1 << 16;
-        return m_registers->present_state & card_inserted;
+        return m_registers->present_state.card_inserted;
     }
 
     SD::HostVersion host_version() { return m_registers->slot_interrupt_status_and_version.specification_version_number; }