Revise the TMC2130 interface for stepping

Change the TMC2130 class after starting to review the Motion API.
Move motor mode handling and stepping to this module.

Create a new MotorParams class for compile-time settings (currently
pins, direction, microstepping).

Keep other settings separate, so that we can pass constexpr expressions
while stepping and still get 1 instruction without overhead.

src/hal/tmc2130.h

@@ -1,18 +1,82 @@
 #pragma once
-
-/// TMC2130 interface
-/// There are multiple TMC2130 on our board, so there will be multiple instances of this class
-/// @@TODO @leptun - design some lightweight TMC2130 interface
+#include "../hal/gpio.h"
+#include "../hal/shr16.h"
 
 namespace hal {
 
-class TMC2130 {
+/// TMC2130 interface
+/// There are multiple TMC2130 on our board, so there will be multiple
+/// instances of this class
+/// @@TODO @leptun - design some lightweight TMC2130 interface
+namespace tmc2130 {
 
-public:
-    /// constructor - do some one-time init stuff here
-    TMC2130(uint8_t id);
-    /// (re)initialization of the chip
-    void Init();
+enum MotorMode : uint8_t {
+    Stealth,
+    Normal
 };
 
+struct MotorParams {
+    uint8_t idx;            ///< SHR16 index
+    bool dirOn;             ///< forward direction
+    gpio::GPIO_pin csPin;   ///< CS pin
+    gpio::GPIO_pin stepPin; ///< step pin
+    gpio::GPIO_pin sgPin;   ///< stallguard pin
+    uint8_t uSteps;         ///< microstep resolution
+};
+
+struct MotorCurrents {
+    uint8_t iRun;           ///< Running current
+    uint8_t iHold;          ///< Holding current
+};
+
+class TMC2130 {
+    MotorMode mode;
+    MotorCurrents currents;
+
+public:
+    /// constructor
+    TMC2130(const MotorParams& params,
+            const MotorCurrents& currents,
+            MotorMode mode);
+
+    /// (re)initialization of the chip
+    void Init(const MotorParams& params);
+
+    /// Get/Change the current motor mode
+    MotorMode Mode() { return mode; } const
+    void SetMode(MotorMode mode);
+
+    /// Get/Change the current motor currents
+    const MotorCurrents& Currents() { return currents; } const
+    void SetCurrents(const MotorCurrents& currents);
+
+    /// Return enabled state
+    bool Enabled() const;
+
+    /// Enable/Disable the motor
+    void SetEnabled(const MotorParams& params, bool enabled)
+    {
+        hal::shr16::shr16.SetTMCDir(params.idx, enabled);
+    }
+
+    /// Set direction
+    void SetDir(const MotorParams& params, bool dir)
+    {
+        hal::shr16::shr16.SetTMCDir(params.idx, dir ^ params.dirOn);
+    }
+
+    /// Step the motor
+    inline void Step(const MotorParams& params)
+    {
+        gpio::TogglePin(params.stepPin); // assumes DEDGE
+    }
+
+    /// Return SG state
+    inline bool Stall(const MotorParams& params)
+    {
+        return gpio::ReadPin(params.sgPin) == gpio::Level::high;
+    }
+};
+
+} // namespace tmc2130
 } // namespace hal