AP_HAL_Linux: Adapt Heat_Pwm to use PWM_Sysfs

Only compiled on Bebop, the constructor will need to be modified to
pass the pwm chip number and to create a PWM_Sysfs instead of a PWM_Sysfs_Bebop
in case it is used on a mainline linux board

libraries/AP_HAL/AP_HAL_Boards.h

@@ -207,7 +207,7 @@
 #define HAL_BARO_MS5607_I2C_ADDR 0x77
 #define HAL_BARO_DEFAULT HAL_BARO_MS5607
 #define HAL_UTILS_HEAT HAL_LINUX_HEAT_PWM
-#define HAL_LINUX_HEAT_PWM_SYSFS_DIR "/sys/class/pwm/pwm_6"
+#define HAL_LINUX_HEAT_PWM_NUM  6
 #define HAL_LINUX_HEAT_KP 20000
 #define HAL_LINUX_HEAT_KI 6
 #define HAL_LINUX_HEAT_PERIOD_NS 125000

libraries/AP_HAL_Linux/Heat_Pwm.cpp

@@ -30,60 +30,18 @@
 
 extern const AP_HAL::HAL& hal;
 
-#define HEAT_PWM_DUTY "duty_ns"
-#define HEAT_PWM_PERIOD "period_ns"
-#define HEAT_PWM_RUN "run"
-
 using namespace Linux;
 
-/*
+HeatPwm::HeatPwm(uint8_t pwm_num, float Kp, float Ki, uint32_t period_ns, float target) :
- * Constructor :
- * argument : pwm_sysfs_path is the path to the pwm directory,
- * i.e /sys/class/pwm/pwm_6 on the bebop
- */
-HeatPwm::HeatPwm(const char* pwm_sysfs_path, float Kp, float Ki, uint32_t period_ns, float target) :
     _Kp(Kp),
     _Ki(Ki),
     _period_ns(period_ns),
     _target(target)
 {
-    char *duty_path;
+    _pwm = new PWM_Sysfs_Bebop(pwm_num);
-    char *period_path;
+    _pwm->set_period(_period_ns);
-    char *run_path;
+    _pwm->set_duty_cycle(0);
-
+    _pwm->enable(true);
-    if (asprintf(&duty_path, "%s/%s", pwm_sysfs_path, HEAT_PWM_DUTY) == -1) {
-        AP_HAL::panic("HeatPwm not enough memory\n");
-    }
-    _duty_fd = open(duty_path, O_RDWR);
-    if (_duty_fd == -1) {
-        perror("opening duty");
-        AP_HAL::panic("Error Initializing Pwm heat\n");
-    }
-    free(duty_path);
-
-    if (asprintf(&period_path, "%s/%s", pwm_sysfs_path, HEAT_PWM_PERIOD) == -1) {
-        AP_HAL::panic("HeatPwm not enough memory\n");
-    }
-    _period_fd = open(period_path, O_RDWR);
-    if (_period_fd == -1) {
-        perror("opening period");
-        AP_HAL::panic("Error Initializing Pwm heat\n");
-    }
-    free(period_path);
-
-    if (asprintf(&run_path, "%s/%s", pwm_sysfs_path, HEAT_PWM_RUN) == -1) {
-        AP_HAL::panic("HeatPwm not enough memory\n");
-    }
-    _run_fd = open(run_path, O_RDWR);
-    if (_run_fd == -1) {
-        perror("opening run");
-        AP_HAL::panic("Error Initializing Pwm heat\n");
-    }
-    free(run_path);
-
-    _set_period(_period_ns);
-    _set_duty(0);
-    _set_run();
 }
 
 void HeatPwm::set_imu_temp(float current)
@@ -111,29 +69,8 @@ void HeatPwm::set_imu_temp(float current)
         output = 0;
     }
 
-    _set_duty(output);
+    _pwm->set_duty_cycle(output);
     _last_temp_update = AP_HAL::millis();
 }
 
-void HeatPwm::_set_duty(uint32_t duty)
-{
-    if (dprintf(_duty_fd, "0x%x", duty) < 0) {
-        perror("pwm set_duty");
-    }
-}
-
-void HeatPwm::_set_period(uint32_t period)
-{
-    if (dprintf(_period_fd, "0x%x", period) < 0) {
-        perror("pwm set_period");
-    }
-}
-
-void HeatPwm::_set_run()
-{
-    if (dprintf(_run_fd, "1") < 0) {
-        perror("pwm set_run");
-    }
-}
-
 #endif

libraries/AP_HAL_Linux/Heat_Pwm.h

@@ -18,26 +18,22 @@
 #define __HEAT_PWM_H__
 
 #include "AP_HAL_Linux.h"
+#include "PWM_Sysfs.h"
 #include "Heat.h"
 
 class Linux::HeatPwm : public Linux::Heat {
 public:
-    HeatPwm(const char* pwm_sysfs_path, float Kp, float Ki,uint32_t period_ns, float target);
+    HeatPwm(uint8_t pwm_num, float Kp, float Ki,
+            uint32_t period_ns, float target);
     void set_imu_temp(float current)override;
 
 private:
-    int _duty_fd = -1;
+    PWM_Sysfs_Base *_pwm;
-    int _period_fd = -1;
-    int _run_fd = -1;
     uint32_t _last_temp_update = 0;
     float _Kp;
     float _Ki;
     uint32_t _period_ns;
     float _sum_error;
     float _target;
-
-    void _set_duty(uint32_t duty);
-    void _set_period(uint32_t period);
-    void _set_run();
 };
 #endif

libraries/AP_HAL_Linux/Util.cpp

@@ -26,7 +26,7 @@ void Util::init(int argc, char * const *argv) {
 
 #ifdef HAL_UTILS_HEAT
 #if HAL_UTILS_HEAT == HAL_LINUX_HEAT_PWM
-    _heat = new Linux::HeatPwm(HAL_LINUX_HEAT_PWM_SYSFS_DIR,
+    _heat = new Linux::HeatPwm(HAL_LINUX_HEAT_PWM_NUM,
                             HAL_LINUX_HEAT_KP,
                             HAL_LINUX_HEAT_KI,
                             HAL_LINUX_HEAT_PERIOD_NS,