Beaglebone: Update PWM driver imported from BBBIO

This patch adapts the previously added Beaglebone PWM code from BBBIO to RTEMS.
This work was done in the context of the Google Summer of Code 2016, and further
patches will follow to improve the code quality and documentation.

1 files changed, 138 insertions, 24 deletions

diff --git a/c/src/lib/libbsp/arm/beagle/include/bbb-pwm.h b/c/src/lib/libbsp/arm/beagle/include/bbb-pwm.h
index 761eae2b37..ef016f036b 100644
--- a/c/src/lib/libbsp/arm/beagle/include/bbb-pwm.h
+++ b/c/src/lib/libbsp/arm/beagle/include/bbb-pwm.h
@@ -1,3 +1,23 @@
+/**
+ * @file
+ *
+ * @ingroup arm_beagle
+ *
+ * @brief BeagleBone Black BSP definitions.
+ */
+
+/**
+ * Copyright (c) 2016 Punit Vara <punitvara at gmail.com>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+/** Some constants are taken from 
+ * https://github.com/VegetableAvenger/BBBIOlib/blob/master/BBBio_lib/BBBiolib_PWMSS.h
+ */
+
 #ifndef LIBBSP_ARM_BEAGLE_BBB_PWM_H
 #define LIBBSP_ARM_BEAGLE_BBB_PWM_H
 
@@ -8,31 +28,125 @@ extern "C" {
 /**
  * @brief  BeagleBone Black PWM Macros.
  */
-#define BBBIO_PWMSS_COUNT       3
-#define BBBIO_PWMSS0           0
-#define BBBIO_PWMSS1           1
-#define BBBIO_PWMSS2           2
-
-#define MUXMODE0               0
-#define MUXMODE1                1
-#define MUXMODE2               2
-#define MUXMODE3               3
-#define MUXMODE4               4
-#define MUXMODE5               5
-#define MUXMODE6               6
-#define MUXMODE7               7
-
-#define EPWM_GROUP1    1
-#define EPWM_GROUP2    2
-#define EPWM_GROUP0    0
-
-int BBBIO_PWMSS_Setting(unsigned int PWMID , float HZ ,float dutyA ,float dutyB);
-int BBBIO_PWM_Init();
-void BBBIO_PWM_Release();
-int BBBIO_PWMSS_Status(unsigned int PWMID);
-void BBBIO_ehrPWM_Enable(unsigned int PWMSS_ID);
-void BBBIO_ehrPWM_Disable(unsigned int PWMSS_ID);
+#define BBB_CONTROL_CONF_GPMC_AD(n)   (0x800 + (n * 4))
+#define BBB_CONTROL_CONF_LCD_DATA(n)   (0x8a0 + (n * 4))
+
+#define BBB_PWMSS_COUNT       3
+#define BBB_PWMSS0  0
+#define BBB_PWMSS1  1  
+#define BBB_PWMSS2  2
+
+#define BBB_P8_13_2B  3
+#define BBB_P8_19_2A  4
+#define BBB_P8_45_2A  5
+#define BBB_P8_46_2B  6
+#define BBB_P8_34_1B  7
+#define BBB_P8_36_1A  8
+#define BBB_P9_14_1A  9
+#define BBB_P9_16_1B  10
+#define BBB_P9_21_0B  11
+#define BBB_P9_22_0A  12
+#define BBB_P9_29_0B  13
+#define BBB_P9_31_0A  14
+
+#define BBB_MUX0      0
+#define BBB_MUX1      1
+#define BBB_MUX2      2
+#define BBB_MUX3      3
+#define BBB_MUX4      4
+#define BBB_MUX5      5
+#define BBB_MUX6      6
+#define BBB_MUX7      7
+
+#define BBB_EPWM1     1
+#define BBB_EPWM2     2
+#define BBB_EPWM0     0
+
+/**
+ * @brief  BeagleBone Black PWM API.
+ */
+
+/**
+ * @brief This function intilize clock and pinmuxing for pwm sub system.
+ *
+ * @param PWMSS_ID It is the instance number of EPWM of pwm sub system.
+ * 
+ * @return true if successful 
+ * @return false if not successful
+ *
+ **/
+bool beagle_pwm_init(uint32_t pwmss_id);
+
+/* PWMSS setting
+ *      set pulse argument of epwm module
+ *
+ *      @param pwm_id    : EPWMSS number , 0~2
+ *      @param pwm_freq : frequency to be generated
+ *      @param dutyA    : Duty Cycle in ePWM A
+ *      @param dutyB    : Duty Cycle in ePWM B
+ *
+ *      @return         : 1 for success
+ *      @return         : 0 for failed
+ *
+ *      @example        :  PWMSS_Setting(0 , 50.0f , 50.0f , 25.0f);      // Generate 50HZ pwm in PWM0 ,
+ *                                                                              // duty cycle is 50% for ePWM0A , 25% for ePWM0B
+ *
+ *      @Note :
+ *              find an number nearst 65535 for TBPRD , to improve duty precision,
+ *
+ *              Using big TBPRD can increase the range of CMPA and CMPB ,
+ *              and it means we can get better precision on duty cycle.
+ *
+ *              EX : 20.25% duty cycle
+ *                  on TBPRD = 62500 , CMPA = 12656.25 ( .25 rejection) , real duty : 20.2496% (12656 /62500)
+ *                  on TBPRD = 6250  , CMPA = 1265.625 ( .625 rejection), real duty : 20.24%   (1265 6250)
+ *                  on TBPRD = 500   , CMPA = 101.25   ( .25 rejection) , real duty : 20.2%    (101/500)
+ *
+ *              Divisor = CLKDIV * HSPCLKDIV
+ *                      1 TBPRD : 10 ns (default)
+ *                      65535 TBPRD : 655350 ns
+ *                      65535 TBPRD : 655350 * Divisor ns  = X TBPRD : Cyclens
+ *
+ *              accrooding to that , we must find a Divisor value , let X nearest 65535 .
+ *              so , Divisor must  Nearest Cyclens/655350
+ */
+int beagle_pwmss_setting(uint32_t pwm_id, float pwm_freq, float dutyA, float dutyB);
+
+/**
+ * @brief   This API enables the particular PWM module.
+ *
+ * @param   pwmid  It is the instance number of EPWM of pwm sub system.
+ *
+ * @return  true if successful
+ * @return  false if fail
+ *
+ **/
+bool beagle_ehrpwm_enable(uint32_t pwmid);
 
+/**
+ * @brief   This API disables the HR sub-module.
+ *
+ * @param   pwmid  It is the instance number of EPWM of pwm sub system.
+ *
+ * @return  true if successful
+ * @return  false if fail
+ *
+ **/
+bool beagle_ehrpwm_disable(uint32_t pwmid);
+
+/**
+ * @brief   This function Enables pinmuxing for PWM module.
+ *
+ * @param   pin_no  It is individual pin at which freuqency need to be generated.
+ *                  It should be according to pwm sub system.
+ *
+ * @param   pwm_id  It is the instance number of EPWM of pwmsubsystem.
+ *
+ * @return  true if successful
+ * @return  false if fail
+ *
+ **/
+bool beagle_epwm_pinmux_setup(uint32_t pin_no, uint32_t pwm_id);
 
 #ifdef __cplusplus
 }