/**
 * @file
 *
 * @ingroup arm_beagle
 *
 * @brief Support for eQEP for the BeagleBone Black.
 */

/*
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2020, 2021 James Fitzsimons <james.fitzsimons@gmail.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <libcpu/am335x.h>
#include <stdio.h>
#include <bsp.h>
#include <bsp/pwmss.h>
#include <bsp/beagleboneblack.h>


/**
 * @brief   This function configures the L3 and L4_PER system clocks.
 *          It also configures the system clocks for the specified ePWMSS
 *          instance.
 *
 * @param   pwmss_id    The instance number of ePWMSS whose system clocks
 *                         have to be configured.
 *
 * 'pwmss_id' can take one of the following values:
 * (0 <= pwmss_id <= 2)
 *
 * @return  True if successful
 *          False if Unsuccessful
 */
rtems_status_code pwmss_module_clk_config(BBB_PWMSS pwmss_id)
{
    uint32_t clkctrl;

    /* calculate the address of the clock control register for the PWMSS
     * module we are configuring */
    if(pwmss_id == BBB_PWMSS0) {
        clkctrl = AM335X_CM_PER_ADDR + AM335X_CM_PER_EPWMSS0_CLKCTRL;
    } else if(pwmss_id == BBB_PWMSS1) {
        clkctrl = AM335X_CM_PER_ADDR + AM335X_CM_PER_EPWMSS1_CLKCTRL;
    } else if(pwmss_id == BBB_PWMSS2) {
        clkctrl = AM335X_CM_PER_ADDR + AM335X_CM_PER_EPWMSS2_CLKCTRL;
    }

    /* when the module is functional the IDLEST bits (16 -17) of the
     * CM_PER_EPWMSSx_CLKCTRL register will be 0x0. */
    const uint32_t is_functional = 0x0;
    const uint32_t idle_bits = AM335X_CM_PER_EPWMSSx_CLKCTRL_IDLEST;
    const uint32_t is_enable = AM335X_CM_PER_EPWMSSx_CLKCTRL_MODULEMODE_ENABLE;
    const uint32_t module_mode = AM335X_CM_PER_EPWMSSx_CLKCTRL_MODULEMODE;

    REG(clkctrl) |= is_enable;
    while((REG(clkctrl) & module_mode) != is_enable);
    while((REG(clkctrl) & idle_bits) != is_functional);

    return RTEMS_SUCCESSFUL;
}