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/**
* @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;
}
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