/**
 * \file
 *
 * \brief Chip-specific system clock management functions
 *
 * Copyright (c) 2010-2013 Atmel Corporation. All rights reserved.
 *
 * \asf_license_start
 *
 * \page License
 *
 * 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.
 *
 * 3. The name of Atmel may not be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * 4. This software may only be redistributed and used in connection with an
 *    Atmel microcontroller product.
 *
 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
 *
 * \asf_license_stop
 *
 */

#include <compiler.h>

#include <sysclk.h>
#include <osc.h>
#include <pll.h>

#if XMEGA_AU || XMEGA_B || XMEGA_C
#  include <nvm.h>
#endif


void sysclk_init(void)
{
    uint8_t *reg = (uint8_t *) & PR.PRGEN;
    uint8_t i;
#ifdef CONFIG_OSC_RC32_CAL
    uint16_t cal;
    /* avoid Cppcheck Warning */
    UNUSED(cal);
#endif
    bool need_rc2mhz = false;

    /* Turn off all peripheral clocks that can be turned off. */
    for (i = 0; i <= SYSCLK_PORT_F; i++) {
        *(reg++) = 0xff;
    }

    /* Set up system clock prescalers if different from defaults */
    if ((CONFIG_SYSCLK_PSADIV != SYSCLK_PSADIV_1)
        || (CONFIG_SYSCLK_PSBCDIV != SYSCLK_PSBCDIV_1_1)) {
        sysclk_set_prescalers(CONFIG_SYSCLK_PSADIV, CONFIG_SYSCLK_PSBCDIV);
    }
#if (CONFIG_OSC_RC32_CAL==48000000UL)
    MSB(cal) =
        nvm_read_production_signature_row
        (nvm_get_production_signature_row_offset(USBRCOSC));
    LSB(cal) =
        nvm_read_production_signature_row
        (nvm_get_production_signature_row_offset(USBRCOSCA));
    /*
       * If a device has an uncalibrated value in the
       * production signature row (early sample part), load a
       * sane default calibration value.
     */
    if (cal == 0xFFFF) {
        cal = 0x2340;
    }
    osc_user_calibration(OSC_ID_RC32MHZ, cal);
#endif
    /*
     * Switch to the selected initial system clock source, unless
     * the default internal 2 MHz oscillator is selected.
     */
    if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_RC2MHZ) {
        need_rc2mhz = true;
    } else {
        switch (CONFIG_SYSCLK_SOURCE) {
            case SYSCLK_SRC_RC32MHZ:
                osc_enable(OSC_ID_RC32MHZ);
                osc_wait_ready(OSC_ID_RC32MHZ);
#ifdef CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC
                if (CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC != OSC_ID_USBSOF) {
                    osc_enable(CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC);
                    osc_wait_ready(CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC);
                }
                osc_enable_autocalibration(OSC_ID_RC32MHZ,
                    CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC);
#endif
                break;

            case SYSCLK_SRC_RC32KHZ:
                osc_enable(OSC_ID_RC32KHZ);
                osc_wait_ready(OSC_ID_RC32KHZ);
                break;

            case SYSCLK_SRC_XOSC:
                osc_enable(OSC_ID_XOSC);
                osc_wait_ready(OSC_ID_XOSC);
                break;

#ifdef CONFIG_PLL0_SOURCE
            case SYSCLK_SRC_PLL:
                if (CONFIG_PLL0_SOURCE == PLL_SRC_RC2MHZ) {
                    need_rc2mhz = true;
                }
                pll_enable_config_defaults(0);
                break;
#endif
#if XMEGA_E
            case SYSCLK_SRC_RC8MHZ:
                osc_enable(OSC_ID_RC8MHZ);
                osc_wait_ready(OSC_ID_RC8MHZ);
                break;
#endif
            default:
                //unhandled_case(CONFIG_SYSCLK_SOURCE);
                return;
        }

        ccp_write_io((uint8_t *) & CLK.CTRL, CONFIG_SYSCLK_SOURCE);
        Assert(CLK.CTRL == CONFIG_SYSCLK_SOURCE);
    }

    if (need_rc2mhz) {
#ifdef CONFIG_OSC_AUTOCAL_RC2MHZ_REF_OSC
        osc_enable(CONFIG_OSC_AUTOCAL_RC2MHZ_REF_OSC);
        osc_wait_ready(CONFIG_OSC_AUTOCAL_RC2MHZ_REF_OSC);
        osc_enable_autocalibration(OSC_ID_RC2MHZ,
            CONFIG_OSC_AUTOCAL_RC2MHZ_REF_OSC);
#endif
    } else {
        osc_disable(OSC_ID_RC2MHZ);
    }

#ifdef CONFIG_RTC_SOURCE
    sysclk_rtcsrc_enable(CONFIG_RTC_SOURCE);
#endif
}

void sysclk_enable_module(enum sysclk_port_id port,
    uint8_t id)
{
    irqflags_t flags = cpu_irq_save();

    *((uint8_t *) & PR.PRGEN + port) &= ~id;

    cpu_irq_restore(flags);
}

void sysclk_disable_module(enum sysclk_port_id port,
    uint8_t id)
{
    irqflags_t flags = cpu_irq_save();

    *((uint8_t *) & PR.PRGEN + port) |= id;

    cpu_irq_restore(flags);
}

#if XMEGA_AU || XMEGA_B || XMEGA_C || defined(__DOXYGEN__)

/**
 * \brief Enable clock for the USB module
 *
 * \pre CONFIG_USBCLK_SOURCE must be defined.
 *
 * \param frequency The required USB clock frequency in MHz:
 * \arg \c 6 for 6 MHz
 * \arg \c 48 for 48 MHz
 */
void sysclk_enable_usb(uint8_t frequency)
{
    uint8_t prescaler;

    Assert((frequency == 6) || (frequency == 48));

    /*
     * Enable or disable prescaler depending on if the USB frequency is 6
     * MHz or 48 MHz. Only 6 MHz USB frequency requires prescaling.
     */
    if (frequency == 6) {
        prescaler = CLK_USBPSDIV_8_gc;
    } else {
        prescaler = 0;
    }

    /*
     * Switch to the system clock selected by the user.
     */
    switch (CONFIG_USBCLK_SOURCE) {
        case USBCLK_SRC_RCOSC:
            if (!osc_is_ready(OSC_ID_RC32MHZ)) {
                osc_enable(OSC_ID_RC32MHZ);
                osc_wait_ready(OSC_ID_RC32MHZ);
#ifdef CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC
                if (CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC != OSC_ID_USBSOF) {
                    osc_enable(CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC);
                    osc_wait_ready(CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC);
                }
                osc_enable_autocalibration(OSC_ID_RC32MHZ,
                    CONFIG_OSC_AUTOCAL_RC32MHZ_REF_OSC);
#endif
            }
            ccp_write_io((uint8_t *) & CLK.USBCTRL, (prescaler)
                | CLK_USBSRC_RC32M_gc | CLK_USBSEN_bm);
            break;

#ifdef CONFIG_PLL0_SOURCE
        case USBCLK_SRC_PLL:
            pll_enable_config_defaults(0);
            ccp_write_io((uint8_t *) & CLK.USBCTRL, (prescaler)
                | CLK_USBSRC_PLL_gc | CLK_USBSEN_bm);
            break;
#endif

        default:
            Assert(false);
            break;
    }

    sysclk_enable_module(SYSCLK_PORT_GEN, SYSCLK_USB);
}

/**
 * \brief Disable clock for the USB module
 */
void sysclk_disable_usb(void)
{
    sysclk_disable_module(SYSCLK_PORT_GEN, SYSCLK_USB);
    ccp_write_io((uint8_t *) & CLK.USBCTRL, 0);
}
#endif // XMEGA_AU || XMEGA_B || XMEGA_C