#include "ch.h"
#include "hal.h"

#include "eeconfig.h"

/*************************************/
/*          Hardware backend         */
/*                                   */
/*    Code from PJRC/Teensyduino     */
/*************************************/

/* Teensyduino Core Library
 * http://www.pjrc.com/teensy/
 * Copyright (c) 2013 PJRC.COM, LLC.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * 1. The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * 2. If the Software is incorporated into a build system that allows
 * selection among a list of target devices, then similar target
 * devices manufactured by PJRC.COM must be included in the list of
 * target devices and selectable in the same manner.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#if defined(K20x) /* chip selection */
/* Teensy 3.0, 3.1, 3.2; mchck; infinity keyboard */

// The EEPROM is really RAM with a hardware-based backup system to
// flash memory.  Selecting a smaller size EEPROM allows more wear
// leveling, for higher write endurance.  If you edit this file,
// set this to the smallest size your application can use.  Also,
// due to Freescale's implementation, writing 16 or 32 bit words
// (aligned to 2 or 4 byte boundaries) has twice the endurance
// compared to writing 8 bit bytes.
//
#    define EEPROM_SIZE 32

// Writing unaligned 16 or 32 bit data is handled automatically when
// this is defined, but at a cost of extra code size.  Without this,
// any unaligned write will cause a hard fault exception!  If you're
// absolutely sure all 16 and 32 bit writes will be aligned, you can
// remove the extra unnecessary code.
//
#    define HANDLE_UNALIGNED_WRITES

// Minimum EEPROM Endurance
// ------------------------
#    if (EEPROM_SIZE == 2048)  // 35000 writes/byte or 70000 writes/word
#        define EEESIZE 0x33
#    elif (EEPROM_SIZE == 1024)  // 75000 writes/byte or 150000 writes/word
#        define EEESIZE 0x34
#    elif (EEPROM_SIZE == 512)  // 155000 writes/byte or 310000 writes/word
#        define EEESIZE 0x35
#    elif (EEPROM_SIZE == 256)  // 315000 writes/byte or 630000 writes/word
#        define EEESIZE 0x36
#    elif (EEPROM_SIZE == 128)  // 635000 writes/byte or 1270000 writes/word
#        define EEESIZE 0x37
#    elif (EEPROM_SIZE == 64)  // 1275000 writes/byte or 2550000 writes/word
#        define EEESIZE 0x38
#    elif (EEPROM_SIZE == 32)  // 2555000 writes/byte or 5110000 writes/word
#        define EEESIZE 0x39
#    endif

/** \brief eeprom initialization
 *
 * FIXME: needs doc
 */
void eeprom_initialize(void) {
    uint32_t count          = 0;
    uint16_t do_flash_cmd[] = {0xf06f, 0x037f, 0x7003, 0x7803, 0xf013, 0x0f80, 0xd0fb, 0x4770};
    uint8_t  status;

    if (FTFL->FCNFG & FTFL_FCNFG_RAMRDY) {
        // FlexRAM is configured as traditional RAM
        // We need to reconfigure for EEPROM usage
        FTFL->FCCOB0 = 0x80;     // PGMPART = Program Partition Command
        FTFL->FCCOB4 = EEESIZE;  // EEPROM Size
        FTFL->FCCOB5 = 0x03;     // 0K for Dataflash, 32K for EEPROM backup
        __disable_irq();
        // do_flash_cmd() must execute from RAM.  Luckily the C syntax is simple...
        (*((void (*)(volatile uint8_t *))((uint32_t)do_flash_cmd | 1)))(&(FTFL->FSTAT));
        __enable_irq();
        status = FTFL->FSTAT;
        if (status & (FTFL_FSTAT_RDCOLERR | FTFL_FSTAT_ACCERR | FTFL_FSTAT_FPVIOL)) {
            FTFL->FSTAT = (status & (FTFL_FSTAT_RDCOLERR | FTFL_FSTAT_ACCERR | FTFL_FSTAT_FPVIOL));
            return;  // error
        }
    }
    // wait for eeprom to become ready (is this really necessary?)
    while (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) {
        if (++count > 20000) break;
    }
}

#    define FlexRAM ((uint8_t *)0x14000000)

/** \brief eeprom read byte
 *
 * FIXME: needs doc
 */
uint8_t eeprom_read_byte(const uint8_t *addr) {
    uint32_t offset = (uint32_t)addr;
    if (offset >= EEPROM_SIZE) return 0;
    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
    return FlexRAM[offset];
}

/** \brief eeprom read word
 *
 * FIXME: needs doc
 */
uint16_t eeprom_read_word(const uint16_t *addr) {
    uint32_t offset = (uint32_t)addr;
    if (offset >= EEPROM_SIZE - 1) return 0;
    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
    return *(uint16_t *)(&FlexRAM[offset]);
}

/** \brief eeprom read dword
 *
 * FIXME: needs doc
 */
uint32_t eeprom_read_dword(const uint32_t *addr) {
    uint32_t offset = (uint32_t)addr;
    if (offset >= EEPROM_SIZE - 3) return 0;
    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
    return *(uint32_t *)(&FlexRAM[offset]);
}

/** \brief eeprom read block
 *
 * FIXME: needs doc
 */
void eeprom_read_block(void *buf, const void *addr, uint32_t len) {
    uint32_t offset = (uint32_t)addr;
    uint8_t *dest   = (uint8_t *)buf;
    uint32_t end    = offset + len;

    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
    if (end > EEPROM_SIZE) end = EEPROM_SIZE;
    while (offset < end) {
        *dest++ = FlexRAM[offset++];
    }
}

/** \brief eeprom is ready
 *
 * FIXME: needs doc
 */
int eeprom_is_ready(void) { return (FTFL->FCNFG & FTFL_FCNFG_EEERDY) ? 1 : 0; }

/** \brief flexram wait
 *
 * FIXME: needs doc
 */
static void flexram_wait(void) {
    while (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) {
        // TODO: timeout
    }
}

/** \brief eeprom_write_byte
 *
 * FIXME: needs doc
 */
void eeprom_write_byte(uint8_t *addr, uint8_t value) {
    uint32_t offset = (uint32_t)addr;

    if (offset >= EEPROM_SIZE) return;
    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
    if (FlexRAM[offset] != value) {
        FlexRAM[offset] = value;
        flexram_wait();
    }
}

/** \brief eeprom write word
 *
 * FIXME: needs doc
 */
void eeprom_write_word(uint16_t *addr, uint16_t value) {
    uint32_t offset = (uint32_t)addr;

    if (offset >= EEPROM_SIZE - 1) return;
    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
#    ifdef HANDLE_UNALIGNED_WRITES
    if ((offset & 1) == 0) {
#    endif
        if (*(uint16_t *)(&FlexRAM[offset]) != value) {
            *(uint16_t *)(&FlexRAM[offset]) = value;
            flexram_wait();
        }
#    ifdef HANDLE_UNALIGNED_WRITES
    } else {
        if (FlexRAM[offset] != value) {
            FlexRAM[offset] = value;
            flexram_wait();
        }
        if (FlexRAM[offset + 1] != (value >> 8)) {
            FlexRAM[offset + 1] = value >> 8;
            flexram_wait();
        }
    }
#    endif
}

/** \brief eeprom write dword
 *
 * FIXME: needs doc
 */
void eeprom_write_dword(uint32_t *addr, uint32_t value) {
    uint32_t offset = (uint32_t)addr;

    if (offset >= EEPROM_SIZE - 3) return;
    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
#    ifdef HANDLE_UNALIGNED_WRITES
    switch (offset & 3) {
        case 0:
#    endif
            if (*(uint32_t *)(&FlexRAM[offset]) != value) {
                *(uint32_t *)(&FlexRAM[offset]) = value;
                flexram_wait();
            }
            return;
#    ifdef HANDLE_UNALIGNED_WRITES
        case 2:
            if (*(uint16_t *)(&FlexRAM[offset]) != value) {
                *(uint16_t *)(&FlexRAM[offset]) = value;
                flexram_wait();
            }
            if (*(uint16_t *)(&FlexRAM[offset + 2]) != (value >> 16)) {
                *(uint16_t *)(&FlexRAM[offset + 2]) = value >> 16;
                flexram_wait();
            }
            return;
        default:
            if (FlexRAM[offset] != value) {
                FlexRAM[offset] = value;
                flexram_wait();
            }
            if (*(uint16_t *)(&FlexRAM[offset + 1]) != (value >> 8)) {
                *(uint16_t *)(&FlexRAM[offset + 1]) = value >> 8;
                flexram_wait();
            }
            if (FlexRAM[offset + 3] != (value >> 24)) {
                FlexRAM[offset + 3] = value >> 24;
                flexram_wait();
            }
    }
#    endif
}

/** \brief eeprom write block
 *
 * FIXME: needs doc
 */
void eeprom_write_block(const void *buf, void *addr, uint32_t len) {
    uint32_t       offset = (uint32_t)addr;
    const uint8_t *src    = (const uint8_t *)buf;

    if (offset >= EEPROM_SIZE) return;
    if (!(FTFL->FCNFG & FTFL_FCNFG_EEERDY)) eeprom_initialize();
    if (len >= EEPROM_SIZE) len = EEPROM_SIZE;
    if (offset + len >= EEPROM_SIZE) len = EEPROM_SIZE - offset;
    while (len > 0) {
        uint32_t lsb = offset & 3;
        if (lsb == 0 && len >= 4) {
            // write aligned 32 bits
            uint32_t val32;
            val32 = *src++;
            val32 |= (*src++ << 8);
            val32 |= (*src++ << 16);
            val32 |= (*src++ << 24);
            if (*(uint32_t *)(&FlexRAM[offset]) != val32) {
                *(uint32_t *)(&FlexRAM[offset]) = val32;
                flexram_wait();
            }
            offset += 4;
            len -= 4;
        } else if ((lsb == 0 || lsb == 2) && len >= 2) {
            // write aligned 16 bits
            uint16_t val16;
            val16 = *src++;
            val16 |= (*src++ << 8);
            if (*(uint16_t *)(&FlexRAM[offset]) != val16) {
                *(uint16_t *)(&FlexRAM[offset]) = val16;
                flexram_wait();
            }
            offset += 2;
            len -= 2;
        } else {
            // write 8 bits
            uint8_t val8 = *src++;
            if (FlexRAM[offset] != val8) {
                FlexRAM[offset] = val8;
                flexram_wait();
            }
            offset++;
            len--;
        }
    }
}

/*
void do_flash_cmd(volatile uint8_t *fstat)
{
    *fstat = 0x80;
    while ((*fstat & 0x80) == 0) ; // wait
}
00000000 <do_flash_cmd>:
   0:	f06f 037f 	mvn.w	r3, #127	; 0x7f
   4:	7003      	strb	r3, [r0, #0]
   6:	7803      	ldrb	r3, [r0, #0]
   8:	f013 0f80 	tst.w	r3, #128	; 0x80
   c:	d0fb      	beq.n	6 <do_flash_cmd+0x6>
   e:	4770      	bx	lr
*/

#elif defined(KL2x) /* chip selection */
/* Teensy LC (emulated) */

#    define SYMVAL(sym) (uint32_t)(((uint8_t *)&(sym)) - ((uint8_t *)0))

extern uint32_t __eeprom_workarea_start__;
extern uint32_t __eeprom_workarea_end__;

#    define EEPROM_SIZE 128

static uint32_t flashend = 0;

void eeprom_initialize(void) {
    const uint16_t *p = (uint16_t *)SYMVAL(__eeprom_workarea_start__);

    do {
        if (*p++ == 0xFFFF) {
            flashend = (uint32_t)(p - 2);
            return;
        }
    } while (p < (uint16_t *)SYMVAL(__eeprom_workarea_end__));
    flashend = (uint32_t)((uint16_t *)SYMVAL(__eeprom_workarea_end__) - 1);
}

uint8_t eeprom_read_byte(const uint8_t *addr) {
    uint32_t        offset = (uint32_t)addr;
    const uint16_t *p      = (uint16_t *)SYMVAL(__eeprom_workarea_start__);
    const uint16_t *end    = (const uint16_t *)((uint32_t)flashend);
    uint16_t        val;
    uint8_t         data = 0xFF;

    if (!end) {
        eeprom_initialize();
        end = (const uint16_t *)((uint32_t)flashend);
    }
    if (offset < EEPROM_SIZE) {
        while (p <= end) {
            val = *p++;
            if ((val & 255) == offset) data = val >> 8;
        }
    }
    return data;
}

static void flash_write(const uint16_t *code, uint32_t addr, uint32_t data) {
    // with great power comes great responsibility....
    uint32_t stat;
    *(uint32_t *)&(FTFA->FCCOB3) = 0x06000000 | (addr & 0x00FFFFFC);
    *(uint32_t *)&(FTFA->FCCOB7) = data;
    __disable_irq();
    (*((void (*)(volatile uint8_t *))((uint32_t)code | 1)))(&(FTFA->FSTAT));
    __enable_irq();
    stat = FTFA->FSTAT & (FTFA_FSTAT_RDCOLERR | FTFA_FSTAT_ACCERR | FTFA_FSTAT_FPVIOL);
    if (stat) {
        FTFA->FSTAT = stat;
    }
    MCM->PLACR |= MCM_PLACR_CFCC;
}

void eeprom_write_byte(uint8_t *addr, uint8_t data) {
    uint32_t        offset = (uint32_t)addr;
    const uint16_t *p, *end = (const uint16_t *)((uint32_t)flashend);
    uint32_t        i, val, flashaddr;
    uint16_t        do_flash_cmd[] = {0x2380, 0x7003, 0x7803, 0xb25b, 0x2b00, 0xdafb, 0x4770};
    uint8_t         buf[EEPROM_SIZE];

    if (offset >= EEPROM_SIZE) return;
    if (!end) {
        eeprom_initialize();
        end = (const uint16_t *)((uint32_t)flashend);
    }
    if (++end < (uint16_t *)SYMVAL(__eeprom_workarea_end__)) {
        val       = (data << 8) | offset;
        flashaddr = (uint32_t)end;
        flashend  = flashaddr;
        if ((flashaddr & 2) == 0) {
            val |= 0xFFFF0000;
        } else {
            val <<= 16;
            val |= 0x0000FFFF;
        }
        flash_write(do_flash_cmd, flashaddr, val);
    } else {
        for (i = 0; i < EEPROM_SIZE; i++) {
            buf[i] = 0xFF;
        }
        val = 0;
        for (p = (uint16_t *)SYMVAL(__eeprom_workarea_start__); p < (uint16_t *)SYMVAL(__eeprom_workarea_end__); p++) {
            val = *p;
            if ((val & 255) < EEPROM_SIZE) {
                buf[val & 255] = val >> 8;
            }
        }
        buf[offset] = data;
        for (flashaddr = (uint32_t)(uint16_t *)SYMVAL(__eeprom_workarea_start__); flashaddr < (uint32_t)(uint16_t *)SYMVAL(__eeprom_workarea_end__); flashaddr += 1024) {
            *(uint32_t *)&(FTFA->FCCOB3) = 0x09000000 | flashaddr;
            __disable_irq();
            (*((void (*)(volatile uint8_t *))((uint32_t)do_flash_cmd | 1)))(&(FTFA->FSTAT));
            __enable_irq();
            val = FTFA->FSTAT & (FTFA_FSTAT_RDCOLERR | FTFA_FSTAT_ACCERR | FTFA_FSTAT_FPVIOL);
            ;
            if (val) FTFA->FSTAT = val;
            MCM->PLACR |= MCM_PLACR_CFCC;
        }
        flashaddr = (uint32_t)(uint16_t *)SYMVAL(__eeprom_workarea_start__);
        for (i = 0; i < EEPROM_SIZE; i++) {
            if (buf[i] == 0xFF) continue;
            if ((flashaddr & 2) == 0) {
                val = (buf[i] << 8) | i;
            } else {
                val = val | (buf[i] << 24) | (i << 16);
                flash_write(do_flash_cmd, flashaddr, val);
            }
            flashaddr += 2;
        }
        flashend = flashaddr;
        if ((flashaddr & 2)) {
            val |= 0xFFFF0000;
            flash_write(do_flash_cmd, flashaddr, val);
        }
    }
}

/*
void do_flash_cmd(volatile uint8_t *fstat)
{
        *fstat = 0x80;
        while ((*fstat & 0x80) == 0) ; // wait
}
00000000 <do_flash_cmd>:
   0:	2380      	movs	r3, #128	; 0x80
   2:	7003      	strb	r3, [r0, #0]
   4:	7803      	ldrb	r3, [r0, #0]
   6:	b25b      	sxtb	r3, r3
   8:	2b00      	cmp	r3, #0
   a:	dafb      	bge.n	4 <do_flash_cmd+0x4>
   c:	4770      	bx	lr
*/

uint16_t eeprom_read_word(const uint16_t *addr) {
    const uint8_t *p = (const uint8_t *)addr;
    return eeprom_read_byte(p) | (eeprom_read_byte(p + 1) << 8);
}

uint32_t eeprom_read_dword(const uint32_t *addr) {
    const uint8_t *p = (const uint8_t *)addr;
    return eeprom_read_byte(p) | (eeprom_read_byte(p + 1) << 8) | (eeprom_read_byte(p + 2) << 16) | (eeprom_read_byte(p + 3) << 24);
}

void eeprom_read_block(void *buf, const void *addr, uint32_t len) {
    const uint8_t *p    = (const uint8_t *)addr;
    uint8_t *      dest = (uint8_t *)buf;
    while (len--) {
        *dest++ = eeprom_read_byte(p++);
    }
}

int eeprom_is_ready(void) { return 1; }

void eeprom_write_word(uint16_t *addr, uint16_t value) {
    uint8_t *p = (uint8_t *)addr;
    eeprom_write_byte(p++, value);
    eeprom_write_byte(p, value >> 8);
}

void eeprom_write_dword(uint32_t *addr, uint32_t value) {
    uint8_t *p = (uint8_t *)addr;
    eeprom_write_byte(p++, value);
    eeprom_write_byte(p++, value >> 8);
    eeprom_write_byte(p++, value >> 16);
    eeprom_write_byte(p, value >> 24);
}

void eeprom_write_block(const void *buf, void *addr, uint32_t len) {
    uint8_t *      p   = (uint8_t *)addr;
    const uint8_t *src = (const uint8_t *)buf;
    while (len--) {
        eeprom_write_byte(p++, *src++);
    }
}

#else
// No EEPROM supported, so emulate it

#    define EEPROM_SIZE 32
static uint8_t buffer[EEPROM_SIZE];

uint8_t eeprom_read_byte(const uint8_t *addr) {
    uint32_t offset = (uint32_t)addr;
    return buffer[offset];
}

void eeprom_write_byte(uint8_t *addr, uint8_t value) {
    uint32_t offset = (uint32_t)addr;
    buffer[offset]  = value;
}

uint16_t eeprom_read_word(const uint16_t *addr) {
    const uint8_t *p = (const uint8_t *)addr;
    return eeprom_read_byte(p) | (eeprom_read_byte(p + 1) << 8);
}

uint32_t eeprom_read_dword(const uint32_t *addr) {
    const uint8_t *p = (const uint8_t *)addr;
    return eeprom_read_byte(p) | (eeprom_read_byte(p + 1) << 8) | (eeprom_read_byte(p + 2) << 16) | (eeprom_read_byte(p + 3) << 24);
}

void eeprom_read_block(void *buf, const void *addr, uint32_t len) {
    const uint8_t *p    = (const uint8_t *)addr;
    uint8_t *      dest = (uint8_t *)buf;
    while (len--) {
        *dest++ = eeprom_read_byte(p++);
    }
}

void eeprom_write_word(uint16_t *addr, uint16_t value) {
    uint8_t *p = (uint8_t *)addr;
    eeprom_write_byte(p++, value);
    eeprom_write_byte(p, value >> 8);
}

void eeprom_write_dword(uint32_t *addr, uint32_t value) {
    uint8_t *p = (uint8_t *)addr;
    eeprom_write_byte(p++, value);
    eeprom_write_byte(p++, value >> 8);
    eeprom_write_byte(p++, value >> 16);
    eeprom_write_byte(p, value >> 24);
}

void eeprom_write_block(const void *buf, void *addr, uint32_t len) {
    uint8_t *      p   = (uint8_t *)addr;
    const uint8_t *src = (const uint8_t *)buf;
    while (len--) {
        eeprom_write_byte(p++, *src++);
    }
}

#endif /* chip selection */
// The update functions just calls write for now, but could probably be optimized

void eeprom_update_byte(uint8_t *addr, uint8_t value) { eeprom_write_byte(addr, value); }

void eeprom_update_word(uint16_t *addr, uint16_t value) {
    uint8_t *p = (uint8_t *)addr;
    eeprom_write_byte(p++, value);
    eeprom_write_byte(p, value >> 8);
}

void eeprom_update_dword(uint32_t *addr, uint32_t value) {
    uint8_t *p = (uint8_t *)addr;
    eeprom_write_byte(p++, value);
    eeprom_write_byte(p++, value >> 8);
    eeprom_write_byte(p++, value >> 16);
    eeprom_write_byte(p, value >> 24);
}

void eeprom_update_block(const void *buf, void *addr, uint32_t len) {
    uint8_t *      p   = (uint8_t *)addr;
    const uint8_t *src = (const uint8_t *)buf;
    while (len--) {
        eeprom_write_byte(p++, *src++);
    }
}