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//==========================================================================

//

//      devs/wallclock/ds1307.inl

//

//      Wallclock implementation for Dallas 1307

//

//==========================================================================

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//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):     gthomas

// Contributors:  

// Date:          2003-09-19

// Purpose:       Wallclock driver for Dallas 1307

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include <pkgconf/hal.h>                // Platform specific configury

#include <pkgconf/wallclock.h>          // Wallclock device config

#include <pkgconf/devices_wallclock_dallas_ds1307.h>

#include <cyg/hal/hal_io.h>             // IO macros

#include <cyg/hal/hal_intr.h>           // interrupt enable/disable

#include <cyg/infra/cyg_type.h>         // Common type definitions and support

#include <string.h>                     // memcpy()

#include <cyg/io/wallclock.hxx>         // The WallClock API

#include <cyg/io/wallclock/wallclock.inl> // Helpers

#include <cyg/infra/diag.h>

#if 1

# define DEBUG(_format_, ...)

#else

# define DEBUG(_format_, ...) diag_printf(_format_, ## __VA_ARGS__)

#endif

// Registers.

// FIXME: there is no need to include the control register here, it

// controls a square wave output which is independent from the wallclock.

// However fixing it would require changing any platforms that use the

// old DS_GET()/DS_PUT() functionality.

#define DS_SECONDS         0x00

#define DS_MINUTES         0x01

#define DS_HOURS           0x02

#define DS_DOW             0x03

#define DS_DOM             0x04

#define DS_MONTH           0x05

#define DS_YEAR            0x06

#define DS_CONTROL         0x07

#define DS_REGS_SIZE       0x08   // Size of register space

#define DS_SECONDS_CH      0x80   // Clock Halt

#define DS_HOURS_24        0x40   // 24 hour clock mode

// The DS1307 chip is accessed via I2C (2-wire protocol). This can be

// implemented in one of two ways. If the platform supports the generic

// I2C API then it should also export a cyg_i2c_device structure

// cyg_i2c_wallclock_ds1307, and this can be manipulated via the

// usual cyg_i2c_tx() and cyg_i2c_rx() functions. Alternatively (and

// primarily for older ports predating the generic I2C package)

// the platform HAL can provide the following two macros/functions:

//

// void DS_GET(cyg_uint8 *regs)

//    Reads the entire set of registers (8 bytes) into *regs

// void DS_PUT(cyg_uint8 *regs)

//    Updated the entire set of registers (8 bytes) from *regs

//

// Using this method, the data in the registers is guaranteed to be

// stable (if the access function manipulates the registers in an

// single operation)

//

// If the platform HAL implements the CDL interface

// CYGINT_DEVICES_WALLCLOCK_DALLAS_DS1307_I2C then the I2C API will be used.

#ifdef CYGINT_DEVICES_WALLCLOCK_DALLAS_DS1307_I2C

# if defined(DS_GET) || defined(DS_PUT)

#  error The macros DS_GET and DS_PUT should not be defined if the generic I2C API is used

# endif

#include <cyg/io/i2c.h>

static void

DS_GET(cyg_uint8* regs)

{

    cyg_uint8   tx_data[1];

    cyg_bool    ok = true;

    tx_data[0]  = 0x00; // Initial register to read

    cyg_i2c_transaction_begin(&cyg_i2c_wallclock_ds1307);

    if (1 != cyg_i2c_transaction_tx(&cyg_i2c_wallclock_ds1307, true, tx_data, 1, false)) {

        // The device has not responded to the address byte.

        ok = false;

    } else {

        // Now fetch the data

        cyg_i2c_transaction_rx(&cyg_i2c_wallclock_ds1307, true, regs, 8, true, true);

        // Verify that there are reasonable default settings. The

        // register values can be used as array indices so bogus

        // values can lead to bus errors or similar problems.

        // Years: 00 - 99, with 70-99 interpreted as 1970 onwards.

        if ((regs[DS_YEAR] & 0x0F) > 0x09) {

            ok = false;

        }

        // Month: 1 - 12

        if ((regs[DS_MONTH] == 0x00) ||

            ((regs[DS_MONTH] > 0x09) && (regs[DS_MONTH] < 0x10)) ||

            (regs[DS_MONTH] > 0x12)) {

            ok = false;

        }

        // Day: 1 - 31. This check does not allow for 28-30 day months.

        if ((regs[DS_DOM] == 0x00) ||

            ((regs[DS_DOM] & 0x0F) > 0x09) ||

            (regs[DS_DOM] > 0x31)) {

            ok = false;

        }

        // Hours: 0 - 23. Always run in 24-hour mode

        if ((0 != (regs[DS_HOURS] & DS_HOURS_24)) ||

            ((regs[DS_HOURS] & 0x0F) > 0x09) ||

            ((regs[DS_HOURS] & 0x3F) > 0x023)) {

            ok = false;

        }

        // Ignore the DOW field. The wallclock code does not need it, and

        // it is hard to calculate.

        // Minutes: 0 - 59

        if (((regs[DS_MINUTES] & 0x0F) > 0x09) ||

            (regs[DS_MINUTES] > 0x59)) {

            ok = false;

        }

        // Seconds: 0 - 59

        if (((regs[DS_SECONDS] & 0x0F) > 0x09) ||

            (regs[DS_SECONDS] > 0x59)) {

            ok = false;

        }

    }

    cyg_i2c_transaction_end(&cyg_i2c_wallclock_ds1307);

    if (! ok) {

        // Any problems, return Jan 1 1970 but do not update the hardware.

        // Leave it to the user or other code to set the clock to a sensible

        // value.

        regs[DS_SECONDS]  = 0x00;

        regs[DS_MINUTES]  = 0x00;

        regs[DS_HOURS]    = 0x00;

        regs[DS_DOW]      = 0x00;

        regs[DS_DOM]      = 0x01;

        regs[DS_MONTH]    = 0x01;

        regs[DS_YEAR]     = 0x70;

        regs[DS_CONTROL]  = 0x00;

    }

}

static void

DS_PUT(cyg_uint8* regs)

{

    cyg_uint8 tx_data[9];

    tx_data[0] = 0;

    memcpy(&(tx_data[1]), regs, 8);

    cyg_i2c_tx(&cyg_i2c_wallclock_ds1307, tx_data, 9);

}

#else

// Platform details. The platform HAL or some other package should

// provide this header, containing the required macros

# include CYGDAT_DEVS_WALLCLOCK_DALLAS_1307_INL

#endif

//----------------------------------------------------------------------------

// Accessor functions

static inline void

init_ds_hwclock(void)

{

    cyg_uint8 regs[DS_REGS_SIZE];

    // Fetch the current state

    DS_GET(regs);

    // If the clock is not currently running or is not in 24-hours mode,

    // update it. Otherwise skip the update because the clock may have

    // ticked between DS_GET() and DS_PUT() and we could be losing the

    // occasional second.

    if ((0 != (regs[DS_HOURS] & DS_HOURS_24)) ||

        (0 != (regs[DS_SECONDS] & DS_SECONDS_CH))) {

        regs[DS_SECONDS] &= ~DS_SECONDS_CH;

        regs[DS_HOURS]   &= ~DS_HOURS_24;

        DS_PUT(regs);

    }

}

static inline void

set_ds_hwclock(cyg_uint32 year, cyg_uint32 month, cyg_uint32 mday,

               cyg_uint32 hour, cyg_uint32 minute, cyg_uint32 second)

{

    cyg_uint8 regs[DS_REGS_SIZE];

    // Set up the registers

    regs[DS_CONTROL]    = 0x00;

    regs[DS_YEAR]       = TO_BCD((cyg_uint8)(year % 100));

    regs[DS_MONTH]      = TO_BCD((cyg_uint8)month);

    regs[DS_DOM]        = TO_BCD((cyg_uint8)mday);

    regs[DS_DOW]        = TO_BCD(0x01);     // Not accurate, but not used by this driver either

    regs[DS_HOURS]      = TO_BCD((cyg_uint8)hour);

    regs[DS_MINUTES]    = TO_BCD((cyg_uint8)minute);

    // This also starts the clock

    regs[DS_SECONDS]    = TO_BCD((cyg_uint8)second);

    // Send the register set to the hardware

    DS_PUT(regs);

    // These debugs will cause the test to eventually fail due to

    // the printouts causing timer interrupts to be lost...

    DEBUG("DS1307 set -------------\n");

    DEBUG("regs %02x %02x %02x %02x %02x %02x %02x %02x\n",

          regs[0], regs[1], regs[2], regs[3], regs[4], regs[5], regs[6], regs[7]);

    DEBUG("year %02d\n", year);

    DEBUG("month %02d\n", month);

    DEBUG("mday %02d\n", mday);

    DEBUG("hour %02d\n", hour);

    DEBUG("minute %02d\n", minute);

    DEBUG("second %02d\n", second);

}

static inline void

get_ds_hwclock(cyg_uint32* year, cyg_uint32* month, cyg_uint32* mday,

               cyg_uint32* hour, cyg_uint32* minute, cyg_uint32* second)

{

    cyg_uint8 regs[DS_REGS_SIZE];

    // Fetch the current state

    DS_GET(regs);

    *year = (cyg_uint32)TO_DEC(regs[DS_YEAR]);

    // The year field only has the 2 least significant digits :-(

    if (*year >= 70) {

        *year += 1900;

    } else {

        *year += 2000;

    }

    *month = (cyg_uint32)TO_DEC(regs[DS_MONTH]);

    *mday = (cyg_uint32)TO_DEC(regs[DS_DOM]);

    *hour = (cyg_uint32)TO_DEC(regs[DS_HOURS] & 0x3F);

    *minute = (cyg_uint32)TO_DEC(regs[DS_MINUTES]);

    *second = (cyg_uint32)TO_DEC(regs[DS_SECONDS] & 0x7F);

    // These debugs will cause the test to eventually fail due to

    // the printouts causing timer interrupts to be lost...

    DEBUG("DS1307 get -------------\n");

    DEBUG("regs %02x %02x %02x %02x %02x %02x %02x %02x\n",

          regs[0], regs[1], regs[2], regs[3], regs[4], regs[5], regs[6], regs[7]);

    DEBUG("year %02d\n", *year);

    DEBUG("month %02d\n", *month);

    DEBUG("mday %02d\n", *mday);

    DEBUG("hour %02d\n", *hour);

    DEBUG("minute %02d\n", *minute);

    DEBUG("second %02d\n", *second);

}

//-----------------------------------------------------------------------------

// Functions required for the hardware-driver API.

// Returns the number of seconds elapsed since 1970-01-01 00:00:00.

cyg_uint32

Cyg_WallClock::get_hw_seconds(void)

{

    cyg_uint32 year, month, mday, hour, minute, second;

    get_ds_hwclock(&year, &month, &mday, &hour, &minute, &second);

    cyg_uint32 now = _simple_mktime(year, month, mday, hour, minute, second);

    return now;

}

#ifdef CYGSEM_WALLCLOCK_SET_GET_MODE

// Sets the clock. Argument is seconds elapsed since 1970-01-01 00:00:00.

void

Cyg_WallClock::set_hw_seconds( cyg_uint32 secs )

{

    cyg_uint32 year, month, mday, hour, minute, second;

    _simple_mkdate(secs, &year, &month, &mday, &hour, &minute, &second);

    set_ds_hwclock(year, month, mday, hour, minute, second);

}

#endif

void

Cyg_WallClock::init_hw_seconds(void)

{

#ifdef CYGSEM_WALLCLOCK_SET_GET_MODE

    init_ds_hwclock();

#else

    // This is our base: 1970-01-01 00:00:00

    // Set the HW clock - if for nothing else, just to be sure it's in a

    // legal range. Any arbitrary base could be used.

    // After this the hardware clock is only read.

    set_ds_hwclock(1970,1,1,0,0,0);

#endif

}

//-----------------------------------------------------------------------------

// End of devs/wallclock/ds1307.inl