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//==========================================================================
//
//      io/serial/arm/s3c4510_serial.c
//
//      ARM S3C4510 Serial I/O Interface Module (interrupt driven)
//
//==========================================================================
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// ====================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    Lars.Lindqvist@combitechsystems.com
// Contributors: jlarmour
// Date:         2001-10-19
// Purpose:      ARM S3C4510 Serial I/O Interface Module (interrupt driven)
// Description:
//
//####DESCRIPTIONEND####
//
// ====================================================================
 
#include <pkgconf/system.h>
#include <pkgconf/io_serial.h>
#include <pkgconf/io.h>
#include <cyg/io/io.h>
#include <cyg/hal/hal_intr.h>
#include <cyg/io/devtab.h>
#include <cyg/io/serial.h>
#include <cyg/io/serialio.h>
#include <cyg/infra/diag.h>
 
#if defined(CYGPKG_IO_SERIAL_ARM_S3C4510) && defined(CYGDAT_IO_SERIAL_ARM_S3C4510_INL)
 
typedef struct s3c4510_serial_info {
    CYG_ADDRWORD   base;
    CYG_WORD       tx_int_num;
    CYG_WORD       rx_int_num;
    cyg_interrupt  serial_tx_interrupt;
    cyg_interrupt  serial_rx_interrupt;
    cyg_handle_t   serial_tx_interrupt_handle;
    cyg_handle_t   serial_rx_interrupt_handle;
    bool           tx_enabled;
} s3c4510_serial_info;
 
static bool s3c4510_serial_init(struct cyg_devtab_entry *tab);
static bool s3c4510_serial_putc(serial_channel *chan, unsigned char c);
static Cyg_ErrNo s3c4510_serial_lookup(struct cyg_devtab_entry **tab, 
                                   struct cyg_devtab_entry *sub_tab,
                                   const char *name);
static unsigned char s3c4510_serial_getc(serial_channel *chan);
static Cyg_ErrNo s3c4510_serial_set_config(serial_channel *chan, 
                                       cyg_uint32 key,
                                       const void *xbuf, cyg_uint32 *len);
static void s3c4510_serial_start_xmit(serial_channel *chan);
static void s3c4510_serial_stop_xmit(serial_channel *chan);
 
static cyg_uint32 s3c4510_serial_tx_ISR(cyg_vector_t vector, cyg_addrword_t data);
static void       s3c4510_serial_tx_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data);
static cyg_uint32 s3c4510_serial_rx_ISR(cyg_vector_t vector, cyg_addrword_t data);
static void       s3c4510_serial_rx_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data);
 
static SERIAL_FUNS(s3c4510_serial_funs, 
                   s3c4510_serial_putc, 
                   s3c4510_serial_getc,
                   s3c4510_serial_set_config,
                   s3c4510_serial_start_xmit,
                   s3c4510_serial_stop_xmit
    );
 
#include CYGDAT_IO_SERIAL_ARM_S3C4510_INL
 
#include "s3c4510_serial.h"
 
// Internal function to actually configure the hardware to desired baud rate, etc.
static bool
s3c4510_serial_config_port(serial_channel *chan, cyg_serial_info_t *new_config, bool init)
{
  s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
  volatile struct serial_port *port = (volatile struct serial_port *)s3c4510_chan->base;
  cyg_uint32 word_length = select_word_length[(new_config->word_length)-CYGNUM_SERIAL_WORD_LENGTH_5];
  cyg_uint32 stop_bits = select_stop_bits[(new_config->stop)-CYGNUM_SERIAL_STOP_1];
  cyg_uint32 parity_mode = select_parity[(new_config->parity)-CYGNUM_SERIAL_PARITY_NONE];
  cyg_uint32 baud_divisor = select_baud[(new_config->baud)-CYGNUM_SERIAL_BAUD_50];
  cyg_uint32 res = word_length | stop_bits | parity_mode | ULCON_SCI | ULCON_IROFF;
  if ((word_length|stop_bits|parity_mode|baud_divisor) == U_NOT_SUPP) {
    return false;
  };
  port->REG_ULCON = res;
  port->REG_UCON = UCON_RXMINT | UCON_RXSIOFF | UCON_TXMINT | UCON_DSROFF | UCON_SBKOFF | UCON_LPBOFF;
  port->REG_UBRDIV = baud_divisor;
  if (new_config != &chan->config) {
    chan->config = *new_config;
  };
  return true;
}
 
// Function to initialize the device.  Called at bootstrap time.
static bool 
s3c4510_serial_init(struct cyg_devtab_entry *tab)
{
    serial_channel *chan = (serial_channel *)tab->priv;
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
#ifdef CYGDBG_IO_INIT
    diag_printf("S3C4510 SERIAL init - dev: %x.%d.%d\n", s3c4510_chan->base, s3c4510_chan->tx_int_num, s3c4510_chan->rx_int_num);
#endif
    (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices
    if (chan->out_cbuf.len != 0) {         // If bufferlength > 0 then interrupts are used for tx
        cyg_drv_interrupt_create(s3c4510_chan->tx_int_num,
                                 99,                     // Priority - unused
                                 (cyg_addrword_t)chan,   //  Data item passed to interrupt handler
                                 s3c4510_serial_tx_ISR,
                                 s3c4510_serial_tx_DSR,
                                 &s3c4510_chan->serial_tx_interrupt_handle,
                                 &s3c4510_chan->serial_tx_interrupt);
        cyg_drv_interrupt_attach(s3c4510_chan->serial_tx_interrupt_handle);
        cyg_drv_interrupt_mask(s3c4510_chan->tx_int_num);
        s3c4510_chan->tx_enabled = false;
    }
    if (chan->in_cbuf.len != 0) {         // If bufferlength > 0 then interrupts are used for rx
        cyg_drv_interrupt_create(s3c4510_chan->rx_int_num,
                                 99,                     // Priority - unused
                                 (cyg_addrword_t)chan,   //  Data item passed to interrupt handler
                                 s3c4510_serial_rx_ISR,
                                 s3c4510_serial_rx_DSR,
                                 &s3c4510_chan->serial_rx_interrupt_handle,
                                 &s3c4510_chan->serial_rx_interrupt);
        cyg_drv_interrupt_attach(s3c4510_chan->serial_rx_interrupt_handle);
        cyg_drv_interrupt_unmask(s3c4510_chan->rx_int_num);
    }
    s3c4510_serial_config_port(chan, &chan->config, true);
    return true;
}
 
// This routine is called when the device is "looked" up (i.e. attached)
static Cyg_ErrNo 
s3c4510_serial_lookup(struct cyg_devtab_entry **tab, 
                  struct cyg_devtab_entry *sub_tab,
                  const char *name)
{
    serial_channel *chan = (serial_channel *)(*tab)->priv;
    (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices
    return ENOERR;
}
 
// Send a character to the device output buffer.
// Return 'true' if character is sent to device
static bool
s3c4510_serial_putc(serial_channel *chan, unsigned char c)
{
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    volatile struct serial_port *port = (volatile struct serial_port *)s3c4510_chan->base;
 
    if (port->REG_USTAT & USTAT_TBE) {
      // Transmit buffer is empty
      port->REG_UTXBUF = c;
      return true;
    } else {
      // No space
      return false;
    }
}
 
// Fetch a character from the device input buffer, waiting if necessary
static unsigned char 
s3c4510_serial_getc(serial_channel *chan)
{
    unsigned char c;
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    volatile struct serial_port *port = (volatile struct serial_port *)s3c4510_chan->base;
    while ((port->REG_USTAT & USTAT_RDR) == 0) ;   // Wait for char
    c = port->REG_URXBUF;
    return c;
}
 
// Set up the device characteristics; baud rate, etc.
static Cyg_ErrNo
s3c4510_serial_set_config(serial_channel *chan, cyg_uint32 key,
                      const void *xbuf, cyg_uint32 *len)
{
    switch (key) {
    case CYG_IO_SET_CONFIG_SERIAL_INFO:
      {
        cyg_serial_info_t *config = (cyg_serial_info_t *)xbuf;
        if ( *len < sizeof(cyg_serial_info_t) ) {
            return -EINVAL;
        }
        *len = sizeof(cyg_serial_info_t);
        if ( true != s3c4510_serial_config_port(chan, config, false) )
            return -EINVAL;
      }
      break;
    default:
        return -EINVAL;
    }
    return ENOERR;
}
 
// Enable the transmitter on the device
static void
s3c4510_serial_start_xmit(serial_channel *chan)
{
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    s3c4510_chan->tx_enabled = true;
    (chan->callbacks->xmt_char)(chan);
    if (s3c4510_chan->tx_enabled) {
        cyg_drv_interrupt_unmask(s3c4510_chan->tx_int_num);
    }
}
 
// Disable the transmitter on the device
static void 
s3c4510_serial_stop_xmit(serial_channel *chan)
{
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    cyg_drv_interrupt_mask(s3c4510_chan->tx_int_num);
    s3c4510_chan->tx_enabled = false;
}
 
// Serial I/O - low level tx interrupt handler (ISR)
static cyg_uint32 
s3c4510_serial_tx_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    cyg_drv_interrupt_mask(s3c4510_chan->tx_int_num);
    cyg_drv_interrupt_acknowledge(s3c4510_chan->tx_int_num);
    return CYG_ISR_CALL_DSR;  // Cause DSR to be run
}
 
// Serial I/O - high level tx interrupt handler (DSR)
static void       
s3c4510_serial_tx_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    (chan->callbacks->xmt_char)(chan);
    if (s3c4510_chan->tx_enabled) {
        cyg_drv_interrupt_unmask(s3c4510_chan->tx_int_num);
    }
}
 
// Serial I/O - low level rx interrupt handler (ISR)
static cyg_uint32 
s3c4510_serial_rx_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    cyg_drv_interrupt_mask(s3c4510_chan->rx_int_num);
    cyg_drv_interrupt_acknowledge(s3c4510_chan->rx_int_num);
    return CYG_ISR_CALL_DSR;  // Cause DSR to be run
}
 
// Serial I/O - high level rx interrupt handler (DSR)
static void       
s3c4510_serial_rx_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    s3c4510_serial_info *s3c4510_chan = (s3c4510_serial_info *)chan->dev_priv;
    volatile struct serial_port *port = (volatile struct serial_port *)s3c4510_chan->base;
    (chan->callbacks->rcv_char)(chan, port->REG_URXBUF);
    cyg_drv_interrupt_unmask(s3c4510_chan->rx_int_num);
}
 
#endif // CYGPKG_IO_SERIAL_ARM_S3C4510 && CYGDAT_IO_SERIAL_ARM_S3C4510_INL
 
// EOF s3c4510_serial.c