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 /* SPDX-License-Identifier: BSD-2-Clause */
 
 /*
  * RTEMS support for MPC83xx
  *
  * This file contains the MPC83xx SPI driver.
  * NOTE: it uses the same API as the I2C driver.
  */
 
 /*
  * Copyright (c) 2007 embedded brains GmbH & Co. KG
  *
  * 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 <stdlib.h>
 #include <bsp.h>
 #include <bsp/irq.h>
 #include <mpc83xx/mpc83xx.h>
 #include <mpc83xx/mpc83xx_spidrv.h>
 #include <rtems/error.h>
 #include <rtems/bspIo.h>
 #include <errno.h>
 #include <rtems/libi2c.h>
 
 #undef DEBUG
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 static rtems_status_code mpc83xx_spi_baud_to_mode
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   determine proper divider value                                          |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  uint32_t baudrate,                      /* desired baudrate               */
  uint32_t base_frq,                      /* input frequency                */
  uint32_t *spimode                       /* result value                   */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    o = ok or error code                                                   |
 \*=========================================================================*/
 {
   uint32_t divider;
   uint32_t tmpmode = 0;
   /*
    * determine clock divider and DIV16 bit
    */
   divider = (base_frq+baudrate-1)/baudrate;
   if (divider > 64) {
     tmpmode = MPC83XX_SPIMODE_DIV16;
     divider /= 16;
   }
   if ((divider <  1) ||
       (divider > 64)) {
     return RTEMS_INVALID_NUMBER;
   }
   else {
     tmpmode |= MPC83XX_SPIMODE_PM(divider/4-1);
   }
   *spimode = tmpmode;
   return RTEMS_SUCCESSFUL;
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 static rtems_status_code mpc83xx_spi_char_mode
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   determine proper value for character size                               |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  mpc83xx_spi_softc_t *softc_ptr,         /* handle                         */
  uint32_t bits_per_char,                 /* bits per character             */
  bool     lsb_first,                     /* TRUE: send LSB first           */
  uint32_t *spimode                       /* result value                   */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    o = ok or error code                                                   |
 \*=========================================================================*/
 {
   uint32_t tmpmode;
 
   if (bits_per_char == 32) {
     tmpmode = 0;
     softc_ptr->bytes_per_char = 4;
     softc_ptr->bit_shift      = 0;
   }
   else {
     if (lsb_first) {
       /*
        * non-reversed data (LSB first): 4..16 bits valid
        * always aligned to bit 16 of data register
        */
       if ((bits_per_char >= 4) &&
       (bits_per_char <= 16)) {
     tmpmode = MPC83XX_SPIMODE_LEN( bits_per_char-1);
     softc_ptr->bytes_per_char = (bits_per_char > 8) ? 2 : 1;
     softc_ptr->bit_shift      = 16-bits_per_char;
       }
       else {
     return RTEMS_INVALID_NUMBER;
       }
     }
     else {
       /*
        * reversed data (MSB first): only 8/16/32 bits valid,
        * always in lowest bits of data register
        */
       if (bits_per_char == 8) {
     tmpmode = MPC83XX_SPIMODE_LEN(8-1);
     softc_ptr->bytes_per_char = 1;
     softc_ptr->bit_shift      = 0;
       }
       else if (bits_per_char == 16) {
     tmpmode = MPC83XX_SPIMODE_LEN(16-1);
     softc_ptr->bytes_per_char = 2;
     softc_ptr->bit_shift      = 0;
       }
       else {
     return RTEMS_INVALID_NUMBER;
       }
     }
   }
 
   *spimode = tmpmode;
   return 0;
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 static int mpc83xx_spi_wait
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   wait for spi to become idle                                             |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  mpc83xx_spi_softc_t *softc_ptr,          /* handle              */
  uint32_t             irq_mask,           /* irq mask to use     */
  uint32_t             desired_status,     /* desired status word */
  uint32_t             status_mask         /* status word mask    */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    o = ok or error code                                                   |
 \*=========================================================================*/
 {
   uint32_t act_status;
   rtems_status_code rc;
   uint32_t tout;
 
 #if defined(DEBUG)
   printk("mpc83xx_spi_wait called... ");
 #endif
   if (softc_ptr->initialized) {
     /*
      * allow interrupts, when receiver is not empty
      */
     softc_ptr->reg_ptr->spim = irq_mask;
     rc = rtems_semaphore_obtain(softc_ptr->irq_sema_id,RTEMS_WAIT,100);
     if (rc != RTEMS_SUCCESSFUL) {
       return rc;
     }
   }
   else {
     tout = 0;
     do {
       if (tout++ > 1000000) {
 #if defined(DEBUG)
     printk("... exit with RTEMS_TIMEOUT\r\n");
 #endif
     return RTEMS_TIMEOUT;
       }
       /*
        * wait for SPI to terminate
        */
     } while (!(softc_ptr->reg_ptr->spie & MPC83XX_SPIE_NE));
   }
 
   act_status = softc_ptr->reg_ptr->spie;
   if ((act_status  & status_mask)!= desired_status) {
 #if defined(DEBUG)
     printk("... exit with RTEMS_IO_ERROR,"
        "act_status=0x%04x,mask=0x%04x,desired_status=0x%04x\r\n",
        act_status,status_mask,desired_status);
 #endif
     return RTEMS_IO_ERROR;
   }
 #if defined(DEBUG)
     printk("... exit OK\r\n");
 #endif
   return RTEMS_SUCCESSFUL;
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 static void mpc83xx_spi_irq_handler
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   handle interrupts                                                       |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  rtems_irq_hdl_param handle     /* handle, is softc_ptr structure          */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    <none>                                                                 |
 \*=========================================================================*/
 {
   mpc83xx_spi_softc_t *softc_ptr = (mpc83xx_spi_softc_t *)handle;
 
   /*
    * disable interrupt mask
    */
   softc_ptr->reg_ptr->spim = 0;
   if (softc_ptr->initialized) {
     rtems_semaphore_release(softc_ptr->irq_sema_id);
   }
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 static void mpc83xx_spi_irq_on_off
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   enable/disable interrupts (void, handled at different position)         |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  const
  rtems_irq_connect_data *irq_conn_data   /* irq connect data                */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    <none>                                                                 |
 \*=========================================================================*/
 {
 }
 
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 static int mpc83xx_spi_irq_isOn
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   check state of interrupts, void, done differently                       |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  const
  rtems_irq_connect_data *irq_conn_data  /* irq connect data                */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    TRUE, if enabled                                                       |
 \*=========================================================================*/
 {
   return (TRUE);
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 static void mpc83xx_spi_install_irq_handler
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   (un-)install the interrupt handler                                      |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  mpc83xx_spi_softc_t *softc_ptr,        /* ptr to control structure        */
  int install                            /* TRUE: install, FALSE: remove    */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    <none>                                                                 |
 \*=========================================================================*/
 {
   rtems_status_code rc = RTEMS_SUCCESSFUL;
 
   rtems_irq_connect_data irq_conn_data = {
     softc_ptr->irq_number,
     mpc83xx_spi_irq_handler,        /* rtems_irq_hdl           */
     (rtems_irq_hdl_param)softc_ptr, /* (rtems_irq_hdl_param)   */
     mpc83xx_spi_irq_on_off,         /* (rtems_irq_enable)      */
     mpc83xx_spi_irq_on_off,         /* (rtems_irq_disable)     */
     mpc83xx_spi_irq_isOn            /* (rtems_irq_is_enabled)  */
   };
 
   /*
    * (un-)install handler for SPI device
    */
   if (install) {
     /*
      * create semaphore for IRQ synchronization
      */
     rc = rtems_semaphore_create(rtems_build_name('s','p','i','s'),
                 0,
                 RTEMS_FIFO
                 | RTEMS_SIMPLE_BINARY_SEMAPHORE,
                 0,
                 &softc_ptr->irq_sema_id);
     if (rc != RTEMS_SUCCESSFUL) {
       rtems_panic("SPI: cannot create semaphore");
     }
     if (!BSP_install_rtems_irq_handler (&irq_conn_data)) {
       rtems_panic("SPI: cannot install IRQ handler");
     }
   }
   else {
     if (!BSP_remove_rtems_irq_handler (&irq_conn_data)) {
       rtems_panic("SPI: cannot uninstall IRQ handler");
     }
     /*
      * delete sync semaphore
      */
     if (softc_ptr->irq_sema_id != 0) {
       rc = rtems_semaphore_delete(softc_ptr->irq_sema_id);
       if (rc != RTEMS_SUCCESSFUL) {
     rtems_panic("SPI: cannot delete semaphore");
       }
     }
   }
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 rtems_status_code mpc83xx_spi_init
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   initialize the driver                                                   |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  rtems_libi2c_bus_t *bh                  /* bus specifier structure        */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    o = ok or error code                                                   |
 \*=========================================================================*/
 {
   mpc83xx_spi_softc_t *softc_ptr = &(((mpc83xx_spi_desc_t *)(bh))->softc);
 #if defined(DEBUG)
   printk("mpc83xx_spi_init called... ");
 #endif
   /*
    * init HW registers:
    */
   /*
    * FIXME: set default mode in SPIM
    */
 
   /*
    * init interrupt stuff
    */
   mpc83xx_spi_install_irq_handler(softc_ptr,TRUE);
 
   /*
    * mark, that we have initialized
    */
   softc_ptr->initialized = TRUE;
 #if defined(DEBUG)
   printk("... exit OK\r\n");
 #endif
   return RTEMS_SUCCESSFUL;
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 int mpc83xx_spi_read_write_bytes
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   transmit/receive some bytes from SPI device                             |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  rtems_libi2c_bus_t *bh,                 /* bus specifier structure        */
  unsigned char *rbuf,                    /* buffer to store bytes          */
  const unsigned char *tbuf,              /* buffer to send  bytes          */
  int len                                 /* number of bytes to transceive  */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    number of bytes received or (negative) error code                      |
 \*=========================================================================*/
 {
   mpc83xx_spi_softc_t *softc_ptr = &(((mpc83xx_spi_desc_t *)(bh))->softc);
   rtems_status_code rc;
   int bc = 0;
   int bytes_per_char = softc_ptr->bytes_per_char;
   int bit_shift      = softc_ptr->bit_shift;
   uint32_t spird_val;
 
 #if defined(DEBUG)
   printk("mpc83xx_spi_read_write_bytes called... ");
 #endif
 
   while (len > bytes_per_char-1) {
     len -= bytes_per_char;
     /*
      * mark last byte in SPCOM
      */
 #if defined(USE_LAST_BIT)
     softc_ptr->reg_ptr->spcom = (len < bytes_per_char) ? MPC83XX_SPCOM_LST : 0;
 #else
     softc_ptr->reg_ptr->spcom = 0;
 #endif
     if (tbuf == NULL) {
       /*
        * perform idle char write to read byte
        */
       softc_ptr->reg_ptr->spitd = softc_ptr->idle_char << bit_shift;
     }
     else {
       switch(bytes_per_char) {
       case 1:
     softc_ptr->reg_ptr->spitd = (*(uint8_t *)tbuf) << bit_shift;
     break;
       case 2:
     softc_ptr->reg_ptr->spitd = (*(uint16_t *)tbuf) << bit_shift;
     break;
       case 4:
     softc_ptr->reg_ptr->spitd = (*(uint32_t *)tbuf) << bit_shift;
     break;
       }
       tbuf += softc_ptr->bytes_per_char;
     }
     /*
      * wait 'til end of transfer
      */
 #if defined(USE_LAST_BIT)
     rc = mpc83xx_spi_wait(softc_ptr,
               ((len == 0)
                ? MPC83XX_SPIE_LT
                : MPC83XX_SPIE_NE),
               ((len == 0)
                ? MPC83XX_SPIE_LT
                : MPC83XX_SPIE_NF)
               | MPC83XX_SPIE_NE,
               MPC83XX_SPIE_LT
                 | MPC83XX_SPIE_OV
               | MPC83XX_SPIE_UN
               | MPC83XX_SPIE_NE
               | MPC83XX_SPIE_NF);
     if (len == 0) {
       /*
        * clear the "last transfer complete" event
        */
       softc_ptr->reg_ptr->spie = MPC83XX_SPIE_LT;
     }
 #else
     rc = mpc83xx_spi_wait(softc_ptr,
               MPC83XX_SPIE_NE,
               MPC83XX_SPIE_NF
               | MPC83XX_SPIE_NE,
               MPC83XX_SPIE_OV
               | MPC83XX_SPIE_UN
               | MPC83XX_SPIE_NE
               | MPC83XX_SPIE_NF);
 #endif
     if (rc != RTEMS_SUCCESSFUL) {
 #if defined(DEBUG)
       printk("... exit rc=%d\r\n",-rc);
 #endif
       return -rc;
     }
     spird_val = softc_ptr->reg_ptr->spird;
     if (rbuf != NULL) {
       switch(bytes_per_char) {
       case 1:
      (*(uint8_t  *)rbuf) = spird_val >> bit_shift;
     break;
       case 2:
      (*(uint16_t *)rbuf) = spird_val >> bit_shift;
     break;
       case 4:
      (*(uint32_t *)rbuf) = spird_val >> bit_shift;
     break;
       }
       rbuf += bytes_per_char;
     }
     bc += bytes_per_char;
   }
 #if defined(DEBUG)
   printk("... exit OK, rc=%d\r\n",bc);
 #endif
   return bc;
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 int mpc83xx_spi_read_bytes
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   receive some bytes from SPI device                                      |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  rtems_libi2c_bus_t *bh,                 /* bus specifier structure        */
  unsigned char *buf,                     /* buffer to store bytes          */
  int len                                 /* number of bytes to receive     */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    number of bytes received or (negative) error code                      |
 \*=========================================================================*/
 {
   return mpc83xx_spi_read_write_bytes(bh,buf,NULL,len);
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 int mpc83xx_spi_write_bytes
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   send some bytes to SPI device                                           |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  rtems_libi2c_bus_t *bh,                 /* bus specifier structure        */
  unsigned char *buf,                     /* buffer to send                 */
  int len                                 /* number of bytes to send        */
 
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    number of bytes sent or (negative) error code                          |
 \*=========================================================================*/
 {
   return mpc83xx_spi_read_write_bytes(bh,NULL,buf,len);
 }
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 rtems_status_code mpc83xx_spi_set_tfr_mode
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   set SPI to desired baudrate/clock mode/character mode                   |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  rtems_libi2c_bus_t *bh,                 /* bus specifier structure        */
  const rtems_libi2c_tfr_mode_t *tfr_mode /* transfer mode info             */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    rtems_status_code                                                      |
 \*=========================================================================*/
 {
   mpc83xx_spi_softc_t *softc_ptr = &(((mpc83xx_spi_desc_t *)(bh))->softc);
   uint32_t spimode_baud,spimode;
   rtems_status_code rc = RTEMS_SUCCESSFUL;
 
   /* Set idle character */
   softc_ptr->idle_char = tfr_mode->idle_char;
 
   /*
    * FIXME: set proper mode
    */
   if (rc == RTEMS_SUCCESSFUL) {
     rc = mpc83xx_spi_baud_to_mode(tfr_mode->baudrate,
                   softc_ptr->base_frq,
                   &spimode_baud);
   }
   if (rc == RTEMS_SUCCESSFUL) {
     rc = mpc83xx_spi_char_mode(softc_ptr,
                    tfr_mode->bits_per_char,
                    tfr_mode->lsb_first,
                    &spimode);
   }
   if (rc == RTEMS_SUCCESSFUL) {
     spimode |= spimode_baud;
     spimode |= MPC83XX_SPIMODE_M_S; /* set master mode */
     if (!tfr_mode->lsb_first) {
       spimode |= MPC83XX_SPIMODE_REV;
     }
     if (tfr_mode->clock_inv) {
       spimode |= MPC83XX_SPIMODE_CI;
     }
     if (tfr_mode->clock_phs) {
       spimode |= MPC83XX_SPIMODE_CP;
     }
   }
 
   if (rc == RTEMS_SUCCESSFUL) {
     /*
      * disable SPI
      */
     softc_ptr->reg_ptr->spmode &= ~MPC83XX_SPIMODE_EN;
     /*
      * set new mode and reenable SPI
      */
     softc_ptr->reg_ptr->spmode = spimode | MPC83XX_SPIMODE_EN;
   }
   return rc;
 }
 
 
 /*=========================================================================*\
 | Function:                                                                 |
 \*-------------------------------------------------------------------------*/
 int mpc83xx_spi_ioctl
 (
 /*-------------------------------------------------------------------------*\
 | Purpose:                                                                  |
 |   perform selected ioctl function for SPI                                 |
 +---------------------------------------------------------------------------+
 | Input Parameters:                                                         |
 \*-------------------------------------------------------------------------*/
  rtems_libi2c_bus_t *bh,                 /* bus specifier structure        */
  int                 cmd,                /* ioctl command code             */
  void               *arg                 /* additional argument array      */
 )
 /*-------------------------------------------------------------------------*\
 | Return Value:                                                             |
 |    rtems_status_code                                                      |
 \*=========================================================================*/
 {
   int ret_val = -1;
 
   switch(cmd) {
   case RTEMS_LIBI2C_IOCTL_SET_TFRMODE:
     ret_val =
       -mpc83xx_spi_set_tfr_mode(bh,
                 (const rtems_libi2c_tfr_mode_t *)arg);
     break;
   case RTEMS_LIBI2C_IOCTL_READ_WRITE:
     ret_val =
       mpc83xx_spi_read_write_bytes(bh,
                    ((rtems_libi2c_read_write_t *)arg)->rd_buf,
                    ((rtems_libi2c_read_write_t *)arg)->wr_buf,
                    ((rtems_libi2c_read_write_t *)arg)->byte_cnt);
     break;
   default:
     ret_val = -RTEMS_NOT_DEFINED;
     break;
   }
   return ret_val;
 }
 
 
 

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