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  1. /*
  2.  * Copyright (c) 2009 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genarch
  30.  * @{
  31.  */
  32. /**
  33.  * @file
  34.  * @brief   NS 16550 serial controller driver.
  35.  */
  36.  
  37. #include <genarch/drivers/ns16550/ns16550.h>
  38. #include <ddi/irq.h>
  39. #include <arch/asm.h>
  40. #include <console/chardev.h>
  41. #include <mm/slab.h>
  42.  
  43. #define LSR_DATA_READY  0x01
  44.  
  45. /** Initialize ns16550.
  46.  *
  47.  * @param dev       Addrress of the beginning of the device in I/O space.
  48.  * @param devno     Device number.
  49.  * @param inr       Interrupt number.
  50.  * @param cir       Clear interrupt function.
  51.  * @param cir_arg   First argument to cir.
  52.  * @param devout    Output character device.
  53.  *
  54.  * @return      True on success, false on failure.
  55.  */
  56. bool
  57. ns16550_init(ns16550_t *dev, devno_t devno, inr_t inr, cir_t cir, void *cir_arg,
  58.     chardev_t *devout)
  59. {
  60.     ns16550_instance_t *instance;
  61.    
  62.     instance = malloc(sizeof(ns16550_instance_t), FRAME_ATOMIC);
  63.     if (!instance)
  64.         return false;
  65.  
  66.     instance->devno = devno;
  67.     instance->ns16550 = dev;
  68.     instance->devout = devout;
  69.    
  70.     irq_initialize(&instance->irq);
  71.     instance->irq.devno = devno;
  72.     instance->irq.inr = inr;
  73.     instance->irq.claim = ns16550_claim;
  74.     instance->irq.handler = ns16550_irq_handler;
  75.     instance->irq.instance = instance;
  76.     instance->irq.cir = cir;
  77.     instance->irq.cir_arg = cir_arg;
  78.     irq_register(&instance->irq);
  79.  
  80.     while ((pio_read_8(&dev->lsr) & LSR_DATA_READY))
  81.         (void) pio_read_8(&dev->rbr);
  82.    
  83.     /* Enable interrupts */
  84.     pio_write_8(&dev->ier, IER_ERBFI);
  85.     pio_write_8(&dev->mcr, MCR_OUT2);
  86.    
  87.     return true;
  88. }
  89.  
  90. irq_ownership_t ns16550_claim(irq_t *irq)
  91. {
  92.     ns16550_instance_t *instance = irq->instance;
  93.     ns16550_t *dev = instance->ns16550;
  94.  
  95.     if (pio_read_8(&dev->lsr) & LSR_DATA_READY)
  96.         return IRQ_ACCEPT;
  97.     else
  98.         return IRQ_DECLINE;
  99. }
  100.  
  101. void ns16550_irq_handler(irq_t *irq)
  102. {
  103.     ns16550_instance_t *instance = irq->instance;
  104.     ns16550_t *dev = instance->ns16550;
  105.  
  106.     if (pio_read_8(&dev->lsr) & LSR_DATA_READY) {
  107.         uint8_t x;
  108.        
  109.         x = pio_read_8(&dev->rbr);
  110.         if (instance->devout)
  111.             chardev_push_character(instance->devout, x);
  112.     }
  113. }
  114.  
  115. /** @}
  116.  */
  117.