drivers/misc/ibmasm/uart.c

   1
   2 /*
   3  * IBM ASM Service Processor Device Driver
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  *
  19  * Copyright (C) IBM Corporation, 2004
  20  *
  21  * Author: Max Asböck <amax@us.ibm.com>
  22  *
  23  */
  24
  25 #include <linux/termios.h>
  26 #include <linux/tty.h>
  27 #include <linux/serial_core.h>
  28 #include <linux/serial.h>
  29 #include <linux/serial_reg.h>
  30 #include "ibmasm.h"
  31 #include "lowlevel.h"
  32
  33
  34 void ibmasm_register_uart(struct service_processor *sp)
  35 {
  36         struct serial_struct serial;
  37         void __iomem *iomem_base;
  38
  39         iomem_base = sp->base_address + SCOUT_COM_B_BASE;
  40
  41         /* read the uart scratch register to determine if the UART
  42          * is dedicated to the service processor or if the OS can use it
  43          */
  44         if (0 == readl(iomem_base + UART_SCR)) {
  45                 dev_info(sp->dev, "IBM SP UART not registered, owned by service processor\n");
  46                 sp->serial_line = -1;
  47                 return;
  48         }
  49
  50         memset(&serial, 0, sizeof(serial));
  51         serial.irq              = sp->irq;
  52         serial.baud_base        = 3686400 / 16;
  53         serial.flags            = UPF_AUTOPROBE | UPF_SHARE_IRQ;
  54         serial.io_type          = UPIO_MEM;
  55         serial.iomem_base       = iomem_base;
  56
  57         sp->serial_line = register_serial(&serial);
  58         if (sp->serial_line < 0) {
  59                 dev_err(sp->dev, "Failed to register serial port\n");
  60                 return;
  61         }
  62         enable_uart_interrupts(sp->base_address);
  63 }
  64
  65 void ibmasm_unregister_uart(struct service_processor *sp)
  66 {
  67         if (sp->serial_line < 0)
  68                 return;
  69
  70         disable_uart_interrupts(sp->base_address);
  71         unregister_serial(sp->serial_line);
  72 }