arch/mips/pmc-sierra/yosemite/py-console.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2001, 2002, 2004 Ralf Baechle
   7  */
   8 #include <linux/init.h>
   9 #include <linux/console.h>
  10 #include <linux/kdev_t.h>
  11 #include <linux/major.h>
  12 #include <linux/termios.h>
  13 #include <linux/sched.h>
  14 #include <linux/tty.h>
  15
  16 #include <linux/serial.h>
  17 #include <linux/serial_core.h>
  18 #include <asm/serial.h>
  19 #include <asm/io.h>
  20
  21 /* SUPERIO uart register map */
  22 struct yo_uartregs {
  23         union {
  24                 volatile u8     rbr;    /* read only, DLAB == 0 */
  25                 volatile u8     thr;    /* write only, DLAB == 0 */
  26                 volatile u8     dll;    /* DLAB == 1 */
  27         } u1;
  28         union {
  29                 volatile u8     ier;    /* DLAB == 0 */
  30                 volatile u8     dlm;    /* DLAB == 1 */
  31         } u2;
  32         union {
  33                 volatile u8     iir;    /* read only */
  34                 volatile u8     fcr;    /* write only */
  35         } u3;
  36         volatile u8     iu_lcr;
  37         volatile u8     iu_mcr;
  38         volatile u8     iu_lsr;
  39         volatile u8     iu_msr;
  40         volatile u8     iu_scr;
  41 } yo_uregs_t;
  42
  43 #define iu_rbr u1.rbr
  44 #define iu_thr u1.thr
  45 #define iu_dll u1.dll
  46 #define iu_ier u2.ier
  47 #define iu_dlm u2.dlm
  48 #define iu_iir u3.iir
  49 #define iu_fcr u3.fcr
  50
  51 #define ssnop()         __asm__ __volatile__("sll       $0, $0, 1\n");
  52 #define ssnop_4()       do { ssnop(); ssnop(); ssnop(); ssnop(); } while (0)
  53
  54 #define IO_BASE_64      0x9000000000000000ULL
  55
  56 static unsigned char readb_outer_space(unsigned long long phys)
  57 {
  58         unsigned long long vaddr = IO_BASE_64 | phys;
  59         unsigned char res;
  60         unsigned int sr;
  61
  62         sr = read_c0_status();
  63         write_c0_status((sr | ST0_KX) & ~ ST0_IE);
  64         ssnop_4();
  65
  66         __asm__ __volatile__ (
  67         "       .set    mips3           \n"
  68         "       .set    push            \n"
  69         "       .set    noreorder       \n"
  70         "       .set    nomacro         \n"
  71         "       ld      %0, %1          \n"
  72         "       .set    pop             \n"
  73         "       lbu     %0, (%0)        \n"
  74         "       .set    mips0           \n"
  75         : "=r" (res)
  76         : "R" (vaddr));
  77
  78         write_c0_status(sr);
  79         ssnop_4();
  80
  81         return res;
  82 }
  83
  84 static void writeb_outer_space(unsigned long long phys, unsigned char c)
  85 {
  86         unsigned long long vaddr = IO_BASE_64 | phys;
  87         unsigned long tmp;
  88         unsigned int sr;
  89
  90         sr = read_c0_status();
  91         write_c0_status((sr | ST0_KX) & ~ ST0_IE);
  92         ssnop_4();
  93
  94         __asm__ __volatile__ (
  95         "       .set    mips3           \n"
  96         "       .set    push            \n"
  97         "       .set    noreorder       \n"
  98         "       .set    nomacro         \n"
  99         "       ld      %0, %1          \n"
 100         "       .set    pop             \n"
 101         "       sb      %2, (%0)        \n"
 102         "       .set    mips0           \n"
 103         : "=&r" (tmp)
 104         : "R" (vaddr), "r" (c));
 105
 106         write_c0_status(sr);
 107         ssnop_4();
 108 }
 109
 110 void prom_putchar(char c)
 111 {
 112         unsigned long lsr = 0xfd000008ULL + offsetof(struct yo_uartregs, iu_lsr);
 113         unsigned long thr = 0xfd000008ULL + offsetof(struct yo_uartregs, iu_thr);
 114
 115         while ((readb_outer_space(lsr) & 0x20) == 0);
 116         writeb_outer_space(thr, c);
 117 }