arch/powerpc/sysdev/mv64x60_udbg.c

   1 /*
   2  * udbg serial input/output routines for the Marvell MV64x60 (Discovery).
   3  *
   4  * Author: Dale Farnsworth <dale@farnsworth.org>
   5  *
   6  * 2007 (c) MontaVista Software, Inc.  This file is licensed under
   7  * the terms of the GNU General Public License version 2.  This program
   8  * is licensed "as is" without any warranty of any kind, whether express
   9  * or implied.
  10  */
  11
  12 #include <asm/io.h>
  13 #include <asm/prom.h>
  14 #include <asm/udbg.h>
  15
  16 #include <sysdev/mv64x60.h>
  17
  18 #define MPSC_0_CR1_OFFSET       0x000c
  19
  20 #define MPSC_0_CR2_OFFSET       0x0010
  21 #define MPSC_CHR_2_TCS          (1 << 9)
  22
  23 #define MPSC_0_CHR_10_OFFSET    0x0030
  24
  25 #define MPSC_INTR_CAUSE_OFF_0   0x0004
  26 #define MPSC_INTR_CAUSE_OFF_1   0x000c
  27 #define MPSC_INTR_CAUSE_RCC     (1<<6)
  28
  29 static void __iomem *mpsc_base;
  30 static void __iomem *mpsc_intr_cause;
  31
  32 static void mv64x60_udbg_putc(char c)
  33 {
  34         if (c == '\n')
  35                 mv64x60_udbg_putc('\r');
  36
  37         while(in_le32(mpsc_base + MPSC_0_CR2_OFFSET) & MPSC_CHR_2_TCS)
  38                 ;
  39         out_le32(mpsc_base + MPSC_0_CR1_OFFSET, c);
  40         out_le32(mpsc_base + MPSC_0_CR2_OFFSET, MPSC_CHR_2_TCS);
  41 }
  42
  43 static int mv64x60_udbg_testc(void)
  44 {
  45         return (in_le32(mpsc_intr_cause) & MPSC_INTR_CAUSE_RCC) != 0;
  46 }
  47
  48 static int mv64x60_udbg_getc(void)
  49 {
  50         int cause = 0;
  51         int c;
  52
  53         while (!mv64x60_udbg_testc())
  54                 ;
  55
  56         c = in_8(mpsc_base + MPSC_0_CHR_10_OFFSET + 2);
  57         out_8(mpsc_base + MPSC_0_CHR_10_OFFSET + 2, c);
  58         out_le32(mpsc_intr_cause, cause & ~MPSC_INTR_CAUSE_RCC);
  59         return c;
  60 }
  61
  62 static int mv64x60_udbg_getc_poll(void)
  63 {
  64         if (!mv64x60_udbg_testc())
  65                 return -1;
  66
  67         return mv64x60_udbg_getc();
  68 }
  69
  70 static void mv64x60_udbg_init(void)
  71 {
  72         struct device_node *np, *mpscintr, *stdout = NULL;
  73         const char *path;
  74         const phandle *ph;
  75         struct resource r[2];
  76         const int *block_index;
  77         int intr_cause_offset;
  78         int err;
  79
  80         path = of_get_property(of_chosen, "linux,stdout-path", NULL);
  81         if (!path)
  82                 return;
  83
  84         stdout = of_find_node_by_path(path);
  85         if (!stdout)
  86                 return;
  87
  88         for_each_compatible_node(np, "serial", "marvell,mv64360-mpsc") {
  89                 if (np == stdout)
  90                         break;
  91         }
  92
  93         of_node_put(stdout);
  94         if (!np)
  95                 return;
  96
  97         block_index = of_get_property(np, "cell-index", NULL);
  98         if (!block_index)
  99                 goto error;
 100
 101         switch (*block_index) {
 102         case 0:
 103                 intr_cause_offset = MPSC_INTR_CAUSE_OFF_0;
 104                 break;
 105         case 1:
 106                 intr_cause_offset = MPSC_INTR_CAUSE_OFF_1;
 107                 break;
 108         default:
 109                 goto error;
 110         }
 111
 112         err = of_address_to_resource(np, 0, &r[0]);
 113         if (err)
 114                 goto error;
 115
 116         ph = of_get_property(np, "mpscintr", NULL);
 117         mpscintr = of_find_node_by_phandle(*ph);
 118         if (!mpscintr)
 119                 goto error;
 120
 121         err = of_address_to_resource(mpscintr, 0, &r[1]);
 122         of_node_put(mpscintr);
 123         if (err)
 124                 goto error;
 125
 126         of_node_put(np);
 127
 128         mpsc_base = ioremap(r[0].start, r[0].end - r[0].start + 1);
 129         if (!mpsc_base)
 130                 return;
 131
 132         mpsc_intr_cause = ioremap(r[1].start, r[1].end - r[1].start + 1);
 133         if (!mpsc_intr_cause) {
 134                 iounmap(mpsc_base);
 135                 return;
 136         }
 137         mpsc_intr_cause += intr_cause_offset;
 138
 139         udbg_putc = mv64x60_udbg_putc;
 140         udbg_getc = mv64x60_udbg_getc;
 141         udbg_getc_poll = mv64x60_udbg_getc_poll;
 142
 143         return;
 144
 145 error:
 146         of_node_put(np);
 147 }
 148
 149 void mv64x60_init_early(void)
 150 {
 151         mv64x60_udbg_init();
 152 }