Merge branch 'for-2.6.24' of master.kernel.org:/pub/scm/linux/kernel/git/jwboyer...
[linux-2.6] / arch / powerpc / boot / uartlite.c
1 /*
2  * Xilinx UARTLITE bootloader driver
3  *
4  * Copyright (C) 2007 Secret Lab Technologies Ltd.
5  *
6  * This file is licensed under the terms of the GNU General Public License
7  * version 2. This program is licensed "as is" without any warranty of any
8  * kind, whether express or implied.
9  */
10
11 #include <stdarg.h>
12 #include <stddef.h>
13 #include "types.h"
14 #include "string.h"
15 #include "stdio.h"
16 #include "io.h"
17 #include "ops.h"
18
19 #define ULITE_RX                0x00
20 #define ULITE_TX                0x04
21 #define ULITE_STATUS            0x08
22 #define ULITE_CONTROL           0x0c
23
24 #define ULITE_STATUS_RXVALID    0x01
25 #define ULITE_STATUS_TXFULL     0x08
26
27 #define ULITE_CONTROL_RST_RX    0x02
28
29 static void * reg_base;
30
31 static int uartlite_open(void)
32 {
33         /* Clear the RX FIFO */
34         out_be32(reg_base + ULITE_CONTROL, ULITE_CONTROL_RST_RX);
35         return 0;
36 }
37
38 static void uartlite_putc(unsigned char c)
39 {
40         u32 reg = ULITE_STATUS_TXFULL;
41         while (reg & ULITE_STATUS_TXFULL) /* spin on TXFULL bit */
42                 reg = in_be32(reg_base + ULITE_STATUS);
43         out_be32(reg_base + ULITE_TX, c);
44 }
45
46 static unsigned char uartlite_getc(void)
47 {
48         u32 reg = 0;
49         while (!(reg & ULITE_STATUS_RXVALID)) /* spin waiting for RXVALID bit */
50                 reg = in_be32(reg_base + ULITE_STATUS);
51         return in_be32(reg_base + ULITE_RX);
52 }
53
54 static u8 uartlite_tstc(void)
55 {
56         u32 reg = in_be32(reg_base + ULITE_STATUS);
57         return reg & ULITE_STATUS_RXVALID;
58 }
59
60 int uartlite_console_init(void *devp, struct serial_console_data *scdp)
61 {
62         int n;
63         unsigned long reg_phys;
64
65         n = getprop(devp, "virtual-reg", &reg_base, sizeof(reg_base));
66         if (n != sizeof(reg_base)) {
67                 if (!dt_xlate_reg(devp, 0, &reg_phys, NULL))
68                         return -1;
69
70                 reg_base = (void *)reg_phys;
71         }
72
73         scdp->open = uartlite_open;
74         scdp->putc = uartlite_putc;
75         scdp->getc = uartlite_getc;
76         scdp->tstc = uartlite_tstc;
77         scdp->close = NULL;
78         return 0;
79 }