2 * udbg for for zilog scc ports as found on Apple PowerMacs
4 * Copyright (C) 2001-2005 PPC 64 Team, IBM Corp
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 #include <linux/config.h>
12 #include <linux/types.h>
14 #include <asm/processor.h>
17 #include <asm/pmac_feature.h>
19 extern u8
real_readb(volatile u8 __iomem
*addr
);
20 extern void real_writeb(u8 data
, volatile u8 __iomem
*addr
);
25 static volatile u8 __iomem
*sccc
;
26 static volatile u8 __iomem
*sccd
;
28 static void udbg_scc_putc(unsigned char c
)
31 while ((in_8(sccc
) & SCC_TXRDY
) == 0)
39 static int udbg_scc_getc_poll(void)
42 if ((in_8(sccc
) & SCC_RXRDY
) != 0)
50 static unsigned char udbg_scc_getc(void)
53 while ((in_8(sccc
) & SCC_RXRDY
) == 0)
60 static unsigned char scc_inittab
[] = {
61 13, 0, /* set baud rate divisor */
63 14, 1, /* baud rate gen enable, src=rtxc */
64 11, 0x50, /* clocks = br gen */
65 5, 0xea, /* tx 8 bits, assert DTR & RTS */
66 4, 0x46, /* x16 clock, 1 stop */
67 3, 0xc1, /* rx enable, 8 bits */
70 void udbg_init_scc(struct device_node
*np
)
77 np
= of_find_node_by_name(NULL
, "escc");
78 if (np
== NULL
|| np
->parent
== NULL
)
81 udbg_printf("found SCC...\n");
82 /* Get address within mac-io ASIC */
83 reg
= (u32
*)get_property(np
, "reg", NULL
);
87 udbg_printf("local addr: %lx\n", addr
);
88 /* Get address of mac-io PCI itself */
89 reg
= (u32
*)get_property(np
->parent
, "assigned-addresses", NULL
);
93 udbg_printf("final addr: %lx\n", addr
);
95 /* Setup for 57600 8N1 */
97 sccc
= (volatile u8
* __iomem
) ioremap(addr
& PAGE_MASK
, PAGE_SIZE
) ;
98 sccc
+= addr
& ~PAGE_MASK
;
101 udbg_printf("ioremap result sccc: %p\n", sccc
);
104 for (i
= 20000; i
!= 0; --i
)
106 out_8(sccc
, 0x09); /* reset A or B side */
108 for (i
= 0; i
< sizeof(scc_inittab
); ++i
)
109 out_8(sccc
, scc_inittab
[i
]);
111 udbg_putc
= udbg_scc_putc
;
112 udbg_getc
= udbg_scc_getc
;
113 udbg_getc_poll
= udbg_scc_getc_poll
;
115 udbg_puts("Hello World !\n");
118 static void udbg_real_scc_putc(unsigned char c
)
120 while ((real_readb(sccc
) & SCC_TXRDY
) == 0)
122 real_writeb(c
, sccd
);
124 udbg_real_scc_putc('\r');
127 void udbg_init_pmac_realmode(void)
129 sccc
= (volatile u8 __iomem
*)0x80013020ul
;
130 sccd
= (volatile u8 __iomem
*)0x80013030ul
;
132 udbg_putc
= udbg_real_scc_putc
;
134 udbg_getc_poll
= NULL
;