136 lines
3.0 KiB
C
136 lines
3.0 KiB
C
/*
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* udbg for for zilog scc ports as found on Apple PowerMacs
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*
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* Copyright (C) 2001-2005 PPC 64 Team, IBM Corp
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/config.h>
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#include <linux/types.h>
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#include <asm/udbg.h>
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#include <asm/processor.h>
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#include <asm/io.h>
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#include <asm/prom.h>
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#include <asm/pmac_feature.h>
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extern u8 real_readb(volatile u8 __iomem *addr);
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extern void real_writeb(u8 data, volatile u8 __iomem *addr);
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#define SCC_TXRDY 4
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#define SCC_RXRDY 1
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static volatile u8 __iomem *sccc;
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static volatile u8 __iomem *sccd;
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static void udbg_scc_putc(unsigned char c)
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{
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if (sccc) {
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while ((in_8(sccc) & SCC_TXRDY) == 0)
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;
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out_8(sccd, c);
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if (c == '\n')
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udbg_scc_putc('\r');
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}
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}
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static int udbg_scc_getc_poll(void)
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{
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if (sccc) {
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if ((in_8(sccc) & SCC_RXRDY) != 0)
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return in_8(sccd);
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else
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return -1;
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}
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return -1;
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}
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static unsigned char udbg_scc_getc(void)
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{
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if (sccc) {
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while ((in_8(sccc) & SCC_RXRDY) == 0)
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;
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return in_8(sccd);
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}
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return 0;
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}
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static unsigned char scc_inittab[] = {
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13, 0, /* set baud rate divisor */
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12, 0,
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14, 1, /* baud rate gen enable, src=rtxc */
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11, 0x50, /* clocks = br gen */
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5, 0xea, /* tx 8 bits, assert DTR & RTS */
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4, 0x46, /* x16 clock, 1 stop */
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3, 0xc1, /* rx enable, 8 bits */
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};
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void udbg_init_scc(struct device_node *np)
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{
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u32 *reg;
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unsigned long addr;
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int i, x;
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if (np == NULL)
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np = of_find_node_by_name(NULL, "escc");
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if (np == NULL || np->parent == NULL)
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return;
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udbg_printf("found SCC...\n");
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/* Get address within mac-io ASIC */
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reg = (u32 *)get_property(np, "reg", NULL);
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if (reg == NULL)
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return;
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addr = reg[0];
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udbg_printf("local addr: %lx\n", addr);
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/* Get address of mac-io PCI itself */
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reg = (u32 *)get_property(np->parent, "assigned-addresses", NULL);
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if (reg == NULL)
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return;
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addr += reg[2];
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udbg_printf("final addr: %lx\n", addr);
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/* Setup for 57600 8N1 */
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addr += 0x20;
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sccc = (volatile u8 * __iomem) ioremap(addr & PAGE_MASK, PAGE_SIZE) ;
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sccc += addr & ~PAGE_MASK;
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sccd = sccc + 0x10;
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udbg_printf("ioremap result sccc: %p\n", sccc);
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mb();
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for (i = 20000; i != 0; --i)
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x = in_8(sccc);
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out_8(sccc, 0x09); /* reset A or B side */
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out_8(sccc, 0xc0);
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for (i = 0; i < sizeof(scc_inittab); ++i)
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out_8(sccc, scc_inittab[i]);
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udbg_putc = udbg_scc_putc;
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udbg_getc = udbg_scc_getc;
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udbg_getc_poll = udbg_scc_getc_poll;
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udbg_puts("Hello World !\n");
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}
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static void udbg_real_scc_putc(unsigned char c)
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{
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while ((real_readb(sccc) & SCC_TXRDY) == 0)
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;
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real_writeb(c, sccd);
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if (c == '\n')
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udbg_real_scc_putc('\r');
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}
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void udbg_init_pmac_realmode(void)
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{
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sccc = (volatile u8 __iomem *)0x80013020ul;
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sccd = (volatile u8 __iomem *)0x80013030ul;
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udbg_putc = udbg_real_scc_putc;
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udbg_getc = NULL;
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udbg_getc_poll = NULL;
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}
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