summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/udbg_scc.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/udbg_scc.c')
-rw-r--r--arch/powerpc/kernel/udbg_scc.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/udbg_scc.c b/arch/powerpc/kernel/udbg_scc.c
new file mode 100644
index 00000000000..820c5355150
--- /dev/null
+++ b/arch/powerpc/kernel/udbg_scc.c
@@ -0,0 +1,135 @@
+/*
+ * udbg for for zilog scc ports as found on Apple PowerMacs
+ *
+ * Copyright (C) 2001-2005 PPC 64 Team, IBM Corp
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/config.h>
+#include <linux/types.h>
+#include <asm/udbg.h>
+#include <asm/processor.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/pmac_feature.h>
+
+extern u8 real_readb(volatile u8 __iomem *addr);
+extern void real_writeb(u8 data, volatile u8 __iomem *addr);
+
+#define SCC_TXRDY 4
+#define SCC_RXRDY 1
+
+static volatile u8 __iomem *sccc;
+static volatile u8 __iomem *sccd;
+
+static void udbg_scc_putc(unsigned char c)
+{
+ if (sccc) {
+ while ((in_8(sccc) & SCC_TXRDY) == 0)
+ ;
+ out_8(sccd, c);
+ if (c == '\n')
+ udbg_scc_putc('\r');
+ }
+}
+
+static int udbg_scc_getc_poll(void)
+{
+ if (sccc) {
+ if ((in_8(sccc) & SCC_RXRDY) != 0)
+ return in_8(sccd);
+ else
+ return -1;
+ }
+ return -1;
+}
+
+static unsigned char udbg_scc_getc(void)
+{
+ if (sccc) {
+ while ((in_8(sccc) & SCC_RXRDY) == 0)
+ ;
+ return in_8(sccd);
+ }
+ return 0;
+}
+
+static unsigned char scc_inittab[] = {
+ 13, 0, /* set baud rate divisor */
+ 12, 0,
+ 14, 1, /* baud rate gen enable, src=rtxc */
+ 11, 0x50, /* clocks = br gen */
+ 5, 0xea, /* tx 8 bits, assert DTR & RTS */
+ 4, 0x46, /* x16 clock, 1 stop */
+ 3, 0xc1, /* rx enable, 8 bits */
+};
+
+void udbg_init_scc(struct device_node *np)
+{
+ u32 *reg;
+ unsigned long addr;
+ int i, x;
+
+ if (np == NULL)
+ np = of_find_node_by_name(NULL, "escc");
+ if (np == NULL || np->parent == NULL)
+ return;
+
+ udbg_printf("found SCC...\n");
+ /* Get address within mac-io ASIC */
+ reg = (u32 *)get_property(np, "reg", NULL);
+ if (reg == NULL)
+ return;
+ addr = reg[0];
+ udbg_printf("local addr: %lx\n", addr);
+ /* Get address of mac-io PCI itself */
+ reg = (u32 *)get_property(np->parent, "assigned-addresses", NULL);
+ if (reg == NULL)
+ return;
+ addr += reg[2];
+ udbg_printf("final addr: %lx\n", addr);
+
+ /* Setup for 57600 8N1 */
+ addr += 0x20;
+ sccc = (volatile u8 * __iomem) ioremap(addr & PAGE_MASK, PAGE_SIZE) ;
+ sccc += addr & ~PAGE_MASK;
+ sccd = sccc + 0x10;
+
+ udbg_printf("ioremap result sccc: %p\n", sccc);
+ mb();
+
+ for (i = 20000; i != 0; --i)
+ x = in_8(sccc);
+ out_8(sccc, 0x09); /* reset A or B side */
+ out_8(sccc, 0xc0);
+ for (i = 0; i < sizeof(scc_inittab); ++i)
+ out_8(sccc, scc_inittab[i]);
+
+ udbg_putc = udbg_scc_putc;
+ udbg_getc = udbg_scc_getc;
+ udbg_getc_poll = udbg_scc_getc_poll;
+
+ udbg_puts("Hello World !\n");
+}
+
+static void udbg_real_scc_putc(unsigned char c)
+{
+ while ((real_readb(sccc) & SCC_TXRDY) == 0)
+ ;
+ real_writeb(c, sccd);
+ if (c == '\n')
+ udbg_real_scc_putc('\r');
+}
+
+void udbg_init_pmac_realmode(void)
+{
+ sccc = (volatile u8 __iomem *)0x80013020ul;
+ sccd = (volatile u8 __iomem *)0x80013030ul;
+
+ udbg_putc = udbg_real_scc_putc;
+ udbg_getc = NULL;
+ udbg_getc_poll = NULL;
+}