[PATCH 4/4] powerpc: Add non-OF serial console support
Mark A. Greer
mgreer at mvista.com
Tue Oct 10 16:13:31 EST 2006
Add serial console support for non-OF systems. There is a generic serial
console layer which calls a serial console driver. Included is the serial
console driver for the ns16550 class of uarts. Necessary support routines
are added as well.
Signed-off-by: Mark A. Greer <mgreer at mvista.com>
---
Makefile | 4 -
io.h | 53 +++++++++++++++++++++++
ns16550.c | 76 +++++++++++++++++++++++++++++++++
serial.c | 142 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
util.S | 101 ++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 374 insertions(+), 2 deletions(-)
---
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index d4042ad..9aad574 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -40,8 +40,8 @@ zliblinuxheader := zlib.h zconf.h zutil.
$(addprefix $(obj)/,$(zlib) main.o): $(addprefix $(obj)/,$(zliblinuxheader)) \
$(addprefix $(obj)/,$(zlibheader))
-src-wlib := string.S stdio.c main.c flatdevtree.c flatdevtree_misc.c div64.S \
- $(zlib)
+src-wlib := string.S stdio.c main.c flatdevtree.c flatdevtree_misc.c ns16550.c \
+ serial.c div64.S util.S $(zlib)
src-plat := of.c
src-boot := crt0.S $(src-wlib) $(src-plat) empty.c
diff --git a/arch/powerpc/boot/io.h b/arch/powerpc/boot/io.h
new file mode 100644
index 0000000..32974ed
--- /dev/null
+++ b/arch/powerpc/boot/io.h
@@ -0,0 +1,53 @@
+#ifndef _IO_H
+#define __IO_H
+/*
+ * Low-level I/O routines.
+ *
+ * Copied from <file:include/asm-powerpc/io.h> (which has no copyright)
+ */
+static inline int in_8(const volatile unsigned char *addr)
+{
+ int ret;
+
+ __asm__ __volatile__("lbz%U1%X1 %0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "m" (*addr));
+ return ret;
+}
+
+static inline void out_8(volatile unsigned char *addr, int val)
+{
+ __asm__ __volatile__("stb%U0%X0 %1,%0; sync"
+ : "=m" (*addr) : "r" (val));
+}
+
+static inline unsigned in_le32(const volatile unsigned *addr)
+{
+ unsigned ret;
+
+ __asm__ __volatile__("lwbrx %0,0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "r" (addr), "m" (*addr));
+ return ret;
+}
+
+static inline unsigned in_be32(const volatile unsigned *addr)
+{
+ unsigned ret;
+
+ __asm__ __volatile__("lwz%U1%X1 %0,%1; twi 0,%0,0; isync"
+ : "=r" (ret) : "m" (*addr));
+ return ret;
+}
+
+static inline void out_le32(volatile unsigned *addr, int val)
+{
+ __asm__ __volatile__("stwbrx %1,0,%2; sync" : "=m" (*addr)
+ : "r" (val), "r" (addr));
+}
+
+static inline void out_be32(volatile unsigned *addr, int val)
+{
+ __asm__ __volatile__("stw%U0%X0 %1,%0; sync"
+ : "=m" (*addr) : "r" (val));
+}
+
+#endif /* _IO_H */
diff --git a/arch/powerpc/boot/ns16550.c b/arch/powerpc/boot/ns16550.c
new file mode 100644
index 0000000..e066942
--- /dev/null
+++ b/arch/powerpc/boot/ns16550.c
@@ -0,0 +1,76 @@
+/*
+ * 16550 serial console support.
+ *
+ * Original copied from <file:arch/ppc/boot/common/ns16550.c>
+ * (which had no copyright)
+ * Modifications: 2006 (c) MontaVista Software, Inc.
+ *
+ * Modified by: Mark A. Greer <mgreer at mvista.com>
+ */
+#include <stdarg.h>
+#include <stddef.h>
+#include "types.h"
+#include "string.h"
+#include "stdio.h"
+#include "io.h"
+#include "ops.h"
+
+#define UART_DLL 0 /* Out: Divisor Latch Low */
+#define UART_DLM 1 /* Out: Divisor Latch High */
+#define UART_FCR 2 /* Out: FIFO Control Register */
+#define UART_LCR 3 /* Out: Line Control Register */
+#define UART_MCR 4 /* Out: Modem Control Register */
+#define UART_LSR 5 /* In: Line Status Register */
+#define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */
+#define UART_LSR_DR 0x01 /* Receiver data ready */
+#define UART_MSR 6 /* In: Modem Status Register */
+#define UART_SCR 7 /* I/O: Scratch Register */
+
+static unsigned char *reg_base;
+static u8 reg_shift;
+
+static int ns16550_open(void)
+{
+ out_8(reg_base + (UART_FCR << reg_shift), 0x06);
+ return 0;
+}
+
+static void ns16550_putc(unsigned char c)
+{
+ while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_THRE) == 0);
+ out_8(reg_base, c);
+}
+
+static unsigned char ns16550_getc(void)
+{
+ while ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) == 0);
+ return in_8(reg_base);
+}
+
+static u8 ns16550_tstc(void)
+{
+ return ((in_8(reg_base + (UART_LSR << reg_shift)) & UART_LSR_DR) != 0);
+}
+
+int ns16550_console_init(void *devp, struct serial_console_data *scdp)
+{
+ u32 reg[2];
+ int n;
+
+ n = getprop(devp, "virtual-reg", ®, sizeof(reg)) / 4;
+ if (n < 1)
+ return -1;
+ reg_base = (unsigned char *)((n == 1) ? reg[0] : reg[0] | reg[1]);
+
+ if (getprop(devp, "reg_shift", ®_shift, sizeof(reg_shift))
+ != sizeof(reg_shift))
+ reg_shift = 0;
+
+ scdp->open = ns16550_open;
+ scdp->putc = ns16550_putc;
+ scdp->getc = ns16550_getc;
+ scdp->tstc = ns16550_tstc;
+ scdp->close = NULL;
+
+ return 0;
+}
diff --git a/arch/powerpc/boot/serial.c b/arch/powerpc/boot/serial.c
new file mode 100644
index 0000000..e8de4cf
--- /dev/null
+++ b/arch/powerpc/boot/serial.c
@@ -0,0 +1,142 @@
+/*
+ * Generic serial console support
+ *
+ * Author: Mark A. Greer <mgreer at mvista.com>
+ *
+ * Code in serial_edit_cmdline() copied from <file:arch/ppc/boot/simple/misc.c>
+ * and was written by Matt Porter <mporter at kernel.crashing.org>.
+ *
+ * 2001,2006 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+#include <stdarg.h>
+#include <stddef.h>
+#include "types.h"
+#include "string.h"
+#include "stdio.h"
+#include "io.h"
+#include "ops.h"
+
+extern void udelay(long delay);
+
+static int serial_open(void)
+{
+ struct serial_console_data *scdp = console_ops.data;
+ return scdp->open();
+}
+
+static void serial_write(char *buf, int len)
+{
+ struct serial_console_data *scdp = console_ops.data;
+
+ while (*buf != '\0')
+ scdp->putc(*buf++);
+}
+
+static void serial_edit_cmdline(char *buf, int len)
+{
+ int timer = 0, count;
+ char ch, *cp;
+ struct serial_console_data *scdp = console_ops.data;
+
+ cp = buf;
+ count = strlen(buf);
+ cp = &buf[count];
+ count++;
+
+ while (timer++ < 5*1000) {
+ if (scdp->tstc()) {
+ while (((ch = scdp->getc()) != '\n') && (ch != '\r')) {
+ /* Test for backspace/delete */
+ if ((ch == '\b') || (ch == '\177')) {
+ if (cp != buf) {
+ cp--;
+ count--;
+ printf("\b \b");
+ }
+ /* Test for ^x/^u (and wipe the line) */
+ } else if ((ch == '\030') || (ch == '\025')) {
+ while (cp != buf) {
+ cp--;
+ count--;
+ printf("\b \b");
+ }
+ } else if (count < len) {
+ *cp++ = ch;
+ count++;
+ scdp->putc(ch);
+ }
+ }
+ break; /* Exit 'timer' loop */
+ }
+ udelay(1000); /* 1 msec */
+ }
+ *cp = 0;
+}
+
+static void serial_close(void)
+{
+ struct serial_console_data *scdp = console_ops.data;
+
+ if (scdp->close)
+ scdp->close();
+}
+
+static void *serial_get_stdout_devp(void)
+{
+ void *devp;
+ char devtype[MAX_PROP_LEN];
+ char path[MAX_PATH_LEN];
+
+ devp = finddevice("/chosen");
+ if (devp == NULL)
+ goto err_out;
+
+ if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0) {
+ devp = finddevice(path);
+ if (devp == NULL)
+ goto err_out;
+
+ if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
+ && !strcmp(devtype, "serial"))
+ return devp;
+ }
+err_out:
+ return NULL;
+}
+
+static struct serial_console_data serial_cd;
+
+/* Node's "compatible" property determines which serial driver to use */
+int serial_console_init(void)
+{
+ void *devp;
+ int rc = -1;
+ char compat[MAX_PROP_LEN];
+
+ devp = serial_get_stdout_devp();
+ if (devp == NULL)
+ goto err_out;
+
+ if (getprop(devp, "compatible", compat, sizeof(compat)) < 0)
+ goto err_out;
+
+ if (!strcmp(compat, "ns16550"))
+ rc = ns16550_console_init(devp, &serial_cd);
+
+ /* Add other serial console driver calls here */
+
+ if (!rc) {
+ console_ops.open = serial_open;
+ console_ops.write = serial_write;
+ console_ops.edit_cmdline = serial_edit_cmdline;
+ console_ops.close = serial_close;
+ console_ops.data = &serial_cd;
+
+ return 0;
+ }
+err_out:
+ return -1;
+}
diff --git a/arch/powerpc/boot/util.S b/arch/powerpc/boot/util.S
new file mode 100644
index 0000000..b8e1c23
--- /dev/null
+++ b/arch/powerpc/boot/util.S
@@ -0,0 +1,101 @@
+/*
+ * Copied from <file:arch/powerpc/kernel/misc_32.S>
+ *
+ * This file contains miscellaneous low-level functions.
+ * Copyright (C) 1995-1996 Gary Thomas (gdt at linuxppc.org)
+ *
+ * Largely rewritten by Cort Dougan (cort at cs.nmt.edu)
+ * and Paul Mackerras.
+ *
+ * kexec bits:
+ * Copyright (C) 2002-2003 Eric Biederman <ebiederm at xmission.com>
+ * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ *
+ * 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 "ppc_asm.h"
+
+#define SPRN_PVR 0x11F /* Processor Version Register */
+
+ .text
+/*
+ * complement mask on the msr then "or" some values on.
+ * _nmask_and_or_msr(nmask, value_to_or)
+ */
+ .globl _nmask_and_or_msr
+_nmask_and_or_msr:
+ mfmsr r0 /* Get current msr */
+ andc r0,r0,r3 /* And off the bits set in r3 (first parm) */
+ or r0,r0,r4 /* Or on the bits in r4 (second parm) */
+ SYNC /* Some chip revs have problems here... */
+ mtmsr r0 /* Update machine state */
+ isync
+ blr /* Done */
+
+/* udelay (on non-601 processors) needs to know the period of the
+ * timebase in nanoseconds. This used to be hardcoded to be 60ns
+ * (period of 66MHz/4). Now a variable is used that is initialized to
+ * 60 for backward compatibility, but it can be overridden as necessary
+ * with code something like this:
+ * extern unsigned long timebase_period_ns;
+ * timebase_period_ns = 1000000000 / bd->bi_tbfreq;
+ */
+ .data
+ .globl timebase_period_ns
+timebase_period_ns:
+ .long 60
+
+ .text
+/*
+ * Delay for a number of microseconds
+ */
+ .globl udelay
+udelay:
+ mfspr r4,SPRN_PVR
+ srwi r4,r4,16
+ cmpwi 0,r4,1 /* 601 ? */
+ bne .udelay_not_601
+00: li r0,86 /* Instructions / microsecond? */
+ mtctr r0
+10: addi r0,r0,0 /* NOP */
+ bdnz 10b
+ subic. r3,r3,1
+ bne 00b
+ blr
+
+.udelay_not_601:
+ mulli r4,r3,1000 /* nanoseconds */
+ /* Change r4 to be the number of ticks using:
+ * (nanoseconds + (timebase_period_ns - 1 )) / timebase_period_ns
+ * timebase_period_ns defaults to 60 (16.6MHz) */
+ mflr r5
+ bl 0f
+0: mflr r6
+ mtlr r5
+ lis r5,0b at ha
+ addi r5,r5,0b at l
+ subf r5,r5,r6 /* In case we're relocated */
+ addis r5,r5,timebase_period_ns at ha
+ lwz r5,timebase_period_ns at l(r5)
+ add r4,r4,r5
+ addi r4,r4,-1
+ divw r4,r4,r5 /* BUS ticks */
+1: mftbu r5
+ mftb r6
+ mftbu r7
+ cmpw 0,r5,r7
+ bne 1b /* Get [synced] base time */
+ addc r9,r6,r4 /* Compute end time */
+ addze r8,r5
+2: mftbu r5
+ cmpw 0,r5,r8
+ blt 2b
+ bgt 3f
+ mftb r6
+ cmpw 0,r6,r9
+ blt 2b
+3: blr
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