[PATCH 4/6] bootwrapper: Add non-OF serial console support
Mark A. Greer
mgreer at mvista.com
Fri Sep 8 13:39:11 EST 2006
This patch adds support for serial I/O to the bootwrapper.
It is broken into 2 layers. The first layer is generic serial
operations that calls uart-specific routines to do the actual I/O.
The second layer contains support for a 16550 compatible uart.
The division allows support for other serial devices to be easily
added in the future (e.g., the Marvell MPSC and the Freescale CPM).
Signed-off-by: Mark A. Greer <mgreer at mvista.com>
--
io.h | 53 ++++++++++++++++++++
ns16550.c | 81 +++++++++++++++++++++++++++++++
serial.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
util.S | 101 +++++++++++++++++++++++++++++++++++++++
4 files changed, 394 insertions(+)
--
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..06a6d32
--- /dev/null
+++ b/arch/powerpc/boot/ns16550.c
@@ -0,0 +1,81 @@
+/*
+ * 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_probe_init(char *compat, void *devp, char *path,
+ struct serial_console_data *scdp)
+{
+ u64 addr;
+ u32 reg[2];
+
+ if (strcmp("ns16550", compat))
+ return 0; /* Not my device */
+
+ if (getprop(devp, "reg", reg, sizeof(reg)) != sizeof(reg))
+ return -1; /* dt must be horked so fail */
+
+ addr = dt_ops.translate_addr(path, reg, sizeof(reg));
+ reg_base = (unsigned char *)((u32)addr & 0xffffffffu);
+
+ 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 1; /* My device and I initialized okay */
+}
diff --git a/arch/powerpc/boot/serial.c b/arch/powerpc/boot/serial.c
new file mode 100644
index 0000000..368cce8
--- /dev/null
+++ b/arch/powerpc/boot/serial.c
@@ -0,0 +1,159 @@
+/*
+ * 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 int serial_get_stdout_info(void **devpp, char *path)
+{
+ void *devp;
+ char devtype[MAX_PROP_LEN];
+
+ devp = finddevice("/chosen");
+ if ((devp != NULL) && (getprop(devp, "linux,stdout-path", path,
+ MAX_PATH_LEN) > 0)) {
+ /* Check that device_type of stdout device is serial */
+ devp = finddevice(path);
+ if ((devp != NULL) && (getprop(devp, "device_type", devtype,
+ sizeof(devtype)) > 0)
+ && !strcmp(devtype, "serial")) {
+ *devpp = devp;
+ /* *path param is set as well */
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+/* Add "weak" definition for each serial driver */
+int __attribute__ ((weak)) ns16550_console_probe_init(char *compat, void *devp,
+ char *path, struct serial_console_data *scdp)
+{
+ return 0; /* "not mine" */
+}
+
+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;
+ char path[MAX_PATH_LEN], compat[MAX_PROP_LEN];
+
+ if (serial_get_stdout_info(&devp, path))
+ goto fail;
+
+ if (getprop(devp, "compatible", compat, sizeof(compat)) < 0)
+ goto fail;
+
+ /* Call various serial driver probe routines.
+ * DO NOT put the routine addresses into a table because they
+ * will not be relocated.
+ *
+ * Probe routine return values:
+ * -1: driver owns the device but init failed
+ * 0: driver does not own the device
+ * 1: driver owns the device and initialized it okay
+ */
+ rc = ns16550_console_probe_init(compat, devp, path, &serial_cd);
+ /* Do something like:
+ * if (rc == 0)
+ * rc = next_console_probe_init(compat, devp, path, &serial_cd);
+ * if (rc == 0)
+ * ...
+ */
+
+ if (rc == 1) {
+ 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;
+ }
+fail:
+ 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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