[U-Boot] [PATCH 6/7] Implement SC520 timers
Graeme Russ
graeme.russ at gmail.com
Tue Feb 24 11:14:45 CET 2009
Implement SC520 timers
Signed-off-by: Graeme Russ <graeme.russ at gmail.com>
---
cpu/i386/Makefile | 2
cpu/i386/sc520/sc520_timer.c | 71 ++++++++-----
cpu/i386/timer.c | 211 ----------------------------------------
include/asm-i386/u-boot-i386.h | 7 +
lib_i386/Makefile | 2
lib_i386/pcat_timer.c | 102 +++++++++++++++++++
lib_i386/timer.c | 107 ++++++++++++++++++++
7 files changed, 259 insertions(+), 243 deletions(-)
delete mode 100644 cpu/i386/timer.c
create mode 100644 lib_i386/pcat_timer.c
create mode 100644 lib_i386/timer.c
diff --git a/cpu/i386/Makefile b/cpu/i386/Makefile
index f72cd6e..e98bd3d 100644
--- a/cpu/i386/Makefile
+++ b/cpu/i386/Makefile
@@ -29,7 +29,7 @@ include $(TOPDIR)/config.mk
LIB = $(obj)lib$(CPU).a
START = start.o start16.o resetvec.o
-COBJS = serial.o interrupts.o exceptions.o cpu.o timer.o
+COBJS = serial.o interrupts.o exceptions.o cpu.o
SRCS := $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)
OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS))
diff --git a/cpu/i386/sc520/sc520_timer.c b/cpu/i386/sc520/sc520_timer.c
index 7578511..2cb8656 100644
--- a/cpu/i386/sc520/sc520_timer.c
+++ b/cpu/i386/sc520/sc520_timer.c
@@ -27,47 +27,56 @@
#include <asm/interrupt.h>
#include <asm/ic/sc520.h>
-void reset_timer(void)
+void sc520_timer_isr(void)
{
- write_mmcr_word(SC520_GPTMR0CNT, 0);
- write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
-
+ /* Ack the GP Timer Interrupt */
+ write_mmcr_byte (SC520_GPTMRSTA, 0x02);
}
-ulong get_timer(ulong base)
+int timer_init(void)
{
- /* fixme: 30 or 33 */
- return read_mmcr_word(SC520_GPTMR0CNT) / 33;
-}
+ /* Map GP Timer 1 to Master PIC IR0 */
+ write_mmcr_byte (SC520_GPTMR1MAP, 0x01);
-void set_timer(ulong t)
-{
- /* FixMe: use two cascade coupled timers */
- write_mmcr_word(SC520_GPTMR0CTL, 0x4001);
- write_mmcr_word(SC520_GPTMR0CNT, t*33);
- write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
-}
+ /* Disable GP Timers 1 & 2 - Allow configuration writes */
+ write_mmcr_word (SC520_GPTMR1CTL, 0x4000);
+ write_mmcr_word (SC520_GPTMR2CTL, 0x4000);
+
+ /* Reset GP Timers 1 & 2 */
+ write_mmcr_word (SC520_GPTMR1CNT, 0x0000);
+ write_mmcr_word (SC520_GPTMR2CNT, 0x0000);
+
+ /* Setup GP Timer 2 as a 100kHz (10us) prescaler */
+ write_mmcr_word (SC520_GPTMR2MAXCMPA, 83);
+ write_mmcr_word (SC520_GPTMR2CTL, 0xc001);
+
+ /* Setup GP Timer 1 as a 1000 Hz (1ms) interrupt generator */
+ write_mmcr_word (SC520_GPTMR1MAXCMPA, 100);
+ write_mmcr_word (SC520_GPTMR1CTL, 0xe009);
+ /* Clear the GP Timers status register */
+ write_mmcr_byte (SC520_GPTMRSTA, 0x07);
+
+ /* Register the SC520 specific timer interrupt handler */
+ register_timer_isr (sc520_timer_isr);
+
+ /* Install interrupt handler for GP Timer 1 */
+ irq_install_handler (0, timer_isr, NULL);
+ unmask_irq (0);
+
+ return 0;
+}
void udelay(unsigned long usec)
{
- int m=0;
+ int m = 0;
long u;
- read_mmcr_word(SC520_SWTMRMILLI);
- read_mmcr_word(SC520_SWTMRMICRO);
-
-#if 0
- /* do not enable this line, udelay is used in the serial driver -> recursion */
- printf("udelay: %ld m.u %d.%d tm.tu %d.%d\n", usec, m, u, tm, tu);
-#endif
- while (1) {
-
- m += read_mmcr_word(SC520_SWTMRMILLI);
- u = read_mmcr_word(SC520_SWTMRMICRO) + (m * 1000);
+ read_mmcr_word (SC520_SWTMRMILLI);
+ read_mmcr_word (SC520_SWTMRMICRO);
- if (usec <= u) {
- break;
- }
- }
+ do {
+ m += read_mmcr_word (SC520_SWTMRMILLI);
+ u = read_mmcr_word (SC520_SWTMRMICRO) + (m * 1000);
+ } while (u < usec);
}
diff --git a/cpu/i386/timer.c b/cpu/i386/timer.c
deleted file mode 100644
index 79039c2..0000000
--- a/cpu/i386/timer.c
+++ /dev/null
@@ -1,211 +0,0 @@
-/*
- * (C) Copyright 2002
- * Daniel Engström, Omicron Ceti AB, daniel at omicron.se.
- *
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- */
-
-#include <common.h>
-#include <asm/io.h>
-#include <asm/i8254.h>
-#include <asm/ibmpc.h>
-
-
-static volatile unsigned long system_ticks;
-static int timer_init_done =0;
-
-static void timer_isr(void *unused)
-{
- system_ticks++;
-}
-
-unsigned long get_system_ticks(void)
-{
- return system_ticks;
-}
-
-#define TIMER0_VALUE 0x04aa /* 1kHz 1.9318MHz / 1000 */
-#define TIMER2_VALUE 0x0a8e /* 440Hz */
-
-int timer_init(void)
-{
- system_ticks = 0;
-
- irq_install_handler(0, timer_isr, NULL);
-
- /* initialize timer 0 and 2
- *
- * Timer 0 is used to increment system_tick 1000 times/sec
- * Timer 1 was used for DRAM refresh in early PC's
- * Timer 2 is used to drive the speaker
- * (to stasrt a beep: write 3 to port 0x61,
- * to stop it again: write 0)
- */
-
- outb(PIT_CMD_CTR0|PIT_CMD_BOTH|PIT_CMD_MODE2, PIT_BASE + PIT_COMMAND);
- outb(TIMER0_VALUE&0xff, PIT_BASE + PIT_T0);
- outb(TIMER0_VALUE>>8, PIT_BASE + PIT_T0);
-
- outb(PIT_CMD_CTR2|PIT_CMD_BOTH|PIT_CMD_MODE3, PIT_BASE + PIT_COMMAND);
- outb(TIMER2_VALUE&0xff, PIT_BASE + PIT_T2);
- outb(TIMER2_VALUE>>8, PIT_BASE + PIT_T2);
-
- timer_init_done = 1;
-
- return 0;
-}
-
-
-#ifdef CONFIG_SYS_GENERIC_TIMER
-
-/* the unit for these is CONFIG_SYS_HZ */
-
-/* FixMe: implement these */
-void reset_timer (void)
-{
- system_ticks = 0;
-}
-
-ulong get_timer (ulong base)
-{
- return (system_ticks - base);
-}
-
-void set_timer (ulong t)
-{
- system_ticks = t;
-}
-
-static u16 read_pit(void)
-{
- u8 low;
- outb(PIT_CMD_LATCH, PIT_BASE + PIT_COMMAND);
- low = inb(PIT_BASE + PIT_T0);
- return ((inb(PIT_BASE + PIT_T0) << 8) | low);
-}
-
-/* this is not very exact */
-void udelay (unsigned long usec)
-{
- int counter;
- int wraps;
-
- if (!timer_init_done) {
- return;
- }
- counter = read_pit();
- wraps = usec/1000;
- usec = usec%1000;
-
- usec*=1194;
- usec/=1000;
- usec+=counter;
- if (usec > 1194) {
- usec-=1194;
- wraps++;
- }
-
- while (1) {
- int new_count = read_pit();
-
- if (((new_count < usec) && !wraps) || wraps < 0) {
- break;
- }
-
- if (new_count > counter) {
- wraps--;
- }
- counter = new_count;
- }
-
-}
-
-#if 0
-/* this is a version with debug output */
-void _udelay (unsigned long usec)
-{
- int counter;
- int wraps;
-
- int usec1, usec2, usec3;
- int wraps1, wraps2, wraps3, wraps4;
- int ctr1, ctr2, ctr3, nct1, nct2;
- int i;
- usec1=usec;
- if (!timer_init_done) {
- return;
- }
- counter = read_pit();
- ctr1 = counter;
- wraps = usec/1000;
- usec = usec%1000;
-
- usec2 = usec;
- wraps1 = wraps;
-
- usec*=1194;
- usec/=1000;
- usec+=counter;
- if (usec > 1194) {
- usec-=1194;
- wraps++;
- }
-
- usec3 = usec;
- wraps2 = wraps;
-
- ctr2 = wraps3 = nct1 = 4711;
- ctr3 = wraps4 = nct2 = 4711;
- i=0;
- while (1) {
- int new_count = read_pit();
- i++;
- if ((new_count < usec && !wraps) || wraps < 0) {
- break;
- }
-
- if (new_count > counter) {
- wraps--;
- }
- if (ctr2==4711) {
- ctr2 = counter;
- wraps3 = wraps;
- nct1 = new_count;
- } else {
- ctr3 = counter;
- wraps4 = wraps;
- nct2 = new_count;
- }
-
- counter = new_count;
- }
-
- printf("udelay(%d)\n", usec1);
- printf("counter %d\n", ctr1);
- printf("1: wraps %d, usec %d\n", wraps1, usec2);
- printf("2: wraps %d, usec %d\n", wraps2, usec3);
- printf("new_count[0] %d counter %d wraps %d\n", nct1, ctr2, wraps3);
- printf("new_count[%d] %d counter %d wraps %d\n", i, nct2, ctr3, wraps4);
-
- printf("%d %d %d %d %d\n",
- read_pit(), read_pit(), read_pit(),
- read_pit(), read_pit());
-}
-#endif
-#endif
diff --git a/include/asm-i386/u-boot-i386.h b/include/asm-i386/u-boot-i386.h
index 9a60cac..3921e01 100644
--- a/include/asm-i386/u-boot-i386.h
+++ b/include/asm-i386/u-boot-i386.h
@@ -43,6 +43,13 @@ extern ulong i386boot_bios_size; /* size of BIOS emulation code */
/* cpu/.../cpu.c */
int cpu_init(void);
+
+/* cpu/.../timer.c */
+void timer_isr(void *);
+typedef void (timer_fnc_t) (void);
+int register_timer_isr (timer_fnc_t *isr_func);
+
+/* Architecture specific - can be in cpu/i386/, lib_i386/, or $(BOARD)/ */
int timer_init(void);
/* cpu/.../interrupts.c */
diff --git a/lib_i386/Makefile b/lib_i386/Makefile
index fb4184b..ec6f236 100644
--- a/lib_i386/Makefile
+++ b/lib_i386/Makefile
@@ -39,7 +39,9 @@ COBJS-y += video_bios.o
COBJS-y += video.o
COBJS-y += zimage.o
COBJS-y += interrupts.o
+COBJS-y += timer.o
COBJS-$(CONFIG_SYS_PCAT_INTERRUPTS) += pcat_interrupts.o
+COBJS-$(CONFIG_SYS_GENERIC_TIMER) += pcat_timer.o
SRCS := $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
OBJS := $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))
diff --git a/lib_i386/pcat_timer.c b/lib_i386/pcat_timer.c
new file mode 100644
index 0000000..e282f64
--- /dev/null
+++ b/lib_i386/pcat_timer.c
@@ -0,0 +1,102 @@
+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, daniel at omicron.se.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/i8254.h>
+#include <asm/ibmpc.h>
+
+#define TIMER0_VALUE 0x04aa /* 1kHz 1.9318MHz / 1000 */
+#define TIMER2_VALUE 0x0a8e /* 440Hz */
+
+int timer_init(void)
+{
+ /* initialize timer 0 and 2
+ *
+ * Timer 0 is used to increment system_tick 1000 times/sec
+ * Timer 1 was used for DRAM refresh in early PC's
+ * Timer 2 is used to drive the speaker
+ * (to stasrt a beep: write 3 to port 0x61,
+ * to stop it again: write 0)
+ */
+ outb (PIT_CMD_CTR0 | PIT_CMD_BOTH | PIT_CMD_MODE2,
+ PIT_BASE + PIT_COMMAND);
+ outb (TIMER0_VALUE & 0xff, PIT_BASE + PIT_T0);
+ outb (TIMER0_VALUE >> 8, PIT_BASE + PIT_T0);
+
+ outb (PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3,
+ PIT_BASE + PIT_COMMAND);
+ outb (TIMER2_VALUE & 0xff, PIT_BASE + PIT_T2);
+ outb (TIMER2_VALUE >> 8, PIT_BASE + PIT_T2);
+
+ irq_install_handler (0, timer_isr, NULL);
+ unmask_irq (0);
+
+ return 0;
+}
+
+static u16 read_pit(void)
+{
+ u8 low;
+
+ outb (PIT_CMD_LATCH, PIT_BASE + PIT_COMMAND);
+ low = inb (PIT_BASE + PIT_T0);
+
+ return ((inb (PIT_BASE + PIT_T0) << 8) | low);
+}
+
+/* this is not very exact */
+void udelay (unsigned long usec)
+{
+ int counter;
+ int wraps;
+
+ if (timer_init_done)
+ {
+ counter = read_pit ();
+ wraps = usec / 1000;
+ usec = usec % 1000;
+
+ usec *= 1194;
+ usec /= 1000;
+ usec += counter;
+
+ while (usec > 1194) {
+ usec -= 1194;
+ wraps++;
+ }
+
+ while (1) {
+ int new_count = read_pit ();
+
+ if (((new_count < usec) && !wraps) || wraps < 0)
+ break;
+
+ if (new_count > counter)
+ wraps--;
+
+ counter = new_count;
+ }
+ }
+
+}
diff --git a/lib_i386/timer.c b/lib_i386/timer.c
new file mode 100644
index 0000000..5cb1f54
--- /dev/null
+++ b/lib_i386/timer.c
@@ -0,0 +1,107 @@
+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, daniel at omicron.se.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/i8254.h>
+#include <asm/ibmpc.h>
+
+struct timer_isr_function {
+ struct timer_isr_function *next;
+ timer_fnc_t *isr_func;
+};
+
+static struct timer_isr_function *first_timer_isr = NULL;
+static volatile unsigned long system_ticks = 0;
+
+/*
+ * register_timer_isr() allows multiple architecture and board specific
+ * functions to be called every millisecond. Keep the execution time of
+ * each function as low as possible
+ */
+int register_timer_isr (timer_fnc_t *isr_func)
+{
+ struct timer_isr_function *new_func;
+ struct timer_isr_function *temp;
+ int flag;
+
+ new_func = malloc(sizeof(struct timer_isr_function));
+
+ if (new_func == NULL)
+ return 1;
+
+ new_func->isr_func = isr_func;
+ new_func->next = NULL;
+
+ /*
+ * Don't allow timer interrupts while the
+ * linked list is being modified
+ */
+ flag = disable_interrupts ();
+
+ if (first_timer_isr == NULL) {
+ first_timer_isr = new_func;
+ } else {
+ temp = first_timer_isr;
+ while (temp->next != NULL)
+ temp = temp->next;
+ temp->next = new_func;
+ }
+
+ if (flag)
+ enable_interrupts ();
+
+ return 0;
+}
+
+/*
+ * timer_isr() MUST be the registered interrupt handler for
+ */
+void timer_isr(void *unused)
+{
+ struct timer_isr_function *temp = first_timer_isr;
+
+ system_ticks++;
+
+ /* Execute each registered function */
+ while (temp != NULL) {
+ temp->isr_func ();
+ temp = temp->next;
+ }
+}
+
+void reset_timer (void)
+{
+ system_ticks = 0;
+}
+
+ulong get_timer (ulong base)
+{
+ return (system_ticks - base);
+}
+
+void set_timer (ulong t)
+{
+ system_ticks = t;
+}
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