Gigabeat: Add timer functionality. Rework tick timer setup to be exactly 100Hz. Metronome should work now but some pcm changes are needed to have faster tocks work correctly (in the works).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13806 a1c6a512-1295-4272-9138-f99709370657

4 files changed, 229 insertions, 32 deletions

diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c
index 9df90a2344..39e4efab49 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/kernel-meg-fx.c
@@ -1,13 +1,49 @@
+#include "config.h"
+#include "system.h"
 #include "kernel.h"
+#include "timer.h"
 #include "thread.h"
 
-#include <stdio.h>
-#include "lcd.h"
-
 extern void (*tick_funcs[MAX_NUM_TICK_TASKS])(void);
 
-void timer4(void) {
-        int i;
+void tick_start(unsigned int interval_in_ms)
+{
+    /*
+     * Based on default PCLK of 49.1568MHz - scaling chosen to give
+     * remainder-free result for tick interval of 10ms (100Hz)
+     * Timer input clock frequency =
+     *      fPCLK / {prescaler value+1} / {divider value}
+     * TIMER_FREQ = 49156800 / 2
+     * 13300 = TIMER_FREQ / 231 / 8
+     * 49156800 = 19*(11)*(7)*7*5*5*(3)*2*2*2*2*2*2
+     * 231 = 11*7*3
+     */
+
+    /* stop timer 4 */
+    TCON &= ~(1 << 20);
+    /* Set the count for timer 4 */
+    TCNTB4 = (TIMER_FREQ / 231 / 8) * interval_in_ms / 1000;
+    /* Set the the prescaler value for timers 2,3, and 4 */
+    TCFG0 = (TCFG0 & ~0xff00) | ((231-1) << 8);
+    /* MUX4 = 1/16 */
+    TCFG1 = (TCFG1 & ~0xff0000) | 0x030000;
+    /* set manual bit */
+    TCON |= 1 << 21;
+    /* reset manual bit */
+    TCON &= ~(1 << 21);
+    /* interval mode */
+    TCON |= 1 << 22;
+    /* start timer 4 */
+    TCON |= (1 << 20);
+
+    /* timer 4 unmask interrupts */
+    INTMSK &= ~TIMER4_MASK;
+}
+
+void TIMER4(void)
+{
+    int i;
+
     /* Run through the list of tick tasks */
     for(i = 0; i < MAX_NUM_TICK_TASKS; i++)
     {
@@ -19,7 +55,6 @@ void timer4(void) {
 
     current_tick++;
 
-    /* following needs to be fixed.  */
-    /*wake_up_thread();*/
+    SRCPND = TIMER4_MASK;
+    INTPND = TIMER4_MASK;
 }
-
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c
new file mode 100644
index 0000000000..4654c7c845
--- /dev/null
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c
@@ -0,0 +1,127 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2007 by Michael Sevakis
+*
+* All files in this archive are subject to the GNU General Public License.
+* See the file COPYING in the source tree root for full license agreement.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+#include "config.h"
+#include "cpu.h"
+#include "system.h"
+#include "timer.h"
+#include "logf.h"
+
+/* GPB0/TOUT0 should already have been configured as output so that pin
+   should not be a functional pin and TIMER0 output unseen there */
+void TIMER0(void)
+{
+    if (pfn_timer != NULL)
+        pfn_timer();
+
+    SRCPND = TIMER0_MASK;
+    INTPND = TIMER0_MASK;
+}
+
+static void stop_timer(void)
+{
+    /* mask interrupt */
+    INTMSK |= TIMER0_MASK;
+
+    /* stop any running TIMER0 */
+    TCON &= ~(1 << 0);
+
+    /* clear pending */
+    SRCPND = TIMER0_MASK;
+    INTPND = TIMER0_MASK;
+}
+
+bool __timer_set(long cycles, bool start)
+{
+    bool retval = false;
+
+    /* Find the minimum factor that puts the counter in range 1-65535 */
+    unsigned int prescaler = (cycles + 65534) / 65535;
+
+    /* Maximum divider setting is x / 256 / 16 = x / 4096 */
+    if (prescaler <= 4096)
+    {
+        int oldlevel;
+        unsigned int divider;
+
+        if (start && pfn_unregister != NULL)
+        {
+            pfn_unregister();
+            pfn_unregister = NULL;
+        }
+
+        oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+
+        TCMPB0 = 0;
+        TCNTB0 = (unsigned int)cycles / prescaler;
+
+        /* Max prescale is 255+1 */
+        for (divider = 0; prescaler > 256; prescaler >>= 1, divider++);
+
+        TCFG0 = (TCFG0 & ~0xff) | (prescaler - 1);
+        TCFG1 = (TCFG1 & ~0xf) | divider;
+
+        set_irq_level(oldlevel);
+
+        retval = true;
+    }
+
+    return retval;
+}
+
+bool __timer_register(void)
+{
+    bool retval = true;
+
+    int oldstatus = set_interrupt_status(IRQ_FIQ_DISABLED, IRQ_FIQ_STATUS);
+
+    stop_timer();
+
+    /* neurosis - make sure something didn't set GPB0 to TOUT0 */
+    if ((GPBCON & 0x3) != 0x2)
+    {
+        /* manual update: on (to reset count) */
+        TCON |= (1 << 1);
+        /* dead zone: off, inverter: off, manual off */
+        TCON &= ~((1 << 4) | (1 << 2) | (1 << 1));
+        /* interval mode (auto reload): on */
+        TCON |= (1 << 3);
+        /* start timer */
+        TCON |= (1 << 0);
+        /* unmask interrupt */
+        INTMSK &= ~TIMER0_MASK;
+    }
+
+    if (!(TCON & (1 << 0)))
+    {
+        /* timer could not be started due to config error */
+        logf("Timer error: GPB0 set to TOUT0");
+        retval = false;
+    }
+
+    set_interrupt_status(oldstatus, IRQ_FIQ_STATUS);
+
+    return retval;
+}
+
+void __timer_unregister(void)
+{
+    int oldstatus = set_interrupt_status(IRQ_FIQ_DISABLED, IRQ_FIQ_STATUS);
+    stop_timer();
+    set_interrupt_status(oldstatus, IRQ_FIQ_STATUS);
+}
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h b/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
new file mode 100644
index 0000000000..e9f330cf8e
--- /dev/null
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/timer-target.h
@@ -0,0 +1,39 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2007 by Michael Sevakis
+*
+* All files in this archive are subject to the GNU General Public License.
+* See the file COPYING in the source tree root for full license agreement.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+#ifndef TIMER_TARGET_H
+#define TIMER_TARGET_H
+
+/* timer is based on PCLK and minimum division is 2 */
+#define TIMER_FREQ (49156800/2)
+
+bool __timer_set(long cycles, bool set);
+bool __timer_register(void);
+void __timer_unregister(void);
+
+#define __TIMER_SET(cycles, set) \
+    __timer_set(cycles, set)
+
+#define __TIMER_REGISTER(reg_prio, unregister_callback, cycles, \
+                              int_prio, timer_callback) \
+    __timer_register()
+
+#define __TIMER_UNREGISTER(...) \
+    __timer_unregister()
+
+#endif /* TIMER_TARGET_H */
diff --git a/firmware/target/arm/system-arm.h b/firmware/target/arm/system-arm.h
index 99cab9e1a3..37c367fdc4 100644
--- a/firmware/target/arm/system-arm.h
+++ b/firmware/target/arm/system-arm.h
@@ -87,23 +87,6 @@ static inline uint32_t swap_odd_even32(uint32_t value)
     return value;
 }
 
-#define HIGHEST_IRQ_LEVEL (0x80)
-
-static inline int set_irq_level(int level)
-{
-    unsigned long cpsr;
-    int oldlevel;
-    /* Read the old level and set the new one */
-    asm volatile (
-        "mrs    %1, cpsr        \n"
-        "bic    %0, %1, #0x80   \n"
-        "orr    %0, %0, %2      \n"
-        "msr    cpsr_c, %0      \n"
-        : "=&r,r"(cpsr), "=&r,r"(oldlevel) : "r,i"(level & 0x80)
-    );
-    return oldlevel;
-}
-
 static inline void set_fiq_handler(void(*fiq_handler)(void))
 {
     /* Install the FIQ handler */
@@ -133,22 +116,35 @@ static inline void disable_fiq(void)
 }
 
 /* This one returns the old status */
-#define FIQ_ENABLED  0x00
-#define FIQ_DISABLED 0x40
-static inline int set_fiq_status(int status)
+#define IRQ_ENABLED      0x00
+#define IRQ_DISABLED     0x80
+#define IRQ_STATUS       0x80
+#define FIQ_ENABLED      0x00
+#define FIQ_DISABLED     0x40
+#define FIQ_STATUS       0x40
+#define IRQ_FIQ_ENABLED  0x00
+#define IRQ_FIQ_DISABLED 0xc0
+#define IRQ_FIQ_STATUS   0xc0
+#define HIGHEST_IRQ_LEVEL IRQ_DISABLED
+
+#define set_irq_level(status)  set_interrupt_status((status), IRQ_STATUS)
+#define set_fiq_status(status) set_interrupt_status((status), FIQ_STATUS)
+
+static inline int set_interrupt_status(int status, int mask)
 {
     unsigned long cpsr;
     int oldstatus;
-    /* Read the old level and set the new one */
+    /* Read the old levels and set the new ones */
     asm volatile (
         "mrs    %1, cpsr        \n"
-        "bic    %0, %1, #0x40   \n"
+        "bic    %0, %1, %[mask] \n"
         "orr    %0, %0, %2      \n"
         "msr    cpsr_c, %0      \n"
-        : "=&r,r"(cpsr), "=&r,r"(oldstatus) : "r,i"(status & 0x40)
+        : "=&r,r"(cpsr), "=&r,r"(oldstatus)
+        : "r,i"(status & mask), [mask]"i,i"(mask)
     );
+
     return oldstatus;
 }
 
-
 #endif /* SYSTEM_ARM_H */