[ARM] 3822/1: iop3xx: rewrite time handling

Merge and rewrite the iop32x/iop33x time code to do lost jiffy
tracking properly, and put the result in plat-iop/time.c.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

5 files changed, 127 insertions, 1 deletions

diff --git a/arch/arm/plat-iop/Makefile b/arch/arm/plat-iop/Makefile
index efde7a513fb7..d20cdec3a944 100644
--- a/arch/arm/plat-iop/Makefile
+++ b/arch/arm/plat-iop/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-obj-y                   := i2c.o pci.o setup.o
+obj-y                   := i2c.o pci.o setup.o time.o
 obj-m                   :=
 obj-n                   :=
 obj-                    :=
diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c
new file mode 100644
index 000000000000..5730a0d7ed67
--- /dev/null
+++ b/arch/arm/plat-iop/time.c
@@ -0,0 +1,94 @@
+/*
+ * arch/arm/plat-iop/time.c
+ *
+ * Timer code for IOP32x and IOP33x based systems
+ *
+ * Author: Deepak Saxena <dsaxena@mvista.com>
+ *
+ * Copyright 2002-2003 MontaVista Software Inc.
+ *
+ * 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/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/timex.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+#include <asm/mach/irq.h>
+#include <asm/mach/time.h>
+
+#ifdef CONFIG_ARCH_IOP32X
+#define IRQ_IOP3XX_TIMER0       IRQ_IOP321_TIMER0
+#else
+#ifdef CONFIG_ARCH_IOP33X
+#define IRQ_IOP3XX_TIMER0       IRQ_IOP331_TIMER0
+#endif
+#endif
+
+static unsigned long ticks_per_jiffy;
+static unsigned long ticks_per_usec;
+static unsigned long next_jiffy_time;
+
+unsigned long iop3xx_gettimeoffset(void)
+{
+        unsigned long offset;
+
+        offset = next_jiffy_time - *IOP3XX_TU_TCR1;
+
+        return offset / ticks_per_usec;
+}
+
+static irqreturn_t
+iop3xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+        write_seqlock(&xtime_lock);
+
+        asm volatile("mcr p6, 0, %0, c6, c1, 0" : : "r" (1));
+
+        while ((signed long)(next_jiffy_time - *IOP3XX_TU_TCR1)
+                                                        >= ticks_per_jiffy) {
+                timer_tick(regs);
+                next_jiffy_time -= ticks_per_jiffy;
+        }
+
+        write_sequnlock(&xtime_lock);
+
+        return IRQ_HANDLED;
+}
+
+static struct irqaction iop3xx_timer_irq = {
+        .name           = "IOP3XX Timer Tick",
+        .handler        = iop3xx_timer_interrupt,
+        .flags          = IRQF_DISABLED | IRQF_TIMER,
+};
+
+void __init iop3xx_init_time(unsigned long tick_rate)
+{
+        u32 timer_ctl;
+
+        ticks_per_jiffy = (tick_rate + HZ/2) / HZ;
+        ticks_per_usec = tick_rate / 1000000;
+        next_jiffy_time = 0xffffffff;
+
+        timer_ctl = IOP3XX_TMR_EN | IOP3XX_TMR_PRIVILEGED |
+                        IOP3XX_TMR_RELOAD | IOP3XX_TMR_RATIO_1_1;
+
+        /*
+         * We use timer 0 for our timer interrupt, and timer 1 as
+         * monotonic counter for tracking missed jiffies.
+         */
+        asm volatile("mcr p6, 0, %0, c4, c1, 0" : : "r" (ticks_per_jiffy - 1));
+        asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (timer_ctl));
+        asm volatile("mcr p6, 0, %0, c5, c1, 0" : : "r" (0xffffffff));
+        asm volatile("mcr p6, 0, %0, c1, c1, 0" : : "r" (timer_ctl));
+
+        setup_irq(IRQ_IOP3XX_TIMER0, &iop3xx_timer_irq);
+}
diff --git a/include/asm-arm/arch-iop32x/iop321.h b/include/asm-arm/arch-iop32x/iop321.h
index e3c85a05e73a..bd96b8d55a76 100644
--- a/include/asm-arm/arch-iop32x/iop321.h
+++ b/include/asm-arm/arch-iop32x/iop321.h
@@ -233,6 +233,12 @@
 
 /* for I2C bit defs see drivers/i2c/i2c-iop3xx.h */
 
+/*
+ * Peripherals that are shared between the iop32x and iop33x but
+ * located at different addresses.
+ */
+#define IOP3XX_TIMER_REG(reg)  (IOP3XX_PERIPHERAL_VIRT_BASE + 0x07e0 + (reg))
+
 #include <asm/hardware/iop3xx.h>
 
 
diff --git a/include/asm-arm/arch-iop33x/iop331.h b/include/asm-arm/arch-iop33x/iop331.h
index e85e1a2e1a86..b301ef8f7f32 100644
--- a/include/asm-arm/arch-iop33x/iop331.h
+++ b/include/asm-arm/arch-iop33x/iop331.h
@@ -238,6 +238,12 @@
 
 /* Reserved 0x0000178c through 0x000019ff */
 
+/*
+ * Peripherals that are shared between the iop32x and iop33x but
+ * located at different addresses.
+ */
+#define IOP3XX_TIMER_REG(reg)  (IOP3XX_PERIPHERAL_VIRT_BASE + 0x07d0 + (reg))
+
 #include <asm/hardware/iop3xx.h>
 
 
diff --git a/include/asm-arm/hardware/iop3xx.h b/include/asm-arm/hardware/iop3xx.h
index d488ced2e12d..b21ea41b149e 100644
--- a/include/asm-arm/hardware/iop3xx.h
+++ b/include/asm-arm/hardware/iop3xx.h
@@ -81,6 +81,24 @@
 #define IOP3XX_PCIXSR           (volatile u32 *)IOP3XX_REG_ADDR(0x01e4)
 #define IOP3XX_PCIIRSR          (volatile u32 *)IOP3XX_REG_ADDR(0x01ec)
 
+/* Timers  */
+#define IOP3XX_TU_TMR0          (volatile u32 *)IOP3XX_TIMER_REG(0x0000)
+#define IOP3XX_TU_TMR1          (volatile u32 *)IOP3XX_TIMER_REG(0x0004)
+#define IOP3XX_TU_TCR0          (volatile u32 *)IOP3XX_TIMER_REG(0x0008)
+#define IOP3XX_TU_TCR1          (volatile u32 *)IOP3XX_TIMER_REG(0x000c)
+#define IOP3XX_TU_TRR0          (volatile u32 *)IOP3XX_TIMER_REG(0x0010)
+#define IOP3XX_TU_TRR1          (volatile u32 *)IOP3XX_TIMER_REG(0x0014)
+#define IOP3XX_TU_TISR          (volatile u32 *)IOP3XX_TIMER_REG(0x0018)
+#define IOP3XX_TU_WDTCR         (volatile u32 *)IOP3XX_TIMER_REG(0x001c)
+#define IOP3XX_TMR_TC           0x01
+#define IOP3XX_TMR_EN           0x02
+#define IOP3XX_TMR_RELOAD       0x04
+#define IOP3XX_TMR_PRIVILEGED   0x09
+#define IOP3XX_TMR_RATIO_1_1    0x00
+#define IOP3XX_TMR_RATIO_4_1    0x10
+#define IOP3XX_TMR_RATIO_8_1    0x20
+#define IOP3XX_TMR_RATIO_16_1   0x30
+
 /* I2C bus interface unit  */
 #define IOP3XX_ICR0             (volatile u32 *)IOP3XX_REG_ADDR(0x1680)
 #define IOP3XX_ISR0             (volatile u32 *)IOP3XX_REG_ADDR(0x1684)
@@ -109,6 +127,8 @@
 
 #ifndef __ASSEMBLY__
 void iop3xx_map_io(void);
+void iop3xx_init_time(unsigned long);
+unsigned long iop3xx_gettimeoffset(void);
 
 extern struct platform_device iop3xx_i2c0_device;
 extern struct platform_device iop3xx_i2c1_device;