[MIPS] time: Add GT641xx timer0 clockevent driver

And make use of it for Cobalt.  A few others such as the Malta could make
use of it as well.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

7 files changed, 193 insertions, 22 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 3ecff5e9e4f3..61262c5f9c62 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -66,6 +66,7 @@ config BCM47XX
 config MIPS_COBALT
         bool "Cobalt Server"
         select CEVT_R4K
+        select CEVT_GT641XX
         select DMA_NONCOHERENT
         select HW_HAS_PCI
         select I8253
@@ -729,6 +730,9 @@ config ARCH_MAY_HAVE_PC_FDC
 config BOOT_RAW
         bool
 
+config CEVT_GT641XX
+        bool
+
 config CEVT_R4K
         bool
 
diff --git a/arch/mips/cobalt/Makefile b/arch/mips/cobalt/Makefile
index 6b83f4ddc8fc..d73833b7c781 100644
--- a/arch/mips/cobalt/Makefile
+++ b/arch/mips/cobalt/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the Cobalt micro systems family specific parts of the kernel
 #
 
-obj-y := buttons.o irq.o led.o reset.o rtc.o serial.o setup.o
+obj-y := buttons.o irq.o led.o reset.o rtc.o serial.o setup.o time.o
 
 obj-$(CONFIG_PCI)               += pci.o
 obj-$(CONFIG_EARLY_PRINTK)      += console.o
diff --git a/arch/mips/cobalt/setup.c b/arch/mips/cobalt/setup.c
index d11bb1bc7b6b..dd23beb8604f 100644
--- a/arch/mips/cobalt/setup.c
+++ b/arch/mips/cobalt/setup.c
@@ -9,19 +9,17 @@
  * Copyright (C) 2001, 2002, 2003 by Liam Davies (ldavies@agile.tv)
  *
  */
-#include <linux/interrupt.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
 #include <linux/pm.h>
 
 #include <asm/bootinfo.h>
-#include <asm/time.h>
-#include <asm/i8253.h>
-#include <asm/io.h>
 #include <asm/reboot.h>
 #include <asm/gt64120.h>
 
 #include <cobalt.h>
-#include <irq.h>
 
 extern void cobalt_machine_restart(char *command);
 extern void cobalt_machine_halt(void);
@@ -41,17 +39,6 @@ const char *get_system_type(void)
         return "MIPS Cobalt";
 }
 
-void __init plat_timer_setup(struct irqaction *irq)
-{
-        /* Load timer value for HZ (TCLK is 50MHz) */
-        GT_WRITE(GT_TC0_OFS, 50*1000*1000 / HZ);
-
-        /* Enable timer0 */
-        GT_WRITE(GT_TC_CONTROL_OFS, GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
-
-        setup_irq(GT641XX_TIMER0_IRQ, irq);
-}
-
 /*
  * Cobalt doesn't have PS/2 keyboard/mouse interfaces,
  * keyboard conntroller is never used.
@@ -84,11 +71,6 @@ static struct resource cobalt_reserved_resources[] = {
         },
 };
 
-void __init plat_time_init(void)
-{
-        setup_pit_timer();
-}
-
 void __init plat_mem_setup(void)
 {
         int i;
diff --git a/arch/mips/cobalt/time.c b/arch/mips/cobalt/time.c
new file mode 100644
index 000000000000..fa819fccd5db
--- /dev/null
+++ b/arch/mips/cobalt/time.c
@@ -0,0 +1,35 @@
+/*
+ *  Cobalt time initialization.
+ *
+ *  Copyright (C) 2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
+ *
+ *  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/init.h>
+
+#include <asm/gt64120.h>
+#include <asm/i8253.h>
+#include <asm/time.h>
+
+#define GT641XX_BASE_CLOCK      50000000        /* 50MHz */
+
+void __init plat_time_init(void)
+{
+        setup_pit_timer();
+
+        gt641xx_set_base_clock(GT641XX_BASE_CLOCK);
+
+        mips_timer_state = gt641xx_timer0_state;
+}
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index a3afa39faae5..d7745c8976f6 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -9,6 +9,7 @@ obj-y		+= cpu-probe.o branch.o entry.o genex.o irq.o process.o \
                    time.o topology.o traps.o unaligned.o
 
 obj-$(CONFIG_CEVT_R4K)          += cevt-r4k.o
+obj-$(CONFIG_CEVT_GT641XX)      += cevt-gt641xx.o
 
 binfmt_irix-objs        := irixelf.o irixinv.o irixioctl.o irixsig.o    \
                            irix5sys.o sysirix.o
diff --git a/arch/mips/kernel/cevt-gt641xx.c b/arch/mips/kernel/cevt-gt641xx.c
new file mode 100644
index 000000000000..4c651b2680f9
--- /dev/null
+++ b/arch/mips/kernel/cevt-gt641xx.c
@@ -0,0 +1,144 @@
+/*
+ *  GT641xx clockevent routines.
+ *
+ *  Copyright (C) 2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
+ *
+ *  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/clockchips.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+
+#include <asm/gt64120.h>
+#include <asm/time.h>
+
+#include <irq.h>
+
+static DEFINE_SPINLOCK(gt641xx_timer_lock);
+static unsigned int gt641xx_base_clock;
+
+void gt641xx_set_base_clock(unsigned int clock)
+{
+        gt641xx_base_clock = clock;
+}
+
+int gt641xx_timer0_state(void)
+{
+        if (GT_READ(GT_TC0_OFS))
+                return 0;
+
+        GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
+        GT_WRITE(GT_TC_CONTROL_OFS, GT_TC_CONTROL_ENTC0_MSK);
+
+        return 1;
+}
+
+static int gt641xx_timer0_set_next_event(unsigned long delta,
+                                         struct clock_event_device *evt)
+{
+        unsigned long flags;
+        u32 ctrl;
+
+        spin_lock_irqsave(&gt641xx_timer_lock, flags);
+
+        ctrl = GT_READ(GT_TC_CONTROL_OFS);
+        ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
+        ctrl |= GT_TC_CONTROL_ENTC0_MSK;
+
+        GT_WRITE(GT_TC0_OFS, delta);
+        GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
+
+        spin_unlock_irqrestore(&gt641xx_timer_lock, flags);
+
+        return 0;
+}
+
+static void gt641xx_timer0_set_mode(enum clock_event_mode mode,
+                                    struct clock_event_device *evt)
+{
+        unsigned long flags;
+        u32 ctrl;
+
+        spin_lock_irqsave(&gt641xx_timer_lock, flags);
+
+        ctrl = GT_READ(GT_TC_CONTROL_OFS);
+        ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
+
+        switch (mode) {
+        case CLOCK_EVT_MODE_PERIODIC:
+                ctrl |= GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK;
+                break;
+        case CLOCK_EVT_MODE_ONESHOT:
+                ctrl |= GT_TC_CONTROL_ENTC0_MSK;
+                break;
+        default:
+                break;
+        }
+
+        GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
+
+        spin_unlock_irqrestore(&gt641xx_timer_lock, flags);
+}
+
+static void gt641xx_timer0_event_handler(struct clock_event_device *dev)
+{
+}
+
+static struct clock_event_device gt641xx_timer0_clockevent = {
+        .name           = "gt641xx-timer0",
+        .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+        .cpumask        = CPU_MASK_CPU0,
+        .irq            = GT641XX_TIMER0_IRQ,
+        .set_next_event = gt641xx_timer0_set_next_event,
+        .set_mode       = gt641xx_timer0_set_mode,
+        .event_handler  = gt641xx_timer0_event_handler,
+};
+
+static irqreturn_t gt641xx_timer0_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *cd = &gt641xx_timer0_clockevent;
+
+        cd->event_handler(cd);
+
+        return IRQ_HANDLED;
+}
+
+static struct irqaction gt641xx_timer0_irqaction = {
+        .handler        = gt641xx_timer0_interrupt,
+        .flags          = IRQF_DISABLED | IRQF_PERCPU,
+        .name           = "gt641xx_timer0",
+};
+
+static int __init gt641xx_timer0_clockevent_init(void)
+{
+        struct clock_event_device *cd;
+
+        if (!gt641xx_base_clock)
+                return 0;
+
+        GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
+
+        cd = &gt641xx_timer0_clockevent;
+        cd->rating = 200 + gt641xx_base_clock / 10000000;
+        cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
+        cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
+        clockevent_set_clock(cd, gt641xx_base_clock);
+
+        clockevents_register_device(&gt641xx_timer0_clockevent);
+
+        return setup_irq(GT641XX_TIMER0_IRQ, &gt641xx_timer0_irqaction);
+}
+arch_initcall(gt641xx_timer0_clockevent_init);
diff --git a/include/asm-mips/gt64120.h b/include/asm-mips/gt64120.h
index 4bf8e28f8850..e64b41093c49 100644
--- a/include/asm-mips/gt64120.h
+++ b/include/asm-mips/gt64120.h
@@ -21,6 +21,8 @@
 #ifndef _ASM_GT64120_H
 #define _ASM_GT64120_H
 
+#include <linux/clocksource.h>
+
 #include <asm/addrspace.h>
 #include <asm/byteorder.h>
 
@@ -572,4 +574,7 @@
 #define GT_READ(ofs)            le32_to_cpu(__GT_READ(ofs))
 #define GT_WRITE(ofs, data)     __GT_WRITE(ofs, cpu_to_le32(data))
 
+extern void gt641xx_set_base_clock(unsigned int clock);
+extern int gt641xx_timer0_state(void);
+
 #endif /* _ASM_GT64120_H */