[MIPS] txx9tmr clockevent/clocksource driver

Convert jmr3927_clock_event_device to more generic
txx9tmr_clock_event_device which supports one-shot mode.  The
txx9tmr_clock_event_device can be used for TX49 too if the cp0 timer
interrupt was not available.

Convert jmr3927_hpt_read to txx9_clocksource driver which does not
depends jiffies anymore.  The txx9_clocksource itself can be used for
TX49, but normally TX49 uses higher precision clocksource_mips.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 172 insertions, 0 deletions

diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index d7745c8976f6..3196509a28d5 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -10,6 +10,7 @@ obj-y		+= cpu-probe.o branch.o entry.o genex.o irq.o process.o \
 
 obj-$(CONFIG_CEVT_R4K)		+= cevt-r4k.o
 obj-$(CONFIG_CEVT_GT641XX)	+= cevt-gt641xx.o
+obj-$(CONFIG_CEVT_TXX9)		+= cevt-txx9.o
 
 binfmt_irix-objs	:= irixelf.o irixinv.o irixioctl.o irixsig.o	\
 			   irix5sys.o sysirix.o
diff --git a/arch/mips/kernel/cevt-txx9.c b/arch/mips/kernel/cevt-txx9.c
new file mode 100644
index 000000000000..795cb8fb0d74
--- /dev/null
+++ b/arch/mips/kernel/cevt-txx9.c
@@ -0,0 +1,171 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Based on linux/arch/mips/kernel/cevt-r4k.c,
+ *          linux/arch/mips/jmr3927/rbhma3100/setup.c
+ *
+ * Copyright 2001 MontaVista Software Inc.
+ * Copyright (C) 2000-2001 Toshiba Corporation
+ * Copyright (C) 2007 MIPS Technologies, Inc.
+ * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <asm/time.h>
+#include <asm/txx9tmr.h>
+
+#define TCR_BASE (TXx9_TMTCR_CCDE | TXx9_TMTCR_CRE | TXx9_TMTCR_TMODE_ITVL)
+#define TIMER_CCD	0	/* 1/2 */
+#define TIMER_CLK(imclk)	((imclk) / (2 << TIMER_CCD))
+
+static struct txx9_tmr_reg __iomem *txx9_cs_tmrptr;
+
+static cycle_t txx9_cs_read(void)
+{
+	return __raw_readl(&txx9_cs_tmrptr->trr);
+}
+
+/* Use 1 bit smaller width to use full bits in that width */
+#define TXX9_CLOCKSOURCE_BITS (TXX9_TIMER_BITS - 1)
+
+static struct clocksource txx9_clocksource = {
+	.name		= "TXx9",
+	.rating		= 200,
+	.read		= txx9_cs_read,
+	.mask		= CLOCKSOURCE_MASK(TXX9_CLOCKSOURCE_BITS),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+void __init txx9_clocksource_init(unsigned long baseaddr,
+				  unsigned int imbusclk)
+{
+	struct txx9_tmr_reg __iomem *tmrptr;
+
+	clocksource_set_clock(&txx9_clocksource, TIMER_CLK(imbusclk));
+	clocksource_register(&txx9_clocksource);
+
+	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
+	__raw_writel(TCR_BASE, &tmrptr->tcr);
+	__raw_writel(0, &tmrptr->tisr);
+	__raw_writel(TIMER_CCD, &tmrptr->ccdr);
+	__raw_writel(TXx9_TMITMR_TZCE, &tmrptr->itmr);
+	__raw_writel(1 << TXX9_CLOCKSOURCE_BITS, &tmrptr->cpra);
+	__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
+	txx9_cs_tmrptr = tmrptr;
+}
+
+static struct txx9_tmr_reg __iomem *txx9_tmrptr;
+
+static void txx9tmr_stop_and_clear(struct txx9_tmr_reg __iomem *tmrptr)
+{
+	/* stop and reset counter */
+	__raw_writel(TCR_BASE, &tmrptr->tcr);
+	/* clear pending interrupt */
+	__raw_writel(0, &tmrptr->tisr);
+}
+
+static void txx9tmr_set_mode(enum clock_event_mode mode,
+			     struct clock_event_device *evt)
+{
+	struct txx9_tmr_reg __iomem *tmrptr = txx9_tmrptr;
+
+	txx9tmr_stop_and_clear(tmrptr);
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		__raw_writel(TXx9_TMITMR_TIIE | TXx9_TMITMR_TZCE,
+			     &tmrptr->itmr);
+		/* start timer */
+		__raw_writel(((u64)(NSEC_PER_SEC / HZ) * evt->mult) >>
+			     evt->shift,
+			     &tmrptr->cpra);
+		__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
+		break;
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_UNUSED:
+		__raw_writel(0, &tmrptr->itmr);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		__raw_writel(TXx9_TMITMR_TIIE, &tmrptr->itmr);
+		break;
+	case CLOCK_EVT_MODE_RESUME:
+		__raw_writel(TIMER_CCD, &tmrptr->ccdr);
+		__raw_writel(0, &tmrptr->itmr);
+		break;
+	}
+}
+
+static int txx9tmr_set_next_event(unsigned long delta,
+				  struct clock_event_device *evt)
+{
+	struct txx9_tmr_reg __iomem *tmrptr = txx9_tmrptr;
+
+	txx9tmr_stop_and_clear(tmrptr);
+	/* start timer */
+	__raw_writel(delta, &tmrptr->cpra);
+	__raw_writel(TCR_BASE | TXx9_TMTCR_TCE, &tmrptr->tcr);
+	return 0;
+}
+
+static struct clock_event_device txx9tmr_clock_event_device = {
+	.name		= "TXx9",
+	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 200,
+	.cpumask	= CPU_MASK_CPU0,
+	.set_mode	= txx9tmr_set_mode,
+	.set_next_event	= txx9tmr_set_next_event,
+};
+
+static irqreturn_t txx9tmr_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *cd = &txx9tmr_clock_event_device;
+	struct txx9_tmr_reg __iomem *tmrptr = txx9_tmrptr;
+
+	__raw_writel(0, &tmrptr->tisr);	/* ack interrupt */
+	cd->event_handler(cd);
+	return IRQ_HANDLED;
+}
+
+static struct irqaction txx9tmr_irq = {
+	.handler	= txx9tmr_interrupt,
+	.flags		= IRQF_DISABLED | IRQF_PERCPU,
+	.name		= "txx9tmr",
+};
+
+void __init txx9_clockevent_init(unsigned long baseaddr, int irq,
+				 unsigned int imbusclk)
+{
+	struct clock_event_device *cd = &txx9tmr_clock_event_device;
+	struct txx9_tmr_reg __iomem *tmrptr;
+
+	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
+	txx9tmr_stop_and_clear(tmrptr);
+	__raw_writel(TIMER_CCD, &tmrptr->ccdr);
+	__raw_writel(0, &tmrptr->itmr);
+	txx9_tmrptr = tmrptr;
+
+	clockevent_set_clock(cd, TIMER_CLK(imbusclk));
+	cd->max_delta_ns =
+		clockevent_delta2ns(0xffffffff >> (32 - TXX9_TIMER_BITS), cd);
+	cd->min_delta_ns = clockevent_delta2ns(0xf, cd);
+	cd->irq = irq;
+	clockevents_register_device(cd);
+	setup_irq(irq, &txx9tmr_irq);
+	printk(KERN_INFO "TXx9: clockevent device at 0x%lx, irq %d\n",
+	       baseaddr, irq);
+}
+
+void __init txx9_tmr_init(unsigned long baseaddr)
+{
+	struct txx9_tmr_reg __iomem *tmrptr;
+
+	tmrptr = ioremap(baseaddr, sizeof(struct txx9_tmr_reg));
+	__raw_writel(TXx9_TMTCR_CRE, &tmrptr->tcr);
+	__raw_writel(0, &tmrptr->tisr);
+	__raw_writel(0xffffffff, &tmrptr->cpra);
+	__raw_writel(0, &tmrptr->itmr);
+	__raw_writel(0, &tmrptr->ccdr);
+	__raw_writel(0, &tmrptr->pgmr);
+	iounmap(tmrptr);
+}