[RFC/example] powerpc: add the mpic global timer support
Kumar Gala
galak at kernel.crashing.org
Thu Jan 29 16:09:42 EST 2009
From: Dave Liu <daveliu at freescale.com>
The mpic timer works as wake up source for power management,
the max timer period is 336 seconds when the CCB freq is 400MHz.
to setup timer, type
echo 30 > /sys/devices/ffe00000.soc8572/ffe41100.timer/timeout
before the system enter to sleep mode.
Signed-off-by: Dave Liu <daveliu at freescale.com>
---
Posting this both as a example of timer code for Regis as well as code for
partial review.. need to clean up a number of things.
- k
arch/powerpc/boot/dts/mpc8572ds.dts | 7 +
arch/powerpc/include/asm/mpic.h | 1 +
arch/powerpc/sysdev/Makefile | 2 +-
arch/powerpc/sysdev/mpic.c | 89 ++++++++++++-
arch/powerpc/sysdev/mpic_timer.c | 257 +++++++++++++++++++++++++++++++++++
5 files changed, 350 insertions(+), 6 deletions(-)
create mode 100644 arch/powerpc/sysdev/mpic_timer.c
diff --git a/arch/powerpc/boot/dts/mpc8572ds.dts b/arch/powerpc/boot/dts/mpc8572ds.dts
index 82a8845..f3620a6 100644
--- a/arch/powerpc/boot/dts/mpc8572ds.dts
+++ b/arch/powerpc/boot/dts/mpc8572ds.dts
@@ -464,6 +464,13 @@
fsl,has-rstcr;
};
+ timer at 41100 {
+ compatible = "fsl,mpic-global-timer";
+ reg = <0x41100 0x204>;
+ interrupts = <0xf7 0x2>;
+ interrupt-parent = <&mpic>;
+ };
+
msi at 41600 {
compatible = "fsl,mpc8572-msi", "fsl,mpic-msi";
reg = <0x41600 0x80>;
diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h
index eb685ed..a98be7d 100644
--- a/arch/powerpc/include/asm/mpic.h
+++ b/arch/powerpc/include/asm/mpic.h
@@ -254,6 +254,7 @@ struct mpic
#ifdef CONFIG_SMP
struct irq_chip hc_ipi;
#endif
+ struct irq_chip hc_tm;
const char *name;
/* Flags */
unsigned int flags;
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index a90054b..58414fa 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -3,7 +3,7 @@ EXTRA_CFLAGS += -mno-minimal-toc
endif
mpic-msi-obj-$(CONFIG_PCI_MSI) += mpic_msi.o mpic_u3msi.o mpic_pasemi_msi.o
-obj-$(CONFIG_MPIC) += mpic.o $(mpic-msi-obj-y)
+obj-$(CONFIG_MPIC) += mpic.o mpic_timer.o $(mpic-msi-obj-y)
fsl-msi-obj-$(CONFIG_PCI_MSI) += fsl_msi.o
obj-$(CONFIG_PPC_MPC106) += grackle.o
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index e1d77ab..0cd9dac 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -207,6 +207,22 @@ static inline void _mpic_ipi_write(struct mpic *mpic, unsigned int ipi, u32 valu
_mpic_write(mpic->reg_type, &mpic->gregs, offset, value);
}
+static inline u32 _mpic_tm_read(struct mpic *mpic, unsigned int tm)
+{
+ unsigned int offset = MPIC_INFO(TIMER_VECTOR_PRI) +
+ (tm * MPIC_INFO(TIMER_STRIDE));
+
+ return _mpic_read(mpic->reg_type, &mpic->tmregs, offset);
+}
+
+static inline void _mpic_tm_write(struct mpic *mpic, unsigned int tm, u32 value)
+{
+ unsigned int offset = MPIC_INFO(TIMER_VECTOR_PRI) +
+ (tm * MPIC_INFO(TIMER_STRIDE));
+
+ _mpic_write(mpic->reg_type, &mpic->tmregs, offset, value);
+}
+
static inline u32 _mpic_cpu_read(struct mpic *mpic, unsigned int reg)
{
unsigned int cpu = 0;
@@ -259,6 +275,8 @@ static inline void _mpic_irq_write(struct mpic *mpic, unsigned int src_no,
#define mpic_write(b,r,v) _mpic_write(mpic->reg_type,&(b),(r),(v))
#define mpic_ipi_read(i) _mpic_ipi_read(mpic,(i))
#define mpic_ipi_write(i,v) _mpic_ipi_write(mpic,(i),(v))
+#define mpic_tm_read(i) _mpic_tm_read(mpic,(i))
+#define mpic_tm_write(i,v) _mpic_tm_write(mpic,(i),(v))
#define mpic_cpu_read(i) _mpic_cpu_read(mpic,(i))
#define mpic_cpu_write(i,v) _mpic_cpu_write(mpic,(i),(v))
#define mpic_irq_read(s,r) _mpic_irq_read(mpic,(s),(r))
@@ -612,7 +630,8 @@ static int irq_choose_cpu(unsigned int virt_irq)
#define mpic_irq_to_hw(virq) ((unsigned int)irq_map[virq].hwirq)
/* Find an mpic associated with a given linux interrupt */
-static struct mpic *mpic_find(unsigned int irq, unsigned int *is_ipi)
+static struct mpic *mpic_find(unsigned int irq, unsigned int *is_ipi,
+ unsigned int *is_tm)
{
unsigned int src = mpic_irq_to_hw(irq);
struct mpic *mpic;
@@ -625,6 +644,9 @@ static struct mpic *mpic_find(unsigned int irq, unsigned int *is_ipi)
if (is_ipi)
*is_ipi = (src >= mpic->ipi_vecs[0] &&
src <= mpic->ipi_vecs[3]);
+ if (is_tm)
+ *is_tm = (src >= mpic->timer_vecs[0] &&
+ src <= mpic->timer_vecs[3]);
return mpic;
}
@@ -648,6 +670,12 @@ static inline struct mpic * mpic_from_ipi(unsigned int ipi)
}
#endif
+/* Get the mpic structure from the tm number */
+static inline struct mpic * mpic_from_tm(unsigned int tm)
+{
+ return irq_desc[tm].chip_data;
+}
+
/* Get the mpic structure from the irq number */
static inline struct mpic * mpic_from_irq(unsigned int irq)
{
@@ -817,6 +845,32 @@ static void mpic_end_ipi(unsigned int irq)
#endif /* CONFIG_SMP */
+static void mpic_unmask_tm(unsigned int irq)
+{
+ struct mpic *mpic = mpic_from_tm(irq);
+ unsigned int src = mpic_irq_to_hw(irq) - mpic->timer_vecs[0];
+
+ DBG("%s: enable_tm: %d (tm %d)\n", mpic->name, irq, src);
+ mpic_tm_write(src, mpic_tm_read(src) & ~MPIC_VECPRI_MASK);
+ mpic_tm_read(src);
+}
+
+static void mpic_mask_tm(unsigned int irq)
+{
+ struct mpic *mpic = mpic_from_tm(irq);
+ unsigned int src = mpic_irq_to_hw(irq) - mpic->timer_vecs[0];
+
+ mpic_tm_write(src, mpic_tm_read(src) | MPIC_VECPRI_MASK);
+ mpic_tm_read(src);
+}
+
+static void mpic_end_tm(unsigned int irq)
+{
+ struct mpic *mpic = mpic_from_tm(irq);
+
+ mpic_eoi(mpic);
+}
+
void mpic_set_affinity(unsigned int irq, cpumask_t cpumask)
{
struct mpic *mpic = mpic_from_irq(irq);
@@ -930,6 +984,12 @@ static struct irq_chip mpic_ipi_chip = {
};
#endif /* CONFIG_SMP */
+static struct irq_chip mpic_tm_chip = {
+ .mask = mpic_mask_tm,
+ .unmask = mpic_unmask_tm,
+ .eoi = mpic_end_tm,
+};
+
#ifdef CONFIG_MPIC_U3_HT_IRQS
static struct irq_chip mpic_irq_ht_chip = {
.startup = mpic_startup_ht_irq,
@@ -961,6 +1021,15 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq,
if (mpic->protected && test_bit(hw, mpic->protected))
return -EINVAL;
+ else if (hw >= mpic->timer_vecs[0] && hw <= mpic->timer_vecs[3]) {
+ WARN_ON(!(mpic->flags & MPIC_PRIMARY));
+
+ DBG("mpic: mapping as timer\n");
+ set_irq_chip_data(virq, mpic);
+ set_irq_chip_and_handler(virq, &mpic->hc_tm,
+ handle_fasteoi_irq);
+ return 0;
+ }
#ifdef CONFIG_SMP
else if (hw >= mpic->ipi_vecs[0]) {
WARN_ON(!(mpic->flags & MPIC_PRIMARY));
@@ -1090,6 +1159,9 @@ struct mpic * __init mpic_alloc(struct device_node *node,
mpic->hc_ipi.typename = name;
#endif /* CONFIG_SMP */
+ mpic->hc_tm = mpic_tm_chip;
+ mpic->hc_tm.typename = name;
+
mpic->flags = flags;
mpic->isu_size = isu_size;
mpic->irq_count = irq_count;
@@ -1279,15 +1351,17 @@ void __init mpic_init(struct mpic *mpic)
/* Set current processor priority to max */
mpic_cpu_write(MPIC_INFO(CPU_CURRENT_TASK_PRI), 0xf);
- /* Initialize timers: just disable them all */
+ /* Initialize timers to our reserved vectors and mask them for now */
for (i = 0; i < 4; i++) {
mpic_write(mpic->tmregs,
i * MPIC_INFO(TIMER_STRIDE) +
- MPIC_INFO(TIMER_DESTINATION), 0);
+ MPIC_INFO(TIMER_DESTINATION),
+ 1 << hard_smp_processor_id());
mpic_write(mpic->tmregs,
i * MPIC_INFO(TIMER_STRIDE) +
MPIC_INFO(TIMER_VECTOR_PRI),
MPIC_VECPRI_MASK |
+ (9 << MPIC_VECPRI_PRIORITY_SHIFT) |
(mpic->timer_vecs[0] + i));
}
@@ -1378,8 +1452,8 @@ void __init mpic_set_serial_int(struct mpic *mpic, int enable)
void mpic_irq_set_priority(unsigned int irq, unsigned int pri)
{
- unsigned int is_ipi;
- struct mpic *mpic = mpic_find(irq, &is_ipi);
+ unsigned int is_ipi, is_tm;
+ struct mpic *mpic = mpic_find(irq, &is_ipi, &is_tm);
unsigned int src = mpic_irq_to_hw(irq);
unsigned long flags;
u32 reg;
@@ -1393,6 +1467,11 @@ void mpic_irq_set_priority(unsigned int irq, unsigned int pri)
~MPIC_VECPRI_PRIORITY_MASK;
mpic_ipi_write(src - mpic->ipi_vecs[0],
reg | (pri << MPIC_VECPRI_PRIORITY_SHIFT));
+ } else if (is_tm) {
+ reg = mpic_tm_read(src - mpic->timer_vecs[0]) &
+ ~MPIC_VECPRI_PRIORITY_MASK;
+ mpic_tm_write(src - mpic->timer_vecs[0],
+ reg | (pri << MPIC_VECPRI_PRIORITY_SHIFT));
} else {
reg = mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI))
& ~MPIC_VECPRI_PRIORITY_MASK;
diff --git a/arch/powerpc/sysdev/mpic_timer.c b/arch/powerpc/sysdev/mpic_timer.c
new file mode 100644
index 0000000..1d39732
--- /dev/null
+++ b/arch/powerpc/sysdev/mpic_timer.c
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 2008 Freescale Semiconductor, Inc. All rights reserved.
+ * Dave Liu <daveliu at freescale.com>
+ * copy from the 83xx GTM driver and modify for MPIC global timer,
+ * implement the global timer 0 function.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/interrupt.h>
+#include <linux/sysfs.h>
+#include <linux/of_platform.h>
+
+#include <linux/io.h>
+#include <linux/irq.h>
+
+#include <sysdev/fsl_soc.h>
+
+#define MPIC_TIMER_TCR_OFFSET 0x200
+#define MPIC_TIMER_TCR_CLKDIV_64 0x00000300
+#define MPIC_TIMER_STOP 0x80000000
+
+struct mpic_tm_regs {
+ u32 gtccr;
+ u32 res0[3];
+ u32 gtbcr;
+ u32 res1[3];
+ u32 gtvpr;
+ u32 res2[3];
+ u32 gtdr;
+ u32 res3[3];
+};
+
+struct mpic_tm_priv {
+ struct mpic_tm_regs __iomem *regs;
+ int irq;
+ int ticks_per_sec;
+ spinlock_t lock;
+};
+
+struct mpic_type {
+ int has_tcr;
+};
+
+static irqreturn_t mpic_tm_isr(int irq, void *dev_id)
+{
+ struct mpic_tm_priv *priv = dev_id;
+ unsigned long flags;
+ unsigned long temp;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ temp = in_be32(&priv->regs->gtbcr);
+ temp |= MPIC_TIMER_STOP; /* counting inhibited */
+ out_be32(&priv->regs->gtbcr, temp);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static ssize_t mpic_tm_timeout_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct mpic_tm_priv *priv = dev_get_drvdata(dev);
+ unsigned long interval = simple_strtoul(buf, NULL, 0);
+ unsigned long temp;
+
+ if (interval > 0x7fffffff) {
+ dev_dbg(dev, "mpic_tm: interval %lu (in ns) too long\n", interval);
+ return -EINVAL;
+ }
+
+ interval *= priv->ticks_per_sec;
+
+ if (interval > 0x7fffffff) {
+ dev_dbg(dev, "mpic_tm: interval %lu (in ticks) too long\n",
+ interval);
+ return -EINVAL;
+ }
+
+ spin_lock_irq(&priv->lock);
+
+ /* stop timer 0 */
+ temp = in_be32(&priv->regs->gtbcr);
+ temp |= MPIC_TIMER_STOP; /* counting inhibited */
+ out_be32(&priv->regs->gtbcr, temp);
+
+ if (interval != 0) {
+ /* start timer */
+ out_be32(&priv->regs->gtbcr, interval | MPIC_TIMER_STOP);
+ out_be32(&priv->regs->gtbcr, interval);
+ }
+
+ spin_unlock_irq(&priv->lock);
+ return count;
+}
+
+static ssize_t mpic_tm_timeout_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct mpic_tm_priv *priv = dev_get_drvdata(dev);
+ int timeout = 0;
+
+ spin_lock_irq(&priv->lock);
+
+ if (!(in_be32(&priv->regs->gtbcr) & MPIC_TIMER_STOP)) {
+ timeout = in_be32(&priv->regs->gtccr);
+ timeout += priv->ticks_per_sec - 1;
+ timeout /= priv->ticks_per_sec;
+ }
+
+ spin_unlock_irq(&priv->lock);
+ return sprintf(buf, "%u\n", timeout);
+}
+
+static DEVICE_ATTR(timeout, 0660, mpic_tm_timeout_show, mpic_tm_timeout_store);
+
+static int __devinit mpic_tm_probe(struct of_device *dev,
+ const struct of_device_id *match)
+{
+ struct device_node *np = dev->node;
+ struct resource res;
+ struct mpic_tm_priv *priv;
+ struct mpic_type *type = match->data;
+ int has_tcr = type->has_tcr;
+ u32 busfreq = fsl_get_sys_freq();
+ int ret = 0;
+
+ if (busfreq == 0) {
+ dev_err(&dev->dev, "mpic_tm: No bus frequency in device tree.\n");
+ return -ENODEV;
+ }
+
+ priv = kmalloc(sizeof(struct mpic_tm_priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ spin_lock_init(&priv->lock);
+ dev_set_drvdata(&dev->dev, priv);
+
+ ret = of_address_to_resource(np, 0, &res);
+ if (ret)
+ goto out;
+
+ priv->irq = irq_of_parse_and_map(np, 0);
+ if (priv->irq == NO_IRQ) {
+ dev_err(&dev->dev, "MPIC global timer0 exists in device tree "
+ "without an IRQ.\n");
+ ret = -ENODEV;
+ goto out;
+ }
+
+ ret = request_irq(priv->irq, mpic_tm_isr, 0, "mpic timer 0", priv);
+ if (ret)
+ goto out;
+
+ priv->regs = ioremap(res.start, res.end - res.start + 1);
+ if (!priv->regs) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * MPIC implementation from Freescale has the TCR register,
+ * the MPIC_TIMER_TCR_OFFSET is 0x200 from global timer base
+ * the default clock source to the MPIC timer 0 is CCB freq / 8.
+ * to extend the timer period, we divide the timer clock source
+ * as CCB freq / 64, so the max timer period is 336 seconds
+ * when the CCB frequence is 400MHz.
+ */
+ if (!has_tcr) {
+ priv->ticks_per_sec = busfreq / 8;
+ } else {
+ u32 __iomem *tcr;
+ tcr = (u32 __iomem *)((u32)priv->regs + MPIC_TIMER_TCR_OFFSET);
+ out_be32(tcr, in_be32(tcr) | MPIC_TIMER_TCR_CLKDIV_64);
+ priv->ticks_per_sec = busfreq / 64;
+ }
+
+ ret = device_create_file(&dev->dev, &dev_attr_timeout);
+ if (ret)
+ goto out;
+
+ printk("MPIC global timer init done.\n");
+
+ return 0;
+
+out:
+ kfree(priv);
+ return ret;
+}
+
+static int __devexit mpic_tm_remove(struct of_device *dev)
+{
+ struct mpic_tm_priv *priv = dev_get_drvdata(&dev->dev);
+
+ device_remove_file(&dev->dev, &dev_attr_timeout);
+ free_irq(priv->irq, priv);
+ iounmap(priv->regs);
+
+ dev_set_drvdata(&dev->dev, NULL);
+ kfree(priv);
+ return 0;
+}
+
+static struct mpic_type mpic_types[] = {
+ {
+ .has_tcr = 0,
+ },
+ {
+ .has_tcr = 1,
+ }
+};
+
+static struct of_device_id mpic_tm_match[] = {
+ {
+ .compatible = "mpic-global-timer",
+ .data = &mpic_types[0],
+ },
+ {
+ .compatible = "fsl,mpic-global-timer",
+ .data = &mpic_types[1],
+ },
+ {},
+};
+
+static struct of_platform_driver mpic_tm_driver = {
+ .name = "mpic-global-timer",
+ .match_table = mpic_tm_match,
+ .probe = mpic_tm_probe,
+ .remove = __devexit_p(mpic_tm_remove)
+};
+
+static int __init mpic_tm_init(void)
+{
+ return of_register_platform_driver(&mpic_tm_driver);
+}
+
+static void __exit mpic_tm_exit(void)
+{
+ of_unregister_platform_driver(&mpic_tm_driver);
+}
+
+module_init(mpic_tm_init);
+module_exit(mpic_tm_exit);
--
1.5.6.5
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