Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=83d7384f8d4aa216b49cf9cb286ea743054b119f
Commit: 83d7384f8d4aa216b49cf9cb286ea743054b119f
Parent: 5fa3a246ea2e1be2ffaa01343bc183c8c0bfa472
Author: Andres Salomon <[EMAIL PROTECTED]>
AuthorDate: Fri Oct 12 23:04:06 2007 +0200
Committer: Thomas Gleixner <[EMAIL PROTECTED]>
CommitDate: Fri Oct 12 23:04:06 2007 +0200
x86: Geode Multi-Function General Purpose Timers support
This adds support for Multi-Function General Purpose Timers. It detects the
available timers during southbridge init, and provides an API for allocating
and setting the timers. They're higher resolution than the standard PIT, so
the MFGPTs come in handy for quite a few things.
Note that we never clobber the timers that the BIOS might have opted to use;
we just check for unused timers.
Signed-off-by: Jordan Crouse <[EMAIL PROTECTED]>
Signed-off-by: Andres Salomon <[EMAIL PROTECTED]>
Cc: Andi Kleen <[EMAIL PROTECTED]>
Cc: Alan Cox <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
Signed-off-by: Arjan van de Ven <[EMAIL PROTECTED]>
Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]>
---
Documentation/kernel-parameters.txt | 3 +
arch/x86/kernel/Makefile_32 | 2 +-
arch/x86/kernel/geode_32.c | 4 +
arch/x86/kernel/mfgpt_32.c | 197 +++++++++++++++++++++++++++++++++++
include/asm-x86/geode.h | 50 +++++++++
5 files changed, 255 insertions(+), 1 deletions(-)
diff --git a/Documentation/kernel-parameters.txt
b/Documentation/kernel-parameters.txt
index a57c1f2..2128de6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1160,6 +1160,9 @@ and is between 256 and 4096 characters. It is defined in
the file
nomce [X86-32] Machine Check Exception
+ nomfgpt [X86-32] Disable Multi-Function General Purpose
+ Timer usage (for AMD Geode machines).
+
noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32
index c624193..1035644 100644
--- a/arch/x86/kernel/Makefile_32
+++ b/arch/x86/kernel/Makefile_32
@@ -39,7 +39,7 @@ obj-$(CONFIG_VM86) += vm86_32.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_HPET_TIMER) += hpet_32.o
obj-$(CONFIG_K8_NB) += k8.o
-obj-$(CONFIG_MGEODE_LX) += geode_32.o
+obj-$(CONFIG_MGEODE_LX) += geode_32.o mfgpt_32.o
obj-$(CONFIG_VMI) += vmi_32.o vmiclock_32.o
obj-$(CONFIG_PARAVIRT) += paravirt_32.o
diff --git a/arch/x86/kernel/geode_32.c b/arch/x86/kernel/geode_32.c
index 41e8aec..f12d8c5 100644
--- a/arch/x86/kernel/geode_32.c
+++ b/arch/x86/kernel/geode_32.c
@@ -145,10 +145,14 @@ EXPORT_SYMBOL_GPL(geode_gpio_setup_event);
static int __init geode_southbridge_init(void)
{
+ int timers;
+
if (!is_geode())
return -ENODEV;
init_lbars();
+ timers = geode_mfgpt_detect();
+ printk(KERN_INFO "geode: %d MFGPT timers available.\n", timers);
return 0;
}
diff --git a/arch/x86/kernel/mfgpt_32.c b/arch/x86/kernel/mfgpt_32.c
new file mode 100644
index 0000000..3a63a2d
--- /dev/null
+++ b/arch/x86/kernel/mfgpt_32.c
@@ -0,0 +1,197 @@
+/*
+ * Driver/API for AMD Geode Multi-Function General Purpose Timers (MFGPT)
+ *
+ * Copyright (C) 2006, Advanced Micro Devices, Inc.
+ * Copyright (C) 2007, Andres Salomon <[EMAIL PROTECTED]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ *
+ * The MFGPTs are documented in AMD Geode CS5536 Companion Device Data Book.
+ */
+
+/*
+ * We are using the 32Khz input clock - its the only one that has the
+ * ranges we find desirable. The following table lists the suitable
+ * divisors and the associated hz, minimum interval
+ * and the maximum interval:
+ *
+ * Divisor Hz Min Delta (S) Max Delta (S)
+ * 1 32000 .0005 2.048
+ * 2 16000 .001 4.096
+ * 4 8000 .002 8.192
+ * 8 4000 .004 16.384
+ * 16 2000 .008 32.768
+ * 32 1000 .016 65.536
+ * 64 500 .032 131.072
+ * 128 250 .064 262.144
+ * 256 125 .128 524.288
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <asm/geode.h>
+
+#define F_AVAIL 0x01
+
+static struct mfgpt_timer_t {
+ int flags;
+ struct module *owner;
+} mfgpt_timers[MFGPT_MAX_TIMERS];
+
+/* Selected from the table above */
+
+#define MFGPT_DIVISOR 16
+#define MFGPT_SCALE 4 /* divisor = 2^(scale) */
+#define MFGPT_HZ (32000 / MFGPT_DIVISOR)
+#define MFGPT_PERIODIC (MFGPT_HZ / HZ)
+
+/* Allow for disabling of MFGPTs */
+static int disable;
+static int __init mfgpt_disable(char *s)
+{
+ disable = 1;
+ return 1;
+}
+__setup("nomfgpt", mfgpt_disable);
+
+/*
+ * Check whether any MFGPTs are available for the kernel to use. In most
+ * cases, firmware that uses AMD's VSA code will claim all timers during
+ * bootup; we certainly don't want to take them if they're already in use.
+ * In other cases (such as with VSAless OpenFirmware), the system firmware
+ * leaves timers available for us to use.
+ */
+int __init geode_mfgpt_detect(void)
+{
+ int count = 0, i;
+ u16 val;
+
+ if (disable) {
+ printk(KERN_INFO "geode-mfgpt: Skipping MFGPT setup\n");
+ return 0;
+ }
+
+ for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
+ val = geode_mfgpt_read(i, MFGPT_REG_SETUP);
+ if (!(val & MFGPT_SETUP_SETUP)) {
+ mfgpt_timers[i].flags = F_AVAIL;
+ count++;
+ }
+ }
+
+ return count;
+}
+
+int geode_mfgpt_toggle_event(int timer, int cmp, int event, int enable)
+{
+ u32 msr, mask, value, dummy;
+ int shift = (cmp == MFGPT_CMP1) ? 0 : 8;
+
+ if (timer < 0 || timer >= MFGPT_MAX_TIMERS)
+ return -EIO;
+
+ /*
+ * The register maps for these are described in sections 6.17.1.x of
+ * the AMD Geode CS5536 Companion Device Data Book.
+ */
+ switch (event) {
+ case MFGPT_EVENT_RESET:
+ /*
+ * XXX: According to the docs, we cannot reset timers above
+ * 6; that is, resets for 7 and 8 will be ignored. Is this
+ * a problem? -dilinger
+ */
+ msr = MFGPT_NR_MSR;
+ mask = 1 << (timer + 24);
+ break;
+
+ case MFGPT_EVENT_NMI:
+ msr = MFGPT_NR_MSR;
+ mask = 1 << (timer + shift);
+ break;
+
+ case MFGPT_EVENT_IRQ:
+ msr = MFGPT_IRQ_MSR;
+ mask = 1 << (timer + shift);
+ break;
+
+ default:
+ return -EIO;
+ }
+
+ rdmsr(msr, value, dummy);
+
+ if (enable)
+ value |= mask;
+ else
+ value &= ~mask;
+
+ wrmsr(msr, value, dummy);
+ return 0;
+}
+
+int geode_mfgpt_set_irq(int timer, int cmp, int irq, int enable)
+{
+ u32 val, dummy;
+ int offset;
+
+ if (timer < 0 || timer >= MFGPT_MAX_TIMERS)
+ return -EIO;
+
+ if (geode_mfgpt_toggle_event(timer, cmp, MFGPT_EVENT_IRQ, enable))
+ return -EIO;
+
+ rdmsr(MSR_PIC_ZSEL_LOW, val, dummy);
+
+ offset = (timer % 4) * 4;
+
+ val &= ~((0xF << offset) | (0xF << (offset + 16)));
+
+ if (enable) {
+ val |= (irq & 0x0F) << (offset);
+ val |= (irq & 0x0F) << (offset + 16);
+ }
+
+ wrmsr(MSR_PIC_ZSEL_LOW, val, dummy);
+ return 0;
+}
+
+static int mfgpt_get(int timer, struct module *owner)
+{
+ mfgpt_timers[timer].flags &= ~F_AVAIL;
+ mfgpt_timers[timer].owner = owner;
+ printk(KERN_INFO "geode-mfgpt: Registered timer %d\n", timer);
+ return timer;
+}
+
+int geode_mfgpt_alloc_timer(int timer, int domain, struct module *owner)
+{
+ int i;
+
+ if (!geode_get_dev_base(GEODE_DEV_MFGPT))
+ return -ENODEV;
+ if (timer >= MFGPT_MAX_TIMERS)
+ return -EIO;
+
+ if (timer < 0) {
+ /* Try to find an available timer */
+ for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
+ if (mfgpt_timers[i].flags & F_AVAIL)
+ return mfgpt_get(i, owner);
+
+ if (i == 5 && domain == MFGPT_DOMAIN_WORKING)
+ break;
+ }
+ } else {
+ /* If they requested a specific timer, try to honor that */
+ if (mfgpt_timers[timer].flags & F_AVAIL)
+ return mfgpt_get(timer, owner);
+ }
+
+ /* No timers available - too bad */
+ return -1;
+}
+
diff --git a/include/asm-x86/geode.h b/include/asm-x86/geode.h
index 6da4bbb..d948988 100644
--- a/include/asm-x86/geode.h
+++ b/include/asm-x86/geode.h
@@ -156,4 +156,54 @@ static inline int is_geode(void)
return (is_geode_gx() || is_geode_lx());
}
+/* MFGPTs */
+
+#define MFGPT_MAX_TIMERS 8
+#define MFGPT_TIMER_ANY -1
+
+#define MFGPT_DOMAIN_WORKING 1
+#define MFGPT_DOMAIN_STANDBY 2
+#define MFGPT_DOMAIN_ANY (MFGPT_DOMAIN_WORKING | MFGPT_DOMAIN_STANDBY)
+
+#define MFGPT_CMP1 0
+#define MFGPT_CMP2 1
+
+#define MFGPT_EVENT_IRQ 0
+#define MFGPT_EVENT_NMI 1
+#define MFGPT_EVENT_RESET 3
+
+#define MFGPT_REG_CMP1 0
+#define MFGPT_REG_CMP2 2
+#define MFGPT_REG_COUNTER 4
+#define MFGPT_REG_SETUP 6
+
+#define MFGPT_SETUP_CNTEN (1 << 15)
+#define MFGPT_SETUP_CMP2 (1 << 14)
+#define MFGPT_SETUP_CMP1 (1 << 13)
+#define MFGPT_SETUP_SETUP (1 << 12)
+#define MFGPT_SETUP_STOPEN (1 << 11)
+#define MFGPT_SETUP_EXTEN (1 << 10)
+#define MFGPT_SETUP_REVEN (1 << 5)
+#define MFGPT_SETUP_CLKSEL (1 << 4)
+
+static inline void geode_mfgpt_write(int timer, u16 reg, u16 value)
+{
+ u32 base = geode_get_dev_base(GEODE_DEV_MFGPT);
+ outw(value, base + reg + (timer * 8));
+}
+
+static inline u16 geode_mfgpt_read(int timer, u16 reg)
+{
+ u32 base = geode_get_dev_base(GEODE_DEV_MFGPT);
+ return inw(base + reg + (timer * 8));
+}
+
+extern int __init geode_mfgpt_detect(void);
+extern int geode_mfgpt_toggle_event(int timer, int cmp, int event, int enable);
+extern int geode_mfgpt_set_irq(int timer, int cmp, int irq, int enable);
+extern int geode_mfgpt_alloc_timer(int timer, int domain, struct module
*owner);
+
+#define geode_mfgpt_setup_irq(t, c, i) geode_mfgpt_set_irq((t), (c), (i), 1)
+#define geode_mfgpt_release_irq(t, c, i) geode_mfgpt_set_irq((t), (c), (i), 0)
+
#endif
-
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