[PATCH] IBM PReP power down

[PATCH] IBM PReP power down

[Hollis Blanchard]

This patch allows IBM PReP machines to power down (instead of 'while (1);') on
poweroff. It works on 7248-43P, and should work on the other Carolina
machines: 6070 and 6050 (which are still having serious i8259 problems).
Because all the older IBM systems seem to have an identical power management
system, it should also work on the 7043-140 (Tiger 1) in PReP mode and
probably most other IBM PReP machines.

The patch is against _2_4, but applies with slight offsets to _2_4_devel as
well. Please commit to both?

-Hollis

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: [PATCH] IBM PReP power down

[Hollis Blanchard]

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On Fri, Aug 03, 2001 at 11:46:08AM -0500, Hollis Blanchard wrote:
>
> The patch is against _2_4, but applies with slight offsets to _2_4_devel as
> well. Please commit to both?

[-- Attachment #2: ibmprep_poweroff.patch --]
[-- Type: text/plain, Size: 3511 bytes --]

===== arch/ppc/kernel/prep_setup.c 1.22 vs edited =====
--- 1.22/arch/ppc/kernel/prep_setup.c	Tue Jun  5 05:45:53 2001
+++ edited/arch/ppc/kernel/prep_setup.c	Tue Jul 31 17:02:24 2001
@@ -14,6 +14,7 @@
  */

 #include <linux/config.h>
+#include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
@@ -496,21 +497,20 @@
 void __prep
 prep_restart(char *cmd)
 {
-        unsigned long i = 10000;
-
+	unsigned long i = 10000;

 	__cli();

-        /* set exception prefix high - to the prom */
-        _nmask_and_or_msr(0, MSR_IP);
+	/* set exception prefix high - to the prom */
+	_nmask_and_or_msr(0, MSR_IP);

-        /* make sure bit 0 (reset) is a 0 */
-        outb( inb(0x92) & ~1L , 0x92 );
-        /* signal a reset to system control port A - soft reset */
-        outb( inb(0x92) | 1 , 0x92 );
+	/* make sure bit 0 (reset) is a 0 */
+	outb( inb(0x92) & ~1L , 0x92 );
+	/* signal a reset to system control port A - soft reset */
+	outb( inb(0x92) | 1 , 0x92 );

-        while ( i != 0 ) i++;
-        panic("restart failed\n");
+	while ( i != 0 ) i++;
+	panic("restart failed\n");
 }

 /*
@@ -542,27 +542,92 @@
 void __prep
 prep_halt(void)
 {
-        unsigned long flags;
+	unsigned long flags;
 	__cli();
 	/* set exception prefix high - to the prom */
 	save_flags( flags );
 	restore_flags( flags|MSR_IP );
-
+
 	/* make sure bit 0 (reset) is a 0 */
 	outb( inb(0x92) & ~1L , 0x92 );
 	/* signal a reset to system control port A - soft reset */
 	outb( inb(0x92) | 1 , 0x92 );
-
+
 	while ( 1 ) ;
 	/*
 	 * Not reached
 	 */
 }

+/*
+ * On IBM PReP's, power management is handled by a Signetics 87c750 behind the
+ * Utah component on the ISA bus. To access the 750 you must write a series of
+ * nibbles to port 0x82a (decoded by the Utah). This is described somewhat in
+ * the IBM Carolina Technical Specification.
+ * -Hollis
+ */
+void __prep
+utah_sig87c750_setbit(unsigned int bytenum, unsigned int bitnum, int value)
+{
+	/*
+	 * byte1: 0 0 0 1 0  d  a5 a4
+	 * byte2: 0 0 0 1 a3 a2 a1 a0
+	 *
+	 * d = the bit's value, enabled or disabled
+	 * (a5 a4 a3) = the byte number, minus 20
+	 * (a2 a1 a0) = the bit number
+	 *
+	 * example: set the 5th bit of byte 21 (21.5)
+	 *     a5 a4 a3 = 001 (byte 1)
+	 *     a2 a1 a0 = 101 (bit 5)
+	 *
+	 *     byte1 = 0001 0100 (0x14)
+	 *     byte2 = 0001 1101 (0x1d)
+	 */
+	unsigned char byte1=0x10, byte2=0x10;
+	const unsigned int pm_reg_1=0x82a; /* ISA address */
+
+	/* the 750's '20.0' is accessed as '0.0' through Utah (which adds 20) */
+	bytenum -= 20;
+
+	byte1 |= (!!value) << 2;		/* set d */
+	byte1 |= (bytenum >> 1) & 0x3;	/* set a5, a4 */
+
+	byte2 |= (bytenum & 0x1) << 3;	/* set a3 */
+	byte2 |= bitnum & 0x7;			/* set a2, a1, a0 */
+
+	outb(byte1, pm_reg_1);		/* first nibble */
+	mb();
+	udelay(100);				/* important: let controller recover */
+
+	outb(byte2, pm_reg_1);		/* second nibble */
+	mb();
+	udelay(100);				/* important: let controller recover */
+}
+
 void __prep
 prep_power_off(void)
 {
-	prep_halt();
+	if ( _prep_type == _PREP_IBM) {
+		/* tested on:
+		 * 		7248-43P (Carolina)
+		 * should work on:
+		 * 		6050, 6070 (Carolina's)
+		 * 		7043-140 (Tiger 1)
+		 */
+		unsigned long flags;
+		__cli();
+		/* set exception prefix high - to the prom */
+		save_flags( flags );
+		restore_flags( flags|MSR_IP );
+
+		utah_sig87c750_setbit(21, 5, 1); /* set bit 21.5, "PMEXEC_OFF" */
+
+		while ( 1 ) ;
+		/* not reached */
+	} else {
+		prep_halt();
+	}
 }

 int __prep

Re: [PATCH] IBM PReP power down

[Tom Rini]

On Fri, Aug 03, 2001 at 11:46:08AM -0500, Hollis Blanchard wrote:

> The patch is against _2_4, but applies with slight offsets to _2_4_devel as
> well. Please commit to both?

It currently fails on 2_4, and it's the big hunk too.  Also, can't
utah_sig87c750_setbit be 'static'?  Aside from that it looks good..

--
Tom Rini (TR1265)
http://gate.crashing.org/~trini/

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Re: [PATCH] IBM PReP power down

[Hollis Blanchard]

[-- Attachment #1: Type: text/plain, Size: 421 bytes --]

On Fri, Aug 03, 2001 at 10:02:51AM -0700, Tom Rini wrote:
>
> On Fri, Aug 03, 2001 at 11:46:08AM -0500, Hollis Blanchard wrote:
>
> > The patch is against _2_4, but applies with slight offsets to _2_4_devel as
> > well. Please commit to both?
>
> It currently fails on 2_4, and it's the big hunk too.  Also, can't
> utah_sig87c750_setbit be 'static'?  Aside from that it looks good..

This one should be better.

-Hollis

[-- Attachment #2: ibmprep_poweroff.patch2 --]
[-- Type: text/plain, Size: 3526 bytes --]

diff -Nru a/arch/ppc/kernel/prep_setup.c b/arch/ppc/kernel/prep_setup.c
--- a/arch/ppc/kernel/prep_setup.c	Fri Aug  3 13:33:01 2001
+++ b/arch/ppc/kernel/prep_setup.c	Fri Aug  3 13:33:01 2001
@@ -14,6 +14,7 @@
  */

 #include <linux/config.h>
+#include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
@@ -496,21 +497,20 @@
 void __prep
 prep_restart(char *cmd)
 {
-        unsigned long i = 10000;
-
+	unsigned long i = 10000;

 	__cli();

-        /* set exception prefix high - to the prom */
-        _nmask_and_or_msr(0, MSR_IP);
+	/* set exception prefix high - to the prom */
+	_nmask_and_or_msr(0, MSR_IP);

-        /* make sure bit 0 (reset) is a 0 */
-        outb( inb(0x92) & ~1L , 0x92 );
-        /* signal a reset to system control port A - soft reset */
-        outb( inb(0x92) | 1 , 0x92 );
+	/* make sure bit 0 (reset) is a 0 */
+	outb( inb(0x92) & ~1L , 0x92 );
+	/* signal a reset to system control port A - soft reset */
+	outb( inb(0x92) | 1 , 0x92 );

-        while ( i != 0 ) i++;
-        panic("restart failed\n");
+	while ( i != 0 ) i++;
+	panic("restart failed\n");
 }

 /*
@@ -542,27 +542,92 @@
 void __prep
 prep_halt(void)
 {
-        unsigned long flags;
+	unsigned long flags;
 	__cli();
 	/* set exception prefix high - to the prom */
 	save_flags( flags );
 	restore_flags( flags|MSR_IP );
-
+
 	/* make sure bit 0 (reset) is a 0 */
 	outb( inb(0x92) & ~1L , 0x92 );
 	/* signal a reset to system control port A - soft reset */
 	outb( inb(0x92) | 1 , 0x92 );
-
+
 	while ( 1 ) ;
 	/*
 	 * Not reached
 	 */
 }

+/*
+ * On IBM PReP's, power management is handled by a Signetics 87c750 behind the
+ * Utah component on the ISA bus. To access the 750 you must write a series of
+ * nibbles to port 0x82a (decoded by the Utah). This is described somewhat in
+ * the IBM Carolina Technical Specification.
+ * -Hollis
+ */
+static void __prep
+utah_sig87c750_setbit(unsigned int bytenum, unsigned int bitnum, int value)
+{
+	/*
+	 * byte1: 0 0 0 1 0  d  a5 a4
+	 * byte2: 0 0 0 1 a3 a2 a1 a0
+	 *
+	 * d = the bit's value, enabled or disabled
+	 * (a5 a4 a3) = the byte number, minus 20
+	 * (a2 a1 a0) = the bit number
+	 *
+	 * example: set the 5th bit of byte 21 (21.5)
+	 *     a5 a4 a3 = 001 (byte 1)
+	 *     a2 a1 a0 = 101 (bit 5)
+	 *
+	 *     byte1 = 0001 0100 (0x14)
+	 *     byte2 = 0001 1101 (0x1d)
+	 */
+	unsigned char byte1=0x10, byte2=0x10;
+	const unsigned int pm_reg_1=0x82a; /* ISA address */
+
+	/* the 750's '20.0' is accessed as '0.0' through Utah (which adds 20) */
+	bytenum -= 20;
+
+	byte1 |= (!!value) << 2;		/* set d */
+	byte1 |= (bytenum >> 1) & 0x3;	/* set a5, a4 */
+
+	byte2 |= (bytenum & 0x1) << 3;	/* set a3 */
+	byte2 |= bitnum & 0x7;			/* set a2, a1, a0 */
+
+	outb(byte1, pm_reg_1);		/* first nibble */
+	mb();
+	udelay(100);				/* important: let controller recover */
+
+	outb(byte2, pm_reg_1);		/* second nibble */
+	mb();
+	udelay(100);				/* important: let controller recover */
+}
+
 void __prep
 prep_power_off(void)
 {
-	prep_halt();
+	if ( _prep_type == _PREP_IBM) {
+		/* tested on:
+		 * 		7248-43P (Carolina)
+		 * should work on:
+		 * 		6050, 6070 (Carolina's)
+		 * 		7043-140 (Tiger 1)
+		 */
+		unsigned long flags;
+		__cli();
+		/* set exception prefix high - to the prom */
+		save_flags( flags );
+		restore_flags( flags|MSR_IP );
+
+		utah_sig87c750_setbit(21, 5, 1); /* set bit 21.5, "PMEXEC_OFF" */
+
+		while ( 1 ) ;
+		/* not reached */
+	} else {
+		prep_halt();
+	}
 }

 int __prep