[PATCH] mpic: add support for serial mode interrupts

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

This patch adds the software support for that mode.

Signed-off-by: Mark A. Greer <redacted>
--

 arch/powerpc/sysdev/mpic.c |    6 ++++++
 include/asm-powerpc/mpic.h |    2 ++
 2 files changed, 8 insertions(+)
--

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 7dcdfcb..1829aed 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c

@@ -629,6 +629,12 @@ #endif /* CONFIG_SMP */
 			mb();
 	}
 
+	/* For serial interrupts & set clock ratio */
+	if (flags & MPIC_SERIAL_MODE)
+		mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1,
+			mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1)
+				| (1<<27) | (0x7<<28));
+
 	/* Read feature register, calculate num CPUs and, for non-ISU
 	 * MPICs, num sources as well. On ISU MPICs, sources are counted
 	 * as ISUs are added

diff --git a/include/asm-powerpc/mpic.h b/include/asm-powerpc/mpic.h
index 6b9e781..f35ccdc 100644
--- a/include/asm-powerpc/mpic.h
+++ b/include/asm-powerpc/mpic.h

@@ -186,6 +186,8 @@ #define MPIC_BROKEN_U3			0x00000004
 #define MPIC_BROKEN_IPI			0x00000008
 /* MPIC wants a reset */
 #define MPIC_WANTS_RESET		0x00000010
+/* MPIC serial mode */
+#define MPIC_SERIAL_MODE		0x00000020
 
 /* Allocate the controller structure and setup the linux irq descs
  * for the range if interrupts passed in. No HW initialization is

Hi,

On Mon, Jun 19, 2006 at 01:08:11PM -0700, Mark A. Greer wrote:

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

[...]

+	/* For serial interrupts & set clock ratio */
+	if (flags & MPIC_SERIAL_MODE)
+		mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1,
+			mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1)
+				| (1<<27) | (0x7<<28));

Can you define some constants so others can see just what the bits mean
without digging up documentation, instead of just doing magic numbers?

MPIC_GREG_GLOBAL_CONF_0 already does so; you can copy the style from
there.


Thanks,

-Olof

On Mon, Jun 19, 2006 at 03:11:21PM -0500, Olof Johansson wrote:

Hi,

On Mon, Jun 19, 2006 at 01:08:11PM -0700, Mark A. Greer wrote:

quoted

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

[...]

quoted

+	/* For serial interrupts & set clock ratio */
+	if (flags & MPIC_SERIAL_MODE)
+		mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1,
+			mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1)
+				| (1<<27) | (0x7<<28));

Can you define some constants so others can see just what the bits mean
without digging up documentation, instead of just doing magic numbers?

Yeah, I can probably do that...  :)

Mark

[This patch completely replaces the previous patch.]

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

This patch adds the software support for that mode.

Signed-off-by: Mark A. Greer <redacted>
--

 arch/powerpc/sysdev/mpic.c |    8 ++++++++
 include/asm-powerpc/mpic.h |    5 +++++
 2 files changed, 13 insertions(+)
--

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 7dcdfcb..397b886 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c

@@ -629,6 +629,14 @@ #endif /* CONFIG_SMP */
 			mb();
 	}
 
+	/* For serial interrupts & set clock ratio */
+	if (flags & MPIC_SERIAL_MODE)
+		mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1,
+			(mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1)
+				& ~MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO_MASK)
+					| MPIC_GREG_GLOBAL_CONF_1_SIE
+					| MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO(7));
+
 	/* Read feature register, calculate num CPUs and, for non-ISU
 	 * MPICs, num sources as well. On ISU MPICs, sources are counted
 	 * as ISUs are added

diff --git a/include/asm-powerpc/mpic.h b/include/asm-powerpc/mpic.h
index 6b9e781..0be8254 100644
--- a/include/asm-powerpc/mpic.h
+++ b/include/asm-powerpc/mpic.h

@@ -22,6 +22,9 @@ #define		MPIC_GREG_GCONF_RESET			0x80000
 #define		MPIC_GREG_GCONF_8259_PTHROU_DIS		0x20000000
 #define		MPIC_GREG_GCONF_BASE_MASK		0x000fffff
 #define MPIC_GREG_GLOBAL_CONF_1		0x00030
+#define		MPIC_GREG_GLOBAL_CONF_1_SIE		0x08000000/*Serial Int*/
+#define		MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO_MASK	0x70000000
+#define		MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO(r)	(((r) & 0x7) << 28)
 #define MPIC_GREG_VENDOR_0		0x00040
 #define MPIC_GREG_VENDOR_1		0x00050
 #define MPIC_GREG_VENDOR_2		0x00060

@@ -186,6 +189,8 @@ #define MPIC_BROKEN_U3			0x00000004
 #define MPIC_BROKEN_IPI			0x00000008
 /* MPIC wants a reset */
 #define MPIC_WANTS_RESET		0x00000010
+/* MPIC serial mode */
+#define MPIC_SERIAL_MODE		0x00000020
 
 /* Allocate the controller structure and setup the linux irq descs
  * for the range if interrupts passed in. No HW initialization is

Can you define some constants so others can see just what the bits  
mean
without digging up documentation, instead of just doing magic numbers?

[my favourite argument :-) ]

You'll have to read the documentation to properly understand what
the bit patterns mean anyway.  And if you use symbolic names, you
only add another step: hunting through header files.

MPIC_GREG_GLOBAL_CONF_0 already does so; you can copy the style from
there.

...but yeah, definitely, mixing styles is at least as bad.


Segher

On Mon, 2006-06-19 at 13:08 -0700, Mark A. Greer wrote:

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

This patch adds the software support for that mode.

You hard code the clock ratio... why not add a separate call to be
called after mpic_init,
something like mpic_set_serial_int(int mpic, int enable, int
clock_ratio) ?

Ben.

On Tue, Jun 20, 2006 at 02:01:26PM +1000, Benjamin Herrenschmidt wrote:

On Mon, 2006-06-19 at 13:08 -0700, Mark A. Greer wrote:

quoted

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

This patch adds the software support for that mode.

You hard code the clock ratio...

Basically, I just brought what was already in ppc over to powerpc.
I didn't really think about it much.

why not add a separate call to be called after mpic_init,
something like mpic_set_serial_int(int mpic, int enable, int
clock_ratio) ?

Yeah, that's a better way to do it.

I'll make a new patch.

Mark

On Tue, Jun 20, 2006 at 02:01:26PM +1000, Benjamin Herrenschmidt wrote:

On Mon, 2006-06-19 at 13:08 -0700, Mark A. Greer wrote:

quoted

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

This patch adds the software support for that mode.

You hard code the clock ratio... why not add a separate call to be
called after mpic_init,
something like mpic_set_serial_int(int mpic, int enable, int
clock_ratio) ?

How's this?
--

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

This patch adds the software support for that mode.

Signed-off-by: Mark A. Greer <redacted>
--

 arch/powerpc/sysdev/mpic.c |   20 ++++++++++++++++++++
 include/asm-powerpc/mpic.h |   10 ++++++++++
 2 files changed, 30 insertions(+)
--

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 7dcdfcb..bffe50d 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c

@@ -829,7 +829,27 @@ #endif
 	mpic_cpu_write(MPIC_CPU_CURRENT_TASK_PRI, 0);
 }
 
+void __init mpic_set_clk_ratio(struct mpic *mpic, u32 clock_ratio)
+{
+	u32 v;
+
+	v = mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1);
+	v &= ~MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO_MASK;
+	v |= MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO(clock_ratio);
+	mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1, v);
+}
 
+void __init mpic_set_serial_int(struct mpic *mpic, int enable)
+{
+	u32 v;
+
+	v = mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1);
+	if (enable)
+		v |= MPIC_GREG_GLOBAL_CONF_1_SIE;
+	else
+		v &= ~MPIC_GREG_GLOBAL_CONF_1_SIE;
+	mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1, v);
+}
 
 void mpic_irq_set_priority(unsigned int irq, unsigned int pri)
 {

diff --git a/include/asm-powerpc/mpic.h b/include/asm-powerpc/mpic.h
index 6b9e781..f0d22ac 100644
--- a/include/asm-powerpc/mpic.h
+++ b/include/asm-powerpc/mpic.h

@@ -22,6 +22,10 @@ #define		MPIC_GREG_GCONF_RESET			0x80000
 #define		MPIC_GREG_GCONF_8259_PTHROU_DIS		0x20000000
 #define		MPIC_GREG_GCONF_BASE_MASK		0x000fffff
 #define MPIC_GREG_GLOBAL_CONF_1		0x00030
+#define		MPIC_GREG_GLOBAL_CONF_1_SIE		0x08000000
+#define		MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO_MASK	0x70000000
+#define		MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO(r)	\
+			(((r) << 28) & MPIC_GREG_GLOBAL_CONF_1_CLK_RATIO_MASK)
 #define MPIC_GREG_VENDOR_0		0x00040
 #define MPIC_GREG_VENDOR_1		0x00050
 #define MPIC_GREG_VENDOR_2		0x00060

@@ -284,6 +288,12 @@ extern int mpic_get_one_irq(struct mpic 
 /* This one gets to the primary mpic */
 extern int mpic_get_irq(struct pt_regs *regs);
 
+/* Set the EPIC clock ratio */
+void mpic_set_clk_ratio(struct mpic *mpic, u32 clock_ratio);
+
+/* Enable/Disable EPIC serial interrupt mode */
+void mpic_set_serial_int(struct mpic *mpic, int enable);
+
 /* global mpic for pSeries */
 extern struct mpic *pSeries_mpic;
 

On Tue, 2006-06-20 at 14:15 -0700, Mark A. Greer wrote:

On Tue, Jun 20, 2006 at 02:01:26PM +1000, Benjamin Herrenschmidt wrote:

quoted

On Mon, 2006-06-19 at 13:08 -0700, Mark A. Greer wrote:

quoted

MPC10x-style interrupt controllers have a serial mode that allows
several interrupts to be clocked in through one INT signal.

This patch adds the software support for that mode.

You hard code the clock ratio... why not add a separate call to be
called after mpic_init,
something like mpic_set_serial_int(int mpic, int enable, int
clock_ratio) ?

How's this?

Looks good to me.

Ben.

On Tue, 2006-06-20 at 00:35 +0200, Segher Boessenkool wrote:

quoted

Can you define some constants so others can see just what the bits  
mean
without digging up documentation, instead of just doing magic numbers?

[my favourite argument :-) ]

You'll have to read the documentation to properly understand what
the bit patterns mean anyway.  And if you use symbolic names, you
only add another step: hunting through header files.

Sure, that's why we should remove every symbolic constant in every
driver anywhere in the kernel right ? Sure would help.

Ben.