[POWERPC] mpic: add support for serial mode interrupts

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:
> > 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 <mgreer@mvista.com>
--

 arch/powerpc/sysdev/mpic.c |   20 ++++++++++++++++++++
 include/asm-powerpc/mpic.h |   10 ++++++++++
 2 files changed, 30 insertions(+)
--
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/sysdev/mpic.c

@@ -829,7 +829,27 @@ void __init mpic_init(struct mpic *mpic)
 	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)
 {

include/asm-powerpc/mpic.h

@@ -22,6 +22,10 @@
 #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 *mpic, struct pt_regs *regs);
 /* 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;