powerpc/mpc5121: Add support for CPLD on MPC5121ADS board

Add a interrupt host for the interrupt controller in the mpc5121ads cpld.
PCI interrupts are 0-7 the rest are 8-15 Touchscreen pendown irq is
hardwired to irq1 All other irqs are chained to irq0

Signed-off-by: John Rigby <jrigby@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

5 files changed, 233 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/512x/Kconfig b/arch/powerpc/platforms/512x/Kconfig
index 5d72dc3435af..c62f893ede19 100644
--- a/arch/powerpc/platforms/512x/Kconfig
+++ b/arch/powerpc/platforms/512x/Kconfig
@@ -13,6 +13,7 @@ config MPC5121_ADS
         depends on PPC_MULTIPLATFORM && PPC32
         select DEFAULT_UIMAGE
         select PPC_MPC5121
+        select MPC5121_ADS_CPLD
         help
           This option enables support for the MPC5121E ADS board.
 
diff --git a/arch/powerpc/platforms/512x/Makefile b/arch/powerpc/platforms/512x/Makefile
index 8090e222a2dd..90be2f5717e6 100644
--- a/arch/powerpc/platforms/512x/Makefile
+++ b/arch/powerpc/platforms/512x/Makefile
@@ -2,5 +2,5 @@
 # Makefile for the Freescale PowerPC 512x linux kernel.
 #
 obj-y                           += clock.o mpc512x_shared.o
-obj-$(CONFIG_MPC5121_ADS)       += mpc5121_ads.o
+obj-$(CONFIG_MPC5121_ADS)       += mpc5121_ads.o mpc5121_ads_cpld.o
 obj-$(CONFIG_MPC5121_GENERIC)   += mpc5121_generic.o
diff --git a/arch/powerpc/platforms/512x/mpc5121_ads.c b/arch/powerpc/platforms/512x/mpc5121_ads.c
index 3ec9ca34d8e8..5ebf6939a697 100644
--- a/arch/powerpc/platforms/512x/mpc5121_ads.c
+++ b/arch/powerpc/platforms/512x/mpc5121_ads.c
@@ -23,10 +23,21 @@
 #include <asm/time.h>
 
 #include "mpc512x.h"
+#include "mpc5121_ads.h"
+
+static void __init mpc5121_ads_setup_arch(void)
+{
+        printk(KERN_INFO "MPC5121 ADS board from Freescale Semiconductor\n");
+        /*
+         * cpld regs are needed early
+         */
+        mpc5121_ads_cpld_map();
+}
 
 static void __init mpc5121_ads_init_IRQ(void)
 {
         mpc512x_init_IRQ();
+        mpc5121_ads_cpld_pic_init();
 }
 
 /*
diff --git a/arch/powerpc/platforms/512x/mpc5121_ads.h b/arch/powerpc/platforms/512x/mpc5121_ads.h
new file mode 100644
index 000000000000..662076cfee2f
--- /dev/null
+++ b/arch/powerpc/platforms/512x/mpc5121_ads.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * Prototypes for ADS5121 specific code
+ */
+
+#ifndef __MPC512ADS_H__
+#define __MPC512ADS_H__
+extern void __init mpc5121_ads_cpld_map(void);
+extern void __init mpc5121_ads_cpld_pic_init(void);
+#endif                          /* __MPC512ADS_H__ */
diff --git a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
new file mode 100644
index 000000000000..a6ce80566625
--- /dev/null
+++ b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * Author: John Rigby, <jrigby@freescale.com>
+ *
+ * Description:
+ * MPC5121ADS CPLD irq handling
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <asm/prom.h>
+
+static struct device_node *cpld_pic_node;
+static struct irq_host *cpld_pic_host;
+
+/*
+ * Bits to ignore in the misc_status register
+ * 0x10 touch screen pendown is hard routed to irq1
+ * 0x02 pci status is read from pci status register
+ */
+#define MISC_IGNORE 0x12
+
+/*
+ * Nothing to ignore in pci status register
+ */
+#define PCI_IGNORE 0x00
+
+struct cpld_pic {
+        u8 pci_mask;
+        u8 pci_status;
+        u8 route;
+        u8 misc_mask;
+        u8 misc_status;
+        u8 misc_control;
+};
+
+static struct cpld_pic __iomem *cpld_regs;
+
+static void __iomem *
+irq_to_pic_mask(unsigned int irq)
+{
+        return irq <= 7 ? &cpld_regs->pci_mask : &cpld_regs->misc_mask;
+}
+
+static unsigned int
+irq_to_pic_bit(unsigned int irq)
+{
+        return 1 << (irq & 0x7);
+}
+
+static void
+cpld_mask_irq(unsigned int irq)
+{
+        unsigned int cpld_irq = (unsigned int)irq_map[irq].hwirq;
+        void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);
+
+        out_8(pic_mask,
+              in_8(pic_mask) | irq_to_pic_bit(cpld_irq));
+}
+
+static void
+cpld_unmask_irq(unsigned int irq)
+{
+        unsigned int cpld_irq = (unsigned int)irq_map[irq].hwirq;
+        void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);
+
+        out_8(pic_mask,
+              in_8(pic_mask) & ~irq_to_pic_bit(cpld_irq));
+}
+
+static struct irq_chip cpld_pic = {
+        .typename = " CPLD PIC ",
+        .mask = cpld_mask_irq,
+        .ack = cpld_mask_irq,
+        .unmask = cpld_unmask_irq,
+};
+
+static int
+cpld_pic_get_irq(int offset, u8 ignore, u8 __iomem *statusp,
+                            u8 __iomem *maskp)
+{
+        int cpld_irq;
+        u8 status = in_8(statusp);
+        u8 mask = in_8(maskp);
+
+        /* ignore don't cares and masked irqs */
+        status |= (ignore | mask);
+
+        if (status == 0xff)
+                return NO_IRQ_IGNORE;
+
+        cpld_irq = ffz(status) + offset;
+
+        return irq_linear_revmap(cpld_pic_host, cpld_irq);
+}
+
+static void
+cpld_pic_cascade(unsigned int irq, struct irq_desc *desc)
+{
+        irq = cpld_pic_get_irq(0, PCI_IGNORE, &cpld_regs->pci_status,
+                &cpld_regs->pci_mask);
+        if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
+                generic_handle_irq(irq);
+                return;
+        }
+
+        irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status,
+                &cpld_regs->misc_mask);
+        if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
+                generic_handle_irq(irq);
+                return;
+        }
+}
+
+static int
+cpld_pic_host_match(struct irq_host *h, struct device_node *node)
+{
+        return cpld_pic_node == node;
+}
+
+static int
+cpld_pic_host_map(struct irq_host *h, unsigned int virq,
+                             irq_hw_number_t hw)
+{
+        get_irq_desc(virq)->status |= IRQ_LEVEL;
+        set_irq_chip_and_handler(virq, &cpld_pic, handle_level_irq);
+        return 0;
+}
+
+static struct
+irq_host_ops cpld_pic_host_ops = {
+        .match = cpld_pic_host_match,
+        .map = cpld_pic_host_map,
+};
+
+void __init
+mpc5121_ads_cpld_map(void)
+{
+        struct device_node *np = NULL;
+
+        np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
+        if (!np) {
+                printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
+                return;
+        }
+
+        cpld_regs = of_iomap(np, 0);
+        of_node_put(np);
+}
+
+void __init
+mpc5121_ads_cpld_pic_init(void)
+{
+        unsigned int cascade_irq;
+        struct device_node *np = NULL;
+
+        pr_debug("cpld_ic_init\n");
+
+        np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
+        if (!np) {
+                printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
+                return;
+        }
+
+        if (!cpld_regs)
+                goto end;
+
+        cascade_irq = irq_of_parse_and_map(np, 0);
+        if (cascade_irq == NO_IRQ)
+                goto end;
+
+        /*
+         * statically route touch screen pendown through 1
+         * and ignore it here
+         * route all others through our cascade irq
+         */
+        out_8(&cpld_regs->route, 0xfd);
+        out_8(&cpld_regs->pci_mask, 0xff);
+        /* unmask pci ints in misc mask */
+        out_8(&cpld_regs->misc_mask, ~(MISC_IGNORE));
+
+        cpld_pic_node = of_node_get(np);
+
+        cpld_pic_host =
+            irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 16, &cpld_pic_host_ops, 16);
+        if (!cpld_pic_host) {
+                printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n");
+                goto end;
+        }
+
+        set_irq_chained_handler(cascade_irq, cpld_pic_cascade);
+end:
+        of_node_put(np);
+}