[POWERPC] 8xx: powerpc port of core CPM PIC

This covers common CPM access functions, CPM interrupt controller code,
micropatch and a few compatibility things to kee the same driver base
working with arch/ppc. This version is refined with all the comments
(mostly PIC-related) addressed.

Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 197 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/mpc8xx_pic.c b/arch/powerpc/sysdev/mpc8xx_pic.c
new file mode 100644
index 000000000000..2fc2bcd79b5e
--- /dev/null
+++ b/arch/powerpc/sysdev/mpc8xx_pic.c
@@ -0,0 +1,197 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/irq.h>
+#include <linux/dma-mapping.h>
+#include <asm/prom.h>
+#include <asm/irq.h>
+#include <asm/io.h>
+#include <asm/8xx_immap.h>
+#include <asm/mpc8xx.h>
+
+#include "mpc8xx_pic.h"
+
+
+#define PIC_VEC_SPURRIOUS      15
+
+extern int cpm_get_irq(struct pt_regs *regs);
+
+static struct device_node *mpc8xx_pic_node;
+static struct irq_host *mpc8xx_pic_host;
+#define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
+static unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
+static sysconf8xx_t	*siu_reg;
+
+int cpm_get_irq(struct pt_regs *regs);
+
+static void mpc8xx_unmask_irq(unsigned int virq)
+{
+	int	bit, word;
+	unsigned int irq_nr = (unsigned int)irq_map[virq].hwirq;
+
+	bit = irq_nr & 0x1f;
+	word = irq_nr >> 5;
+
+	ppc_cached_irq_mask[word] |= (1 << (31-bit));
+	out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask[word]);
+}
+
+static void mpc8xx_mask_irq(unsigned int virq)
+{
+	int	bit, word;
+	unsigned int irq_nr = (unsigned int)irq_map[virq].hwirq;
+
+	bit = irq_nr & 0x1f;
+	word = irq_nr >> 5;
+
+	ppc_cached_irq_mask[word] &= ~(1 << (31-bit));
+	out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask[word]);
+}
+
+static void mpc8xx_ack(unsigned int virq)
+{
+	int	bit;
+	unsigned int irq_nr = (unsigned int)irq_map[virq].hwirq;
+
+	bit = irq_nr & 0x1f;
+	out_be32(&siu_reg->sc_sipend, 1 << (31-bit));
+}
+
+static void mpc8xx_end_irq(unsigned int virq)
+{
+	int bit, word;
+	unsigned int irq_nr = (unsigned int)irq_map[virq].hwirq;
+
+	bit = irq_nr & 0x1f;
+	word = irq_nr >> 5;
+
+	ppc_cached_irq_mask[word] |= (1 << (31-bit));
+	out_be32(&siu_reg->sc_simask, ppc_cached_irq_mask[word]);
+}
+
+static int mpc8xx_set_irq_type(unsigned int virq, unsigned int flow_type)
+{
+	struct irq_desc *desc = get_irq_desc(virq);
+
+	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
+	desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
+	if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
+		desc->status |= IRQ_LEVEL;
+
+	if (flow_type & IRQ_TYPE_EDGE_FALLING) {
+		irq_hw_number_t hw = (unsigned int)irq_map[virq].hwirq;
+		unsigned int siel = in_be32(&siu_reg->sc_siel);
+
+		/* only external IRQ senses are programmable */
+		if ((hw & 1) == 0) {
+			siel |= (0x80000000 >> hw);
+			out_be32(&siu_reg->sc_siel, siel);
+			desc->handle_irq = handle_edge_irq;
+		}
+	}
+	return 0;
+}
+
+static struct irq_chip mpc8xx_pic = {
+	.typename = " MPC8XX SIU ",
+	.unmask = mpc8xx_unmask_irq,
+	.mask = mpc8xx_mask_irq,
+	.ack = mpc8xx_ack,
+	.eoi = mpc8xx_end_irq,
+	.set_type = mpc8xx_set_irq_type,
+};
+
+unsigned int mpc8xx_get_irq(void)
+{
+	int irq;
+
+	/* For MPC8xx, read the SIVEC register and shift the bits down
+	 * to get the irq number.
+	 */
+	irq = in_be32(&siu_reg->sc_sivec) >> 26;
+
+	if (irq == PIC_VEC_SPURRIOUS)
+		irq = NO_IRQ;
+
+        return irq_linear_revmap(mpc8xx_pic_host, irq);
+
+}
+
+static int mpc8xx_pic_host_match(struct irq_host *h, struct device_node *node)
+{
+	return mpc8xx_pic_node == node;
+}
+
+static int mpc8xx_pic_host_map(struct irq_host *h, unsigned int virq,
+			  irq_hw_number_t hw)
+{
+	pr_debug("mpc8xx_pic_host_map(%d, 0x%lx)\n", virq, hw);
+
+	/* Set default irq handle */
+	set_irq_chip_and_handler(virq, &mpc8xx_pic, handle_level_irq);
+	return 0;
+}
+
+
+static int mpc8xx_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+			    u32 *intspec, unsigned int intsize,
+			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+{
+	static unsigned char map_pic_senses[4] = {
+		IRQ_TYPE_EDGE_RISING,
+		IRQ_TYPE_LEVEL_LOW,
+		IRQ_TYPE_LEVEL_HIGH,
+		IRQ_TYPE_EDGE_FALLING,
+	};
+
+	*out_hwirq = intspec[0];
+	if (intsize > 1 && intspec[1] < 4)
+		*out_flags = map_pic_senses[intspec[1]];
+	else
+		*out_flags = IRQ_TYPE_NONE;
+
+	return 0;
+}
+
+
+static struct irq_host_ops mpc8xx_pic_host_ops = {
+	.match = mpc8xx_pic_host_match,
+	.map = mpc8xx_pic_host_map,
+	.xlate = mpc8xx_pic_host_xlate,
+};
+
+int mpc8xx_pic_init(void)
+{
+	struct resource res;
+	struct device_node *np = NULL;
+	int ret;
+
+	np = of_find_node_by_type(np, "mpc8xx-pic");
+
+	if (np == NULL) {
+		printk(KERN_ERR "Could not find open-pic node\n");
+		return -ENOMEM;
+	}
+
+	mpc8xx_pic_node = of_node_get(np);
+
+	ret = of_address_to_resource(np, 0, &res);
+	of_node_put(np);
+	if (ret)
+		return ret;
+
+	siu_reg = (void *)ioremap(res.start, res.end - res.start + 1);
+	if (siu_reg == NULL)
+		return -EINVAL;
+
+	mpc8xx_pic_host = irq_alloc_host(IRQ_HOST_MAP_LINEAR, 64, &mpc8xx_pic_host_ops, 64);
+	if (mpc8xx_pic_host == NULL) {
+		printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
+		ret = -ENOMEM;
+	}
+
+	return ret;
+}