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-rw-r--r--arch/powerpc/platforms/85xx/socrates_fpga_pic.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/85xx/socrates_fpga_pic.c b/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
new file mode 100644
index 000000000000..60edf63d0157
--- /dev/null
+++ b/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
@@ -0,0 +1,327 @@
+/*
+ * Copyright (C) 2008 Ilya Yanok, Emcraft Systems
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/irq.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+
+/*
+ * The FPGA supports 9 interrupt sources, which can be routed to 3
+ * interrupt request lines of the MPIC. The line to be used can be
+ * specified through the third cell of FDT property "interrupts".
+ */
+
+#define SOCRATES_FPGA_NUM_IRQS 9
+
+#define FPGA_PIC_IRQCFG (0x0)
+#define FPGA_PIC_IRQMASK(n) (0x4 + 0x4 * (n))
+
+#define SOCRATES_FPGA_IRQ_MASK ((1 << SOCRATES_FPGA_NUM_IRQS) - 1)
+
+struct socrates_fpga_irq_info {
+ unsigned int irq_line;
+ int type;
+};
+
+/*
+ * Interrupt routing and type table
+ *
+ * IRQ_TYPE_NONE means the interrupt type is configurable,
+ * otherwise it's fixed to the specified value.
+ */
+static struct socrates_fpga_irq_info fpga_irqs[SOCRATES_FPGA_NUM_IRQS] = {
+ [0] = {0, IRQ_TYPE_NONE},
+ [1] = {0, IRQ_TYPE_LEVEL_HIGH},
+ [2] = {0, IRQ_TYPE_LEVEL_LOW},
+ [3] = {0, IRQ_TYPE_NONE},
+ [4] = {0, IRQ_TYPE_NONE},
+ [5] = {0, IRQ_TYPE_NONE},
+ [6] = {0, IRQ_TYPE_NONE},
+ [7] = {0, IRQ_TYPE_NONE},
+ [8] = {0, IRQ_TYPE_LEVEL_HIGH},
+};
+
+#define socrates_fpga_irq_to_hw(virq) ((unsigned int)irq_map[virq].hwirq)
+
+static DEFINE_SPINLOCK(socrates_fpga_pic_lock);
+
+static void __iomem *socrates_fpga_pic_iobase;
+static struct irq_host *socrates_fpga_pic_irq_host;
+static unsigned int socrates_fpga_irqs[3];
+
+static inline uint32_t socrates_fpga_pic_read(int reg)
+{
+ return in_be32(socrates_fpga_pic_iobase + reg);
+}
+
+static inline void socrates_fpga_pic_write(int reg, uint32_t val)
+{
+ out_be32(socrates_fpga_pic_iobase + reg, val);
+}
+
+static inline unsigned int socrates_fpga_pic_get_irq(unsigned int irq)
+{
+ uint32_t cause;
+ unsigned long flags;
+ int i;
+
+ /* Check irq line routed to the MPIC */
+ for (i = 0; i < 3; i++) {
+ if (irq == socrates_fpga_irqs[i])
+ break;
+ }
+ if (i == 3)
+ return NO_IRQ;
+
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ cause = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(i));
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+ for (i = SOCRATES_FPGA_NUM_IRQS - 1; i >= 0; i--) {
+ if (cause >> (i + 16))
+ break;
+ }
+ return irq_linear_revmap(socrates_fpga_pic_irq_host,
+ (irq_hw_number_t)i);
+}
+
+void socrates_fpga_pic_cascade(unsigned int irq, struct irq_desc *desc)
+{
+ unsigned int cascade_irq;
+
+ /*
+ * See if we actually have an interrupt, call generic handling code if
+ * we do.
+ */
+ cascade_irq = socrates_fpga_pic_get_irq(irq);
+
+ if (cascade_irq != NO_IRQ)
+ generic_handle_irq(cascade_irq);
+ desc->chip->eoi(irq);
+
+}
+
+static void socrates_fpga_pic_ack(unsigned int virq)
+{
+ unsigned long flags;
+ unsigned int hwirq, irq_line;
+ uint32_t mask;
+
+ hwirq = socrates_fpga_irq_to_hw(virq);
+
+ irq_line = fpga_irqs[hwirq].irq_line;
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
+ & SOCRATES_FPGA_IRQ_MASK;
+ mask |= (1 << (hwirq + 16));
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+}
+
+static void socrates_fpga_pic_mask(unsigned int virq)
+{
+ unsigned long flags;
+ unsigned int hwirq;
+ int irq_line;
+ u32 mask;
+
+ hwirq = socrates_fpga_irq_to_hw(virq);
+
+ irq_line = fpga_irqs[hwirq].irq_line;
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
+ & SOCRATES_FPGA_IRQ_MASK;
+ mask &= ~(1 << hwirq);
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+}
+
+static void socrates_fpga_pic_mask_ack(unsigned int virq)
+{
+ unsigned long flags;
+ unsigned int hwirq;
+ int irq_line;
+ u32 mask;
+
+ hwirq = socrates_fpga_irq_to_hw(virq);
+
+ irq_line = fpga_irqs[hwirq].irq_line;
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
+ & SOCRATES_FPGA_IRQ_MASK;
+ mask &= ~(1 << hwirq);
+ mask |= (1 << (hwirq + 16));
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+}
+
+static void socrates_fpga_pic_unmask(unsigned int virq)
+{
+ unsigned long flags;
+ unsigned int hwirq;
+ int irq_line;
+ u32 mask;
+
+ hwirq = socrates_fpga_irq_to_hw(virq);
+
+ irq_line = fpga_irqs[hwirq].irq_line;
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
+ & SOCRATES_FPGA_IRQ_MASK;
+ mask |= (1 << hwirq);
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+}
+
+static void socrates_fpga_pic_eoi(unsigned int virq)
+{
+ unsigned long flags;
+ unsigned int hwirq;
+ int irq_line;
+ u32 mask;
+
+ hwirq = socrates_fpga_irq_to_hw(virq);
+
+ irq_line = fpga_irqs[hwirq].irq_line;
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ mask = socrates_fpga_pic_read(FPGA_PIC_IRQMASK(irq_line))
+ & SOCRATES_FPGA_IRQ_MASK;
+ mask |= (1 << (hwirq + 16));
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(irq_line), mask);
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+}
+
+static int socrates_fpga_pic_set_type(unsigned int virq,
+ unsigned int flow_type)
+{
+ unsigned long flags;
+ unsigned int hwirq;
+ int polarity;
+ u32 mask;
+
+ hwirq = socrates_fpga_irq_to_hw(virq);
+
+ if (fpga_irqs[hwirq].type != IRQ_TYPE_NONE)
+ return -EINVAL;
+
+ switch (flow_type & IRQ_TYPE_SENSE_MASK) {
+ case IRQ_TYPE_LEVEL_HIGH:
+ polarity = 1;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ polarity = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ mask = socrates_fpga_pic_read(FPGA_PIC_IRQCFG);
+ if (polarity)
+ mask |= (1 << hwirq);
+ else
+ mask &= ~(1 << hwirq);
+ socrates_fpga_pic_write(FPGA_PIC_IRQCFG, mask);
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+ return 0;
+}
+
+static struct irq_chip socrates_fpga_pic_chip = {
+ .typename = " FPGA-PIC ",
+ .ack = socrates_fpga_pic_ack,
+ .mask = socrates_fpga_pic_mask,
+ .mask_ack = socrates_fpga_pic_mask_ack,
+ .unmask = socrates_fpga_pic_unmask,
+ .eoi = socrates_fpga_pic_eoi,
+ .set_type = socrates_fpga_pic_set_type,
+};
+
+static int socrates_fpga_pic_host_map(struct irq_host *h, unsigned int virq,
+ irq_hw_number_t hwirq)
+{
+ /* All interrupts are LEVEL sensitive */
+ get_irq_desc(virq)->status |= IRQ_LEVEL;
+ set_irq_chip_and_handler(virq, &socrates_fpga_pic_chip,
+ handle_fasteoi_irq);
+
+ return 0;
+}
+
+static int socrates_fpga_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)
+{
+ struct socrates_fpga_irq_info *fpga_irq = &fpga_irqs[intspec[0]];
+
+ *out_hwirq = intspec[0];
+ if (fpga_irq->type == IRQ_TYPE_NONE) {
+ /* type is configurable */
+ if (intspec[1] != IRQ_TYPE_LEVEL_LOW &&
+ intspec[1] != IRQ_TYPE_LEVEL_HIGH) {
+ pr_warning("FPGA PIC: invalid irq type, "
+ "setting default active low\n");
+ *out_flags = IRQ_TYPE_LEVEL_LOW;
+ } else {
+ *out_flags = intspec[1];
+ }
+ } else {
+ /* type is fixed */
+ *out_flags = fpga_irq->type;
+ }
+
+ /* Use specified interrupt routing */
+ if (intspec[2] <= 2)
+ fpga_irq->irq_line = intspec[2];
+ else
+ pr_warning("FPGA PIC: invalid irq routing\n");
+
+ return 0;
+}
+
+static struct irq_host_ops socrates_fpga_pic_host_ops = {
+ .map = socrates_fpga_pic_host_map,
+ .xlate = socrates_fpga_pic_host_xlate,
+};
+
+void socrates_fpga_pic_init(struct device_node *pic)
+{
+ unsigned long flags;
+ int i;
+
+ /* Setup an irq_host structure */
+ socrates_fpga_pic_irq_host = irq_alloc_host(pic, IRQ_HOST_MAP_LINEAR,
+ SOCRATES_FPGA_NUM_IRQS, &socrates_fpga_pic_host_ops,
+ SOCRATES_FPGA_NUM_IRQS);
+ if (socrates_fpga_pic_irq_host == NULL) {
+ pr_err("FPGA PIC: Unable to allocate host\n");
+ return;
+ }
+
+ for (i = 0; i < 3; i++) {
+ socrates_fpga_irqs[i] = irq_of_parse_and_map(pic, i);
+ if (socrates_fpga_irqs[i] == NO_IRQ) {
+ pr_warning("FPGA PIC: can't get irq%d.\n", i);
+ continue;
+ }
+ set_irq_chained_handler(socrates_fpga_irqs[i],
+ socrates_fpga_pic_cascade);
+ }
+
+ socrates_fpga_pic_iobase = of_iomap(pic, 0);
+
+ spin_lock_irqsave(&socrates_fpga_pic_lock, flags);
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(0),
+ SOCRATES_FPGA_IRQ_MASK << 16);
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(1),
+ SOCRATES_FPGA_IRQ_MASK << 16);
+ socrates_fpga_pic_write(FPGA_PIC_IRQMASK(2),
+ SOCRATES_FPGA_IRQ_MASK << 16);
+ spin_unlock_irqrestore(&socrates_fpga_pic_lock, flags);
+
+ pr_info("FPGA PIC: Setting up Socrates FPGA PIC\n");
+}