powerpc/85xx: Add support for the "socrates" board (MPC8544).

Supported are Ethernet, serial console, I2C, I2C-based RTC and
temperature sensors, NOR and NAND flash, PCI, USB, CAN and Lime
display controller.

The multiplexing of FPGA interrupts onto PowerPC interrupt lines is
supported through our own fpga_pic interrupt controller driver.

For example the SJA1000 controller is level low sensitive connected to
fpga_pic line 2 and is routed to the second (of three) irq lines to
the CPU:

    can@3,100 {
            compatible = "philips,sja1000";
            reg = <3 0x100 0x80>;
            interrupts = <2 2>;
            interrupts = <2 8 1>;   // number, type, routing
            interrupt-parent = <&fpga_pic>;
    };

Signed-off-by: Sergei Poselenov <sposelenov@emcraft.com>
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Dmitry Rakhchev <rda@emcraft.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

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");
+}