Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 245 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-versatile-fpga.c b/drivers/irqchip/irq-versatile-fpga.c
new file mode 100644
index 0000000000..5018a06060
--- /dev/null
+++ b/drivers/irqchip/irq-versatile-fpga.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Support for Versatile FPGA-based IRQ controllers
+ */
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/seq_file.h>
+
+#include <asm/exception.h>
+#include <asm/mach/irq.h>
+
+#define IRQ_STATUS		0x00
+#define IRQ_RAW_STATUS		0x04
+#define IRQ_ENABLE_SET		0x08
+#define IRQ_ENABLE_CLEAR	0x0c
+#define INT_SOFT_SET		0x10
+#define INT_SOFT_CLEAR		0x14
+#define FIQ_STATUS		0x20
+#define FIQ_RAW_STATUS		0x24
+#define FIQ_ENABLE		0x28
+#define FIQ_ENABLE_SET		0x28
+#define FIQ_ENABLE_CLEAR	0x2C
+
+#define PIC_ENABLES             0x20	/* set interrupt pass through bits */
+
+/**
+ * struct fpga_irq_data - irq data container for the FPGA IRQ controller
+ * @base: memory offset in virtual memory
+ * @domain: IRQ domain for this instance
+ * @valid: mask for valid IRQs on this controller
+ * @used_irqs: number of active IRQs on this controller
+ */
+struct fpga_irq_data {
+	void __iomem *base;
+	u32 valid;
+	struct irq_domain *domain;
+	u8 used_irqs;
+};
+
+/* we cannot allocate memory when the controllers are initially registered */
+static struct fpga_irq_data fpga_irq_devices[CONFIG_VERSATILE_FPGA_IRQ_NR];
+static int fpga_irq_id;
+
+static void fpga_irq_mask(struct irq_data *d)
+{
+	struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << d->hwirq;
+
+	writel(mask, f->base + IRQ_ENABLE_CLEAR);
+}
+
+static void fpga_irq_unmask(struct irq_data *d)
+{
+	struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
+	u32 mask = 1 << d->hwirq;
+
+	writel(mask, f->base + IRQ_ENABLE_SET);
+}
+
+static void fpga_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
+
+	seq_printf(p, irq_domain_get_of_node(f->domain)->name);
+}
+
+static const struct irq_chip fpga_chip = {
+	.irq_ack	= fpga_irq_mask,
+	.irq_mask	= fpga_irq_mask,
+	.irq_unmask	= fpga_irq_unmask,
+	.irq_print_chip	= fpga_irq_print_chip,
+};
+
+static void fpga_irq_handle(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct fpga_irq_data *f = irq_desc_get_handler_data(desc);
+	u32 status;
+
+	chained_irq_enter(chip, desc);
+
+	status = readl(f->base + IRQ_STATUS);
+	if (status == 0) {
+		do_bad_IRQ(desc);
+		goto out;
+	}
+
+	do {
+		unsigned int irq = ffs(status) - 1;
+
+		status &= ~(1 << irq);
+		generic_handle_domain_irq(f->domain, irq);
+	} while (status);
+
+out:
+	chained_irq_exit(chip, desc);
+}
+
+/*
+ * Handle each interrupt in a single FPGA IRQ controller.  Returns non-zero
+ * if we've handled at least one interrupt.  This does a single read of the
+ * status register and handles all interrupts in order from LSB first.
+ */
+static int handle_one_fpga(struct fpga_irq_data *f, struct pt_regs *regs)
+{
+	int handled = 0;
+	int irq;
+	u32 status;
+
+	while ((status  = readl(f->base + IRQ_STATUS))) {
+		irq = ffs(status) - 1;
+		generic_handle_domain_irq(f->domain, irq);
+		handled = 1;
+	}
+
+	return handled;
+}
+
+/*
+ * Keep iterating over all registered FPGA IRQ controllers until there are
+ * no pending interrupts.
+ */
+static asmlinkage void __exception_irq_entry fpga_handle_irq(struct pt_regs *regs)
+{
+	int i, handled;
+
+	do {
+		for (i = 0, handled = 0; i < fpga_irq_id; ++i)
+			handled |= handle_one_fpga(&fpga_irq_devices[i], regs);
+	} while (handled);
+}
+
+static int fpga_irqdomain_map(struct irq_domain *d, unsigned int irq,
+		irq_hw_number_t hwirq)
+{
+	struct fpga_irq_data *f = d->host_data;
+
+	/* Skip invalid IRQs, only register handlers for the real ones */
+	if (!(f->valid & BIT(hwirq)))
+		return -EPERM;
+	irq_set_chip_data(irq, f);
+	irq_set_chip_and_handler(irq, &fpga_chip, handle_level_irq);
+	irq_set_probe(irq);
+	return 0;
+}
+
+static const struct irq_domain_ops fpga_irqdomain_ops = {
+	.map = fpga_irqdomain_map,
+	.xlate = irq_domain_xlate_onetwocell,
+};
+
+static void __init fpga_irq_init(void __iomem *base, int parent_irq,
+				 u32 valid, struct device_node *node)
+{
+	struct fpga_irq_data *f;
+	int i;
+
+	if (fpga_irq_id >= ARRAY_SIZE(fpga_irq_devices)) {
+		pr_err("%s: too few FPGA IRQ controllers, increase CONFIG_VERSATILE_FPGA_IRQ_NR\n", __func__);
+		return;
+	}
+	f = &fpga_irq_devices[fpga_irq_id];
+	f->base = base;
+	f->valid = valid;
+
+	if (parent_irq != -1) {
+		irq_set_chained_handler_and_data(parent_irq, fpga_irq_handle,
+						 f);
+	}
+
+	f->domain = irq_domain_add_linear(node, fls(valid),
+					  &fpga_irqdomain_ops, f);
+
+	/* This will allocate all valid descriptors in the linear case */
+	for (i = 0; i < fls(valid); i++)
+		if (valid & BIT(i)) {
+			/* Is this still required? */
+			irq_create_mapping(f->domain, i);
+			f->used_irqs++;
+		}
+
+	pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs",
+		fpga_irq_id, node->name, base, f->used_irqs);
+	if (parent_irq != -1)
+		pr_cont(", parent IRQ: %d\n", parent_irq);
+	else
+		pr_cont("\n");
+
+	fpga_irq_id++;
+}
+
+#ifdef CONFIG_OF
+static int __init fpga_irq_of_init(struct device_node *node,
+				   struct device_node *parent)
+{
+	void __iomem *base;
+	u32 clear_mask;
+	u32 valid_mask;
+	int parent_irq;
+
+	if (WARN_ON(!node))
+		return -ENODEV;
+
+	base = of_iomap(node, 0);
+	WARN(!base, "unable to map fpga irq registers\n");
+
+	if (of_property_read_u32(node, "clear-mask", &clear_mask))
+		clear_mask = 0;
+
+	if (of_property_read_u32(node, "valid-mask", &valid_mask))
+		valid_mask = 0;
+
+	writel(clear_mask, base + IRQ_ENABLE_CLEAR);
+	writel(clear_mask, base + FIQ_ENABLE_CLEAR);
+
+	/* Some chips are cascaded from a parent IRQ */
+	parent_irq = irq_of_parse_and_map(node, 0);
+	if (!parent_irq) {
+		set_handle_irq(fpga_handle_irq);
+		parent_irq = -1;
+	}
+
+	fpga_irq_init(base, parent_irq, valid_mask, node);
+
+	/*
+	 * On Versatile AB/PB, some secondary interrupts have a direct
+	 * pass-thru to the primary controller for IRQs 20 and 22-31 which need
+	 * to be enabled. See section 3.10 of the Versatile AB user guide.
+	 */
+	if (of_device_is_compatible(node, "arm,versatile-sic"))
+		writel(0xffd00000, base + PIC_ENABLES);
+
+	return 0;
+}
+IRQCHIP_DECLARE(arm_fpga, "arm,versatile-fpga-irq", fpga_irq_of_init);
+IRQCHIP_DECLARE(arm_fpga_sic, "arm,versatile-sic", fpga_irq_of_init);
+#endif