--- /dev/null
+Some socs have a large number of interrupts requests to service
+the needs of its many peripherals and subsystems. All of the
+interrupt lines from the subsystems are not needed at the same
+time, so they have to be muxed to the irq-controller appropriately.
+In such places a interrupt controllers are preceded by an CROSSBAR
+that provides flexibility in muxing the device requests to the controller
+inputs.
+
+Required properties:
+- compatible : Should be "ti,irq-crossbar"
+- reg: Base address and the size of the crossbar registers.
+- ti,max-irqs: Total number of irqs available at the interrupt controller.
+- ti,reg-size: Size of a individual register in bytes. Every individual
+ register is assumed to be of same size. Valid sizes are 1, 2, 4.
+- ti,irqs-reserved: List of the reserved irq lines that are not muxed using
+ crossbar. These interrupt lines are reserved in the soc,
+ so crossbar bar driver should not consider them as free
+ lines.
+
+Examples:
+ crossbar_mpu: @4a020000 {
+ compatible = "ti,irq-crossbar";
+ reg = <0x4a002a48 0x130>;
+ ti,max-irqs = <160>;
+ ti,reg-size = <2>;
+ ti,irqs-reserved = <0 1 2 3 5 6 131 132 139 140>;
+ };
--- /dev/null
+/*
+ * drivers/irqchip/irq-crossbar.c
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Sricharan R <r.sricharan@ti.com>
+ *
+ * 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/err.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/irqchip/arm-gic.h>
+
+#define IRQ_FREE -1
+#define GIC_IRQ_START 32
+
+/*
+ * @int_max: maximum number of supported interrupts
+ * @irq_map: array of interrupts to crossbar number mapping
+ * @crossbar_base: crossbar base address
+ * @register_offsets: offsets for each irq number
+ */
+struct crossbar_device {
+ uint int_max;
+ uint *irq_map;
+ void __iomem *crossbar_base;
+ int *register_offsets;
+ void (*write) (int, int);
+};
+
+static struct crossbar_device *cb;
+
+static inline void crossbar_writel(int irq_no, int cb_no)
+{
+ writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline void crossbar_writew(int irq_no, int cb_no)
+{
+ writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline void crossbar_writeb(int irq_no, int cb_no)
+{
+ writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline int allocate_free_irq(int cb_no)
+{
+ int i;
+
+ for (i = 0; i < cb->int_max; i++) {
+ if (cb->irq_map[i] == IRQ_FREE) {
+ cb->irq_map[i] = cb_no;
+ return i;
+ }
+ }
+
+ return -ENODEV;
+}
+
+static int crossbar_domain_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]);
+ return 0;
+}
+
+static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq)
+{
+ irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
+
+ if (hw > GIC_IRQ_START)
+ cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
+}
+
+static int crossbar_domain_xlate(struct irq_domain *d,
+ struct device_node *controller,
+ const u32 *intspec, unsigned int intsize,
+ unsigned long *out_hwirq,
+ unsigned int *out_type)
+{
+ unsigned long ret;
+
+ ret = allocate_free_irq(intspec[1]);
+
+ if (IS_ERR_VALUE(ret))
+ return ret;
+
+ *out_hwirq = ret + GIC_IRQ_START;
+ return 0;
+}
+
+const struct irq_domain_ops routable_irq_domain_ops = {
+ .map = crossbar_domain_map,
+ .unmap = crossbar_domain_unmap,
+ .xlate = crossbar_domain_xlate
+};
+
+static int __init crossbar_of_init(struct device_node *node)
+{
+ int i, size, max, reserved = 0, entry;
+ const __be32 *irqsr;
+
+ cb = kzalloc(sizeof(struct cb_device *), GFP_KERNEL);
+
+ if (!cb)
+ return -ENOMEM;
+
+ cb->crossbar_base = of_iomap(node, 0);
+ if (!cb->crossbar_base)
+ goto err1;
+
+ of_property_read_u32(node, "ti,max-irqs", &max);
+ cb->irq_map = kzalloc(max * sizeof(int), GFP_KERNEL);
+ if (!cb->irq_map)
+ goto err2;
+
+ cb->int_max = max;
+
+ for (i = 0; i < max; i++)
+ cb->irq_map[i] = IRQ_FREE;
+
+ /* Get and mark reserved irqs */
+ irqsr = of_get_property(node, "ti,irqs-reserved", &size);
+ if (irqsr) {
+ size /= sizeof(__be32);
+
+ for (i = 0; i < size; i++) {
+ of_property_read_u32_index(node,
+ "ti,irqs-reserved",
+ i, &entry);
+ if (entry > max) {
+ pr_err("Invalid reserved entry\n");
+ goto err3;
+ }
+ cb->irq_map[entry] = 0;
+ }
+ }
+
+ cb->register_offsets = kzalloc(max * sizeof(int), GFP_KERNEL);
+ if (!cb->register_offsets)
+ goto err3;
+
+ of_property_read_u32(node, "ti,reg-size", &size);
+
+ switch (size) {
+ case 1:
+ cb->write = crossbar_writeb;
+ break;
+ case 2:
+ cb->write = crossbar_writew;
+ break;
+ case 4:
+ cb->write = crossbar_writel;
+ break;
+ default:
+ pr_err("Invalid reg-size property\n");
+ goto err4;
+ break;
+ }
+
+ /*
+ * Register offsets are not linear because of the
+ * reserved irqs. so find and store the offsets once.
+ */
+ for (i = 0; i < max; i++) {
+ if (!cb->irq_map[i])
+ continue;
+
+ cb->register_offsets[i] = reserved;
+ reserved += size;
+ }
+
+ register_routable_domain_ops(&routable_irq_domain_ops);
+ return 0;
+
+err4:
+ kfree(cb->register_offsets);
+err3:
+ kfree(cb->irq_map);
+err2:
+ iounmap(cb->crossbar_base);
+err1:
+ kfree(cb);
+ return -ENOMEM;
+}
+
+static const struct of_device_id crossbar_match[] __initconst = {
+ { .compatible = "ti,irq-crossbar" },
+ {}
+};
+
+int __init irqcrossbar_init(void)
+{
+ struct device_node *np;
+ np = of_find_matching_node(NULL, crossbar_match);
+ if (!np)
+ return -ENODEV;
+
+ crossbar_of_init(np);
+ return 0;
+}
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff