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irqchip: bcm7120-l2: Add Broadcom BCM7120-style Level 2 interrupt controller
authorFlorian Fainelli <f.fainelli@gmail.com>
Wed, 10 Sep 2014 00:44:21 +0000 (17:44 -0700)
committerJason Cooper <jason@lakedaemon.net>
Sun, 14 Sep 2014 06:20:14 +0000 (06:20 +0000)
This patch adds support for the Level-2 interrupt controller
hardware found in Broadcom Set Top Box System-on-a-Chip devices. This
interrupt controller is implemented using a single enable register.

This interrupt controller is always present on the platforms supported
by the irq-brcmstb-l2 driver, hence the reason why both are compiled
using the same Kconfig symbol.

[jac] removed the following warning:
  drivers/irqchip/irq-bcm7120-l2.c: In function 'bcm7120_l2_intc_irq_handle':
  drivers/irqchip/irq-bcm7120-l2.c:49:27: warning: unused variable 'gc' [-Wunused-variable]

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lkml.kernel.org/r/1410309862-27784-2-git-send-email-f.fainelli@gmail.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
drivers/irqchip/Makefile
drivers/irqchip/irq-bcm7120-l2.c [new file with mode: 0644]

index 73052ba..824f5eb 100644 (file)
@@ -33,4 +33,5 @@ obj-$(CONFIG_TB10X_IRQC)              += irq-tb10x.o
 obj-$(CONFIG_XTENSA)                   += irq-xtensa-pic.o
 obj-$(CONFIG_XTENSA_MX)                        += irq-xtensa-mx.o
 obj-$(CONFIG_IRQ_CROSSBAR)             += irq-crossbar.o
-obj-$(CONFIG_BRCMSTB_L2_IRQ)           += irq-brcmstb-l2.o
+obj-$(CONFIG_BRCMSTB_L2_IRQ)           += irq-brcmstb-l2.o \
+                                          irq-bcm7120-l2.o
diff --git a/drivers/irqchip/irq-bcm7120-l2.c b/drivers/irqchip/irq-bcm7120-l2.c
new file mode 100644 (file)
index 0000000..b9f4fb8
--- /dev/null
@@ -0,0 +1,219 @@
+/*
+ * Broadcom BCM7120 style Level 2 interrupt controller driver
+ *
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt)    KBUILD_MODNAME  ": " fmt
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/reboot.h>
+#include <linux/irqchip/chained_irq.h>
+
+#include "irqchip.h"
+
+#include <asm/mach/irq.h>
+
+/* Register offset in the L2 interrupt controller */
+#define IRQEN          0x00
+#define IRQSTAT                0x04
+
+struct bcm7120_l2_intc_data {
+       void __iomem *base;
+       struct irq_domain *domain;
+       bool can_wake;
+       u32 irq_fwd_mask;
+       u32 irq_map_mask;
+       u32 saved_mask;
+};
+
+static void bcm7120_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)
+{
+       struct bcm7120_l2_intc_data *b = irq_desc_get_handler_data(desc);
+       struct irq_chip *chip = irq_desc_get_chip(desc);
+       u32 status;
+
+       chained_irq_enter(chip, desc);
+
+       status = __raw_readl(b->base + IRQSTAT);
+
+       if (status == 0) {
+               do_bad_IRQ(irq, desc);
+               goto out;
+       }
+
+       do {
+               irq = ffs(status) - 1;
+               status &= ~(1 << irq);
+               generic_handle_irq(irq_find_mapping(b->domain, irq));
+       } while (status);
+
+out:
+       chained_irq_exit(chip, desc);
+}
+
+static void bcm7120_l2_intc_suspend(struct irq_data *d)
+{
+       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+       struct bcm7120_l2_intc_data *b = gc->private;
+       u32 reg;
+
+       irq_gc_lock(gc);
+       /* Save the current mask and the interrupt forward mask */
+       b->saved_mask = __raw_readl(b->base) | b->irq_fwd_mask;
+       if (b->can_wake) {
+               reg = b->saved_mask | gc->wake_active;
+               __raw_writel(reg, b->base);
+       }
+       irq_gc_unlock(gc);
+}
+
+static void bcm7120_l2_intc_resume(struct irq_data *d)
+{
+       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+       struct bcm7120_l2_intc_data *b = gc->private;
+
+       /* Restore the saved mask */
+       irq_gc_lock(gc);
+       __raw_writel(b->saved_mask, b->base);
+       irq_gc_unlock(gc);
+}
+
+static int bcm7120_l2_intc_init_one(struct device_node *dn,
+                                       struct bcm7120_l2_intc_data *data,
+                                       int irq, const __be32 *map_mask)
+{
+       int parent_irq;
+
+       parent_irq = irq_of_parse_and_map(dn, irq);
+       if (parent_irq < 0) {
+               pr_err("failed to map interrupt %d\n", irq);
+               return parent_irq;
+       }
+
+       data->irq_map_mask |= be32_to_cpup(map_mask + irq);
+
+       irq_set_handler_data(parent_irq, data);
+       irq_set_chained_handler(parent_irq, bcm7120_l2_intc_irq_handle);
+
+       return 0;
+}
+
+int __init bcm7120_l2_intc_of_init(struct device_node *dn,
+                                       struct device_node *parent)
+{
+       unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+       struct bcm7120_l2_intc_data *data;
+       struct irq_chip_generic *gc;
+       struct irq_chip_type *ct;
+       const __be32 *map_mask;
+       int num_parent_irqs;
+       int ret = 0, len, irq;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->base = of_iomap(dn, 0);
+       if (!data->base) {
+               pr_err("failed to remap intc L2 registers\n");
+               ret = -ENOMEM;
+               goto out_free;
+       }
+
+       if (of_property_read_u32(dn, "brcm,int-fwd-mask", &data->irq_fwd_mask))
+               data->irq_fwd_mask = 0;
+
+       /* Enable all interrupt specified in the interrupt forward mask and have
+        * the other disabled
+        */
+       __raw_writel(data->irq_fwd_mask, data->base + IRQEN);
+
+       num_parent_irqs = of_irq_count(dn);
+       if (num_parent_irqs <= 0) {
+               pr_err("invalid number of parent interrupts\n");
+               ret = -ENOMEM;
+               goto out_unmap;
+       }
+
+       map_mask = of_get_property(dn, "brcm,int-map-mask", &len);
+       if (!map_mask || (len != (sizeof(*map_mask) * num_parent_irqs))) {
+               pr_err("invalid brcm,int-map-mask property\n");
+               ret = -EINVAL;
+               goto out_unmap;
+       }
+
+       for (irq = 0; irq < num_parent_irqs; irq++) {
+               ret = bcm7120_l2_intc_init_one(dn, data, irq, map_mask);
+               if (ret)
+                       goto out_unmap;
+       }
+
+       data->domain = irq_domain_add_linear(dn, 32,
+                                       &irq_generic_chip_ops, NULL);
+       if (!data->domain) {
+               ret = -ENOMEM;
+               goto out_unmap;
+       }
+
+       ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
+                               dn->full_name, handle_level_irq, clr, 0,
+                               IRQ_GC_INIT_MASK_CACHE);
+       if (ret) {
+               pr_err("failed to allocate generic irq chip\n");
+               goto out_free_domain;
+       }
+
+       gc = irq_get_domain_generic_chip(data->domain, 0);
+       gc->unused = 0xfffffff & ~data->irq_map_mask;
+       gc->reg_base = data->base;
+       gc->private = data;
+       ct = gc->chip_types;
+
+       ct->regs.mask = IRQEN;
+       ct->chip.irq_mask = irq_gc_mask_clr_bit;
+       ct->chip.irq_unmask = irq_gc_mask_set_bit;
+       ct->chip.irq_ack = irq_gc_noop;
+       ct->chip.irq_suspend = bcm7120_l2_intc_suspend;
+       ct->chip.irq_resume = bcm7120_l2_intc_resume;
+
+       if (of_property_read_bool(dn, "brcm,irq-can-wake")) {
+               data->can_wake = true;
+               /* This IRQ chip can wake the system, set all relevant child
+                * interupts in wake_enabled mask
+                */
+               gc->wake_enabled = 0xffffffff;
+               gc->wake_enabled &= ~gc->unused;
+               ct->chip.irq_set_wake = irq_gc_set_wake;
+       }
+
+       pr_info("registered BCM7120 L2 intc (mem: 0x%p, parent IRQ(s): %d)\n",
+                       data->base, num_parent_irqs);
+
+       return 0;
+
+out_free_domain:
+       irq_domain_remove(data->domain);
+out_unmap:
+       iounmap(data->base);
+out_free:
+       kfree(data);
+       return ret;
+}
+IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,bcm7120-l2-intc",
+               bcm7120_l2_intc_of_init);