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irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-2 interrupt controller
authorFlorian Fainelli <f.fainelli@gmail.com>
Sat, 24 May 2014 00:40:53 +0000 (17:40 -0700)
committerJason Cooper <jason@lakedaemon.net>
Tue, 27 May 2014 14:43:06 +0000 (14:43 +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 the generic IRQ chip driver with
separate enable and disable registers.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Link: https://lkml.kernel.org/r/1400892054-24457-2-git-send-email-f.fainelli@gmail.com
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
drivers/irqchip/Kconfig
drivers/irqchip/Makefile
drivers/irqchip/irq-brcmstb-l2.c [new file with mode: 0644]

index d770f74..bbb746e 100644 (file)
@@ -30,6 +30,12 @@ config ARM_VIC_NR
          The maximum number of VICs available in the system, for
          power management.
 
+config BRCMSTB_L2_IRQ
+       bool
+       depends on ARM
+       select GENERIC_IRQ_CHIP
+       select IRQ_DOMAIN
+
 config DW_APB_ICTL
        bool
        select IRQ_DOMAIN
index f180f8d..62a13e5 100644 (file)
@@ -29,3 +29,4 @@ 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
diff --git a/drivers/irqchip/irq-brcmstb-l2.c b/drivers/irqchip/irq-brcmstb-l2.c
new file mode 100644 (file)
index 0000000..8ee2a36
--- /dev/null
@@ -0,0 +1,202 @@
+/*
+ * Generic Broadcom Set Top Box 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+
+#include <asm/mach/irq.h>
+
+#include "irqchip.h"
+
+/* Register offsets in the L2 interrupt controller */
+#define CPU_STATUS     0x00
+#define CPU_SET                0x04
+#define CPU_CLEAR      0x08
+#define CPU_MASK_STATUS        0x0c
+#define CPU_MASK_SET   0x10
+#define CPU_MASK_CLEAR 0x14
+
+/* L2 intc private data structure */
+struct brcmstb_l2_intc_data {
+       int parent_irq;
+       void __iomem *base;
+       struct irq_domain *domain;
+       bool can_wake;
+       u32 saved_mask; /* for suspend/resume */
+};
+
+static void brcmstb_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)
+{
+       struct brcmstb_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 + CPU_STATUS) &
+               ~(__raw_readl(b->base + CPU_MASK_STATUS));
+
+       if (status == 0) {
+               do_bad_IRQ(irq, desc);
+               goto out;
+       }
+
+       do {
+               irq = ffs(status) - 1;
+               /* ack at our level */
+               __raw_writel(1 << irq, b->base + CPU_CLEAR);
+               status &= ~(1 << irq);
+               generic_handle_irq(irq_find_mapping(b->domain, irq));
+       } while (status);
+out:
+       chained_irq_exit(chip, desc);
+}
+
+static void brcmstb_l2_intc_suspend(struct irq_data *d)
+{
+       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+       struct brcmstb_l2_intc_data *b = gc->private;
+
+       irq_gc_lock(gc);
+       /* Save the current mask */
+       b->saved_mask = __raw_readl(b->base + CPU_MASK_STATUS);
+
+       if (b->can_wake) {
+               /* Program the wakeup mask */
+               __raw_writel(~gc->wake_active, b->base + CPU_MASK_SET);
+               __raw_writel(gc->wake_active, b->base + CPU_MASK_CLEAR);
+       }
+       irq_gc_unlock(gc);
+}
+
+static void brcmstb_l2_intc_resume(struct irq_data *d)
+{
+       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+       struct brcmstb_l2_intc_data *b = gc->private;
+
+       irq_gc_lock(gc);
+       /* Clear unmasked non-wakeup interrupts */
+       __raw_writel(~b->saved_mask & ~gc->wake_active, b->base + CPU_CLEAR);
+
+       /* Restore the saved mask */
+       __raw_writel(b->saved_mask, b->base + CPU_MASK_SET);
+       __raw_writel(~b->saved_mask, b->base + CPU_MASK_CLEAR);
+       irq_gc_unlock(gc);
+}
+
+int __init brcmstb_l2_intc_of_init(struct device_node *np,
+                                       struct device_node *parent)
+{
+       unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+       struct brcmstb_l2_intc_data *data;
+       struct irq_chip_generic *gc;
+       struct irq_chip_type *ct;
+       int ret;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->base = of_iomap(np, 0);
+       if (!data->base) {
+               pr_err("failed to remap intc L2 registers\n");
+               ret = -ENOMEM;
+               goto out_free;
+       }
+
+       /* Disable all interrupts by default */
+       __raw_writel(0xffffffff, data->base + CPU_MASK_SET);
+       __raw_writel(0xffffffff, data->base + CPU_CLEAR);
+
+       data->parent_irq = irq_of_parse_and_map(np, 0);
+       if (data->parent_irq < 0) {
+               pr_err("failed to find parent interrupt\n");
+               ret = data->parent_irq;
+               goto out_unmap;
+       }
+
+       data->domain = irq_domain_add_linear(np, 32,
+                               &irq_generic_chip_ops, NULL);
+       if (!data->domain) {
+               ret = -ENOMEM;
+               goto out_unmap;
+       }
+
+       /* Allocate a single Generic IRQ chip for this node */
+       ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
+                               np->full_name, handle_level_irq, clr, 0, 0);
+       if (ret) {
+               pr_err("failed to allocate generic irq chip\n");
+               goto out_free_domain;
+       }
+
+       /* Set the IRQ chaining logic */
+       irq_set_handler_data(data->parent_irq, data);
+       irq_set_chained_handler(data->parent_irq, brcmstb_l2_intc_irq_handle);
+
+       gc = irq_get_domain_generic_chip(data->domain, 0);
+       gc->reg_base = data->base;
+       gc->private = data;
+       ct = gc->chip_types;
+
+       ct->chip.irq_ack = irq_gc_ack_set_bit;
+       ct->regs.ack = CPU_CLEAR;
+
+       ct->chip.irq_mask = irq_gc_mask_disable_reg;
+       ct->regs.disable = CPU_MASK_SET;
+
+       ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
+       ct->regs.enable = CPU_MASK_CLEAR;
+
+       ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
+       ct->chip.irq_resume = brcmstb_l2_intc_resume;
+
+       if (of_property_read_bool(np, "brcm,irq-can-wake")) {
+               data->can_wake = true;
+               /* This IRQ chip can wake the system, set all child interrupts
+                * in wake_enabled mask
+                */
+               gc->wake_enabled = 0xffffffff;
+               ct->chip.irq_set_wake = irq_gc_set_wake;
+       }
+
+       pr_info("registered L2 intc (mem: 0x%p, parent irq: %d)\n",
+                       data->base, data->parent_irq);
+
+       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,l2-intc", brcmstb_l2_intc_of_init);