irqchips/bmips: Add bcm6345-l1 interrupt controller
[cascardo/linux.git] / drivers / irqchip / irq-bcm6345-l1.c
diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
new file mode 100644 (file)
index 0000000..b844c89
--- /dev/null
@@ -0,0 +1,364 @@
+/*
+ * Broadcom BCM6345 style Level 1 interrupt controller driver
+ *
+ * Copyright (C) 2014 Broadcom Corporation
+ * Copyright 2015 Simon Arlott
+ *
+ * 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 is based on the BCM7038 (which supports SMP) but with a single
+ * enable register instead of separate mask/set/clear registers.
+ *
+ * The BCM3380 has a similar mask/status register layout, but each pair
+ * of words is at separate locations (and SMP is not supported).
+ *
+ * ENABLE/STATUS words are packed next to each other for each CPU:
+ *
+ * BCM6368:
+ *   0x1000_0020: CPU0_W0_ENABLE
+ *   0x1000_0024: CPU0_W1_ENABLE
+ *   0x1000_0028: CPU0_W0_STATUS               IRQs 31-63
+ *   0x1000_002c: CPU0_W1_STATUS               IRQs 0-31
+ *   0x1000_0030: CPU1_W0_ENABLE
+ *   0x1000_0034: CPU1_W1_ENABLE
+ *   0x1000_0038: CPU1_W0_STATUS               IRQs 31-63
+ *   0x1000_003c: CPU1_W1_STATUS               IRQs 0-31
+ *
+ * BCM63168:
+ *   0x1000_0020: CPU0_W0_ENABLE
+ *   0x1000_0024: CPU0_W1_ENABLE
+ *   0x1000_0028: CPU0_W2_ENABLE
+ *   0x1000_002c: CPU0_W3_ENABLE
+ *   0x1000_0030: CPU0_W0_STATUS       IRQs 96-127
+ *   0x1000_0034: CPU0_W1_STATUS       IRQs 64-95
+ *   0x1000_0038: CPU0_W2_STATUS       IRQs 32-63
+ *   0x1000_003c: CPU0_W3_STATUS       IRQs 0-31
+ *   0x1000_0040: CPU1_W0_ENABLE
+ *   0x1000_0044: CPU1_W1_ENABLE
+ *   0x1000_0048: CPU1_W2_ENABLE
+ *   0x1000_004c: CPU1_W3_ENABLE
+ *   0x1000_0050: CPU1_W0_STATUS       IRQs 96-127
+ *   0x1000_0054: CPU1_W1_STATUS       IRQs 64-95
+ *   0x1000_0058: CPU1_W2_STATUS       IRQs 32-63
+ *   0x1000_005c: CPU1_W3_STATUS       IRQs 0-31
+ *
+ * IRQs are numbered in CPU native endian order
+ * (which is big-endian in these examples)
+ */
+
+#define pr_fmt(fmt)    KBUILD_MODNAME  ": " fmt
+
+#include <linux/bitops.h>
+#include <linux/cpumask.h>
+#include <linux/kconfig.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/types.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+
+#define IRQS_PER_WORD          32
+#define REG_BYTES_PER_IRQ_WORD (sizeof(u32) * 2)
+
+struct bcm6345_l1_cpu;
+
+struct bcm6345_l1_chip {
+       raw_spinlock_t          lock;
+       unsigned int            n_words;
+       struct irq_domain       *domain;
+       struct cpumask          cpumask;
+       struct bcm6345_l1_cpu   *cpus[NR_CPUS];
+};
+
+struct bcm6345_l1_cpu {
+       void __iomem            *map_base;
+       unsigned int            parent_irq;
+       u32                     enable_cache[];
+};
+
+static inline unsigned int reg_enable(struct bcm6345_l1_chip *intc,
+                                          unsigned int word)
+{
+#ifdef __BIG_ENDIAN
+       return (1 * intc->n_words - word - 1) * sizeof(u32);
+#else
+       return (0 * intc->n_words + word) * sizeof(u32);
+#endif
+}
+
+static inline unsigned int reg_status(struct bcm6345_l1_chip *intc,
+                                     unsigned int word)
+{
+#ifdef __BIG_ENDIAN
+       return (2 * intc->n_words - word - 1) * sizeof(u32);
+#else
+       return (1 * intc->n_words + word) * sizeof(u32);
+#endif
+}
+
+static inline unsigned int cpu_for_irq(struct bcm6345_l1_chip *intc,
+                                       struct irq_data *d)
+{
+       return cpumask_first_and(&intc->cpumask, irq_data_get_affinity_mask(d));
+}
+
+static void bcm6345_l1_irq_handle(struct irq_desc *desc)
+{
+       struct bcm6345_l1_chip *intc = irq_desc_get_handler_data(desc);
+       struct bcm6345_l1_cpu *cpu;
+       struct irq_chip *chip = irq_desc_get_chip(desc);
+       unsigned int idx;
+
+#ifdef CONFIG_SMP
+       cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
+#else
+       cpu = intc->cpus[0];
+#endif
+
+       chained_irq_enter(chip, desc);
+
+       for (idx = 0; idx < intc->n_words; idx++) {
+               int base = idx * IRQS_PER_WORD;
+               unsigned long pending;
+               irq_hw_number_t hwirq;
+               unsigned int irq;
+
+               pending = __raw_readl(cpu->map_base + reg_status(intc, idx));
+               pending &= __raw_readl(cpu->map_base + reg_enable(intc, idx));
+
+               for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
+                       irq = irq_linear_revmap(intc->domain, base + hwirq);
+                       if (irq)
+                               do_IRQ(irq);
+                       else
+                               spurious_interrupt();
+               }
+       }
+
+       chained_irq_exit(chip, desc);
+}
+
+static inline void __bcm6345_l1_unmask(struct irq_data *d)
+{
+       struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+       u32 word = d->hwirq / IRQS_PER_WORD;
+       u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
+       unsigned int cpu_idx = cpu_for_irq(intc, d);
+
+       intc->cpus[cpu_idx]->enable_cache[word] |= mask;
+       __raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
+               intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
+}
+
+static inline void __bcm6345_l1_mask(struct irq_data *d)
+{
+       struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+       u32 word = d->hwirq / IRQS_PER_WORD;
+       u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
+       unsigned int cpu_idx = cpu_for_irq(intc, d);
+
+       intc->cpus[cpu_idx]->enable_cache[word] &= ~mask;
+       __raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
+               intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
+}
+
+static void bcm6345_l1_unmask(struct irq_data *d)
+{
+       struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&intc->lock, flags);
+       __bcm6345_l1_unmask(d);
+       raw_spin_unlock_irqrestore(&intc->lock, flags);
+}
+
+static void bcm6345_l1_mask(struct irq_data *d)
+{
+       struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&intc->lock, flags);
+       __bcm6345_l1_mask(d);
+       raw_spin_unlock_irqrestore(&intc->lock, flags);
+}
+
+static int bcm6345_l1_set_affinity(struct irq_data *d,
+                                  const struct cpumask *dest,
+                                  bool force)
+{
+       struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
+       u32 word = d->hwirq / IRQS_PER_WORD;
+       u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
+       unsigned int old_cpu = cpu_for_irq(intc, d);
+       unsigned int new_cpu;
+       struct cpumask valid;
+       unsigned long flags;
+       bool enabled;
+
+       if (!cpumask_and(&valid, &intc->cpumask, dest))
+               return -EINVAL;
+
+       new_cpu = cpumask_any_and(&valid, cpu_online_mask);
+       if (new_cpu >= nr_cpu_ids)
+               return -EINVAL;
+
+       dest = cpumask_of(new_cpu);
+
+       raw_spin_lock_irqsave(&intc->lock, flags);
+       if (old_cpu != new_cpu) {
+               enabled = intc->cpus[old_cpu]->enable_cache[word] & mask;
+               if (enabled)
+                       __bcm6345_l1_mask(d);
+               cpumask_copy(irq_data_get_affinity_mask(d), dest);
+               if (enabled)
+                       __bcm6345_l1_unmask(d);
+       } else {
+               cpumask_copy(irq_data_get_affinity_mask(d), dest);
+       }
+       raw_spin_unlock_irqrestore(&intc->lock, flags);
+
+       return IRQ_SET_MASK_OK_NOCOPY;
+}
+
+static int __init bcm6345_l1_init_one(struct device_node *dn,
+                                     unsigned int idx,
+                                     struct bcm6345_l1_chip *intc)
+{
+       struct resource res;
+       resource_size_t sz;
+       struct bcm6345_l1_cpu *cpu;
+       unsigned int i, n_words;
+
+       if (of_address_to_resource(dn, idx, &res))
+               return -EINVAL;
+       sz = resource_size(&res);
+       n_words = sz / REG_BYTES_PER_IRQ_WORD;
+
+       if (!intc->n_words)
+               intc->n_words = n_words;
+       else if (intc->n_words != n_words)
+               return -EINVAL;
+
+       cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
+                                       GFP_KERNEL);
+       if (!cpu)
+               return -ENOMEM;
+
+       cpu->map_base = ioremap(res.start, sz);
+       if (!cpu->map_base)
+               return -ENOMEM;
+
+       for (i = 0; i < n_words; i++) {
+               cpu->enable_cache[i] = 0;
+               __raw_writel(0, cpu->map_base + reg_enable(intc, i));
+       }
+
+       cpu->parent_irq = irq_of_parse_and_map(dn, idx);
+       if (!cpu->parent_irq) {
+               pr_err("failed to map parent interrupt %d\n", cpu->parent_irq);
+               return -EINVAL;
+       }
+       irq_set_chained_handler_and_data(cpu->parent_irq,
+                                               bcm6345_l1_irq_handle, intc);
+
+       return 0;
+}
+
+static struct irq_chip bcm6345_l1_irq_chip = {
+       .name                   = "bcm6345-l1",
+       .irq_mask               = bcm6345_l1_mask,
+       .irq_unmask             = bcm6345_l1_unmask,
+       .irq_set_affinity       = bcm6345_l1_set_affinity,
+};
+
+static int bcm6345_l1_map(struct irq_domain *d, unsigned int virq,
+                         irq_hw_number_t hw_irq)
+{
+       irq_set_chip_and_handler(virq,
+               &bcm6345_l1_irq_chip, handle_percpu_irq);
+       irq_set_chip_data(virq, d->host_data);
+       return 0;
+}
+
+static const struct irq_domain_ops bcm6345_l1_domain_ops = {
+       .xlate                  = irq_domain_xlate_onecell,
+       .map                    = bcm6345_l1_map,
+};
+
+static int __init bcm6345_l1_of_init(struct device_node *dn,
+                             struct device_node *parent)
+{
+       struct bcm6345_l1_chip *intc;
+       unsigned int idx;
+       int ret;
+
+       intc = kzalloc(sizeof(*intc), GFP_KERNEL);
+       if (!intc)
+               return -ENOMEM;
+
+       for_each_possible_cpu(idx) {
+               ret = bcm6345_l1_init_one(dn, idx, intc);
+               if (ret)
+                       pr_err("failed to init intc L1 for cpu %d: %d\n",
+                               idx, ret);
+               else
+                       cpumask_set_cpu(idx, &intc->cpumask);
+       }
+
+       if (!cpumask_weight(&intc->cpumask)) {
+               ret = -ENODEV;
+               goto out_free;
+       }
+
+       raw_spin_lock_init(&intc->lock);
+
+       intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
+                                            &bcm6345_l1_domain_ops,
+                                            intc);
+       if (!intc->domain) {
+               ret = -ENOMEM;
+               goto out_unmap;
+       }
+
+       pr_info("registered BCM6345 L1 intc (IRQs: %d)\n",
+                       IRQS_PER_WORD * intc->n_words);
+       for_each_cpu(idx, &intc->cpumask) {
+               struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
+
+               pr_info("  CPU%u at MMIO 0x%p (irq = %d)\n", idx,
+                               cpu->map_base, cpu->parent_irq);
+       }
+
+       return 0;
+
+out_unmap:
+       for_each_possible_cpu(idx) {
+               struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
+
+               if (cpu) {
+                       if (cpu->map_base)
+                               iounmap(cpu->map_base);
+                       kfree(cpu);
+               }
+       }
+out_free:
+       kfree(intc);
+       return ret;
+}
+
+IRQCHIP_DECLARE(bcm6345_l1, "brcm,bcm6345-l1-intc", bcm6345_l1_of_init);