linux/drivers/irqchip/irq-vf610-mscm-ir.c
<<
>>
Prefs
   1/*
   2 * Copyright (C) 2014-2015 Toradex AG
   3 * Author: Stefan Agner <stefan@agner.ch>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 *
   9 *
  10 * IRQ chip driver for MSCM interrupt router available on Vybrid SoC's.
  11 * The interrupt router is between the CPU's interrupt controller and the
  12 * peripheral. The router allows to route the peripheral interrupts to
  13 * one of the two available CPU's on Vybrid VF6xx SoC's (Cortex-A5 or
  14 * Cortex-M4). The router will be configured transparently on a IRQ
  15 * request.
  16 *
  17 * o All peripheral interrupts of the Vybrid SoC can be routed to
  18 *   CPU 0, CPU 1 or both. The routing is useful for dual-core
  19 *   variants of Vybrid SoC such as VF6xx. This driver routes the
  20 *   requested interrupt to the CPU currently running on.
  21 *
  22 * o It is required to setup the interrupt router even on single-core
  23 *   variants of Vybrid.
  24 */
  25
  26#include <linux/cpu_pm.h>
  27#include <linux/io.h>
  28#include <linux/irq.h>
  29#include <linux/irqchip.h>
  30#include <linux/irqdomain.h>
  31#include <linux/mfd/syscon.h>
  32#include <dt-bindings/interrupt-controller/arm-gic.h>
  33#include <linux/of.h>
  34#include <linux/of_address.h>
  35#include <linux/slab.h>
  36#include <linux/regmap.h>
  37
  38#define MSCM_CPxNUM             0x4
  39
  40#define MSCM_IRSPRC(n)          (0x80 + 2 * (n))
  41#define MSCM_IRSPRC_CPEN_MASK   0x3
  42
  43#define MSCM_IRSPRC_NUM         112
  44
  45struct vf610_mscm_ir_chip_data {
  46        void __iomem *mscm_ir_base;
  47        u16 cpu_mask;
  48        u16 saved_irsprc[MSCM_IRSPRC_NUM];
  49        bool is_nvic;
  50};
  51
  52static struct vf610_mscm_ir_chip_data *mscm_ir_data;
  53
  54static inline void vf610_mscm_ir_save(struct vf610_mscm_ir_chip_data *data)
  55{
  56        int i;
  57
  58        for (i = 0; i < MSCM_IRSPRC_NUM; i++)
  59                data->saved_irsprc[i] = readw_relaxed(data->mscm_ir_base + MSCM_IRSPRC(i));
  60}
  61
  62static inline void vf610_mscm_ir_restore(struct vf610_mscm_ir_chip_data *data)
  63{
  64        int i;
  65
  66        for (i = 0; i < MSCM_IRSPRC_NUM; i++)
  67                writew_relaxed(data->saved_irsprc[i], data->mscm_ir_base + MSCM_IRSPRC(i));
  68}
  69
  70static int vf610_mscm_ir_notifier(struct notifier_block *self,
  71                                  unsigned long cmd, void *v)
  72{
  73        switch (cmd) {
  74        case CPU_CLUSTER_PM_ENTER:
  75                vf610_mscm_ir_save(mscm_ir_data);
  76                break;
  77        case CPU_CLUSTER_PM_ENTER_FAILED:
  78        case CPU_CLUSTER_PM_EXIT:
  79                vf610_mscm_ir_restore(mscm_ir_data);
  80                break;
  81        }
  82
  83        return NOTIFY_OK;
  84}
  85
  86static struct notifier_block mscm_ir_notifier_block = {
  87        .notifier_call = vf610_mscm_ir_notifier,
  88};
  89
  90static void vf610_mscm_ir_enable(struct irq_data *data)
  91{
  92        irq_hw_number_t hwirq = data->hwirq;
  93        struct vf610_mscm_ir_chip_data *chip_data = data->chip_data;
  94        u16 irsprc;
  95
  96        irsprc = readw_relaxed(chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
  97        irsprc &= MSCM_IRSPRC_CPEN_MASK;
  98
  99        WARN_ON(irsprc & ~chip_data->cpu_mask);
 100
 101        writew_relaxed(chip_data->cpu_mask,
 102                       chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
 103
 104        irq_chip_enable_parent(data);
 105}
 106
 107static void vf610_mscm_ir_disable(struct irq_data *data)
 108{
 109        irq_hw_number_t hwirq = data->hwirq;
 110        struct vf610_mscm_ir_chip_data *chip_data = data->chip_data;
 111
 112        writew_relaxed(0x0, chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
 113
 114        irq_chip_disable_parent(data);
 115}
 116
 117static struct irq_chip vf610_mscm_ir_irq_chip = {
 118        .name                   = "mscm-ir",
 119        .irq_mask               = irq_chip_mask_parent,
 120        .irq_unmask             = irq_chip_unmask_parent,
 121        .irq_eoi                = irq_chip_eoi_parent,
 122        .irq_enable             = vf610_mscm_ir_enable,
 123        .irq_disable            = vf610_mscm_ir_disable,
 124        .irq_retrigger          = irq_chip_retrigger_hierarchy,
 125        .irq_set_affinity       = irq_chip_set_affinity_parent,
 126};
 127
 128static int vf610_mscm_ir_domain_alloc(struct irq_domain *domain, unsigned int virq,
 129                                      unsigned int nr_irqs, void *arg)
 130{
 131        int i;
 132        irq_hw_number_t hwirq;
 133        struct irq_fwspec *fwspec = arg;
 134        struct irq_fwspec parent_fwspec;
 135
 136        if (!irq_domain_get_of_node(domain->parent))
 137                return -EINVAL;
 138
 139        if (fwspec->param_count != 2)
 140                return -EINVAL;
 141
 142        hwirq = fwspec->param[0];
 143        for (i = 0; i < nr_irqs; i++)
 144                irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
 145                                              &vf610_mscm_ir_irq_chip,
 146                                              domain->host_data);
 147
 148        parent_fwspec.fwnode = domain->parent->fwnode;
 149
 150        if (mscm_ir_data->is_nvic) {
 151                parent_fwspec.param_count = 1;
 152                parent_fwspec.param[0] = fwspec->param[0];
 153        } else {
 154                parent_fwspec.param_count = 3;
 155                parent_fwspec.param[0] = GIC_SPI;
 156                parent_fwspec.param[1] = fwspec->param[0];
 157                parent_fwspec.param[2] = fwspec->param[1];
 158        }
 159
 160        return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
 161                                            &parent_fwspec);
 162}
 163
 164static int vf610_mscm_ir_domain_translate(struct irq_domain *d,
 165                                          struct irq_fwspec *fwspec,
 166                                          unsigned long *hwirq,
 167                                          unsigned int *type)
 168{
 169        if (WARN_ON(fwspec->param_count < 2))
 170                return -EINVAL;
 171        *hwirq = fwspec->param[0];
 172        *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
 173        return 0;
 174}
 175
 176static const struct irq_domain_ops mscm_irq_domain_ops = {
 177        .translate = vf610_mscm_ir_domain_translate,
 178        .alloc = vf610_mscm_ir_domain_alloc,
 179        .free = irq_domain_free_irqs_common,
 180};
 181
 182static int __init vf610_mscm_ir_of_init(struct device_node *node,
 183                               struct device_node *parent)
 184{
 185        struct irq_domain *domain, *domain_parent;
 186        struct regmap *mscm_cp_regmap;
 187        int ret, cpuid;
 188
 189        domain_parent = irq_find_host(parent);
 190        if (!domain_parent) {
 191                pr_err("vf610_mscm_ir: interrupt-parent not found\n");
 192                return -EINVAL;
 193        }
 194
 195        mscm_ir_data = kzalloc(sizeof(*mscm_ir_data), GFP_KERNEL);
 196        if (!mscm_ir_data)
 197                return -ENOMEM;
 198
 199        mscm_ir_data->mscm_ir_base = of_io_request_and_map(node, 0, "mscm-ir");
 200        if (IS_ERR(mscm_ir_data->mscm_ir_base)) {
 201                pr_err("vf610_mscm_ir: unable to map mscm register\n");
 202                ret = PTR_ERR(mscm_ir_data->mscm_ir_base);
 203                goto out_free;
 204        }
 205
 206        mscm_cp_regmap = syscon_regmap_lookup_by_phandle(node, "fsl,cpucfg");
 207        if (IS_ERR(mscm_cp_regmap)) {
 208                ret = PTR_ERR(mscm_cp_regmap);
 209                pr_err("vf610_mscm_ir: regmap lookup for cpucfg failed\n");
 210                goto out_unmap;
 211        }
 212
 213        regmap_read(mscm_cp_regmap, MSCM_CPxNUM, &cpuid);
 214        mscm_ir_data->cpu_mask = 0x1 << cpuid;
 215
 216        domain = irq_domain_add_hierarchy(domain_parent, 0,
 217                                          MSCM_IRSPRC_NUM, node,
 218                                          &mscm_irq_domain_ops, mscm_ir_data);
 219        if (!domain) {
 220                ret = -ENOMEM;
 221                goto out_unmap;
 222        }
 223
 224        if (of_device_is_compatible(irq_domain_get_of_node(domain->parent),
 225                                    "arm,armv7m-nvic"))
 226                mscm_ir_data->is_nvic = true;
 227
 228        cpu_pm_register_notifier(&mscm_ir_notifier_block);
 229
 230        return 0;
 231
 232out_unmap:
 233        iounmap(mscm_ir_data->mscm_ir_base);
 234out_free:
 235        kfree(mscm_ir_data);
 236        return ret;
 237}
 238IRQCHIP_DECLARE(vf610_mscm_ir, "fsl,vf610-mscm-ir", vf610_mscm_ir_of_init);
 239