drivers/irqchip/qcom-irq-combiner.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
   3  */
   4
   5 /*
   6  * Driver for interrupt combiners in the Top-level Control and Status
   7  * Registers (TCSR) hardware block in Qualcomm Technologies chips.
   8  * An interrupt combiner in this block combines a set of interrupts by
   9  * OR'ing the individual interrupt signals into a summary interrupt
  10  * signal routed to a parent interrupt controller, and provides read-
  11  * only, 32-bit registers to query the status of individual interrupts.
  12  * The status bit for IRQ n is bit (n % 32) within register (n / 32)
  13  * of the given combiner. Thus, each combiner can be described as a set
  14  * of register offsets and the number of IRQs managed.
  15  */
  16
  17 #define pr_fmt(fmt) "QCOM80B1:" fmt
  18
  19 #include <linux/acpi.h>
  20 #include <linux/irqchip/chained_irq.h>
  21 #include <linux/irqdomain.h>
  22 #include <linux/platform_device.h>
  23
  24 #define REG_SIZE 32
  25
  26 struct combiner_reg {
  27         void __iomem *addr;
  28         unsigned long enabled;
  29 };
  30
  31 struct combiner {
  32         struct irq_domain   *domain;
  33         int                 parent_irq;
  34         u32                 nirqs;
  35         u32                 nregs;
  36         struct combiner_reg regs[];
  37 };
  38
  39 static inline int irq_nr(u32 reg, u32 bit)
  40 {
  41         return reg * REG_SIZE + bit;
  42 }
  43
  44 /*
  45  * Handler for the cascaded IRQ.
  46  */
  47 static void combiner_handle_irq(struct irq_desc *desc)
  48 {
  49         struct combiner *combiner = irq_desc_get_handler_data(desc);
  50         struct irq_chip *chip = irq_desc_get_chip(desc);
  51         u32 reg;
  52
  53         chained_irq_enter(chip, desc);
  54
  55         for (reg = 0; reg < combiner->nregs; reg++) {
  56                 int hwirq;
  57                 u32 bit;
  58                 u32 status;
  59
  60                 bit = readl_relaxed(combiner->regs[reg].addr);
  61                 status = bit & combiner->regs[reg].enabled;
  62                 if (bit && !status)
  63                         pr_warn_ratelimited("Unexpected IRQ on CPU%d: (%08x %08lx %p)\n",
  64                                             smp_processor_id(), bit,
  65                                             combiner->regs[reg].enabled,
  66                                             combiner->regs[reg].addr);
  67
  68                 while (status) {
  69                         bit = __ffs(status);
  70                         status &= ~(1 << bit);
  71                         hwirq = irq_nr(reg, bit);
  72                         generic_handle_domain_irq(combiner->domain, hwirq);
  73                 }
  74         }
  75
  76         chained_irq_exit(chip, desc);
  77 }
  78
  79 static void combiner_irq_chip_mask_irq(struct irq_data *data)
  80 {
  81         struct combiner *combiner = irq_data_get_irq_chip_data(data);
  82         struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
  83
  84         clear_bit(data->hwirq % REG_SIZE, &reg->enabled);
  85 }
  86
  87 static void combiner_irq_chip_unmask_irq(struct irq_data *data)
  88 {
  89         struct combiner *combiner = irq_data_get_irq_chip_data(data);
  90         struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
  91
  92         set_bit(data->hwirq % REG_SIZE, &reg->enabled);
  93 }
  94
  95 static struct irq_chip irq_chip = {
  96         .irq_mask = combiner_irq_chip_mask_irq,
  97         .irq_unmask = combiner_irq_chip_unmask_irq,
  98         .name = "qcom-irq-combiner"
  99 };
 100
 101 static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
 102                                    irq_hw_number_t hwirq)
 103 {
 104         irq_set_chip_and_handler(irq, &irq_chip, handle_level_irq);
 105         irq_set_chip_data(irq, domain->host_data);
 106         irq_set_noprobe(irq);
 107         return 0;
 108 }
 109
 110 static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
 111 {
 112         irq_domain_reset_irq_data(irq_get_irq_data(irq));
 113 }
 114
 115 static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
 116                                   unsigned long *hwirq, unsigned int *type)
 117 {
 118         struct combiner *combiner = d->host_data;
 119
 120         if (is_acpi_node(fws->fwnode)) {
 121                 if (WARN_ON((fws->param_count != 2) ||
 122                             (fws->param[0] >= combiner->nirqs) ||
 123                             (fws->param[1] & IORESOURCE_IRQ_LOWEDGE) ||
 124                             (fws->param[1] & IORESOURCE_IRQ_HIGHEDGE)))
 125                         return -EINVAL;
 126
 127                 *hwirq = fws->param[0];
 128                 *type = fws->param[1];
 129                 return 0;
 130         }
 131
 132         return -EINVAL;
 133 }
 134
 135 static const struct irq_domain_ops domain_ops = {
 136         .map = combiner_irq_map,
 137         .unmap = combiner_irq_unmap,
 138         .translate = combiner_irq_translate
 139 };
 140
 141 static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
 142 {
 143         int *count = context;
 144
 145         if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
 146                 ++(*count);
 147         return AE_OK;
 148 }
 149
 150 static int count_registers(struct platform_device *pdev)
 151 {
 152         acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
 153         acpi_status status;
 154         int count = 0;
 155
 156         if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
 157                 return -EINVAL;
 158
 159         status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
 160                                      count_registers_cb, &count);
 161         if (ACPI_FAILURE(status))
 162                 return -EINVAL;
 163         return count;
 164 }
 165
 166 struct get_registers_context {
 167         struct device *dev;
 168         struct combiner *combiner;
 169         int err;
 170 };
 171
 172 static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
 173 {
 174         struct get_registers_context *ctx = context;
 175         struct acpi_resource_generic_register *reg;
 176         phys_addr_t paddr;
 177         void __iomem *vaddr;
 178
 179         if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
 180                 return AE_OK;
 181
 182         reg = &ares->data.generic_reg;
 183         paddr = reg->address;
 184         if ((reg->space_id != ACPI_SPACE_MEM) ||
 185             (reg->bit_offset != 0) ||
 186             (reg->bit_width > REG_SIZE)) {
 187                 dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
 188                 ctx->err = -EINVAL;
 189                 return AE_ERROR;
 190         }
 191
 192         vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
 193         if (!vaddr) {
 194                 dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
 195                 ctx->err = -ENOMEM;
 196                 return AE_ERROR;
 197         }
 198
 199         ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
 200         ctx->combiner->nirqs += reg->bit_width;
 201         ctx->combiner->nregs++;
 202         return AE_OK;
 203 }
 204
 205 static int get_registers(struct platform_device *pdev, struct combiner *comb)
 206 {
 207         acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
 208         acpi_status status;
 209         struct get_registers_context ctx;
 210
 211         if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
 212                 return -EINVAL;
 213
 214         ctx.dev = &pdev->dev;
 215         ctx.combiner = comb;
 216         ctx.err = 0;
 217
 218         status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
 219                                      get_registers_cb, &ctx);
 220         if (ACPI_FAILURE(status))
 221                 return ctx.err;
 222         return 0;
 223 }
 224
 225 static int __init combiner_probe(struct platform_device *pdev)
 226 {
 227         struct combiner *combiner;
 228         int nregs;
 229         int err;
 230
 231         nregs = count_registers(pdev);
 232         if (nregs <= 0) {
 233                 dev_err(&pdev->dev, "Error reading register resources\n");
 234                 return -EINVAL;
 235         }
 236
 237         combiner = devm_kzalloc(&pdev->dev, struct_size(combiner, regs, nregs),
 238                                 GFP_KERNEL);
 239         if (!combiner)
 240                 return -ENOMEM;
 241
 242         err = get_registers(pdev, combiner);
 243         if (err < 0)
 244                 return err;
 245
 246         combiner->parent_irq = platform_get_irq(pdev, 0);
 247         if (combiner->parent_irq <= 0)
 248                 return -EPROBE_DEFER;
 249
 250         combiner->domain = irq_domain_create_linear(pdev->dev.fwnode, combiner->nirqs,
 251                                                     &domain_ops, combiner);
 252         if (!combiner->domain)
 253                 /* Errors printed by irq_domain_create_linear */
 254                 return -ENODEV;
 255
 256         irq_set_chained_handler_and_data(combiner->parent_irq,
 257                                          combiner_handle_irq, combiner);
 258
 259         dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
 260                  combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
 261         return 0;
 262 }
 263
 264 static const struct acpi_device_id qcom_irq_combiner_ids[] = {
 265         { "QCOM80B1", },
 266         { }
 267 };
 268
 269 static struct platform_driver qcom_irq_combiner_probe = {
 270         .driver = {
 271                 .name = "qcom-irq-combiner",
 272                 .acpi_match_table = ACPI_PTR(qcom_irq_combiner_ids),
 273         },
 274         .probe = combiner_probe,
 275 };
 276 builtin_platform_driver(qcom_irq_combiner_probe);