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 virq;
  57                 int hwirq;
  58                 u32 bit;
  59                 u32 status;
  60
  61                 bit = readl_relaxed(combiner->regs[reg].addr);
  62                 status = bit & combiner->regs[reg].enabled;
  63                 if (bit && !status)
  64                         pr_warn_ratelimited("Unexpected IRQ on CPU%d: (%08x %08lx %p)\n",
  65                                             smp_processor_id(), bit,
  66                                             combiner->regs[reg].enabled,
  67                                             combiner->regs[reg].addr);
  68
  69                 while (status) {
  70                         bit = __ffs(status);
  71                         status &= ~(1 << bit);
  72                         hwirq = irq_nr(reg, bit);
  73                         virq = irq_find_mapping(combiner->domain, hwirq);
  74                         if (virq > 0)
  75                                 generic_handle_irq(virq);
  76
  77                 }
  78         }
  79
  80         chained_irq_exit(chip, desc);
  81 }
  82
  83 static void combiner_irq_chip_mask_irq(struct irq_data *data)
  84 {
  85         struct combiner *combiner = irq_data_get_irq_chip_data(data);
  86         struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
  87
  88         clear_bit(data->hwirq % REG_SIZE, &reg->enabled);
  89 }
  90
  91 static void combiner_irq_chip_unmask_irq(struct irq_data *data)
  92 {
  93         struct combiner *combiner = irq_data_get_irq_chip_data(data);
  94         struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
  95
  96         set_bit(data->hwirq % REG_SIZE, &reg->enabled);
  97 }
  98
  99 static struct irq_chip irq_chip = {
 100         .irq_mask = combiner_irq_chip_mask_irq,
 101         .irq_unmask = combiner_irq_chip_unmask_irq,
 102         .name = "qcom-irq-combiner"
 103 };
 104
 105 static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
 106                                    irq_hw_number_t hwirq)
 107 {
 108         irq_set_chip_and_handler(irq, &irq_chip, handle_level_irq);
 109         irq_set_chip_data(irq, domain->host_data);
 110         irq_set_noprobe(irq);
 111         return 0;
 112 }
 113
 114 static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
 115 {
 116         irq_domain_reset_irq_data(irq_get_irq_data(irq));
 117 }
 118
 119 static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
 120                                   unsigned long *hwirq, unsigned int *type)
 121 {
 122         struct combiner *combiner = d->host_data;
 123
 124         if (is_acpi_node(fws->fwnode)) {
 125                 if (WARN_ON((fws->param_count != 2) ||
 126                             (fws->param[0] >= combiner->nirqs) ||
 127                             (fws->param[1] & IORESOURCE_IRQ_LOWEDGE) ||
 128                             (fws->param[1] & IORESOURCE_IRQ_HIGHEDGE)))
 129                         return -EINVAL;
 130
 131                 *hwirq = fws->param[0];
 132                 *type = fws->param[1];
 133                 return 0;
 134         }
 135
 136         return -EINVAL;
 137 }
 138
 139 static const struct irq_domain_ops domain_ops = {
 140         .map = combiner_irq_map,
 141         .unmap = combiner_irq_unmap,
 142         .translate = combiner_irq_translate
 143 };
 144
 145 static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
 146 {
 147         int *count = context;
 148
 149         if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
 150                 ++(*count);
 151         return AE_OK;
 152 }
 153
 154 static int count_registers(struct platform_device *pdev)
 155 {
 156         acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
 157         acpi_status status;
 158         int count = 0;
 159
 160         if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
 161                 return -EINVAL;
 162
 163         status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
 164                                      count_registers_cb, &count);
 165         if (ACPI_FAILURE(status))
 166                 return -EINVAL;
 167         return count;
 168 }
 169
 170 struct get_registers_context {
 171         struct device *dev;
 172         struct combiner *combiner;
 173         int err;
 174 };
 175
 176 static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
 177 {
 178         struct get_registers_context *ctx = context;
 179         struct acpi_resource_generic_register *reg;
 180         phys_addr_t paddr;
 181         void __iomem *vaddr;
 182
 183         if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
 184                 return AE_OK;
 185
 186         reg = &ares->data.generic_reg;
 187         paddr = reg->address;
 188         if ((reg->space_id != ACPI_SPACE_MEM) ||
 189             (reg->bit_offset != 0) ||
 190             (reg->bit_width > REG_SIZE)) {
 191                 dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
 192                 ctx->err = -EINVAL;
 193                 return AE_ERROR;
 194         }
 195
 196         vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
 197         if (!vaddr) {
 198                 dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
 199                 ctx->err = -ENOMEM;
 200                 return AE_ERROR;
 201         }
 202
 203         ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
 204         ctx->combiner->nirqs += reg->bit_width;
 205         ctx->combiner->nregs++;
 206         return AE_OK;
 207 }
 208
 209 static int get_registers(struct platform_device *pdev, struct combiner *comb)
 210 {
 211         acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
 212         acpi_status status;
 213         struct get_registers_context ctx;
 214
 215         if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
 216                 return -EINVAL;
 217
 218         ctx.dev = &pdev->dev;
 219         ctx.combiner = comb;
 220         ctx.err = 0;
 221
 222         status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
 223                                      get_registers_cb, &ctx);
 224         if (ACPI_FAILURE(status))
 225                 return ctx.err;
 226         return 0;
 227 }
 228
 229 static int __init combiner_probe(struct platform_device *pdev)
 230 {
 231         struct combiner *combiner;
 232         int nregs;
 233         int err;
 234
 235         nregs = count_registers(pdev);
 236         if (nregs <= 0) {
 237                 dev_err(&pdev->dev, "Error reading register resources\n");
 238                 return -EINVAL;
 239         }
 240
 241         combiner = devm_kzalloc(&pdev->dev, struct_size(combiner, regs, nregs),
 242                                 GFP_KERNEL);
 243         if (!combiner)
 244                 return -ENOMEM;
 245
 246         err = get_registers(pdev, combiner);
 247         if (err < 0)
 248                 return err;
 249
 250         combiner->parent_irq = platform_get_irq(pdev, 0);
 251         if (combiner->parent_irq <= 0)
 252                 return -EPROBE_DEFER;
 253
 254         combiner->domain = irq_domain_create_linear(pdev->dev.fwnode, combiner->nirqs,
 255                                                     &domain_ops, combiner);
 256         if (!combiner->domain)
 257                 /* Errors printed by irq_domain_create_linear */
 258                 return -ENODEV;
 259
 260         irq_set_chained_handler_and_data(combiner->parent_irq,
 261                                          combiner_handle_irq, combiner);
 262
 263         dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
 264                  combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
 265         return 0;
 266 }
 267
 268 static const struct acpi_device_id qcom_irq_combiner_ids[] = {
 269         { "QCOM80B1", },
 270         { }
 271 };
 272
 273 static struct platform_driver qcom_irq_combiner_probe = {
 274         .driver = {
 275                 .name = "qcom-irq-combiner",
 276                 .acpi_match_table = ACPI_PTR(qcom_irq_combiner_ids),
 277         },
 278         .probe = combiner_probe,
 279 };
 280 builtin_platform_driver(qcom_irq_combiner_probe);