--- /dev/null
+/* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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.
+ */
+
+/*
+ * Driver for interrupt combiners in the Top-level Control and Status
+ * Registers (TCSR) hardware block in Qualcomm Technologies chips.
+ * An interrupt combiner in this block combines a set of interrupts by
+ * OR'ing the individual interrupt signals into a summary interrupt
+ * signal routed to a parent interrupt controller, and provides read-
+ * only, 32-bit registers to query the status of individual interrupts.
+ * The status bit for IRQ n is bit (n % 32) within register (n / 32)
+ * of the given combiner. Thus, each combiner can be described as a set
+ * of register offsets and the number of IRQs managed.
+ */
+
+#define pr_fmt(fmt) "QCOM80B1:" fmt
+
+#include <linux/acpi.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/platform_device.h>
+
+#define REG_SIZE 32
+
+struct combiner_reg {
+ void __iomem *addr;
+ unsigned long enabled;
+};
+
+struct combiner {
+ struct irq_domain *domain;
+ int parent_irq;
+ u32 nirqs;
+ u32 nregs;
+ struct combiner_reg regs[0];
+};
+
+static inline int irq_nr(u32 reg, u32 bit)
+{
+ return reg * REG_SIZE + bit;
+}
+
+/*
+ * Handler for the cascaded IRQ.
+ */
+static void combiner_handle_irq(struct irq_desc *desc)
+{
+ struct combiner *combiner = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ u32 reg;
+
+ chained_irq_enter(chip, desc);
+
+ for (reg = 0; reg < combiner->nregs; reg++) {
+ int virq;
+ int hwirq;
+ u32 bit;
+ u32 status;
+
+ bit = readl_relaxed(combiner->regs[reg].addr);
+ status = bit & combiner->regs[reg].enabled;
+ if (!status)
+ pr_warn_ratelimited("Unexpected IRQ on CPU%d: (%08x %08lx %p)\n",
+ smp_processor_id(), bit,
+ combiner->regs[reg].enabled,
+ combiner->regs[reg].addr);
+
+ while (status) {
+ bit = __ffs(status);
+ status &= ~(1 << bit);
+ hwirq = irq_nr(reg, bit);
+ virq = irq_find_mapping(combiner->domain, hwirq);
+ if (virq > 0)
+ generic_handle_irq(virq);
+
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void combiner_irq_chip_mask_irq(struct irq_data *data)
+{
+ struct combiner *combiner = irq_data_get_irq_chip_data(data);
+ struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
+
+ clear_bit(data->hwirq % REG_SIZE, ®->enabled);
+}
+
+static void combiner_irq_chip_unmask_irq(struct irq_data *data)
+{
+ struct combiner *combiner = irq_data_get_irq_chip_data(data);
+ struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;
+
+ set_bit(data->hwirq % REG_SIZE, ®->enabled);
+}
+
+static struct irq_chip irq_chip = {
+ .irq_mask = combiner_irq_chip_mask_irq,
+ .irq_unmask = combiner_irq_chip_unmask_irq,
+ .name = "qcom-irq-combiner"
+};
+
+static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &irq_chip, handle_level_irq);
+ irq_set_chip_data(irq, domain->host_data);
+ irq_set_noprobe(irq);
+ return 0;
+}
+
+static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
+{
+ irq_domain_reset_irq_data(irq_get_irq_data(irq));
+}
+
+static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
+ unsigned long *hwirq, unsigned int *type)
+{
+ struct combiner *combiner = d->host_data;
+
+ if (is_acpi_node(fws->fwnode)) {
+ if (WARN_ON((fws->param_count != 2) ||
+ (fws->param[0] >= combiner->nirqs) ||
+ (fws->param[1] & IORESOURCE_IRQ_LOWEDGE) ||
+ (fws->param[1] & IORESOURCE_IRQ_HIGHEDGE)))
+ return -EINVAL;
+
+ *hwirq = fws->param[0];
+ *type = fws->param[1];
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static const struct irq_domain_ops domain_ops = {
+ .map = combiner_irq_map,
+ .unmap = combiner_irq_unmap,
+ .translate = combiner_irq_translate
+};
+
+static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
+{
+ int *count = context;
+
+ if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+ ++(*count);
+ return AE_OK;
+}
+
+static int count_registers(struct platform_device *pdev)
+{
+ acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
+ acpi_status status;
+ int count = 0;
+
+ if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
+ return -EINVAL;
+
+ status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
+ count_registers_cb, &count);
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+ return count;
+}
+
+struct get_registers_context {
+ struct device *dev;
+ struct combiner *combiner;
+ int err;
+};
+
+static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
+{
+ struct get_registers_context *ctx = context;
+ struct acpi_resource_generic_register *reg;
+ phys_addr_t paddr;
+ void __iomem *vaddr;
+
+ if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+ return AE_OK;
+
+ reg = &ares->data.generic_reg;
+ paddr = reg->address;
+ if ((reg->space_id != ACPI_SPACE_MEM) ||
+ (reg->bit_offset != 0) ||
+ (reg->bit_width > REG_SIZE)) {
+ dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
+ ctx->err = -EINVAL;
+ return AE_ERROR;
+ }
+
+ vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
+ if (IS_ERR(vaddr)) {
+ dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
+ ctx->err = PTR_ERR(vaddr);
+ return AE_ERROR;
+ }
+
+ ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
+ ctx->combiner->nirqs += reg->bit_width;
+ ctx->combiner->nregs++;
+ return AE_OK;
+}
+
+static int get_registers(struct platform_device *pdev, struct combiner *comb)
+{
+ acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
+ acpi_status status;
+ struct get_registers_context ctx;
+
+ if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
+ return -EINVAL;
+
+ ctx.dev = &pdev->dev;
+ ctx.combiner = comb;
+ ctx.err = 0;
+
+ status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
+ get_registers_cb, &ctx);
+ if (ACPI_FAILURE(status))
+ return ctx.err;
+ return 0;
+}
+
+static int __init combiner_probe(struct platform_device *pdev)
+{
+ struct combiner *combiner;
+ size_t alloc_sz;
+ u32 nregs;
+ int err;
+
+ nregs = count_registers(pdev);
+ if (nregs <= 0) {
+ dev_err(&pdev->dev, "Error reading register resources\n");
+ return -EINVAL;
+ }
+
+ alloc_sz = sizeof(*combiner) + sizeof(struct combiner_reg) * nregs;
+ combiner = devm_kzalloc(&pdev->dev, alloc_sz, GFP_KERNEL);
+ if (!combiner)
+ return -ENOMEM;
+
+ err = get_registers(pdev, combiner);
+ if (err < 0)
+ return err;
+
+ combiner->parent_irq = platform_get_irq(pdev, 0);
+ if (combiner->parent_irq <= 0) {
+ dev_err(&pdev->dev, "Error getting IRQ resource\n");
+ return -EPROBE_DEFER;
+ }
+
+ combiner->domain = irq_domain_create_linear(pdev->dev.fwnode, combiner->nirqs,
+ &domain_ops, combiner);
+ if (!combiner->domain)
+ /* Errors printed by irq_domain_create_linear */
+ return -ENODEV;
+
+ irq_set_chained_handler_and_data(combiner->parent_irq,
+ combiner_handle_irq, combiner);
+
+ dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
+ combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
+ return 0;
+}
+
+static const struct acpi_device_id qcom_irq_combiner_ids[] = {
+ { "QCOM80B1", },
+ { }
+};
+
+static struct platform_driver qcom_irq_combiner_probe = {
+ .driver = {
+ .name = "qcom-irq-combiner",
+ .acpi_match_table = ACPI_PTR(qcom_irq_combiner_ids),
+ },
+ .probe = combiner_probe,
+};
+
+static int __init register_qcom_irq_combiner(void)
+{
+ return platform_driver_register(&qcom_irq_combiner_probe);
+}
+device_initcall(register_qcom_irq_combiner);
projects / karo-tx-linux.git / commitdiff