--- /dev/null
+/*
+ * Freescale SCFG MSI(-X) support
+ *
+ * Copyright (C) 2016 Freescale Semiconductor.
+ *
+ * Author: Minghuan Lian <Minghuan.Lian@nxp.com>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/spinlock.h>
+
+#define MSI_MAX_IRQS 32
+#define MSI_IBS_SHIFT 3
+#define MSIR 4
+
+struct ls_scfg_msi {
+ spinlock_t lock;
+ struct platform_device *pdev;
+ struct irq_domain *parent;
+ struct irq_domain *msi_domain;
+ void __iomem *regs;
+ phys_addr_t msiir_addr;
+ int irq;
+ DECLARE_BITMAP(used, MSI_MAX_IRQS);
+};
+
+static struct irq_chip ls_scfg_msi_irq_chip = {
+ .name = "MSI",
+ .irq_mask = pci_msi_mask_irq,
+ .irq_unmask = pci_msi_unmask_irq,
+};
+
+static struct msi_domain_info ls_scfg_msi_domain_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS |
+ MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_PCI_MSIX),
+ .chip = &ls_scfg_msi_irq_chip,
+};
+
+static void ls_scfg_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(data);
+
+ msg->address_hi = upper_32_bits(msi_data->msiir_addr);
+ msg->address_lo = lower_32_bits(msi_data->msiir_addr);
+ msg->data = data->hwirq << MSI_IBS_SHIFT;
+}
+
+static int ls_scfg_msi_set_affinity(struct irq_data *irq_data,
+ const struct cpumask *mask, bool force)
+{
+ return -EINVAL;
+}
+
+static struct irq_chip ls_scfg_msi_parent_chip = {
+ .name = "SCFG",
+ .irq_compose_msi_msg = ls_scfg_msi_compose_msg,
+ .irq_set_affinity = ls_scfg_msi_set_affinity,
+};
+
+static int ls_scfg_msi_domain_irq_alloc(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs,
+ void *args)
+{
+ struct ls_scfg_msi *msi_data = domain->host_data;
+ int pos, err = 0;
+
+ WARN_ON(nr_irqs != 1);
+
+ spin_lock(&msi_data->lock);
+ pos = find_first_zero_bit(msi_data->used, MSI_MAX_IRQS);
+ if (pos < MSI_MAX_IRQS)
+ __set_bit(pos, msi_data->used);
+ else
+ err = -ENOSPC;
+ spin_unlock(&msi_data->lock);
+
+ if (err)
+ return err;
+
+ irq_domain_set_info(domain, virq, pos,
+ &ls_scfg_msi_parent_chip, msi_data,
+ handle_simple_irq, NULL, NULL);
+
+ return 0;
+}
+
+static void ls_scfg_msi_domain_irq_free(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs)
+{
+ struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+ struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(d);
+ int pos;
+
+ pos = d->hwirq;
+ if (pos < 0 || pos >= MSI_MAX_IRQS) {
+ pr_err("failed to teardown msi. Invalid hwirq %d\n", pos);
+ return;
+ }
+
+ spin_lock(&msi_data->lock);
+ __clear_bit(pos, msi_data->used);
+ spin_unlock(&msi_data->lock);
+}
+
+static const struct irq_domain_ops ls_scfg_msi_domain_ops = {
+ .alloc = ls_scfg_msi_domain_irq_alloc,
+ .free = ls_scfg_msi_domain_irq_free,
+};
+
+static void ls_scfg_msi_irq_handler(struct irq_desc *desc)
+{
+ struct ls_scfg_msi *msi_data = irq_desc_get_handler_data(desc);
+ unsigned long val;
+ int pos, virq;
+
+ chained_irq_enter(irq_desc_get_chip(desc), desc);
+
+ val = ioread32be(msi_data->regs + MSIR);
+ for_each_set_bit(pos, &val, MSI_MAX_IRQS) {
+ virq = irq_find_mapping(msi_data->parent, (31 - pos));
+ if (virq)
+ generic_handle_irq(virq);
+ }
+
+ chained_irq_exit(irq_desc_get_chip(desc), desc);
+}
+
+static int ls_scfg_msi_domains_init(struct ls_scfg_msi *msi_data)
+{
+ /* Initialize MSI domain parent */
+ msi_data->parent = irq_domain_add_linear(NULL,
+ MSI_MAX_IRQS,
+ &ls_scfg_msi_domain_ops,
+ msi_data);
+ if (!msi_data->parent) {
+ dev_err(&msi_data->pdev->dev, "failed to create IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ msi_data->msi_domain = pci_msi_create_irq_domain(
+ of_node_to_fwnode(msi_data->pdev->dev.of_node),
+ &ls_scfg_msi_domain_info,
+ msi_data->parent);
+ if (!msi_data->msi_domain) {
+ dev_err(&msi_data->pdev->dev, "failed to create MSI domain\n");
+ irq_domain_remove(msi_data->parent);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int ls_scfg_msi_probe(struct platform_device *pdev)
+{
+ struct ls_scfg_msi *msi_data;
+ struct resource *res;
+ int ret;
+
+ msi_data = devm_kzalloc(&pdev->dev, sizeof(*msi_data), GFP_KERNEL);
+ if (!msi_data)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ msi_data->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(msi_data->regs)) {
+ dev_err(&pdev->dev, "failed to initialize 'regs'\n");
+ return PTR_ERR(msi_data->regs);
+ }
+ msi_data->msiir_addr = res->start;
+
+ msi_data->irq = platform_get_irq(pdev, 0);
+ if (msi_data->irq <= 0) {
+ dev_err(&pdev->dev, "failed to get MSI irq\n");
+ return -ENODEV;
+ }
+
+ msi_data->pdev = pdev;
+ spin_lock_init(&msi_data->lock);
+
+ ret = ls_scfg_msi_domains_init(msi_data);
+ if (ret)
+ return ret;
+
+ irq_set_chained_handler_and_data(msi_data->irq,
+ ls_scfg_msi_irq_handler,
+ msi_data);
+
+ platform_set_drvdata(pdev, msi_data);
+
+ return 0;
+}
+
+static int ls_scfg_msi_remove(struct platform_device *pdev)
+{
+ struct ls_scfg_msi *msi_data = platform_get_drvdata(pdev);
+
+ irq_set_chained_handler_and_data(msi_data->irq, NULL, NULL);
+
+ irq_domain_remove(msi_data->msi_domain);
+ irq_domain_remove(msi_data->parent);
+
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static const struct of_device_id ls_scfg_msi_id[] = {
+ { .compatible = "fsl,1s1021a-msi", },
+ { .compatible = "fsl,1s1043a-msi", },
+ {},
+};
+
+static struct platform_driver ls_scfg_msi_driver = {
+ .driver = {
+ .name = "ls-scfg-msi",
+ .of_match_table = ls_scfg_msi_id,
+ },
+ .probe = ls_scfg_msi_probe,
+ .remove = ls_scfg_msi_remove,
+};
+
+module_platform_driver(ls_scfg_msi_driver);
+
+MODULE_AUTHOR("Minghuan Lian <Minghuan.Lian@nxp.com>");
+MODULE_DESCRIPTION("Freescale Layerscape SCFG MSI controller driver");
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-rpi.git / commitdiff