diff options
Diffstat (limited to 'drivers/irqchip/irq-ls-scfg-msi.c')
| -rw-r--r-- | drivers/irqchip/irq-ls-scfg-msi.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-ls-scfg-msi.c b/drivers/irqchip/irq-ls-scfg-msi.c new file mode 100644 index 000000000000..02cca74cab94 --- /dev/null +++ b/drivers/irqchip/irq-ls-scfg-msi.c @@ -0,0 +1,240 @@ +/* + * 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"); |