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294 lines
7.0 KiB
294 lines
7.0 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Altera PCIe MSI support |
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* |
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* Author: Ley Foon Tan <[email protected]> |
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* |
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* Copyright Altera Corporation (C) 2013-2015. All rights reserved |
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*/ |
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#include <linux/interrupt.h> |
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#include <linux/irqchip/chained_irq.h> |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/msi.h> |
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#include <linux/of_address.h> |
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#include <linux/of_irq.h> |
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#include <linux/of_pci.h> |
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#include <linux/pci.h> |
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#include <linux/platform_device.h> |
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#include <linux/slab.h> |
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#define MSI_STATUS 0x0 |
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#define MSI_ERROR 0x4 |
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#define MSI_INTMASK 0x8 |
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#define MAX_MSI_VECTORS 32 |
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struct altera_msi { |
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DECLARE_BITMAP(used, MAX_MSI_VECTORS); |
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struct mutex lock; /* protect "used" bitmap */ |
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struct platform_device *pdev; |
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struct irq_domain *msi_domain; |
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struct irq_domain *inner_domain; |
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void __iomem *csr_base; |
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void __iomem *vector_base; |
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phys_addr_t vector_phy; |
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u32 num_of_vectors; |
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int irq; |
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}; |
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static inline void msi_writel(struct altera_msi *msi, const u32 value, |
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const u32 reg) |
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{ |
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writel_relaxed(value, msi->csr_base + reg); |
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} |
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static inline u32 msi_readl(struct altera_msi *msi, const u32 reg) |
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{ |
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return readl_relaxed(msi->csr_base + reg); |
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} |
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static void altera_msi_isr(struct irq_desc *desc) |
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{ |
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struct irq_chip *chip = irq_desc_get_chip(desc); |
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struct altera_msi *msi; |
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unsigned long status; |
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u32 bit; |
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int ret; |
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chained_irq_enter(chip, desc); |
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msi = irq_desc_get_handler_data(desc); |
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while ((status = msi_readl(msi, MSI_STATUS)) != 0) { |
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for_each_set_bit(bit, &status, msi->num_of_vectors) { |
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/* Dummy read from vector to clear the interrupt */ |
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readl_relaxed(msi->vector_base + (bit * sizeof(u32))); |
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ret = generic_handle_domain_irq(msi->inner_domain, bit); |
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if (ret) |
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dev_err_ratelimited(&msi->pdev->dev, "unexpected MSI\n"); |
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} |
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} |
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chained_irq_exit(chip, desc); |
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} |
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static struct irq_chip altera_msi_irq_chip = { |
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.name = "Altera PCIe MSI", |
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.irq_mask = pci_msi_mask_irq, |
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.irq_unmask = pci_msi_unmask_irq, |
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}; |
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static struct msi_domain_info altera_msi_domain_info = { |
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.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | |
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MSI_FLAG_PCI_MSIX), |
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.chip = &altera_msi_irq_chip, |
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}; |
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static void altera_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) |
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{ |
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struct altera_msi *msi = irq_data_get_irq_chip_data(data); |
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phys_addr_t addr = msi->vector_phy + (data->hwirq * sizeof(u32)); |
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msg->address_lo = lower_32_bits(addr); |
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msg->address_hi = upper_32_bits(addr); |
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msg->data = data->hwirq; |
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dev_dbg(&msi->pdev->dev, "msi#%d address_hi %#x address_lo %#x\n", |
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(int)data->hwirq, msg->address_hi, msg->address_lo); |
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} |
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static int altera_msi_set_affinity(struct irq_data *irq_data, |
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const struct cpumask *mask, bool force) |
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{ |
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return -EINVAL; |
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} |
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static struct irq_chip altera_msi_bottom_irq_chip = { |
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.name = "Altera MSI", |
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.irq_compose_msi_msg = altera_compose_msi_msg, |
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.irq_set_affinity = altera_msi_set_affinity, |
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}; |
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static int altera_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, |
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unsigned int nr_irqs, void *args) |
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{ |
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struct altera_msi *msi = domain->host_data; |
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unsigned long bit; |
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u32 mask; |
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WARN_ON(nr_irqs != 1); |
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mutex_lock(&msi->lock); |
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bit = find_first_zero_bit(msi->used, msi->num_of_vectors); |
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if (bit >= msi->num_of_vectors) { |
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mutex_unlock(&msi->lock); |
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return -ENOSPC; |
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} |
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set_bit(bit, msi->used); |
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mutex_unlock(&msi->lock); |
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irq_domain_set_info(domain, virq, bit, &altera_msi_bottom_irq_chip, |
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domain->host_data, handle_simple_irq, |
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NULL, NULL); |
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mask = msi_readl(msi, MSI_INTMASK); |
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mask |= 1 << bit; |
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msi_writel(msi, mask, MSI_INTMASK); |
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return 0; |
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} |
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static void altera_irq_domain_free(struct irq_domain *domain, |
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unsigned int virq, unsigned int nr_irqs) |
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{ |
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struct irq_data *d = irq_domain_get_irq_data(domain, virq); |
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struct altera_msi *msi = irq_data_get_irq_chip_data(d); |
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u32 mask; |
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mutex_lock(&msi->lock); |
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if (!test_bit(d->hwirq, msi->used)) { |
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dev_err(&msi->pdev->dev, "trying to free unused MSI#%lu\n", |
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d->hwirq); |
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} else { |
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__clear_bit(d->hwirq, msi->used); |
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mask = msi_readl(msi, MSI_INTMASK); |
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mask &= ~(1 << d->hwirq); |
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msi_writel(msi, mask, MSI_INTMASK); |
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} |
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mutex_unlock(&msi->lock); |
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} |
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static const struct irq_domain_ops msi_domain_ops = { |
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.alloc = altera_irq_domain_alloc, |
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.free = altera_irq_domain_free, |
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}; |
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static int altera_allocate_domains(struct altera_msi *msi) |
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{ |
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struct fwnode_handle *fwnode = of_node_to_fwnode(msi->pdev->dev.of_node); |
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msi->inner_domain = irq_domain_add_linear(NULL, msi->num_of_vectors, |
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&msi_domain_ops, msi); |
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if (!msi->inner_domain) { |
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dev_err(&msi->pdev->dev, "failed to create IRQ domain\n"); |
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return -ENOMEM; |
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} |
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msi->msi_domain = pci_msi_create_irq_domain(fwnode, |
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&altera_msi_domain_info, msi->inner_domain); |
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if (!msi->msi_domain) { |
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dev_err(&msi->pdev->dev, "failed to create MSI domain\n"); |
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irq_domain_remove(msi->inner_domain); |
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return -ENOMEM; |
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} |
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return 0; |
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} |
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static void altera_free_domains(struct altera_msi *msi) |
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{ |
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irq_domain_remove(msi->msi_domain); |
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irq_domain_remove(msi->inner_domain); |
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} |
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static int altera_msi_remove(struct platform_device *pdev) |
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{ |
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struct altera_msi *msi = platform_get_drvdata(pdev); |
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msi_writel(msi, 0, MSI_INTMASK); |
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irq_set_chained_handler_and_data(msi->irq, NULL, NULL); |
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altera_free_domains(msi); |
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platform_set_drvdata(pdev, NULL); |
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return 0; |
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} |
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static int altera_msi_probe(struct platform_device *pdev) |
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{ |
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struct altera_msi *msi; |
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struct device_node *np = pdev->dev.of_node; |
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struct resource *res; |
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int ret; |
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msi = devm_kzalloc(&pdev->dev, sizeof(struct altera_msi), |
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GFP_KERNEL); |
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if (!msi) |
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return -ENOMEM; |
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mutex_init(&msi->lock); |
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msi->pdev = pdev; |
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msi->csr_base = devm_platform_ioremap_resource_byname(pdev, "csr"); |
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if (IS_ERR(msi->csr_base)) { |
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dev_err(&pdev->dev, "failed to map csr memory\n"); |
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return PTR_ERR(msi->csr_base); |
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} |
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res = platform_get_resource_byname(pdev, IORESOURCE_MEM, |
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"vector_slave"); |
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msi->vector_base = devm_ioremap_resource(&pdev->dev, res); |
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if (IS_ERR(msi->vector_base)) |
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return PTR_ERR(msi->vector_base); |
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msi->vector_phy = res->start; |
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if (of_property_read_u32(np, "num-vectors", &msi->num_of_vectors)) { |
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dev_err(&pdev->dev, "failed to parse the number of vectors\n"); |
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return -EINVAL; |
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} |
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ret = altera_allocate_domains(msi); |
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if (ret) |
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return ret; |
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msi->irq = platform_get_irq(pdev, 0); |
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if (msi->irq < 0) { |
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ret = msi->irq; |
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goto err; |
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} |
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irq_set_chained_handler_and_data(msi->irq, altera_msi_isr, msi); |
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platform_set_drvdata(pdev, msi); |
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return 0; |
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err: |
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altera_msi_remove(pdev); |
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return ret; |
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} |
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static const struct of_device_id altera_msi_of_match[] = { |
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{ .compatible = "altr,msi-1.0", NULL }, |
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{ }, |
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}; |
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static struct platform_driver altera_msi_driver = { |
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.driver = { |
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.name = "altera-msi", |
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.of_match_table = altera_msi_of_match, |
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}, |
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.probe = altera_msi_probe, |
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.remove = altera_msi_remove, |
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}; |
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static int __init altera_msi_init(void) |
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{ |
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return platform_driver_register(&altera_msi_driver); |
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} |
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static void __exit altera_msi_exit(void) |
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{ |
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platform_driver_unregister(&altera_msi_driver); |
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} |
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subsys_initcall(altera_msi_init); |
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MODULE_DEVICE_TABLE(of, altera_msi_of_match); |
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module_exit(altera_msi_exit); |
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MODULE_LICENSE("GPL v2");
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