drivers/misc/lan966x_pci.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Microchip LAN966x PCI driver
   4  *
   5  * Copyright (c) 2024 Microchip Technology Inc. and its subsidiaries.
   6  *
   7  * Authors:
   8  *      Clément Léger <[email protected]>
   9  *      Hervé Codina <[email protected]>
  10  */
  11
  12 #include <linux/device.h>
  13 #include <linux/irq.h>
  14 #include <linux/irqdomain.h>
  15 #include <linux/module.h>
  16 #include <linux/of_platform.h>
  17 #include <linux/pci.h>
  18 #include <linux/pci_ids.h>
  19 #include <linux/slab.h>
  20
  21 /* Embedded dtbo symbols created by cmd_wrap_S_dtb in scripts/Makefile.lib */
  22 extern char __dtbo_lan966x_pci_begin[];
  23 extern char __dtbo_lan966x_pci_end[];
  24
  25 struct pci_dev_intr_ctrl {
  26         struct pci_dev *pci_dev;
  27         struct irq_domain *irq_domain;
  28         int irq;
  29 };
  30
  31 static int pci_dev_irq_domain_map(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw)
  32 {
  33         irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
  34         return 0;
  35 }
  36
  37 static const struct irq_domain_ops pci_dev_irq_domain_ops = {
  38         .map = pci_dev_irq_domain_map,
  39         .xlate = irq_domain_xlate_onecell,
  40 };
  41
  42 static irqreturn_t pci_dev_irq_handler(int irq, void *data)
  43 {
  44         struct pci_dev_intr_ctrl *intr_ctrl = data;
  45         int ret;
  46
  47         ret = generic_handle_domain_irq(intr_ctrl->irq_domain, 0);
  48         return ret ? IRQ_NONE : IRQ_HANDLED;
  49 }
  50
  51 static struct pci_dev_intr_ctrl *pci_dev_create_intr_ctrl(struct pci_dev *pdev)
  52 {
  53         struct pci_dev_intr_ctrl *intr_ctrl __free(kfree) = NULL;
  54         struct fwnode_handle *fwnode;
  55         int ret;
  56
  57         fwnode = dev_fwnode(&pdev->dev);
  58         if (!fwnode)
  59                 return ERR_PTR(-ENODEV);
  60
  61         intr_ctrl = kmalloc(sizeof(*intr_ctrl), GFP_KERNEL);
  62         if (!intr_ctrl)
  63                 return ERR_PTR(-ENOMEM);
  64
  65         intr_ctrl->pci_dev = pdev;
  66
  67         intr_ctrl->irq_domain = irq_domain_create_linear(fwnode, 1, &pci_dev_irq_domain_ops,
  68                                                          intr_ctrl);
  69         if (!intr_ctrl->irq_domain) {
  70                 pci_err(pdev, "Failed to create irqdomain\n");
  71                 return ERR_PTR(-ENOMEM);
  72         }
  73
  74         ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);
  75         if (ret < 0) {
  76                 pci_err(pdev, "Unable alloc irq vector (%d)\n", ret);
  77                 goto err_remove_domain;
  78         }
  79         intr_ctrl->irq = pci_irq_vector(pdev, 0);
  80         ret = request_irq(intr_ctrl->irq, pci_dev_irq_handler, IRQF_SHARED,
  81                           pci_name(pdev), intr_ctrl);
  82         if (ret) {
  83                 pci_err(pdev, "Unable to request irq %d (%d)\n", intr_ctrl->irq, ret);
  84                 goto err_free_irq_vector;
  85         }
  86
  87         return_ptr(intr_ctrl);
  88
  89 err_free_irq_vector:
  90         pci_free_irq_vectors(pdev);
  91 err_remove_domain:
  92         irq_domain_remove(intr_ctrl->irq_domain);
  93         return ERR_PTR(ret);
  94 }
  95
  96 static void pci_dev_remove_intr_ctrl(struct pci_dev_intr_ctrl *intr_ctrl)
  97 {
  98         free_irq(intr_ctrl->irq, intr_ctrl);
  99         pci_free_irq_vectors(intr_ctrl->pci_dev);
 100         irq_dispose_mapping(irq_find_mapping(intr_ctrl->irq_domain, 0));
 101         irq_domain_remove(intr_ctrl->irq_domain);
 102         kfree(intr_ctrl);
 103 }
 104
 105 static void devm_pci_dev_remove_intr_ctrl(void *intr_ctrl)
 106 {
 107         pci_dev_remove_intr_ctrl(intr_ctrl);
 108 }
 109
 110 static int devm_pci_dev_create_intr_ctrl(struct pci_dev *pdev)
 111 {
 112         struct pci_dev_intr_ctrl *intr_ctrl;
 113
 114         intr_ctrl = pci_dev_create_intr_ctrl(pdev);
 115         if (IS_ERR(intr_ctrl))
 116                 return PTR_ERR(intr_ctrl);
 117
 118         return devm_add_action_or_reset(&pdev->dev, devm_pci_dev_remove_intr_ctrl, intr_ctrl);
 119 }
 120
 121 struct lan966x_pci {
 122         struct device *dev;
 123         int ovcs_id;
 124 };
 125
 126 static int lan966x_pci_load_overlay(struct lan966x_pci *data)
 127 {
 128         u32 dtbo_size = __dtbo_lan966x_pci_end - __dtbo_lan966x_pci_begin;
 129         void *dtbo_start = __dtbo_lan966x_pci_begin;
 130
 131         return of_overlay_fdt_apply(dtbo_start, dtbo_size, &data->ovcs_id, dev_of_node(data->dev));
 132 }
 133
 134 static void lan966x_pci_unload_overlay(struct lan966x_pci *data)
 135 {
 136         of_overlay_remove(&data->ovcs_id);
 137 }
 138
 139 static int lan966x_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 140 {
 141         struct device *dev = &pdev->dev;
 142         struct lan966x_pci *data;
 143         int ret;
 144
 145         /*
 146          * On ACPI system, fwnode can point to the ACPI node.
 147          * This driver needs an of_node to be used as the device-tree overlay
 148          * target. This of_node should be set by the PCI core if it succeeds in
 149          * creating it (CONFIG_PCI_DYNAMIC_OF_NODES feature).
 150          * Check here for the validity of this of_node.
 151          */
 152         if (!dev_of_node(dev))
 153                 return dev_err_probe(dev, -EINVAL, "Missing of_node for device\n");
 154
 155         /* Need to be done before devm_pci_dev_create_intr_ctrl.
 156          * It allocates an IRQ and so pdev->irq is updated.
 157          */
 158         ret = pcim_enable_device(pdev);
 159         if (ret)
 160                 return ret;
 161
 162         ret = devm_pci_dev_create_intr_ctrl(pdev);
 163         if (ret)
 164                 return ret;
 165
 166         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 167         if (!data)
 168                 return -ENOMEM;
 169
 170         pci_set_drvdata(pdev, data);
 171         data->dev = dev;
 172
 173         ret = lan966x_pci_load_overlay(data);
 174         if (ret)
 175                 return ret;
 176
 177         pci_set_master(pdev);
 178
 179         ret = of_platform_default_populate(dev_of_node(dev), NULL, dev);
 180         if (ret)
 181                 goto err_unload_overlay;
 182
 183         return 0;
 184
 185 err_unload_overlay:
 186         lan966x_pci_unload_overlay(data);
 187         return ret;
 188 }
 189
 190 static void lan966x_pci_remove(struct pci_dev *pdev)
 191 {
 192         struct lan966x_pci *data = pci_get_drvdata(pdev);
 193
 194         of_platform_depopulate(data->dev);
 195
 196         lan966x_pci_unload_overlay(data);
 197 }
 198
 199 static struct pci_device_id lan966x_pci_ids[] = {
 200         { PCI_DEVICE(PCI_VENDOR_ID_EFAR, 0x9660) },
 201         { }
 202 };
 203 MODULE_DEVICE_TABLE(pci, lan966x_pci_ids);
 204
 205 static struct pci_driver lan966x_pci_driver = {
 206         .name = "mchp_lan966x_pci",
 207         .id_table = lan966x_pci_ids,
 208         .probe = lan966x_pci_probe,
 209         .remove = lan966x_pci_remove,
 210 };
 211 module_pci_driver(lan966x_pci_driver);
 212
 213 MODULE_AUTHOR("Herve Codina <[email protected]>");
 214 MODULE_DESCRIPTION("Microchip LAN966x PCI driver");
 215 MODULE_LICENSE("GPL");