drivers/char/xillybus/xillybus_pcie.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/drivers/misc/xillybus_pcie.c
   4  *
   5  * Copyright 2011 Xillybus Ltd, http://xillybus.com
   6  *
   7  * Driver for the Xillybus FPGA/host framework using PCI Express.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/pci.h>
  12 #include <linux/pci-aspm.h>
  13 #include <linux/slab.h>
  14 #include "xillybus.h"
  15
  16 MODULE_DESCRIPTION("Xillybus driver for PCIe");
  17 MODULE_AUTHOR("Eli Billauer, Xillybus Ltd.");
  18 MODULE_VERSION("1.06");
  19 MODULE_ALIAS("xillybus_pcie");
  20 MODULE_LICENSE("GPL v2");
  21
  22 #define PCI_DEVICE_ID_XILLYBUS          0xebeb
  23
  24 #define PCI_VENDOR_ID_ACTEL             0x11aa
  25 #define PCI_VENDOR_ID_LATTICE           0x1204
  26
  27 static const char xillyname[] = "xillybus_pcie";
  28
  29 static const struct pci_device_id xillyids[] = {
  30         {PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_XILLYBUS)},
  31         {PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_XILLYBUS)},
  32         {PCI_DEVICE(PCI_VENDOR_ID_ACTEL, PCI_DEVICE_ID_XILLYBUS)},
  33         {PCI_DEVICE(PCI_VENDOR_ID_LATTICE, PCI_DEVICE_ID_XILLYBUS)},
  34         { /* End: all zeroes */ }
  35 };
  36
  37 static int xilly_pci_direction(int direction)
  38 {
  39         switch (direction) {
  40         case DMA_TO_DEVICE:
  41                 return PCI_DMA_TODEVICE;
  42         case DMA_FROM_DEVICE:
  43                 return PCI_DMA_FROMDEVICE;
  44         default:
  45                 return PCI_DMA_BIDIRECTIONAL;
  46         }
  47 }
  48
  49 static void xilly_dma_sync_single_for_cpu_pci(struct xilly_endpoint *ep,
  50                                               dma_addr_t dma_handle,
  51                                               size_t size,
  52                                               int direction)
  53 {
  54         pci_dma_sync_single_for_cpu(ep->pdev,
  55                                     dma_handle,
  56                                     size,
  57                                     xilly_pci_direction(direction));
  58 }
  59
  60 static void xilly_dma_sync_single_for_device_pci(struct xilly_endpoint *ep,
  61                                                  dma_addr_t dma_handle,
  62                                                  size_t size,
  63                                                  int direction)
  64 {
  65         pci_dma_sync_single_for_device(ep->pdev,
  66                                        dma_handle,
  67                                        size,
  68                                        xilly_pci_direction(direction));
  69 }
  70
  71 static void xilly_pci_unmap(void *ptr)
  72 {
  73         struct xilly_mapping *data = ptr;
  74
  75         pci_unmap_single(data->device, data->dma_addr,
  76                          data->size, data->direction);
  77
  78         kfree(ptr);
  79 }
  80
  81 /*
  82  * Map either through the PCI DMA mapper or the non_PCI one. Behind the
  83  * scenes exactly the same functions are called with the same parameters,
  84  * but that can change.
  85  */
  86
  87 static int xilly_map_single_pci(struct xilly_endpoint *ep,
  88                                 void *ptr,
  89                                 size_t size,
  90                                 int direction,
  91                                 dma_addr_t *ret_dma_handle
  92         )
  93 {
  94         int pci_direction;
  95         dma_addr_t addr;
  96         struct xilly_mapping *this;
  97
  98         this = kzalloc(sizeof(*this), GFP_KERNEL);
  99         if (!this)
 100                 return -ENOMEM;
 101
 102         pci_direction = xilly_pci_direction(direction);
 103
 104         addr = pci_map_single(ep->pdev, ptr, size, pci_direction);
 105
 106         if (pci_dma_mapping_error(ep->pdev, addr)) {
 107                 kfree(this);
 108                 return -ENODEV;
 109         }
 110
 111         this->device = ep->pdev;
 112         this->dma_addr = addr;
 113         this->size = size;
 114         this->direction = pci_direction;
 115
 116         *ret_dma_handle = addr;
 117
 118         return devm_add_action_or_reset(ep->dev, xilly_pci_unmap, this);
 119 }
 120
 121 static struct xilly_endpoint_hardware pci_hw = {
 122         .owner = THIS_MODULE,
 123         .hw_sync_sgl_for_cpu = xilly_dma_sync_single_for_cpu_pci,
 124         .hw_sync_sgl_for_device = xilly_dma_sync_single_for_device_pci,
 125         .map_single = xilly_map_single_pci,
 126 };
 127
 128 static int xilly_probe(struct pci_dev *pdev,
 129                        const struct pci_device_id *ent)
 130 {
 131         struct xilly_endpoint *endpoint;
 132         int rc;
 133
 134         endpoint = xillybus_init_endpoint(pdev, &pdev->dev, &pci_hw);
 135
 136         if (!endpoint)
 137                 return -ENOMEM;
 138
 139         pci_set_drvdata(pdev, endpoint);
 140
 141         rc = pcim_enable_device(pdev);
 142         if (rc) {
 143                 dev_err(endpoint->dev,
 144                         "pcim_enable_device() failed. Aborting.\n");
 145                 return rc;
 146         }
 147
 148         /* L0s has caused packet drops. No power saving, thank you. */
 149
 150         pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S);
 151
 152         if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM)) {
 153                 dev_err(endpoint->dev,
 154                         "Incorrect BAR configuration. Aborting.\n");
 155                 return -ENODEV;
 156         }
 157
 158         rc = pcim_iomap_regions(pdev, 0x01, xillyname);
 159         if (rc) {
 160                 dev_err(endpoint->dev,
 161                         "pcim_iomap_regions() failed. Aborting.\n");
 162                 return rc;
 163         }
 164
 165         endpoint->registers = pcim_iomap_table(pdev)[0];
 166
 167         pci_set_master(pdev);
 168
 169         /* Set up a single MSI interrupt */
 170         if (pci_enable_msi(pdev)) {
 171                 dev_err(endpoint->dev,
 172                         "Failed to enable MSI interrupts. Aborting.\n");
 173                 return -ENODEV;
 174         }
 175         rc = devm_request_irq(&pdev->dev, pdev->irq, xillybus_isr, 0,
 176                               xillyname, endpoint);
 177         if (rc) {
 178                 dev_err(endpoint->dev,
 179                         "Failed to register MSI handler. Aborting.\n");
 180                 return -ENODEV;
 181         }
 182
 183         /*
 184          * Some (old and buggy?) hardware drops 64-bit addressed PCIe packets,
 185          * even when the PCIe driver claims that a 64-bit mask is OK. On the
 186          * other hand, on some architectures, 64-bit addressing is mandatory.
 187          * So go for the 64-bit mask only when failing is the other option.
 188          */
 189
 190         if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
 191                 endpoint->dma_using_dac = 0;
 192         } else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
 193                 endpoint->dma_using_dac = 1;
 194         } else {
 195                 dev_err(endpoint->dev, "Failed to set DMA mask. Aborting.\n");
 196                 return -ENODEV;
 197         }
 198
 199         return xillybus_endpoint_discovery(endpoint);
 200 }
 201
 202 static void xilly_remove(struct pci_dev *pdev)
 203 {
 204         struct xilly_endpoint *endpoint = pci_get_drvdata(pdev);
 205
 206         xillybus_endpoint_remove(endpoint);
 207 }
 208
 209 MODULE_DEVICE_TABLE(pci, xillyids);
 210
 211 static struct pci_driver xillybus_driver = {
 212         .name = xillyname,
 213         .id_table = xillyids,
 214         .probe = xilly_probe,
 215         .remove = xilly_remove,
 216 };
 217
 218 module_pci_driver(xillybus_driver);